Articles tagged with: Mining

Cyber Security – Coming to a Mine Near You

The mining industry is being told to take advantage of digitalization. As an example, here is a link to a recent article that discusses this “Can mining decode the opportunities of the future?”. The article says “To achieve sustainable improvements in productivity, mining companies will need to overcome a digital disconnect that has held them back”.
I fully agreement with this sentiment, although there are some cautions when adopting new technology.

Not everything is positive

The mining industry will see positive impacts from digitalization.  Unfortunately more reliance on technology also brings with it significant risks.  These risks are related to cyber security.
I recently attended a CIM presentation here in Toronto that focused on cyber security, specifically related to the mining industry. The potential negative impacts to a company can be significant.
Some mining companies already have experienced these negative impacts, albeit in some cases it may not be well publicized. I will highlight some examples later in this blog.
(By the way, I appreciate that the CIM presenter gave me access to the information in his presentation).

Attackers and threats

There are several ways that mining companies can be attacked via technology channels. The attackers could be foreign governments, anti-mining groups, disgruntled employees, or just your average everyday miscreant. There are several avenues as described below.
  • Hack-tivsm: Where a company website may be defaced and blocked as part of a campaign against the opening of a new operation.
  • Data Breaches: Security breaches on websites resulting in leaked sensitive data including personal identification, credentials, and investor information.
  • Industrial Control Attack: Amending software code on major equipment resulting in shutdown or damage.
  • Business Interruption: Attacking systems so the company must be temporarily disconnected from the internet and forcing replacement of all hard drives and servers.
  • Dependent Business Interruption: Overwhelming servers in order to degrade cloud services and websites.

Examples

The following are some examples of how different attack approaches have been used with success.
  • April 2016 – a Canadian gold-mining firm suffered a major data breach when hackers leaked 14.8 GBs of data containing employee personal information and financial data.
  • May 2015 – a Canadian gold mining company was hacked resulting in 100GBs+ worth of stolen data being released.
  • May 2013 – a large platinum producer experienced a security breach on their website resulting in leaked sensitive data online including personal data, credentials, and investor information.
  • February 2015 – A junior mining company was the victim of a cyber scam that resulted in the company paying a $10M deposit into an unknown bank account intended for a sub-contractor.
  • November 2011 – In an attempt to gain information on bid information about a potential corporate takeover, hackers attacked the secure networks of several law firms and computers of the Government of Canada’s Finance Department and Treasury Board.
  • August 2008 – Hackers were able to gain access to the operational controls of a pipeline where they were able to increase the pressure in the pipeline without setting off alarms resulting in an explosion. Beyond damaging the pipeline, the attack cost millions of dollars and also caused thousands of barrels of oil to spill close to a water aquifer.
  • 2014 – A steel mill was the victim of a phishing attack which allowed attackers to gain access to their office network causing outages of production networks and production machines. The outages ultimately resulted in a blast furnace not being properly shut down causing significant damage to the plant.
  • 2003 – Cyber attackers were able to gain access to the SCADA network of an oil tanker resulting in an 8 hour shutdown.
  • August 2012 – A large state-owned oil and gas supplier, experienced an attack intended to halt their supply of crude oil and gas which resulted in more than 30,000 hard drives and 2,000 servers being destroyed ultimately forcing I.T. systems to be disconnected from the internet for two weeks.
  • 2014 – Malware was used to gain access to a Ukrainian regional electricity distribution company to gain remote access to SCADA systems and remotely switch substations off, leaving 225,000 without electricity for three hours.
How many similar incidents have occurred, being unreported or not as publicly visible as these?  Recently Air Canada had a major computer outage.  Was that a squirrel chewing through a wire or a full-on cyber attack?

Ask yourself if you are ready

As your mining company continues to move into the digital world, you must ask:
  1. If an attacker were to disable your business application or a production facility, how long would it take to recover? How much would it cost you? How would you even measure the cost?
  2. How do you ensure your third party vendors’ security standards are appropriate? What would you do if a key supplier or key customer had a data breach that impacted you or hinder their deliveries? How do you mitigate your exposure to such events?
  3. What type and how much sensitive information are you responsible for? If you learned today that your network was compromised, what is your response plan?  Who would you call to investigate a data breach? What law firm would you use and do they have breach response experts?
A cyber attack can impact on operations, public perception, legal liability, and corporate trust.  This can mirror the legal impact of a tailings dam failure.  So are there any mitigations?

