Articles tagged with: Mining

A Rookie in the Oilsands – Part 2

Date: June 2, 2025 Author: Ken Kuchling Comments: Leave a reply

The article is Part 2 of discussion on my experiences working in the oilsands at the Syncrude Mine in northern Alberta. Part 1 can be read at this link https://kuchling.com/a-rookie-in-the-oilsands-part-1/

In Part 1, I described the great Engineer-in-Training rotational program that Syncrude had in place for new engineering graduates. Initially I had rotated through the Overburden Geotechnical and Industrial Engineering departments. I was then fortunate enough to go though the Mine Geotechnical department and Short Range Planning. Here are some experiences from those assignments.

Will the Draglines Be Safe

Syncrude had four large walking draglines, each with a 80 cubic metre bucket and 110 metre operating radius. These were very big machines; you could sit one in the end zone of a football field and the bucket would be digging (or dumping) in the other end zone. Two draglines were on the East side of the mine and two were on the West, mining the oilsand in 25 m wide strips.

Mining oilsand while from the top of a 50 metre high and 45 degree highwall had never been done before. The geotechnical conditions were new. They were also dramatically different on the East and West sides of the mine, even though mining in the same orebody.

The East side was far more a greater geotechnical concern than the West side. I happened to be the West side mine geotechnical engineer (lucky for me I guess).

The oil sands are sedimentary deposits, and consist of inter-layered sands, silts and clays. At the Syncrude mine, the clay layers were regionally dipping towards the west at 5 to 10 degrees (as shown in the sketch below). Hence they were dipping into the wall on the West side and dipping out of the wall on the East side. The orebody also contained ancient creek scour channels, now infilled with clays and sands.

On the flanks of these scour zones, the thin clay layers could dip up to 25 degrees out of the wall. This was a problem. In university we learned rock slope failures generally require 30-35 deg dipping joint structures for sliding to occur; but here in the clays, sliding (block slides) could occur along 15 to 25 deg dips.

There were numerous instances of East mine block slides, where large portions of the upper slope would fail as large blocks, 50 metres long and up to 30 metres back from the crest. The fear was that if a dragline happened to be sitting on one of these failing blocks, the entire machine would slide along into the pit. Many block slides did occur over the years, but only a few came close to jeopardizing a machine. The geotechnical monitoring programs in place were successful (described later).

The insitu clay structures were identified using oil and gas borehole logging technology, with tadpole dipmeter plots (see image) used to analyse the bedding (the tail on the tadpole shows the dip direction). The vertical axis is depth from surface or elevation. The geotech engineers would use this information, combined with structural mapping of previously mined faces, to forecast potentially unstable areas.

In these problem areas, the geotech teams would install slope indicators that were monitored while the dragline was mining through the area. Dedicated 24 hour field engineers were assigned to each of the East side draglines and mining operations were closely monitored at all times.

It was not uncommon for the Syncrude geotechnical engineer to get a 2 am phone call at home saying movement has been detected and they walked the dragline back from the face and then get asked “What should we do now?”.

In the places that the engineers knew were going to be very risk, they could implement mitigation measures. How would you deal with the steeper scour zones? They had three main options.

mine through the area with intense geotechnical monitoring in place, using slope indicators, survey prisms, and visual ground inspections.
sub-excavate the zone; using the dragline to dig out the area and then backfill with the same material to destroy the clay bedding. Then they could safely mine through the area, although the days used to sub-excavate would remove the dragline from oilsand production.
another option was to blast the area ahead of time, to destroy the clay bedding and allow pore pressure dissipation.

All three options were available at the discretion of the geotechnical engineering team. However they all cost money and/or loss in mining production, but safety was always the priority.

The four draglines are now mothballed and thankfully none were ever harmed. All oilsand mining operations are now based on truck-shovel systems.

Basal Slope Failures

On the West side of the mine, the bedding was mainly into the highwall, so block slides were not a major concern. In my brief time there, we never had a block slide on the West side although we did continually review dipmeter plots and face mapping results. One still couldn’t be too careful or get lazy.

The main geotechnical issue on the West side were basal slope failures, termed this due to sliding along weak clays and muds at the base of the highwall. This photo shows a typical basal failure. Basal failures also occured on the East side.

Generally, these slope failures did not jeopardize the dragline since they occurred on freshly cut highwalls away from the machine. Eventually the dragline would be required to operate next to existing basal failures when mining the next panel (as shown in the photo).

The dragline would sit 15-25 metres from the wall, the closer is better to maximize reach into the pit.

The main concern with basal failures was that the toe of the failed slope would move beyond the reach of the dragline and could not be mined. As well, sometimes the dragline would need to cast waste layers back into the mined out pit while avoiding the burial of the oilsand toe. If the waste couldn’t be cast back inpit due to toe failure, it would be placed on the operating bench and trucked away later (at a cost).

The Alberta government focused on maximizing oilsand resource recovery. If the dragline could not reach the ore due to a failure, we would need to send mobile equipment down to get it. If we couldn’t do this due to access issues, we needed to prepare an Ore Loss Report that was tracked and submitted to the government agency (ERCB). We hated to submit those reports, taking it as a personal disappointment that we couldn’t get to that ore.

In the basal failure photo, one can see a vertical scarp next to the dragline. The oilsands were a “locked sand” in that the sand grains were tightly compacted or interlocked from the compressive weight of over a kilometre of glacial ice thickness in the past. The vertical scarps would stand indefinitely, sometime spalling off in slabs. The oilsand itself was a very strong geotechnical unit (friction angles in excess of 50 degrees).

Conclusion

Hopefully the above narrative is informative about on mining in the oilsands in the 1980’s. There are plenty more examples of technical issues that our engineering teams had to deal with, whether in the mining operation or tailings disposal area. As a new graduate engineer, it was a great learning experience.

Once our engineer-in-training rotation program was complete, we were to be assigned to a more permanent position. For me, that was going to be as an East side geotechnical engineer – ugh!. It’s at that time I decided to look for greener pastures. Three years was long enough from 1980 to 1983; given the amount of learning and responsibility I had undertaken. Other colleagues left the same time, while many other friends stayed in Ft McMurray for their entire careers.

I enjoyed the mine planning and scheduling work more than geotechnical engineering. The stress of the East side geotechnical role was not really for me. These days, I commend the tailings engineers that willingly accept the Engineer of Record role for tailings dams, knowing the risk, consequences, and potential legal ramifications of their work.

My next career move (after getting an M.Eng from UBC) was going to the Saskatchewan potash industry. One thing common between open pit oil sand mining and the underground potash mining was the heavy reliance on conveyor usage at both. I was getting very comfortable around conveyors. If you found this oilsand narrative mildly interesting, you can read about potash experiences at the blog post “Potash Stories from 3000 Feet Down – Part 1”. .

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Here is short cheesey video of what the oilsands were about in the 1980’s and 1990’s.

A Rookie in the Oilsands – Part 1

Date: May 22, 2025 Author: Ken Kuchling Comments: 2 Replies

Whenever I walk past a road repair crew laying down asphalt, I am taken back to my days working at Syncrude in the oilsands. The smell of the road tar is the same as the smell in the open pit mine. For three years that was my everyday experience. It’s the same as when I get a whiff of diesel fumes, it often reminds me of my days working underground. It seems that smell really can bring back memories, for me at least.

In Part 1 of this two part blog post I would like to share some stories from the early days of my career working in Fort McMurray.

Hopefully they will be interesting and help shed some light on what it can be like working in the mining industry. Syncrude provided my first job out of engineering university and hence will always be special to me.

In the early 1980’s Syncrude was producing about 90,000 barrels of oil a day by processing oilsand at a rate of 180,000 t/day, so it was a big mining operation.

The Engineer in Training Program

I started at Syncrude in the winter of 1980. At that time, the two main places hiring mining engineers were the oilsands in northern Alberta and the iron ore mines in northern Quebec / Labrador. A few mining graduates also went to work in Calgary in the conventional oil & gas industry, since they were looking for engineers and petroleum engineers were in scarcity.

At the time Syncrude had an excellent engineer-in-training program for new graduates. Every six months they would rotate engineers into different technical areas.

These areas could consist of: overburden stripping planning; overburden geotechnical; short range mine planning, mine geotechnical, industrial engineering, tailings planning, and tailings geotechnical. Long range planning tended to be left to the more senior people.

Probably about 15 mining / geological engineers were hired at the same time as me. We came from McGill, Queens, UBC, Laurentian, Univ of Alberta, and Nova Scotia. All of us were in the same boat, rotating through various departments for the first few years.

I ended up in four of the areas listed above; I don’t think anyone actually went through all of them. My first role was in Overburden Geotechnical department, where we had responsibility for waste dump stability, haulroad construction QA/QC, and dragline pad preparation. Each of these tasks required a lot of on the job learning for me.

A Fish Out of Water

At McGill, in the mining engineering program, we took some courses on rock mechanics, focusing on “rock”. The mines in eastern Canada were mainly hardrock mines so that was the learning priority. We leaned about joint mapping, stereonets, compressive and tensile strength testing and kinematic analysis.

Well, at Syncrude there was no rock. All geotechnical work here was based on soil mechanics, something we learned little of at university. Perhaps the civil engineers did more of this. Working in the oilsands, one had to learn about sands, silts, and clays, Atterberg limits, grain size curves, compaction methods, and limit equilibrium stability analysis.

I quickly realized that even after finishing university, the learning does not end. In fact, the real learning starts. Everything you do is now applied on the job site, not just submitted in a term paper for marks, so you better learn fast.