Cyber insurance is available

Companies can now consider the growing cyber insurance industry. Traditional insurance indemnifies property, casualty, crime, errors & omissions, and kidnap & ransom events. Cyber insurance adds additional coverage for breaches related to data confidentiality, operations technology malfunctions, network outages, disruption of 3rd parties, deletion or corruption of data, encryption of data, cyber fraud and theft.
While nobody wants to add another cost burden on their business, the gains from digitalization don’t come without pains.

Conclusion

The bottom line is that there is no stopping the digitalization of the mining industry. It is here whether anybody likes it or not. At the same time, there is likely no stopping the growth of cyber crime.
Likely we will hear more hacking stories as miners adopt more of the new technology.
The first line of defense are your security policies and procedures.  Bring in an expert for a security audit. As an option, you can contact cyber insurance brokers that have the expertise to help.
 Its great to see an executive at the head office operating a scooptram at their underground mine.  Its not so great to see some kid in a basement operating that same scooptram (and setting production records).
Open your doors to technology but at the same time keep them locked.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Otherwise I post notices on LinkedIn, so follow me at: https://www.linkedin.com/in/kenkuchling/.
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Flawed Mining Projects – No Such Thing as Perfection

Recently I read a post on LinkedIn where somebody was asking what key metrics companies are looking for in order to develop (or provide financing to) a new mining project. It’s more than just a project having a good NPV or IRR.  They are also looking at how difficult it is to achieve the targeted NPV.
Mining companies are always on the hunt for new projects to grow their cashflows. They would all like to find the “perfect” project; one with ideal conditions and great attributes.
However those perfect projects likely don’t exist anymore, if they ever even did.
Consequently companies must be willing to accept some potential flaws (or risks) in their go-forward projects.
The question is what flaws are they willing to accept and how far away from the ideal situation are they willing to go.

What makes a perfect project?

If one could envision a perfect mining project, what might it look like?   Here are some attributes that one would want to see (in random order). If a project had 100% of these, it would be a fantastic project.
    • A high grade ore orebody
    • A large reserve and long mine life to ride out commodity price cycles
    • Low operating cost
    • Low cash cost, in the bottom quartile of costs
    • Well defined ore zones, allowing simple mining with low dilution
    • A geotechnically competent rock mass
    • Clean and straightforward metallurgy
    • Consistent and straightforward permitting regulations
    • A stable government and stable fiscal regime
    • Safe security conditions for site personnel
    • High NPV and high IRR
    • No acid runoff issues from waste products
    • Stable tailings disposal conditions
    • Readily available local workforce / local power supply / good water supply
    • Favorable local community and stakeholder support
Other readers may have more attributes that they would like to see if asked to theorize “What constitutes a perfect mining project?”

Take off the promoter hat

backhoe on soft claysNow take an honest look at some recent (or past) projects that you have been involved with. How many of the perfect attributes listed above would be represented? It would be surprising to see them all checked off. Unfortunately that means certain flaws (risks) must be accepted when developing a project.
Each company (or financier) will have their vision as to which attributes are “must have” and which ones are “nice to have”.

But we have risk tools

There are many risk tools available to help in evaluating the potential flaws in a project. Unfortunately these tools don’t make the decisions for management.
Risk based Monte Carlo analysis requires management to pre-define the magnitude of the risks and then decide upon what probability of success is acceptable. Real option analysis or decision trees or Kepner-Tregoe are examples of other tools that can help in the decision making process.
Ultimately risk is risky.  Management must make the go/no-go decision regardless of how many probabilistic histograms and tables they have generated. A 90% chance of success still means there is a 10% chance of failure. The probability of failure may be low, but it is not zero.
It would be interesting to examine recent failed projects to define the cause(s) of failure. One could then see if the cause was something that was pre-determined as a risk, either as a small risk or a large risk. Perhaps the cause was something that management felt could be mitigated or perhaps it was something viewed as highly unlikely. No doubt that successful projects also had risks, which were either mitigated or which (luckily) never occurred.