The following is one such learning experience.

A Powerline in Trouble

As mentioned above, my first role was in Overburden Geotechnical, where waste dump design, stability, and monitoring were part of my job responsibility. We already had about three out of pit dumps underway and a few inpit backfill dumps. The waste dumps were comprised of inter-mixed clay & sand built upon mainly clay foundations. That’s not the same as building rock dumps on rock foundations.

A few months on the job while on my daily site inspection route I noticed that, next to one of our waste dumps, the main 240 kV powerline coming to site was starting to lean over (see sketch). My first thought was “Fiddle sticks this isn’t good”. Gradual creep of the waste dump slope was starting to push on the power line. The guy wire anchors were holding tight but the base of the power poles were being moved.

I hurried back to the office to explain the situation to my supervisor and the issue quickly went up the chain of command. We jumped into action, first by relocating waste dumping activity to another area. Next, we started to investigate the cause to see if we could stop the creep. The dump did not actually fail catastrophically; it was just moving slowly. Generally, when slope creep starts, it is difficult to stop.

We drilled several hollow stem auger holes from the dump surface down into the foundation to see what was there. We installed a few slope indicators to see at what depth the sliding was occurring. These pinched off within a day or two, but at least we knew at what depth (about 20m down the hole).

Next we sampled that depth carefully, revealing that frozen muskeg layers were present. When we installed standpipe piezometers in these holes, we saw water flowing out of the top of the pipes. This means the foundation pore pressure is high, way too high.

We concluded that a few years prior the waste dump was built in winter when the muskeg was frozen. The dump insulated the muskeg from thawing and the frozen layer would not allow upward pore pressure dissipation from the dump surcharge. The clay foundation didn’t allow downward dissipation. The muskeg layer was acting like a water bed, floating the waste dump on top of it.

Every day one could see the power poles leaning a little bit more, so time was of the essence. We tried to implement foundation depressurization measures, but drilling angle holes in soft clay was problematic, and targeting the over-pressured zones was difficult. Management quickly made the decision to relocate a section of the powerline. Helicopters were brought in to help install a new powerline around this area. The entire exercise probably cost several million of dollars, but a major plant outage was avoided.

Welcome to the real world.

Not All Jobs Were Exciting

The one rotation that the engineers generally tried to avoid was Industrial Engineering. This is an area that looks at operational and cost efficiencies in the mine. It tends to focus on smaller details rather than the big picture mining operation. I had a 4 month stint in this department, which taught that me, that in life you don’t always get what you want. The IE projects would vary depending on the mine’s needs.

For example, one project I had was to monitor the performance of different brands and styles of conveyor idlers. We would track about 2,000 individual idlers; when they were installed on the conveyors; when they were removed, why they were removed (bearing failure, cover failure, something else).

The idea was to figure out which idler manufacturers were the best – important but not exciting work. If you liked statistics, this was a good job, although around 1981 we didn’t have Excel (or even Lotus 123) at that time (1982), so it was a manual process.

Another project was to try to improve the time efficiency of mine conveyor belt splicing operations. With steel cord belts, there are numerous steel cords in the interior of the belt that carry the tensile load. When it comes time to do a splice (to add in a new section of belt) each splice took about 2-3 days, which meant that mining area would be out of commission.

To splice, one must clean each steel cord individually then overlay the cords from the two belt section side by side, then cover the cords with rubber and vulcanize under heat and pressure. It all took lots of time. Naturally this time study project required spending long days out with the splice crews, watching them do this work while making notes on the actions and activities and durations. Important .. but less than exciting.

One good thing about this job was that the Industrial Engineering supervisor loved to use the expression “That’s politically explosive” for stuff that really wasn’t. That phrase made such an impression on me that I still try to use it today.

End of Part 1

This concludes Part 1. In the next article I will discuss a few other engineering aspects unique to the oilsands and how the engineering teams dealt with them.

Dragline mining of oilsand was never done before, so engineers were learning on the fly. Given the size of the operation, we could not afford to be wrong on the decisions made. It was an interesting, and also stressful, time for many.

In the 1980’s both Syncrude and Suncor had mainly electrified oilsand mining systems, consisting of bucketwheel excavators & conveyors at Suncor and draglines, bucketwheel reclaimers, conveyors at Syncrude. Years later both operations switched to diesel focused truck and shovel operations and mothballed the electric mega-excavators. I’d be curious to know if in 2025 they would still make the same decision based on carbon emission issues and the push for electrification in mining.

Part 2 of this blog post series can be read at this link “A Rookie in the Oilsands – Part 2“

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Mine Reconciliation – Standardization Please

Date: May 7, 2025 Author: Ken Kuchling Comments: Leave a reply

Mine through mill reconciliation, in my view, is an under appreciated topic that could benefit from more conversation amongst industry members. Unfortunately, reconciliation is sometimes viewed as a time consuming frustrating activity, with what some consider less than verifiable results. However given the ongoing innovation that we are seeing in mining, reconciliation may need to play a bigger role than ever.

The mining industry is implementing more and more technology in the mining cycle.

For example, this can range from AI assisted resource modelling, down hole logging, blast movement tracking, GPS controlled dig limits, MineSense bucket grade tracking, load scanning, truck dispatch control, smart mining and edge computing, online grade analyzers, belt weightometers, drone surveying of stockpiles, and real time process controls.

Lots of different innovations are continually being adopted by the mining industry, contrary to what some may say.

The question is does all this innovation improve the overall performance of a mining operation, and if so, by how much? It can cost a lot of money to implement the new technology, is there a payoff?

One cannot answer those questions if one doesn’t undertake proper mine reconciliation. A concern might be that mining is innovating faster than the ability to assess the results of that innovation. To monitor it, you need to measure it.

What is Mine Reconciliation

Mine reconciliation is the process of comparing and aligning the estimated production with the actual production from mining and processing. It requires assessing the accuracy of pre-mining predictions against actual results to identify inconsistencies in the system and hopefully improve it, be it resource estimation, mine planning, or process efficiency. Comparisons can be made between multiple stages in the mining system, as shown in the image below.

Mine reconciliation requires information such as initial predictions from exploration data and geological models, actual measurement: data from mining sources, such as blast holes, stockpile samples, or mill feed. As well it will need data on the final product being shipped off site. Do the metal quantities balance out throughout the mining operation?
Mine reconciliation tends to aggregate over longer time periods (monthly, quarterly or annually) due to short term impacts of material handling in stockpiles and plant circuits and the labour time needed to collect the input data.
Mine reconciliation ultimately attempts to assess how well the delivery of the final metal product relates to the initial resource model (i.e. what the project decision was originally based on)? It is also tool to evaluate the impact of any innovation implementation on the operation.
Reconciliation will help mine operators highlight issues and optimize extraction, manage costs, and ensure compliance with regulatory or investor expectations. Factors such as poor resource estimation, excessive dilution and ore loss, inaccurate sampling, etc. can cause discrepancies, making reconciliation an important part of any operation.
The reconciliation process is also used to derive Mine Call Factors. These factors are used to modify the forecasts from long range models, short range models, and grade control models to better represent the actual performance the operation will likely see. Large call factors suggest something is amiss in the “forecast to actual” progression. The first problem is to identify the causes. The list of the common sources of error can be lengthy. Then, once identified, the second problem is how to fix them.

Harry Parker initially suggested various reconciliation parametrics and labelled them F1, F2, F3. In a 2009 paper by Fouet titled “Standardising the Reconciliation Factors Required in Governance Reporting”, indicates that Rio Tinto had decided upon fifteen (15) different possible reconciliation correlations (see image below). Each one provides an insight on the efficiency of the operation in one way or another. I have seen modified versions of the reconciliation relationships, so it appears there may be no industry standard at this time. Fouet was asking about industry standardization in 2009 (an excellent paper to read by the way).

Mining Codes Getting Involved

It appears that the JORC Code may be recognizing the importance of reconciliation. In an August 2024 Exposure Draft JORC is suggesting the following text: “Where an Ore Reserve has been publicly reported for an operating mine, the results of both production reconciliation and any prior estimate comparison must also be included in the annual Mineral Resources and Ore Reserves statement. Refer to Clause 2.36. The relationships and variables being reconciled must be described in plain language or depicted graphically and must include reconciliations of both the Mineral Resources and Ore Reserves.”

Interestingly, it appears that NI43-101 has not yet jumped on the bandwagon about the importance of disclosing reconciliation results. However, it may just be a matter of time before it becomes one of their disclosure requirements.

If more regulatory focus will be put on mine reconciliation disclosure, then perhaps more industry standardization is warranted. This would help better define some of the terminology and “F factors” shown in the diagrams above to ensure consistency and help avoid each mine doing reconciliation in their own way.

Excel versus Cloud Based Reconciliation

Each mine site may be unique with respect to; ore sources; terminology; ore types; mining methods; stockpiling philosophy; processing methods; technology availability; and personnel capability. So often the easiest approach for mine reconciliation is based on the Excel spreadsheet. (Reconciliation is generally not an easy undertaking).

Spreadsheets can be built site specific, based on an operation’s unique characteristics.

Spreadsheets are often built by a user for that user. They are tailored for the tailor. In my experience, typically the modeler is the only one comfortable with an Excel model’s logic, since all of us may think differently. Unfortunately, with the spreadsheet approach, it becomes more difficult to standardize an industry wide reconciliation process.

An alternate solution to spreadsheets is to use a cloud based standardized software package. Toronto based Minebright has one option, called Pit Info (see link for more info). There are a few other reconciliation software applications available. They tend to be cloud based, hence multiple people can have access to the input modules or output modules. (I would like to thank the Minebright people for steering me towards some of the technical papers on this subject).