Conclusion

The bottom line is that management understandably have a difficult task in making go/no-go decisions. Financial institutions have similar dilemmas when deciding on whether or not to finance a project.
In my career I have sat in on such management discussions and it’s never been a simple process, mainly because no project is perfect. Management know all the flaws (at least they think they do) and thus have to decide whether to push forward knowing the flaws exist.
I fully expect that future mining project risk will increase due to the complexity of project designs and broadening of stakeholder dynamics. Hence decision making in the mining industry isn’t going to get any easier regardless of the decision tools being used.  Look at your own situation, are your projects getting easier or harder?
One should examine the impact of the project flaws on the project economics.  The most common way to do this is the sensitivity chart (i.e. spider graph).  However this itself is a flawed way to evaluate the flaws.  You can read why at this blog post “Mining Cashflow Sensitivity Analyses – Be Careful“.
A better approach is to use a probabalistic analysis, like Monte Carlo simulation, that can examine multiple factors at the same time.   I discuss the benefits of this approach in a blog post ” Mining Financial Modeling – Make it Better!
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Otherwise I post notices on LinkedIn, so follow me at: https://www.linkedin.com/in/kenkuchling/.
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Is Insitu Leaching the “Green Mining” Future

It is no surprise to anyone that permitting new open pit mines in today’s environment is getting more difficult and even impossible in some areas.   Underground mines also have their challenges, permitting as well as requiring relatively high grades to be economic.
So where might our future metal supplies come from?  What are the options?

Insitu leaching may be the answer

I recently came across an insitu leaching website, called BIOMore.  This was an initiative sponsored by the EU that looked at insitu leaching technology for metal recovery.    Environmental issues associated with mining in Europe, particularly open pit mining, raised concerns about how ore bodies in the EU might be developed in the future.
Insitu leaching technology was viewed as playing an important role.  This is due to its minimal surface disturbance, ability to operate at great depth, and its potential in urban and developed locations.  Sounds like a nice solution to have on hand.
The EU-funded BIOMOre research project was completed in 2018.  It was designed to develop a new technological framework for the insitu recovering of metals from deep deposits.  The process would rely on controlled stimulation of pre-existing fractures in combination with insitu bio-leaching.  The study mainly focused on the application of existing technologies.

Fracing will be an issue

Insitu leaching essentially relies on exposing mineralized surfaces to leach solutions.  This may require hydro-fracturing (fracing) to enhance insitu bio-leaching using bacteria and acid.   Fracing is currently banned in some European countries so this is going to be a potential issue.  From a leaching perspective, the trade-off would be between no fracing, reduced cost & lower metal recovery against higher cost & higher metal recovery with fracing.
If insitu leaching technology development is successful, it could help exploit European base metals from porphyry deposits (Cu, Au, Mo, Cu, REE, PGE, Re, Pb, Cu, Pt, Au) and other gold and uranium deposits.   Insitu leaching would avoid building a mine, mine infrastructure, and it generates almost no tailings nor waste dumps.  Leaching is expected to be cheaper than traditional mining and more acceptable to the public. Insitu leaching is being touted as “Green Mining”

What did they conclude

This study deliverables included comprehensive documentation, an economic evaluation, and risk analysis of a potential insitu bio-leaching operation.  The basis was a theoretical deposit, looking at different well field set-ups.
The study concluded that accessing potential deposits at depths of around 1000 m is economically feasible only if curved wells are used.  The most relevant operational parameters are sufficient permeability in the ore zone and an adequate contact surface between the ore and leaching solution.   The depth of the deposit is indirectly relevant, but more importantly the well installation cost per volume of deposit is critical.  Hence curved wells are optimal.
One interesting suggestion was combining an insitu leach operation with geothermal energy recovery.  This might result in additional project revenue stream with only a marginal cost increase.
It was suggested that insitu leach operations might be attractive in former mining regions where high grade deposits have been mined out yet nearby low grade deposits are well defined. Social license for insitu leaching may also be more accepting in these areas.
If you are interested in learning more about insitu leaching technology and the chemistry aspect, the BIOMore study deliverables are available for downloading at this site.
In the past, mining engineers like myself were told to learn the basics of crushing, grinding, and flotation to become more well rounded.  I may suggest that future mining engineers may need to learn the basics of directional drilling, hydro-fracing, and chemistry.  Sounds like petroleum engineering.
Update: The University of Western Australia is also looking at electric fields to extract metals from hard rock ore, the sample principle as electro-plating.  Check out more information at this link “No more digging – a new environmentally friendly way of mining“.

Some aspects are still uncertain

In practical terms, some things are still not clear to me. For example are how much effort and diligence must go into properly characterizing the permeability of a rock mass.  As well, how complex a task is it to metallurgically characterize the deposit spatially with regards to it being amenable to insitu leaching.  Not all ore types will behave the same and be amenable to leaching.
I am also curious about the ability to finance such projects, given the caution associated with any novel technology.  Many financiers prefer projects that rely on proven and conventional operating methods.
Notwithstanding those concerns, likely insitu leaching technology will continue to advance and show even more promise, and eventually gain greater acceptance.
While some innovators are looking at new ways to drill, blast, and move rock, the real innovators are looking at ways to recover metals without moving any rock at all.
For those interested, Excelsior Mining is looking to open a copper oxide insitu leaching operation in Arizona.  Here is video of how their technology will work.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Otherwise I post notices on LinkedIn, so follow me at: https://www.linkedin.com/in/kenkuchling/.