The cloud based approach may help make reconciliation a group effort instead of a tightly controlled internal function. It may also help standardize reporting from a company’s multiple operations, reporting from the mining industry globally, or simply for consistent JORC reporting.

The downside to the cloud approach is the mine site teams must learn the software and tailor it to their operation. However, once that hurdle is passed, personnel changes become less onerous due to the model consistency. I have seen cases where a person doing the Excel reconciliation task has left their job, and hence forward the reconciliation effort came to a halt. The people remaining may be too busy or simply don’t want to have to figure out the Excel logic of someone else.

The other nice thing about a cloud software approach is that when improvements are rolled out, every user gets the same update. The “wisdom of crowds” will result in learnings and suggestions that will tend to improve the application functionality over time. There are a lot of smart people out there, and it would be nice to see them working together rather than individually, as the open source software community has demonstrated.

With AI, we also may get to the point where cloud based mine reconciliation platforms can use learnings from other projects, and help identify where the likely technical shortfalls are at a mine site and why production is not reconciling. Let’s ask AI do some of the thinking for us to get to the bottom of a problem.

Conclusion

Mine reconciliation is becoming more and more important, but it can be a forgotten aspect. Sometimes this is because it is difficult to do properly. However, that doesn’t mean it shouldn’t be attempted. The more one can learn about one’s operation, the more likely it can stay efficient, relevant, and in business. The more one knows whether technology improvements are making a difference, the more one may be willing to take on even more new technology.

Shifting some people (like me) away from Excel based solutions can be a challenge, but this is an area where it makes sense. Years ago, many engineers did mine production scheduling using Excel, but we have gradually moved away from that, thankfully. Reconciliation should maybe follow that path.

Disclaimer: Mining is a global business, and perhaps more progress is being made on reconciliation standardization than I am aware of sitting here in my Toronto office. Mine operations around the world are at the forefront of developing new systems. Perhaps we are seeing great things being done in the area of mine reconciliation, or maybe we are not. Please share your experiences if you’re comfortable doing that.

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Spying on Tailings Using Satellites

Date: June 28, 2024 Author: Ken Kuchling Comments: 1 Reply

There have been recent heap leach pad failures in the Yukon and Turkey and tailings dam failures in Chile and the Philippines. As a result I have been seeing more posts on LinkedIn about the application of satellite based InSAR deformation monitoring. Prior to that I had never heard of InSAR, so thought a little bit of background study might be worthwhile.

The following are my observations on what InSAR is and where it may be going. I am by no means an expert in this technology. I am merely viewing it from the perspective of a mine design engineer.

What is InSAR

InSAR is satellite-based “Interferometric Synthetic Aperture Radar”. It can measure the distance from a satellite to a ground feature. With repeated imaging it is used to detect changes in distance and measure displacements to within 5-10 millimetre accuracy. Hence it can be used as a potentially cost-effective slope monitoring tool, albeit it cannot be the only tool, as discussed later.

The relevant satellite images have been available for years. Currently the availability of analytical software to interpret the satellite data is improving. It can detect millimeter-scale displacements, however only in the line-of-sight (LOS) direction of the satellite. Using two or more satellites in different orbits, displacements in horizontal and vertical directions can be defined.

An example of a satellite being used is the Sentinel-1, launched in mid-2015 by the European Space Agency. This satellite information is open-source data. It will have a 6 to 12 day revisit cycle in many locations.

The results of an InSAR displacement survey are typically shown as a series of colored data points, typically coloured green for the stable points, trending to yellow and red for points that are moving.

This blog has some example images.

Some Limitations With InSAR

There are some limitations with InSAR, so it can only be part of a monitoring program. These limitations are:

The displacement direction is only measured in the direction of the satellite. Hence one may not know in which direction the movement is occurring. The magnitude of displacement could be underestimated depending on the apparent angle of measurement.
The movement being measured could consist of vertical settlement due to material consolidation and may not be horizontal and related to impending failure.
The displacement magnitude measured on opposite sides of a facility may have different accuracy, depending on the slope orientation versus the line-of-sight.
Areas with heavy vegetation may be difficult to monitor
Areas with heavy or persistent cloud cover can be difficult to monitor.
Areas with snow cover will be difficult to monitor.
The satellite return period may be weekly or every two weeks, so one is not able to analyze daily movements if a situation is critical. If the return visit day has cloud cover, there will be no new satellite data collected.
Areas with on-going construction or tailings deposition will lead to erroneous results.
Due to the line of sight, not all slope failure modes may be detectible (for example piping failure).

Regardless of these limitations, InSAR can still play a role in any monitoring program since it is able to monitor large areas quickly. Consider it as a pre-screening tool, being aware that not all failure modes may be detectible with it.

Discussion

On LinkedIn, one can see numerous posts where independent experts are examining historical InSAR data for recent failures to see whether early movement should have been detected. The results seem to be quite positive in that areas that have failed might have been red-flagged prior to failure.

There are also zones that showed critical displacements but have not failed.

Typically, there are four ways to monitor displacement in pit slopes, tailings dams, heap leach pads, and waste dumps. They are:

Insitu monitoring using embedded instruments, for example slope indicators, extensometers, and settlement gauges. These instruments provide information on what is happening internally within a slope, where actual movement is occurring, and they can be used in warning alert systems.
Surface monitoring using radar (ground based InSAR) systems and survey prisms. These tools measure only surface movements in selected areas, can be monitored as frequently as needed on an automated basis, and integrated into warning alert systems.
Drone or aerial surveys can be used to measure topography and monitor movements over large areas. This method requires a data processing delay (not real time) to derive the movement information, but such surveys can be done as frequently as needed.
InSAR from satellite can be used over very large regions to highlight areas with movement. That should trigger the implementation of one or more of the other monitoring approaches (if not already in place).

Conclusion

A mining site consists of numerous constructed embankments and slopes of all types and heights. Many of these slopes may be creeping and moving all the time – it’s a living beast.

The operator’s awareness about their site will be better the more monitoring tools they use. This awareness is important given the critical role that slope stability plays. We will see if InSAR technology achieves much wider adoption in the mining industry as a first phase of a stability monitoring programs.

Since InSAR monitoring is done from space, it does not require access to a property. Hence it can be used by third parties or NGO’s to “spy” on facilities of concern anywhere.

Possibly over the next few years we will see independent donor-funded organizations monitoring tailings facilities around the globe. They will be able to notify the public and mine operators “Hey, there is some movement on this mine site that needs to be addressed”. An organization called World Mine Tailings Failures has started some discussions on this concept. Check it out.

Finally, it is great for a mine site to collect a lot of displacement data, hopefully to forewarn of movement, displacement acceleration, and imminent failure. However, this assumes that someone experienced is interpreting the data and its not just generating graphs for the file cabinet. Perhaps AI can play a role here in the future, if the technical personnel to do this are lacking.

Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and other mining posts. The entire blog post library can be found at https://kuchling.com/library/

Junior Mining Shams and Scams – Part 2

Date: June 3, 2024 Author: Ken Kuchling Comments: Leave a reply

This is Part 2 of the blog post discussing junior mining scams and the sanctioning of those responsible. Part 1 can be found at this link “Junior Mining Shams and Scams – Part 1” and can be read first to get some background.

Part 2 provides examples involving professional Qualified Persons (QPs). We may have the feeling that QP’s are never held accountable for their work, but that is not always the case. There are numerous instances of QP’s being hauled off in front of their professional organizations for unprofessionalism. This blog will highlight some of those cases.

The lesson is that QP’s signing off on technical information for clients should be proficient in the nature of their work and need to know the reporting rules very well. Some of these incidents involve error and poor judgment, not outright fraud.

These examples involve in-house QP’s that work for a company while others involve independent QP’s that have been contracted by the company.

In most of these cases, any sanctions, if applied, were mainly doled out by the professional engineering or geological associations. The legal courts are often not involved.

Examples (Part 2)

Inaccurate QP Resource Estimate: This example relates to the Barkerville Gold Mines resource estimate complete in 2012. The mineral resource estimate had numerous errors and issues related to assays, capping, cutoff grades, etc. The allegation was the QP had demonstrated incompetence, unprofessional conduct, and negligence. The sanctions on the QP included a $15,000 fine, $20,000 legal costs, re-training, and license suspension.

Link 1:

Link 2:

False QP Statements: Here is an example from 2011. The QP / company Director was charged with multiple allegations, including stating the mine was in commercial production (when it wasn’t), leaving the impression there were mineral resource (which there weren’t any), and generally approving information that was not accurate. Ultimately the allegation was demonstrating incompetence, unprofessional conduct, and negligence. The resulting sanctions included 2 year license suspension, re-training, payment of $80,000 to the professional association.

Link 1:

False QP Statements: This is case were a resource QP failed to comply with the NI43-101, Form 43-101F1, CIM Standards, and CIM Guidelines. The Panel concluded that the Member was guilty of non-compliance with the standards and hence guilty of professional misconduct. Its not clear what specifically was not complied with, but this illustrates that QP’s will be held accountable for their work. The two reports in question were either amended or withdrawn to address the concerns of the regulator in British Columbia, although there had been no intentional non-compliance and no economic impact. The penalty was 2 months suspension (deferred), and the QP had to work under a mentor for 9 months and pay a maximum $10,000 for the mentor’s fees.

Link 1:

False QP Statements: Here is another example of sanctioning a QP in 2018. The person was charged with unprofessional conduct and incompetence. He stated that he was responsible for the preparation of the technical report, had no prior involvement in the project, and was independent of the issuer. This was false. Sanctions included three month license suspension, taking some re-training, require peer review of the report. In 2022, further sanctions consisted of a $75,000 penalty, further sanctioned along with an executive in the company for insider trading issues (see Link 3 below).

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False QP Statements: This is an example for 2017 when an independent QP took responsibility for the resource estimation work in section 14 of the report, yet they did not have the experience to take responsibility. They also misrepresented that the Report complied with 2014 CIM standards, yet it didn’t, resulting in an overestimation of the mineral resource in both confidence and magnitude. Other claims include relying on non-QP experts but not stating that, failing to adequately discuss the nature of sample quality control procedures as required. The sanctions included license suspension of 3 months, must work with a technical supervisor, re-training, and $7,500 in legal fees.

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False QP Statements: This is another example from 2019, when the QP / Director permitted the disclosure of information to the public in multiple news releases where they should have known that that information was misleading. An example is the disclosure of inferred reserves when there were no reserves and “inferred” is not even a classification of reserves. The sanctions were a license suspension of 4 months, $5,000 legal costs, re-training, and requirement not to act as a QP again.

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QP Resource Estimate Error: This occurred in 2012 when a QP and consulting firm delivered a incorrect resource estimate and reportedly withheld negative opinions on the project from the client. The company spent $3 million on a feasibility study during which the resource estimate error was discovered. The “corrected” resource made the project uneconomic, meaning the feasibility study should not have been done. The mining company sought compensation from the consulting firm, ultimately receiving $1.25 million. The Link 3 references is interesting in that it states “As this case demonstrates, it is critically important for professional service firms to be forthcoming about any reservations they may have regarding the work they are being employed to undertake.” Whatever that really means?

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Disclaimers

Many QP’s realize the legal responsibility and liability they have. Hence in 43-101 reports QP’s sometimes attempt to mitigate this by putting in broad disclaimers to limited that liability. If the securities commission notices such disclaimers, they will require that they be removed.

For example, sometimes the QP of a chapter may have other geologists or engineers (i.e. experts) assisting them. They may then put in disclaimers saying “They disclaim responsibility for such expert content” for the work done by the others. A QP essentially has to sign off on the work of others in the sections they are responsible for. A recent example is a Generation Mining technical report prepared by G-Mining, that had to be amended from (March 31_2023 to May 31_2024) removing several QP liability limiting disclaimers.

43-101 regulations state that “An issuer must not file a technical report that contains a disclaimer by any qualified person responsible for preparing or supervising the preparation of all or part of the report that

(a) disclaims responsibility for, or limits reliance by another party on, any information in the part of the report the qualified person prepared or supervised the preparation of;

or (b) limits the use or publication of the report in a manner that interferes with the issuer’s obligation to reproduce the report by filing it on SEDAR.“

” These disclaimers are also potentially misleading disclosure because, in certain circumstances, securities legislation provides investors with a statutory right of action against a qualified person for a misrepresentation in disclosure that is based upon the qualified person’s technical report.

That right of action exists despite any disclaimer to the contrary that appears in the technical report. The securities regulatory authorities will generally require the issuer to have its qualified person remove any blanket disclaimers in a technical report that the issuer uses to support its public offering document.“

Conclusion

This ends Part 2 of this blog post. It hopefully highlights the importance of QP’s being knowledgably on the disclosure rules and the technical aspects of what they are hired to do.

Companies should always ensure that only qualified QP’s are used for their project work, even if some of the others might be less expensive. The potential headaches and costs afterwards may override the higher upfront cost.

It should be noted that this Sham and Scam blog does not discuss the other less than desirable junior mining traits seen from time to time. These relate to; insider trading; abuse of micro-penny founder shares; and the ever present “pump & dump” schemes.

In closing, if anyone is aware of other good examples of QP issues, please provide any links to any publicly disclosed information. I can add them to the blog post.

Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and other mining posts. The entire blog post library can be found at https://kuchling.com/library/

Junior Mining Shams and Scams – Part 1

Date: May 30, 2024 Author: Ken Kuchling Comments: Leave a reply

Recently (in April 2024) Red Pine Exploration issued several press releases highlighting that some assays in their geological database were found to have been manipulated. Numerous assays input into their database did not match the original lab certificates. Is this another mining scam?

The Red Pine event led me to ask some colleagues about similar situations that have occurred and whether the personnel responsible were ever sanctioned. Their feedback provided me with several past examples of such incidents, which I have attempted to summarize in this two-part blog post. Big thanks to my colleagues that took the time to provide these examples.

Raise the Red Flag

The focus of this blog is on the types of activities that raised the red flags in the past. I am less interested in naming the people responsible, although the associated web links do provide more detail on the events.

Not all of the examples listed in these two blogs are scams or deliberate falsification of results. Some may be incompetence, faulty reporting, or lack of diligence and care. Some of these involve company executives, in-house Qualified Persons (QPs), and independent QP’s working for the companies.

Part 1 has examples mainly involving company management or in-house QPs. Part 2 will provide other examples where QP’s have been held to account for their poor quality of their work.

Examples (Part 1)

The following are presented in no particular order. Some of these may still be at the allegation or investigation stage. This blog post can be updated when the issue is eventually resolved.

Tampering with Samples: Bre-X salting of samples is the number one example of a well orchestrated scam. I’m not sure if anyone was ever officially convicted of anything at Bre-X, but it warranted several books, recent podcasts, and even a loosely-based Hollywood movie (Gold). As an aside, I had spoken with the Bre-X team in 1995 about consulting work while I was living in Calgary. However, they were still far from needing mine engineering services at that time. That would have been a wild ride, although with my luck, I would have ended up being the only one in jail. For further information here is an interesting story from Warren Irwin on the Bre-x story. https://redcloudfs.com/25-years-after-bre-x-by-the-man-who-made-a-fortune-going-long-short-of-the-biggest-ever-mining-fraud/

Falsifying QP Signature: The B.C. Securities Commission (BCSC) is alleging that a B.C.-based mining company and its CEO made false or misleading statements about an Idaho mineral deposit in a report that it filed. In 2019, Multi-Metal filed a technical report which contained an electronic signature of a qualified person – a professional engineer – and listed him as an author. The BCSC alleges the qualified person did not review, sign, or consent to filing Multi-Metal’s report. At this time, the BCSC’s allegations have not yet been proven.
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Falsifying Assay Data: The Ontario Securities Commission approved a settlement agreement between a geologist with 30 years of experience and the Qualified Person for Bear Lake Gold Ltd. Between 2007 and 2009 the QP altered certain assay results and transferred these results into the company’s assay database; prepared draft press releases that contained incorrect and inflated data, then provided Independent QP’s with the altered data, and also replaced core and modified a drill core log. In the settlement, the QP agreed to a permanent ban from acting as a Director and Officer of any issuer, an administrative penalty of $750,000, $50,000 in costs, and a prohibition from trading.
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Falsifying Assay Data: In 2024 Red Pine Exploration Inc. reported that there were 382 assay inconsistencies out of a total of 60,000 assay results for the 2019-2024 Period, representing 95 intersections contained within 69 drill holes as follows. An independent investigation is underway, however at the time of this blog, the investigation is still on-going. A link will be provided here once their final report is disclosed publicly.
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Tampering with Samples: This example goes back to 1981, involving New Cinch Uranium. They published test results that showed significant gold and silver at their New Mexico property. After the stock jumped, third party tests showed that samples did not contain any significant amount of precious metals. The New Cinch samples were “salted”. The Vancouver Stock Exchange was sued for not verifying the company’s test results. In response, the VSE made it compulsory for companies to issue a disclaimer on each press release stating that the VSE “neither approves nor disapproves of their contents”. This case goes back 40 years, so limited information is available on it. A bit more discussion on this case and discussing the VSE is found at the link below. While the VSE no longer exists, the TSX has taken over.
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Falsifying Assay Data: This example involves Southwestern Resources, a company with the Boka Project in China. The former CEO and President, John Paterson, was the company’s QP. In 2007, a month after Paterson’s resignation, Southwestern announced there were errors in previously reported assay results. As a result, Southwestern withdrew all of its previously disclosed results for that project. Sounds familiar? An independent investigation by Snowden led to a revised resource estimate that was substantially less than previously reported and identified 433 discrepancies in gold grades reported in dozens of 2003 and 2007. The original assay certificates were sent to Paterson and he was the sole recipient. Instead of transferring the true assay certificate data, Paterson transferred data containing discrepancies into the database. There was 6 years of jail time involved with this case.
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Falsified Resource Estimate: This one goes back to 1997, although sanctioning of parties was only done in 2007. The company geologist was accused of several things, including not having adequate data to support the findings in his 1997 resource report; the methods used to calculate resources were not appropriate; the report portrayed the project as more advanced than it was; the $129 projected share value was based on “unsubstantiated tonnage and grade information and data.”. Exotic assaying methods and duping accredited investors was also part of this operation.
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Using Exploration Targets in Economic Analysis: This event goes back to 2012 and involves a company breaking the rules by disclosing the results of an economic analysis that included a target for further exploration (pie-in-the-sky) of the company’s gold mining operation. The economic analysis was not based on a current resource estimate. The punishment was the proponents had to pay to the commission $20,000 and complete a course of study on the requirements of Canadian mining rules.
Link 1

Conclusion

This ends Part 1 of this blog post. Part 2 will continue with a few more examples, specifically involving Qualified Persons, and can be found at this link Junior Mining Shams and Scams – Part 2

Discipline is typically rendered in two ways; the Security Commission may prosecute; or the professional associations will provide sanctions. Typically, the professional association penalties are more lenient, consisting of a temporary license suspension and the payment of legal fees.