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Blockchain vs Robotic Process Automation

I recently wrote a blog about how Artificial Intelligence (AI) is now being used by the exploration side of the mining industry. My curiosity was whether the application of AI is going to be real or is it just being used as a buzzword to help promote companies. You can read that blog at this link “AI vs The Geologists”.
With the topic of buzzwords in mind, I was curious about some of other technology advances we hear about. Coincidentally Canadian Mining Magazine (Winter 2019 issue) published two articles on upcoming technologies, the links are provided here; blockchain and robotic process automation. As with AI, I’m still curious about these two, mainly due to the limited number of applications thus far.

Blockchain for supply chain

With regards to blockchain, it seems to me the main benefits are being related to supply chains, whether for purchasing or selling activities. Some of the examples given are that one can verify where the cobalt in your phone was mined or where your engagement diamond is from. Oddly though, I don’t recall ever wanting to know where the metal in my phone is from.
Other example applications of blockchain are for inventory management, shipment number tracking, transport log tracking, and bill of lading management. The advantages are transaction speed, trust, and traceability.
Currently there are many ways shipping and receiving activities are being tracked. Hence I am a bit unclear as to where blockchain will provide a groundbreaking improvement. Can’t well designed cloud database achieve the same thing?
Blockchain reportedly has improved security in that copies of its tracking “ledgers” are simultaneously hosted on multiple servers and hence are hack-proof.
Is blockchain over-hyped?  Here’s an article that seems to think so “5 challenges to getting projects off the ground”.
Thus far in my career I have not yet had any direct experience with a real life application of blockchain. Therefore it is a bit difficult to say whether it is a great business innovation or a great business promotion. Perhaps some of you have had experience with actual blockchain applications in the mining industry. Please let me know and I will follow up. So far I am still on the fence.
On the other hand…

Robotic Process Automation

We have seen in manufacturing that robotics will eliminate repetitive type jobs. Will robotic process automation (rPA) be able to do the same by completing repetitive tasks for us?
The types of tasks being targeted for rPA are real time data analysis, daily- weekly-monthly reporting, tracking real time costs and progress schedules, or in other words, monitoring system wide process inputs and outputs.
Having access to real time data is important and it is a growing trend worldwide in all industries. In my view, mine site wide data integration is a key to the future of mining, especially when combined with AI, data mining, and data analysis. It is great to have the ability to instantly know exactly what is going on everywhere at a mine site. It is also great to know what went on in the previous hour, 24 hours, or 30 days.
Modern sensor technology is such that almost anything can be monitored now in real time. Will an action in one part of the operation trigger an impending impact in another part of the operation? For example can a large blast in the pit result in excess vibrations leading to tailings dam creep at the same time and is someone monitoring something this simultaneously? There are many action-reaction type events that occur in a mining operation, each with operational or cost impact. Only technology is able to instantly monitor all of these activities, assess their impacts, and provide quick decisions.
Collecting hoards of data from a site wide sensor network creates a dilemma in what to do with all the data collected. Smart cities are running into this issue. Who can sort through the data, decide what is important and what is noise, then summarize the data and report on it in real time? A human cannot deal with the amount of data being collected in such networks.
I have seen companies use fleet dispatch systems to collect gigabytes of data but then have difficulty in analyzing and making sense of it all. Sometimes the dispatch data is simply used to produce a month end production report. This is one example of where process automation may play a bigger role.
I don’t see repetitive process automation eliminating many jobs. Rather it may even increase the jobs needed to maintain and operate the virtual networks. Employment aside, I see the benefit of rPA is having a better understanding of the functioning organism called a mining operating. An operation is essentially an organism with lots of moving parts constantly making decisions requiring emotional intelligence.