If readers have any other examples of such junior mining stories, email them to me at kjkltd@rogers.com and I can add them to this blog.

Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and other mining posts. The entire blog post library can be found at https://kuchling.com/library/

The Anatomy of 43-101 Chapter 16 – Mining (Part 2)

Date: March 22, 2024 Author: Ken Kuchling Comments: Leave a reply

Part 2 of this blog post will focus on the remaining engineering work to finish Chapter 16 of the Technical Report. We only wrote about half of it in Part 1. The mining engineer can generally handle the rest of these tasks without requiring a lot of external input. You can read Part 1 at this link “The Anatomy of 43-101 Chapter 16 – Mining (Part 1)”.

The pit design and phases were completed at the end of Part 1, and we can move on to scheduling.

4. Production Scheduling

Once the pit design is complete, everyone will be calling for the production schedule as soon as possible. Others on the team are waiting for it. The tailings engineers need the production schedule for the tailings stage design. The process engineers need the scheduled head grades to finalize sizing the plant components. The client wants the schedule to plug into their internal cashflow model for a quick peek at the economics.

However, before the mine engineer can start scheduling, the dilution approach needs to be selected. Dilution is waste that is mixed in with ore during mining. A high amount of dilution can dramatically lower the processed head grades. There may be a desire to “low ball” the dilution to make the grades look better, but the engineer should base the dilution on what they would expect to see.

Two dilution approaches are common. One can either construct a diluted block model; or one can apply dilution afterwards in the production schedule. I have used both approaches at different times.

The production schedule must be on a diluted basis, since that represents what the processing plant will actually see.

Generally, two different production schedules must be created: (i) a Mining schedule, and (ii) a Processing schedule. In some instances, they may be one and the same schedule. However, if any ore stockpiling is done, then the Mining schedule will be separate from the Processing schedule.

The Mining schedule shows ore going directly to the plant and ore going into the stockpiles. The Processing schedule will show ore delivered directly from the mine and ore reclaimed from stockpiles. Building stockpiles and pulling ore from stockpiles are two independent activities.

Sometimes lower grade stockpiles are built up by the mine each year but only processed at the end of the mine life. Periodically the ore mining rate may exceed the processing rate and other times it may be less. This is where the stockpile provides its service, smoothing the ore delivery to the plant.

Scheduling can be done with variable time periods. Perhaps the schedule is generated using monthly time periods, or quarters, or years.

The 43-101 report will normally show the annual production schedule, but that does not mean it was generated that way. I prefer to use short time periods (monthly or quarterly) for the entire mine life, to ensure ore is always available to feed the plant. A 10 year mine life would result in 120 monthly time periods, so output spreadsheets can get large.

Scheduling can be done manually (in Excel) or by using commercial software, like Datamine’s NPVS. The commercial software is better in that it allows one to run different scenarios more quickly, and it does a lot of the thinking for the engineer. It also does a good job of stockpile tracking. It also decides when it is necessary to transition to mining in satellite pits.

Once the schedules are finalized, they are normally reviewed by the client for approval. The strip ratio and ore grade profile by date are of interest. One may then be asked to look to at different stockpiling approaches to see if an NPV (i.e. head grade) improvement is possible.

One can stockpile lower grade ore and feed the plant with better grade by mining at a higher rate with more equipment. One might need to examine iterative schedules of that type.

Sometimes one must take two steps backwards and re-design some of the initial pit phases to reduce waste stripping or improve grades. Then one would run the schedules again until getting one that satisfies everyone.

Now that the schedule is complete, we can write up the Chapter 16 text up to page 15. We’re getting closer to the end.

5. Site Layout Design

With the pit tonnages and mining sequence from the schedule, the mine engineers can start to look at the site layout (waste dumps and haul roads). Normally the tailings engineers will be responsible for the tailings layout. However, if there is no tailings engineer on the PEA team, the mining engineer may look after this too.

First there is a need for a waste balance. This defines how much mined overburden or waste rock will be needed to build haulroads, laydown pads, and tailings dams. Then the remaining waste volume must be placed into waste dumps.

Hopefully the tailings engineers have finished their tailings dam construction sequence by this time to provide their rockfill needs (although unlikely if you only gave them the production schedule two days ago).

The geotechnical engineers will provide the waste dump design criteria; for example, 3:1 overall side slope using 15m high dump lifts. Ideally it is nice to have soil and foundation information beneath the waste dump sites, but at PEA stage most often this isn’t available. The dump locations are only being defined now.

The mining engineers will size the various waste dumps to their required capacity. Then they can lay out the mine haulroads from the pit ramps exits to the ore crusher, the ore stockpiles, and to each waste dump.

That’s it for the site layout input. Add another 2 pages to Chapter 16. Now the mining engineers can look at the mining equipment fleet.

6. Fleet Sizing and Mining Manpower

The last task for the mine engineer in Chapter 16 is estimating the open pit equipment fleet and manpower needs. The capital and operating costs for the mining operation will also be calculated as part of this work, but the costs are only presented in Chapter 21.

The primary pieces of equipment are the haul trucks. They can range in size from 30 tonnes to 350 tonnes and anywhere in between.

Typically, the larger the equipment is, the lower the unit cost ($/t), especially in jurisdictions where labor costs are high. One doesn’t want a mine fleet with only 5 trucks nor one with 50 trucks. So where is the happy medium?

Once the schedule and site layout are complete, the mine engineers can run the truck haul cycles, in minutes. They need to estimate the time to drive from the pit face, up the ramp, to the waste dump, to the ore crusher, and return back into the mine. Cycle times determine the truck productivity, in tonnes per hour per truck and include the time to load the truck. Some destinations may have long cycle times (to a far off crusher) while others may be quick (to an adjacent waste dump).

The cycle time must be calculated for each material type going to each destination. As the pit deepens, the cycle times increase.

Very simplistically, if a 100 tonne truck has a 20 minute cycle time, it can do three cycles in an hour (300 tph). If one has to mine 10 million tonnes of ore per year, then that would require 33,300 truck hours. If a single truck provides 6500 operating hours per year, that activity would require a fleet of 5 trucks. The same calculation goes for waste.

The total trucking hours will vary year to year as waste stripping tonnages change or haul cycle times increase in deeper pits. The required truck fleet may vary year to year. Keeping haul distance short and haul cycles quick is the key to a lower cost mine.

The mine engineers undertake the productivity calculations for loading equipment to estimate annual operating hours, and the required shovel / loader fleet size.

The support equipment needs (dozers, graders, pickups, mechanics trucks, etc.) are typically fixed. For example, 2 graders per year regardless if the annual tonnages mined fluctuate.

The support equipment needs are normally based on the mining engineer’s experience. Hence the benefit of actually working at a mine at some point in your career.

Blasting includes both the blasthole drilling activity and hole charging. The mining engineer estimates drill productivity and specifications based on the bench height, the expected rock mass quality, and the power factor (kg/t) need to properly demolish the rock.

Finally, the mine operation manpower is estimated based on all the equipment operating hours as well as the fixed number of personnel to support and supervise the mine.

This essentially concludes the mining information presented in Chapter 16 of a typical 43-101 open pit report.

Conclusion

These two blog posts hopefully give an overview of some of the things that mining engineers do as part of their jobs. Hopefully the posts also shed light on the amount of work that goes into Chapter 16 of a 43-101 report. While that chapter may not seem that long compared to some of the others, a lot of the effort is behind the scenes.

Some will say PEA’s are not very accurate documents that should be taken with a grain of salt. One should understand that engineers are working with a limited amount of information at this early stage while forming the concept for the proposed operation.

The subsequent study stages are where more accurate costs are expected and can be demanded.

I don’t know if this overview makes one want to sign up to be a mining engineer or learn to code instead. None of this is rocket science; it just requires practical thinking.

If young people want to get into mining, but not sure into which aspect, I suggest go read through a 43-101 report. There are sections describing exploration, resource modelling, mine engineering, metallurgy, geotechnical engineering, environmental, and financial modelling. Its all in one document. See if any of these areas are of interest to you. Universities should use 43-101 reports as part of their mining engineering curriculum.

Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and other mining posts. The entire blog post library can be found at https://kuchling.com/library/

Top Ten Mining Podcasts

Date: March 12, 2024 Author: Ken Kuchling Comments: 1 Reply

Podcasts. There are thousands of them out there, free for anyone to access. I regularly listen to them on all sorts of topics ranging from sports, politics, and even mining. This blog post is about my top mining podcasts that I find entertaining and/or educational. There are likely others missing from this playlist, but one only has so much time in a day.

On YouTube, there are also a lot of educational videos related to mining. Some of the same audio podcast episodes are also available on the YouTube platform. Given an option, I prefer the audio-only podcast format over YouTube.

One doesn’t need to sit there focusing on a video screen. With podcasts, you can do other things at the same time, like exercise, walk the dog, drive a car, etc. One has freedom to multi-task, something that the video format doesn’t allow.

When listening to podcasts, I used the Android phone app called Podcast Addict. However, most likely there are plenty of other smartphone apps to use.

Mining Podcast Categories

In my experience, mining podcasts typically fall into one of two categories; Mining Investment; and Technical Discussions.