Conclusion

Regarding the two technologies discussed in this blog, I personally feel robotic process automation will have far greater impact on mining industry future and its profitability.
For many years we have already seen some application of this technology (i.e. just in the mine or just in the plant). With improving sensors, increased computing power, AI, and cloud data storage, I feel that site wide integrated robotic process automation will lead the way.
However the clouds on the horizon may be the high cost of implementation, the risk of hacking (read https://kuchling.com/66-cyber-security-coming-to-a-mine-near-you), and the fact that different vendors may use different data protocols making system wide integration extremely difficult.
In my view blockchain has not yet made the case for itself. No doubt I need more education on blockchain but that will hopefully come naturally as some real life applications are introduced into our daily activities.  Read the Canadian Mining Magazine articles linked to above and see what you think the future holds for mining.
For those interested in remote tailings dam monitoring,here is an interesting CIM article “The internet of tailings“.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Otherwise I post notices on LinkedIn, so follow me at: https://www.linkedin.com/in/kenkuchling/.
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Ore Dilution – An Underground Perspective

A few months ago I wrote a blog about different approaches that mining engineers are using to predict dilution in an open pit setting. You can read the blog at this link. Since that time I have been in touch with the author of a technical paper on dilution specifically related to underground operations. Given that my previous blog was from an open pit perspective, an underground discussion might be of interest.
The underground paper is titled “Mining Dilution and Mineral Losses – An Underground Operator’s Perspective” by Paul Tim Whillans. You can download the paper at this link.

Here is the abstract

For the underground operator, dilution is often synonymous with over-break, which mining operations struggle to control. However, there are many additional factors impacting dilution which may surpass the importance of overbreak, and these also need to be considered when assessing a project. Among these, ore contour variability is an important component of both dilution and mineral losses which is often overlooked.  Mineral losses are often considered to be less important because it is considered that they will only have a small impact on net present value. This is not necessarily the case and in fact mineral losses may be much higher than indicated in mining studies due to aggregate factors and may have an important impact on shorter term economics.

My key takeaways

I am not going into detail on Paul’s paper, however some of my key takeaways are as follows. Download the paper to read the rationale behind these ideas.
  • Over-break is a component of dilution but may not be the major cause of it. Other aspects are in play.
  • While dilution may be calculated on a volumetric basis, the application of correct ore and waste densities is important. This applies less to gold deposits than base metal deposits, where ore and waste density differences can be greater.
  • Benchmarking dilution at your mine site with published data may not be useful. Nobody likes to report excessively high dilution for various reasons, hence the published dilution numbers may not be entirely truthful.
  • Ore loss factors are important but can be difficult to estimate. In open pit mining, ore losses are not typically given much consideration. However in underground mining they can have a great impact on the project life and economics.
  • Mining method sketches can play a key role in understanding underground dilution and ore losses, even in today’s software driven mining world.
  • Its possible that many mine operators are using cut-off grades that are too low in some situations.
  • High grading, an unacceptable practice in the past, is now viewed differently due to its positive impact on NPV. (Its seems Mark Bristow at Barrick may be putting a stop to this approach).
  • Inferred resources used in a PEA can often decrease significantly when upgraded to the measured and indicated classifications. If there is a likelihood of this happening, it should be factored into the PEA production tonnage.
  • CIM Best Practice Guidelines do not require underground ore exposure for feasibility studies. However exposing the ore faces can have a significant impact on one’s understanding of the variability of the ore contacts and the properties of minor faults.

Conclusion

The bottom line is that not everyone will necessarily agree with all the conclusions of Paul’s paper on underground dilution. However it does raise many issues for technical consideration on your project.
All of us in the industry want to avoid some of the well publicized disappointments seen on recent underground projects. Several have experienced difficulty in delivering the ore tonnes and grades that were predicted in the feasibility studies. No doubt it can be an anxious time for management when commissioning a new underground mine.
Note: previously I had shared another one of Paul’s technical papers in a blog called “Underground Feasibility Forecasts vs Actuals”. It also provides some interesting insights about underground mining projects.
If you need more information, Paul Whillans website is at http://www.whillansminestudies.com/.
The entire blog post library can be found at this LINK with topics ranging from geotechnical, financial modelling, and junior mining investing.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  
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Mining Due Diligence Checklist

It doesn’t matter how long you have worked in the mining industry, at some point you will probably take part in a due diligence review. You might have been asked to help create a data room. Perhaps your company is looking at a potential acquisition. Maybe you’re a consultant with a particular expertise needed by a due diligence team. It’s likely that due diligence has impacted on many of us at some point in our careers.
The scope of a due diligence can be exceptionally wide. There are legal, marketing, and environmental aspects as well as all the technical details associated with a mining project. The amount of information provided can be overwhelming.

Checklists are great

Checklists are great and can be very helpful in a due diligence review. A detailed technical scope checklist is a great way to make sure things don’t fall through the cracks. A checklist helps keep a team on the same page and clarifies individual roles and tasks. Checklists bring focus and minimize sidetracking down unnecessary paths.
Recognizing this, I have created a personal due diligence checklist for these exercises. A screen shot of it is shown below. The list is mainly tailored for an undeveloped mining project still at the study stage, but it still has over 230 items that might need to be considered.