Mining Investment: These are the investor targeted interviews, chatting with corporate executives or newsletter writers. They discuss what is new with their companies or what is happening in the industry. From an engineer’s perspective (not as an investor), I listen to a few of these to catch up on projects that I worked on in the past, or to learn how different executives strategize. These interviews are often paid for promotions by the company, so sometimes the interview questions can be the softball type. I’m not sure how often the interview questions are actually provided in advance.

Technical Discussions: There are also a few podcasts related to technical discussions on geology, exploration methods, resource modelling, mining software, and mining services. I have not found any podcasts specifically related to mine engineering or mineral processing. Most are geared towards the geological and exploration aspects of the industry.

Pick and choose. One can’t listen to all the podcast episodes available or else you wouldn’t have time to do anything else in life. You would also become bored since much of it can be repetitive.

Therefore, I follow multiple podcasters, get updates on their new episodes, and then pick and choose from there. I probably only listen to 10%-20% of the episodes, i.e. only those that are of real interest to me.

Sometimes, especially with investor presentations, the same executives will appear on multiple podcasts. You only need to hear the story once. As well, some executives will be returning frequently to the same podcast with not a lot new to say from their last interview. They need to catch the eyes of investors.

The podcast host will have a lot to do with the style of discussion. Some are better than others. Sometimes the interviewing style is dull and unexciting, even through the topic itself may be great. The following are some of the mining podcasters that I follow.

Mining Investment Podcasts

This list are my favorites, in order of preference. They are the only ones I follow
Mining Stock Education (680 episodes) https://www.miningstockeducation.com/ This podcast can have some lively discussion that focus on both the positives and negatives of mining investment. Some guests definitely provide great learnings on the inner workings of the industry.
Crux Investor (2500 episodes) https://www.cruxinvestor.com/ Matthew and Merlin have an engaging interview style, and sometimes will have a hard edge, putting interviewees on the spot. They say they “…exist to cut through the jargon, bias and bluster.”
Mining Stock Daily (2800 episodes) Mining Stock Daily, hosted by Trevor Hall, provides a daily 8 minute overview of overnight mining news and will also have long form discussions on finance, macro economics, and corporate exploration news.
Global Lithium Podcast (130 episodes) is hosted by Joe Lowry, known as “Mr Lithium” who is a 30 plus year industry veteran. For me, this podcast is the “go to” on everything lithium, whether brines or hard rock production.
Money of Mine (170 episodes) This Aussie mining podcast focusses mainly on Aussie companies, but the three hosts have an interesting style and not afraid to say what they think. Listening to their Aussie accents always makes me think of the Crocodile Dundee movies.

Technical / Informational Mining Podcasts

These are podcasts on the informational and technical side of mining. Unfortunately for we engineers, they mainly focus on geology.

Fresh Thinking by Optiro-Snowden (53 episodes) This podcast is hosted by Snowdon – Optiro consultants. They typically focus on resource modelling and grade reconciliation aspects. The episodes are fairly short (15 mins), which is nice. Although I am not a resource modeller, I can always learn more about the black art of resource modelling.
The Northern Mining Podcast (400 episodes) This podcast provides general industry news, as the Northern Miner newspaper does. It also has interviews with key industry players, but generally avoids the company investor relation interviews.
Discovery to Recovery (50 episodes) This is a podcast produced by the Society of Economic Geologists (SEG), brings geoscience and technology stories from the world of ore deposits. This podcast can be harder to listen to, getting heavy into geology discussions beyond my expertise.
Exploration Radio (73 episodes) This is a podcast focusing on the past, present and future of exploration. They don’t seem to post very often, but can have interesting topics, even for an engineer.

That is the end of my list.

To the best of my knowledge, there are a lack of podcasts related to mine engineering, for topics such as pit optimization, mine design, scheduling, equipment selection, and costing.

There is one podcast on mine scheduling by Mark Bowater, author of “Crimes Against Mine Planning”, but I cannot find it on any podcast platform.

Another honorable mention is Antonio at https://www.youtube.com/@ResourceTalks/ who does a great job at interviewing executives. The downside is that I don’t think he is on audio-podcast format and his episodes are over 1 hour, or 3600 seconds as he likes to present it. That’s beyond my normal attention span.

Update: A follower of my blog posts has suggested a mining investing site on YouTube called “Junior Resource Investing“. The host is Matthew Mick, seems to have a preference for Ni and base metal projects, interviews are up to 50 minutes each with well prepared questions. Check it out. I can’t find it on a podcast platform as of yet.

Conclusion

There is no shortage of material in the podcast world about the mining industry. It all depends on what interests you the most. There is even more mining information available on YouTube, if you have the time to sit and watch videos. Nevertheless the audio-only platform is great, although you don’t get to see the charts being discussed. That’s fine with me, particularly if they take a few seconds to describe the chart.

Let us know what mining podcasts you enjoy and would recommend. I have room to add one more to my list of 9 mining podcasts. I don’t actually have 10 favorites yet.

Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and other mining posts. The entire blog post library can be found at https://kuchling.com/library/

Mine Builders vs Mine Vendors

Date: October 15, 2023 Author: Ken Kuchling Comments: Leave a reply

Normally when Major or Intermediate miners advance their projects through the study stages, they usually have the intent to build the mine at some time. Sometimes they may decide to sell the project if it no longer fits in their corporate vision or if they desperately need some cash. However, selling the project was likely not their initial intent.

On the other hand, Junior miners tend to follow one of two paths. They are either on (a) the Mine Builder path, or (b) the Mine Vendor path (i.e. sell the project). In this article, I will present some examples of companies on each path. There will also be some discussion on whether the engineers undertaking the early stage studies (e.g., PEA’s) should be considering the path being followed.

The Mine Builder Path

The Mine Builder generally follows a systematic approach, as sketched out in the image below. The project advances from drilling to Mineral Resource Estimate (MRE), scoping study (PEA), then through the Pre-Feasibility Study (PFS) and/or Feasibility Study (FS) stages. Environmental permitting is normally proceeding in conjunction with the engineering. Once the FS is complete, the next hurdles for the Mine Builder are financing and construction. The path is fairly orderly.

The amount of the exploration drilling is only needed to define an economic resource to the Measured and Indicated classifications. There is no requirement to delineate the mineral resource on the entire property since there will be time to do that during production. Demonstrating an economic resource, with some upside potential, is often sufficient for the Mine Builder.

Three examples of companies on the Builder path are shown below; Orla Camino Rojo gold project (in operation), SilverCrest Las Chispas gold project (in operation), and Nexgen Rook uranium project (financing stage). Although the duration of each timeline is different due to different project complexities, the development paths are consistent. Most junior miners would not consider themselves on the Builder path.

The Mine Vendor Path

Mine Vendor type organizations have the primary goal of selling their project. These companies may consist of management teams that don’t have the desire, comfort, or capability to put a mine into production. For example, this is often the case with companies founded by exploration geologists, whereby their plan is to explore, grow, and sell all (or part) of the project. In other cases the Junior miner realizes their project is large with a high capital cost. That capital cost is beyond the financial capability of the company. Hence a deep-pocket partner is required or an outright sale is preferred.

The Mine Vendors tend to follow a different development path than the Mine Builders. They don’t have the same long term objectives. Vendors want out at some point.

The Vendor path can be more irregular, with multiple studies undertaken at different levels of detail, sometimes stepping back to lower level of studies as more information is acquired. Their object is to make the project look good to potential buyers, and look better than their junior miner competitors also for sale. Often this ongoing project improvement process is termed “de-risking”.

Not only must the Vendors demonstrate an economic resource, they must demonstrate a highly valuable resource to maximize the acquisition price for the shareholders. They will try to do this through multiple drill campaigns followed by multiple studies, each one looking better than the prior one.

Sometimes you will see a management team indicate that, if the project isn’t sold, they are going to put it into production themselves. This may be true in some cases, or simply part of the negotiating game to try to maximize the acquisition price.

Two quick examples of companies on the Vendor path are shown below: Western Copper Casino project and Seabridge KSM project. The durations of these development timelines are extensive and expensive, while waiting for an interested buyer. During these periods, the companies may continue to spend money de-risk the project further. The hope is that the company can eventually make the project attractive or that changing market conditions will make it attractive for them. Unfortunately, there is always the possibility that no buyer will ever come along.

Engineer’s Perspective

One question is whether the independent geologists and engineers working on the advanced studies should be aware of the path the company is following. Is the company a Builder or a Vendor?

Some may feel that the technical work should be independent of the path being followed. Based on my experience as both an owner’s representative and independent study QP, I have a somewhat different opinion. The technical work should be tailored to the intended path.

The Engineer on the Mine Builder Path:

If an engineer understands that a Mine Builder’s project will move from PEA to PFS to FS in rapid succession, then there is more incentive to ensure each study is somewhat integrated.

For example, a PEA will use Inferred resources in the economics. However, if the project will advance to the PFS stage, where Inferred cannot be used, then it is important for the PEA to understand the role that Inferred plays in the economics. How much drilling will be needed to upgrade Inferred resource to Indicated for the PFS, if needed at all?

Typically, capital costs tend to increase as advancing studies get more accurate due to greater levels of engineering. A Builder wants to avoid large cost increases when moving from PEA to PFS to FS. Therefore, when costing at the PEA stage, one may wish to increase contingency or use conservative design assumptions. After all, one is not trying to sell or promote the project internally, but rather move it towards production.

There is no value to the Mine Builder by fooling themselves with low-balled cost estimates. (Although some may argue there is still a desire to low ball costs to get management to approve the project). Conversely Mine Vendors do have some incentive to low ball the costs.