Every mining due diligence is unique

Not all of the items in the checklist are required for each review. Maybe you’re only doing a high level study to gauge management’s interest in a project. Maybe you’re undertaking a detailed review for an actual acquisition or financing event. It’s up to you to create your own checklist and highlight which items need to be covered off. The more items added the less risk of missing something in the end.
You a create your own checklist but if you would like a copy of mine just email me at KJKLTD@rogers.com and let me know a bit about how you plan to use it (for my own curiosity). Specify if you would prefer the Excel or PDF versions.
Please let me know if you see any items missing or if you have any comments.

Due Diligence isn’t for everyone

Mining due diligence exercises can be interesting and great learning experiences, even for senior people that have seen it all. However they can also be mentally taxing due to the volumes of information that one must find, review, and comprehend, all in a short period of time.
Some people are better at due diligence than others. It helps if one has the ability to quickly develop an understanding of a project. It also helps to know what key things to look for, since many risks are common among projects.
Further on the topic of mining due diligence, I have a previous blog post triggered by my frustrations with some poorly set up data rooms.  You can read that at “Due Diligence Data Rooms – Help!”  My request is that when setting up a mining data room, please think about the people who will be using it.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Otherwise I post notices on LinkedIn, so follow me at: https://www.linkedin.com/in/kenkuchling/.
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Mining Dilution Prediction – Its Not That Simple

mining reserve estimation
Over my years of working on and reviewing mining studies, ore dilution often seems to be one of the much discussed issues.  It is deemed either too low or too high, too optimistic or too pessimistic.  Project economics can see significant impacts depending on what dilution factor is applied.  They are numerous instances where mines have been put into production, and excess dilution has subsequently led to their downfall.  Hence we need to take the time to think about what dilution is being applied and the basis for it.

Everyone has a preferred dilution method.

I have seen several different approaches for modelling and applying dilution.   It seems that engineers and geologists have their own personal favorites and tend to stick with them.   Here are some common dilution approaches that I have seen (and used myself).
1. Pick a Number:
This approach is quite simple.  Just pick a number that sounds appropriate for the orebody and the mining method.  There might not be any solid technical basis for the dilution value, but as long as it seems reasonable, it might go unchallenged.  Possibly its a dilution value commonly seen in numerous other studies.
2. SMU Compositing:
This approach takes each percent block (e.g.  a block is 20% waste and 80% ore) and mathematically composites it into a single Selective Mining Unit (“SMU”) block with an overall weighted average grade.  The SMU compositing approach will dilute the ore in the block with the contained waste.  Ultimately that might convert some highly diluted ore blocks to waste once a cutoff grade is applied.   Some engineers may apply an additional dilution percentage beyond the SMU compositing, while others will consider the blocks fully diluted at this step.
3. Diluting Envelope:
This approach assumes that a waste envelope surrounds the ore zone.  One estimates the volume of this envelope on different benches, assuming that it is mined with the ore.  The width of the waste envelope may be linked with the blast hole spacing used to define the ore and waste contacts for mining.  The diluting grade within the waste envelope can be estimated or one may simply assume a more conservative zero-diluting grade.   In this approach, the average dilution factor can be applied to the final production schedule to arrive at the diluted tonnages and grades sent to the process plant.
4. Diluted Block Model:
This dilution approach uses complex logic to look at individual blocks in the block model, determine how many waste contact sides each block has, and then mathematically applies dilution based on the number of contacts.  A block with waste on three sides would be more heavily diluted than a block with waste only on one side.   Usually this approach relies on a direct swap of ore with waste.  If a block gains 100 m3 of waste, it must then lose 100 m3 of ore to maintain the volume balance.   The production schedule derived from a “diluted” block model usually requires no subsequent dilution factor.
5. Using UG Stope Modelling
I have also heard about, but not yet used, a method of applying open pit dilution by adapting an underground stope
modelling tool.  By considering an SMU as a stope, automatic stope shape creators such as Datamine’s
Mineable Shape Optimiser (MSO) can be used to create wireframes for each mining unit over the entire
deposit. Using these wireframes, the model can be sub-blocked and assigned as either ‘ore’ (inside the
wireframe) or ‘waste’ (outside the wireframe) prior to optimization.   It is not entirely clear to me if this approach creates a diluted block model or generates a dilution factor to be applied afterwards.

 

When is the Cutoff Grade Applied?

Depending on which dilution approach is used, the cutoff grade will be applied either before or after dilution.   When the dilution approach requires adding dilution to the final production schedule, then the cutoff grade will have been applied to the undiluted material (#1 and #2).
When dilution is incorporated into the block model itself (#3 and #4), then the cutoff grade is likely applied to the diluted blocks.
The timing of when the cutoff grade is applied to the ore blocks will have an impact on the ore tonnes and had grade being reported.

Does one apply dilution in pit optimization?

Another occasion when dilution may be used is during pit optimization.  In the software, there are normally input fields for both a dilution factor and an ore loss factor.   Some engineers will apply dilution at this step while others will leave the factors at zero.  There are valid reasons for either approach.
My preference is use a zero dilution factor for optimization since the nature of the ore zones will be different at different revenue factors and hence dilution would be unique to each.   It would be good to verify the impact that the dilution factor has on your own pit optimization by running with a factor to see the result.

Conclusion

My personal experience is that, from a third party review perspective, reviewers tend to focus on the value of the  dilution percentage used and whether it seems reasonable.   The actual dilution approach tends to get less focus.
Regardless of which approach is being used, ensure that you can ultimately determine and quantify the percent dilution being applied.  This can be a bit more difficult with the mathematical block diluting approaches.
Readers may yet have different dilution methods in their toolbox and I it would be interesting to share them.
There is another blog post that discussed dilution from an underground mining perspective.  This discussion was written by another engineer who permitted me to share their paper.    You can read that at “Ore Dilution – An Underground Perspective“.
The entire blog post library can be found at this LINK with topics ranging from geotechnical, financial modelling, and junior mining investing.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  
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The Mining Bank or eBay for Mining Properties

mining properties
I recently attended the Money Show here in Toronto to learn a bit more about personal finanace, investing strategies, and to check out  the latest stock analysis software.
There was also a trade show, but only one mining company booth was present.  This definitely wasn’t the PDAC.  Interestingly there were about five marijuana company booths, so that is where the promotion is today.
The lone mining company was Globex Mining, here is their website.  They referred to themselves as a “mining bank”, so that was something that peaked my interest.

Mining bank

Speaking with their president, Jack Stoch, he gave me an overview on their business model.  As I understood it, GLOBEX’s model is to acquire a portfolio of mineral properties.  They would try to enhance their value by undertaking some limited geological work.  Finally they would option, JV, or sell the property while retaining an NSR royalty.
Mr. Stoch told me that Globex currently has over 140 land packages in their inventory.  Their properties will be at different stages.  Some have resource estimates, others only mineralized drill intersections, mineral showings, untested geophysical targets, or combinations of these.
They are focusing their acquisitions on lower risk jurisdictions like Quebec, Ontario, Nova Scotia, New Brunswick, Tennessee, Nevada, Washington, and Germany.  They try to acquire historical mines that have old shafts, following the adage the best place to find a new mine is next to an old mine.   They also have some industrial mineral properties.

 

Globex’s only NSR revenue property right now is a zinc project in Tennessee that can generate a seven-figure royalty each year, when that operation is up and running.  Unfortunately for Globex the zinc operation has not been in consistent operation the last few years.

Its a good concept

I like the concept that Globex are promoting.  I like the idea of having a one-stop shop that acquires and options out exploration properties to mining companies looking for new projects.
I also like the idea of trying to consolidate land packages in an area,  minimizing the patchwork of multiple ownership claims that can hinder advanced development.
Globex hope that by putting time and effort into a bunch of properties a few of them will pay off.  If they can generate sufficient NSR revenues, the company may get to the self-sustaining stage.

Its not a new idea

The idea of companies involving themselves in a portfolio of early stage prospects isn’t new.  This has been being done by EMX Royalty Corp (formerly Eurasian Minerals) for properties around the globe.    Abitibi Royalties is also doing something vaguely similar, whereby they would help fund prospectors in exchange for a long term royalty on a property. There are likely others.
There is a high risk to being successful but the cost of entry is relatively low.
It will be interesting to watch Globex over the longer term to see how many properties they can acquire and how many of these will pay off. Spending a bit of money on mapping and exploration on a property may benefit them by increasing value in the eyes of potential partners.
Statistically, mineral exploration is a high risk game but by limiting expenditures and diversifying the portfolio, some of that risk can be mitigated.
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Ore Stockpiling – Why are we doing this again?