Perhaps some of the recent project capital cost over-runs we have seen is that the Vendor mentality was used at the PEA stage to optimistically set the capital cost baseline. Subsequent studies were then forced to conform to that initial baseline. Ultimately construction will be the arbiter on the true project cost. Hence there is no real value in underestimating costs, ultimately making management appear incompetent if costs do over-run.

The Mine Builder will also be advancing environmental permitting simultaneously with their advanced studies. Hence at the early stage (PEA) it is important to properly define the site layout, processing method, production rate, facility locations, etc. since they all feed into the permitting documents.

Changing significant design details in the future will set back the permitting and construction timelines. Hence, for the Mine Builder, the engineers should focus on getting the design criteria mostly correct at the PEA stage. For the Mine Vendor, this is not as important since multiple studies are being planned for in the future anyway.

The Engineer on the Mine Vendor Path:

The objective of the Mine Vendor is to make the project attractive to potential buyers. There is less urgency in fast tracking detailed engineering and permitting.

It is not uncommon to see multiple drilling programs, followed my multiple studies of scenarios with different size, production rate, and layout. The degree of engineering conservativeness in design and costing is less critical since future studies may be on substantially different sized projects.

The role that the Inferred resource plays in the economics is also less important at this time, since a lot more drilling may be coming. The Vendor’s objective tends to be on maximizing resource size not necessarily optimizing resource classification.

While the Mine Vendor may also be advancing environmental permitting as another way to de-risk the project, the project design may still be in flux as the resource size changes. Major modifications to the plan may cause permitting to stop and re-start, leading to an extended project timeline and wasted money.

There is also risk in starting the permitting with a project definition that isn’t of economic interest to future buyers. Sometimes the Vendor may be making regulatory commitments that constrain the operating flexibility of future mine operators. Its easy to commit to things when you aren’t the one having to live up to them.

The Mine Vendor will also de-risk the project by moving from PEA to PFS and even to FS. The caution with completing a FS is that it is a costly study and essentially brings one to the end of the study line. What does the company do next if there is still no buyer?

Feasibility studies also have a shelf life, with the cost estimates and economics becoming inaccurate after a few years. Some companies may re-examine the project, re-frame it, and jump back to the PEA or PFS stages. There can be an on-going study loop, requiring continued funding with no guarantee of a sale in sight. Often feasibility studies have the dual role of trying to boost the share price and market cap, as well as frame the project for potential buyers.

Conclusion

As an engineer, it is helpful to understand the objectives of the project owner and then tailor the technical studies to meet those objectives. This does not mean low balling costs to make the study a promotional tool. It means focusing on what is important. It means recognizing the path, and what doesn’t need to be engineered in detail at this time. This may save the client time, money, and improve credibility in the long run.

In many cases, the precise size of the deposit is less important than understanding the site, access, water supply, local community issues, the environmentally acceptable location for dumps and tailings, etc.. It can be more important to focus on these issues rather than having a detailed mine plan with multiple pit phases that immediately becomes obsolete in a few months after the next drilling campaign.

Potential buyers will have their own technical team that will develop their own opinions on what the project should be and what it should cost. Just because a Mine Vendor has a feasibility study in hand, doesn’t mean a potential buyer will believe it.

This post is just a brief discussion of mining project timelines. For those interested, there a few additional project timelines for curiosity purposes. Each path is unique because no two mining projects are the same. You can find these examples at this link “Mining Project Timelines”.

Let me know about other interesting projects that have interesting paths to learn from. I can add them to the list.

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Don’t Cut Corners, Cut Cross-Sections Instead

Date: October 4, 2023 Author: Ken Kuchling Comments: Leave a reply

This article is about the benefit of preparing (cutting) more geological cross-sections and the value they bring.

Geological sections are one of the easiest ways to explain the character of an orebody. They have an inherent simplicity yet provide more information than any other mining related graphic.

Some sections can be simple cartoon-like images while others can be technically complicated, presenting detailed geological data.

Cartoon-stylized sections are typically used to describe the general nature of the orebody. The detailed sections can present technical data such as drill hole traces, color coded assays intervals, ore block grades, ore zone interpretations, mineral classifications, etc.

Sections provide a level of clarity to everyone, including to those new to the mining industry as well as those with decades of experience.

This article briefly describes what story I (as an engineer) am looking for in sections. Geologists may have a different view on what they conclude when reviewing geological sections.

I will describe the three types of geological sections that one can cut and what each may be describing. The three types are: (1) longitudinal (long) sections; (2) cross-sections; (3) bench (level) plans. Each plays a different role in helping to understand the orebody and mining environment.

There is also another way to share simple geological images via3D PDF files. I will provide an example later.

Longitudinal (Long) Sections

Long sections are aligned along the long axis of the deposit. They can be vertically oriented, although sometimes they may be tilted to follow the dip angle of an ore zone.

Long sections are typically shown for narrow structure style deposits (e.g. gold veins) and are typically less relevant for bulk deposits (e.g. porphyry).

The information garnered from long sections includes:

The lateral extent of the mineralized structure, which can be in hundred of metres or even kilometers. This provides a sense for how large the entire system is. Sometimes these sections may show geophysics, drilling to defend the basis for the regional interpretation.
Long sections will often highlight the drill hole pierce points to illustrate how well the mineralized zone is drilled off. Is the ore zone defined with a good drill density or are there only widely spaced holes? As well, long sections can show how deep ore zone has been defined by drilling. On some projects, a few widely spaced deep holes, although insufficient for resource estimation purposes, may confirm that the ore zone extends to great depth. This bodes well for potential development in that a long life deposit may exist.
Sometimes the long section drill intercept pierce points can be contoured on grade, thickness, or grade-thickness. This information provides a sense for the uniformity (or variability) of the ore zone. It also shows the elevations of the higher grade zones, if the deposit is more likely an open pit mine, an underground mine, or a combination of both.

Cross-Sections

Cross-sections are generally the most popular geological sections seen in presentations. These are vertical slices aligned perpendicular to the strike of the orebody. They can show the ore zone interpretation, drill holes traces, assays, rock types, and/or color-coded resource block grades.

As an engineer, my greatest interest is in seeing the resource blocks, color coded by grade. Sometimes open pit shells may be included on the section to define the potential mining volume. The engineering information garnered from block model cross-sections includes:

Where are the higher-grade areas located; at depth or near surface?
If a pit shell profile is included, what will the relative strip ratio look like? Are the ore zones relatively narrow compared to the size of the pit?
How will the topography impact on the pit shape? In mountainous terrain, will a push-back on pit wall result in the need to climb up a hillside and create a very high pit slope? This can result in high stripping ratios or difficult mining conditions.
Does the ore zone extend deeper and if one wants to push the pit a bit deeper, is there a high incremental strip ratio to do this? Does one need to strip a lot of waste to gain a bit more ore?
Are the widths of the mineable ore zones narrow or wide, or are there multiple ore zones separated by internal waste zones? This may indicate if lower-cost bulk mining is possible, or if higher cost selective mining is required to minimize waste dilution.
How difficult will it be to maintain grade control? For example, narrow veins being mined using a 10 metre bench height and 7 metre blast pattern will have difficulty in defining the ore /waste contacts.
Cross-sections that show the ore blocks color coded by classification (Measured, Indicated, Inferred), illustrate where the less reliable (Inferred) resources are located and how much relative tonnage may be in the more certain Measured and Indicated categories.

When looking at cross-sections, it is always important to look at multiple cross-sections across the orebody. Too often in reports one may be presented with the widest and juiciest ore zone, as if that was typical for the entire orebody. It likely is not typical.

Stepping away from that one section to look at others is important. Possibly the character of the ore zones changes and hence its important to cut multiple sections along the orebody.

Bench (Level) Plans

Bench plans (or level plans) are horizontal slices across the ore body at various elevations. In these sections one is looking down on the orebody from above.

Level plans are typically less common to see in presentations, although they are very useful. The level plans may show geological detail, rock types, ore zone interpretations, ore block grades, and underground workings.

The bench plan represents what the open pit mining crews would see as they are working along a bench in the pit. The information garnered from bench plans that include the block model grades includes:

Where are the higher-grade areas found on a level? Are these higher grade areas continuous or do they consist of higher grade pockets scattered amongst lower grade blocks?
Do the ore zones swell or pinch out on a bench? A vertical cross-section may give a false sense the ore zones are uniform. The bench plan gives an indication on how complicated mining, grade control, and dilution control might be for operators.
Do the ore zones on a bench level extend out beyond the pit walls and is there potential to expand the pit to capture that ore?
On a given bench what will the strip ratio be? Are the ore zones small compared to the total area of the bench?

As recommended with cross-sections, when looking at bench plans, one should try to look at multiple elevations. The mineability of the ore zones may change as one moves vertically upwards or downwards through a deposit.

Never mind cross-sections – give me 3D

While geological sections are great, another way to present the orebody is with 3D PDF files to allow users to view the deposit in three-dimensions. Web platforms like VRIFY are great, but I have been told they sometimes can be slow to use.

3D PDF files can be created by some of the geological software packages. They can export specific data of interest; for example topography, ore zone wireframes, underground workings, and block model information. These 3D files allows anyone to rotate an image, zoom in as needed and turn layers off and on.

You can also create your own simplistic cross-sections through the pdf menus (see image).

A simple example of such a 3D PDF file can be downloaded at this link (3D DPF File Example). It only includes two pit designs and some ore blocks to keep it simple.