ore stockpile
In many of the past mining studies that I have worked, stockpiling strategies were discussed and usually implemented. However sometimes team members were surprised at the size of the stockpiles that were generated by the production plan. In some cases it was apparent that not all team members were clear on the purpose of  stockpiling or had preconceived ideas on the rationale behind it. To many stockpiling may seem like a good idea until they saw it in action.
Mine Stockpile
In this blog I won’t go into all the costs and environmental issues associated with stockpile operation.  The discussion focuses on the reasons for stockpiling and why stockpiles can get large in size or numerous in quantity.
In my experience there are four main reasons why ore stockpiling might be done. They are:
1. Campaigning: For metallurgical reasons if there are some ore types that can cause process difficulties if mixed  with other ores. The problematic ore might be stockpiled until sufficient inventory allows one to process that ore (i.e. campaign) through the mill. Such stockpiles will only grow as large as the operator allows them to grow. At any time the operator can process the material and deplete the stockpile. Be aware that mining operations might still be mining other ore types, then those ores may need to be stockpiled during the campaigning.  That means even more ore stockpiles at site.
2. Grade Optimization: This stockpiling approach is used in situations where the mine delivers more ore than is required by the plant, thereby allowing the best grades to be processed directly while lower grades are stockpiled for a future date. Possibly one or more grade stockpiles may be used, for example a low grade and a medium-low grade stockpile. Such stockpiles may not get processed for years, possibly until the mine is depleted or until the mined grades are lower than those in the stockpile. Such stockpiles can grow to enormous size if accumulated over many years.  Oxidation and processability may be a concern with long term stockpiles.
3. Surge Control: Surge piles may be used in cases where the mine may have a fluctuating ore delivery rate and on some days excess ore is produced while other days there is underproduction. The stockpile is simply used to make up the difference to the plant to provide a steady feed rate. These stockpiles are also available as short term emergency supply if for some reason the mine is shut down (e.g. extreme weather). In general such stockpiles may be relatively small in size since they are simply used for surge control.
4. Blending: Blending stockpiles may be used where a processing plant needs a certain quality of feed material with respect to head grade or contaminant ratios (silica, iron, etc.). Blending stockpiles enables the operator to ensure the plant feed quality to be within a consistent range. Such stockpiles may not be large individually; however there could be several of them depending on the nature of the orebody.
There may be other stockpiling strategies beyond the four listed above but those are the most common.

Test Stockpiling Strategies

Using today’s production scheduling software, one can test multiple stockpiling strategies by applying different cutoff grades or using multiple grade stockpiles. The scheduling software algorithms determine whether one should be adding to stockpile or reclaiming from it. The software will track grades in the stockpile and sometimes be able to model stockpile balances assuming reclaim by average grade, or first in-first out (FIFO), or last in-first out (LIFO).
ore stockpile
Stockpiling in most cases provides potential benefits to an operation and the project economics. Even if metallurgical blending or ore campaigning is not required, one should always test the project economics with a few grade stockpiling scenarios.
Unfortunately these are not simple to undertake when using a manual scheduling approach and so are a reason to move towards automated scheduling software.
Make sure everyone on the team understands the rationale for the stockpiling strategy and what the stockpiles might ultimately look like. They might be surprised.
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Landslide Blog – If You Like Failures

slope failure blog
For those of you with a geotechnical background or have a general interest in learning more about rock slides and slope failures, there is an interesting website and blog for you to follow.
The website is hosted by the American Geophysical Union the world’s largest organization of Earth and space scientists. The blogs on their site are written by AGU staff along with contributions from collaborators and guest bloggers.

Landslide Blog screenshot

The independent bloggers have editorial freedom in the topics they choose to cover and their opinions are those of their authors and do not necessarily represent the views of the American Geophysical Union. This provides for some leeway on the discussions and the perspectives the writers wish to take.

Landslide Blog

One specific area they cover well in their Landslide Blog are the various occurrences of rock falls and landslides from any location around the globe. They will present commentary, images, and even videos of slope movements as they happen.
Often they will provide some technical opinion on what possibly caused the failure event to occur. The Landslide Blog has a semi-regular email newsletter that will keep you updated on new stories as they happen.
The following links are a few examples of the type of discussions they have on their website.
Here is a description of a small water dam failure in Greece.
Here is some video of the Samarco tailings runout in Brazil.
From time to time the Landslide Blog will examine mine slopes, tailings dams, and waste dump failures, however much of their information relates to natural earth or rock slopes along roads or in towns.
Some of their videos are quite fascinating, illustrating the forces behind some of earth’s natural erosion processes. Check it out for yourself.
The bottom line on all of this is that the less the mining industry is mentioned in the Landslide Blog, the better it is.
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