The nice thing about these PDF files is that one doesn’t need a standalone viewer program (e.g. Leapfrog viewer) to view them. They are also not huge in size. As far as I know 3D PDF files only work with Adobe Reader, which most everyone already has. It would be good if companies made such 3D PDF files downloadable along with their corporate PowerPoint presentations.

Conclusion

The different types of geological sections all provide useful information. Don’t focus only on cross-sections, and don’t focus only on one typical section. Create more sections at different orientations to help everyone understand better.

In 2019 I wrote an article describing the lack of geological cross-sections in many 43-101 technical reports. The link to that article is her “43-101 Reports – What Sections Are Missing?”

Geological sections are some of the first items I look for in a report. Sometimes they can be hidden away in the appendices at the back of the report. If they are available, take the time to actually study them since they can explain more than you realize.

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The article is Part 2 of discussion on my experiences working in the oilsands at the Syncrude Mine in northern Alberta. Part 1 can be read at this link https://kuchling.com/a-rookie-in-the-oilsands-part-1/

Will the Draglines Be Safe

Mining oilsand while from the top of a 50 metre high and 45 degree highwall had never been done before. The geotechnical conditions were new. They were also dramatically different on the East and West sides of the mine, even though mining in the same orebody.

The East side was far more a greater geotechnical concern than the West side. I happened to be the West side mine geotechnical engineer (lucky for me I guess).

In these problem areas, the geotech teams would install slope indicators that were monitored while the dragline was mining through the area. Dedicated 24 hour field engineers were assigned to each of the East side draglines and mining operations were closely monitored at all times.

It was not uncommon for the Syncrude geotechnical engineer to get a 2 am phone call at home saying movement has been detected and they walked the dragline back from the face and then get asked “What should we do now?”.

In the places that the engineers knew were going to be very risk, they could implement mitigation measures. How would you deal with the steeper scour zones? They had three main options.

mine through the area with intense geotechnical monitoring in place, using slope indicators, survey prisms, and visual ground inspections.

sub-excavate the zone; using the dragline to dig out the area and then backfill with the same material to destroy the clay bedding. Then they could safely mine through the area, although the days used to sub-excavate would remove the dragline from oilsand production.

another option was to blast the area ahead of time, to destroy the clay bedding and allow pore pressure dissipation.

All three options were available at the discretion of the geotechnical engineering team. However they all cost money and/or loss in mining production, but safety was always the priority.

The four draglines are now mothballed and thankfully none were ever harmed. All oilsand mining operations are now based on truck-shovel systems.

Basal Slope Failures

The main geotechnical issue on the West side were basal slope failures, termed this due to sliding along weak clays and muds at the base of the highwall. This photo shows a typical basal failure. Basal failures also occured on the East side.

Generally, these slope failures did not jeopardize the dragline since they occurred on freshly cut highwalls away from the machine. Eventually the dragline would be required to operate next to existing basal failures when mining the next panel (as shown in the photo).

The dragline would sit 15-25 metres from the wall, the closer is better to maximize reach into the pit.

Conclusion

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Here is short cheesey video of what the oilsands were about in the 1980’s and 1990’s.

Mining at Syncrude

In Part 1 of this two part blog post I would like to share some stories from the early days of my career working in Fort McMurray.

Hopefully they will be interesting and help shed some light on what it can be like working in the mining industry. Syncrude provided my first job out of engineering university and hence will always be special to me.

In the early 1980’s Syncrude was producing about 90,000 barrels of oil a day by processing oilsand at a rate of 180,000 t/day, so it was a big mining operation.

The Engineer in Training Program

At the time Syncrude had an excellent engineer-in-training program for new graduates. Every six months they would rotate engineers into different technical areas.

These areas could consist of: overburden stripping planning; overburden geotechnical; short range mine planning, mine geotechnical, industrial engineering, tailings planning, and tailings geotechnical. Long range planning tended to be left to the more senior people.

Probably about 15 mining / geological engineers were hired at the same time as me. We came from McGill, Queens, UBC, Laurentian, Univ of Alberta, and Nova Scotia. All of us were in the same boat, rotating through various departments for the first few years.

A Fish Out of Water

I quickly realized that even after finishing university, the learning does not end. In fact, the real learning starts. Everything you do is now applied on the job site, not just submitted in a term paper for marks, so you better learn fast.

The following is one such learning experience.

A Powerline in Trouble

We drilled several hollow stem auger holes from the dump surface down into the foundation to see what was there. We installed a few slope indicators to see at what depth the sliding was occurring. These pinched off within a day or two, but at least we knew at what depth (about 20m down the hole).

Next we sampled that depth carefully, revealing that frozen muskeg layers were present. When we installed standpipe piezometers in these holes, we saw water flowing out of the top of the pipes. This means the foundation pore pressure is high, way too high.

Welcome to the real world.

Not All Jobs Were Exciting

For example, one project I had was to monitor the performance of different brands and styles of conveyor idlers. We would track about 2,000 individual idlers; when they were installed on the conveyors; when they were removed, why they were removed (bearing failure, cover failure, something else).

The idea was to figure out which idler manufacturers were the best – important but not exciting work. If you liked statistics, this was a good job, although around 1981 we didn’t have Excel (or even Lotus 123) at that time (1982), so it was a manual process.

One good thing about this job was that the Industrial Engineering supervisor loved to use the expression “That’s politically explosive” for stuff that really wasn’t. That phrase made such an impression on me that I still try to use it today.

End of Part 1

This concludes Part 1. In the next article I will discuss a few other engineering aspects unique to the oilsands and how the engineering teams dealt with them.

Dragline mining of oilsand was never done before, so engineers were learning on the fly. Given the size of the operation, we could not afford to be wrong on the decisions made. It was an interesting, and also stressful, time for many.

Part 2 of this blog post series can be read at this link “A Rookie in the Oilsands – Part 2“

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The mining industry is implementing more and more technology in the mining cycle.

Lots of different innovations are continually being adopted by the mining industry, contrary to what some may say.

The question is does all this innovation improve the overall performance of a mining operation, and if so, by how much? It can cost a lot of money to implement the new technology, is there a payoff?

One cannot answer those questions if one doesn’t undertake proper mine reconciliation. A concern might be that mining is innovating faster than the ability to assess the results of that innovation. To monitor it, you need to measure it.

What is Mine Reconciliation

Mine reconciliation tends to aggregate over longer time periods (monthly, quarterly or annually) due to short term impacts of material handling in stockpiles and plant circuits and the labour time needed to collect the input data.

Mine reconciliation ultimately attempts to assess how well the delivery of the final metal product relates to the initial resource model (i.e. what the project decision was originally based on)? It is also tool to evaluate the impact of any innovation implementation on the operation.

Mining Codes Getting Involved

Interestingly, it appears that NI43-101 has not yet jumped on the bandwagon about the importance of disclosing reconciliation results. However, it may just be a matter of time before it becomes one of their disclosure requirements.

Excel versus Cloud Based Reconciliation

Spreadsheets can be built site specific, based on an operation’s unique characteristics.

The cloud based approach may help make reconciliation a group effort instead of a tightly controlled internal function. It may also help standardize reporting from a company’s multiple operations, reporting from the mining industry globally, or simply for consistent JORC reporting.

Conclusion

Shifting some people (like me) away from Excel based solutions can be a challenge, but this is an area where it makes sense. Years ago, many engineers did mine production scheduling using Excel, but we have gradually moved away from that, thankfully. Reconciliation should maybe follow that path.

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The following are my observations on what InSAR is and where it may be going. I am by no means an expert in this technology. I am merely viewing it from the perspective of a mine design engineer.

What is InSAR

An example of a satellite being used is the Sentinel-1, launched in mid-2015 by the European Space Agency. This satellite information is open-source data. It will have a 6 to 12 day revisit cycle in many locations.

The results of an InSAR displacement survey are typically shown as a series of colored data points, typically coloured green for the stable points, trending to yellow and red for points that are moving.

This blog has some example images.

Some Limitations With InSAR

There are some limitations with InSAR, so it can only be part of a monitoring program. These limitations are:

The displacement direction is only measured in the direction of the satellite. Hence one may not know in which direction the movement is occurring. The magnitude of displacement could be underestimated depending on the apparent angle of measurement.

The movement being measured could consist of vertical settlement due to material consolidation and may not be horizontal and related to impending failure.

The displacement magnitude measured on opposite sides of a facility may have different accuracy, depending on the slope orientation versus the line-of-sight.

Areas with heavy vegetation may be difficult to monitor

Areas with heavy or persistent cloud cover can be difficult to monitor.

Areas with snow cover will be difficult to monitor.

The satellite return period may be weekly or every two weeks, so one is not able to analyze daily movements if a situation is critical. If the return visit day has cloud cover, there will be no new satellite data collected.

Areas with on-going construction or tailings deposition will lead to erroneous results.

Due to the line of sight, not all slope failure modes may be detectible (for example piping failure).

Regardless of these limitations, InSAR can still play a role in any monitoring program since it is able to monitor large areas quickly. Consider it as a pre-screening tool, being aware that not all failure modes may be detectible with it.

Discussion

On LinkedIn, one can see numerous posts where independent experts are examining historical InSAR data for recent failures to see whether early movement should have been detected. The results seem to be quite positive in that areas that have failed might have been red-flagged prior to failure.

There are also zones that showed critical displacements but have not failed.

Typically, there are four ways to monitor displacement in pit slopes, tailings dams, heap leach pads, and waste dumps. They are:

Insitu monitoring using embedded instruments, for example slope indicators, extensometers, and settlement gauges. These instruments provide information on what is happening internally within a slope, where actual movement is occurring, and they can be used in warning alert systems.