72. 43-101 Reports – What Sections Are Missing?

Recently as part of a due diligence I was reviewing a couple of 43-101 technical reports and something jumped out at me. There were pages and pages of statistical plots. The plots included QA/QC and check assay diagrams, variograms, box plots, swath plots, and contact plots. There was no lack of statistical information. However, as a mining engineer, there was something missing that was of interest to me. Good geological sections were missing.
Its seems that most technical reports focus heavily on describing the mathematical aspects of the resource, but spend less time describing the physical aspects of the geology and the mineability.

Who is the audience

It’s always open to debate who these 43-101 technical reports are intended for. Generally we can assume correctly that they are not being written mainly for geologists. However if they are intended for a wider audience of future investors, shareholders, engineers, and C-suite management, then (in my view) greater focus needs to be put on the physical orebody description.
Understanding the nature of the orebody brings greater understanding of the entire project.

Everyone likes geology

Whenever I listen to investor conference calls, many of the analyst’s questions relate to the resource and the mining operation. Essentially the participants want to know if this will be an “easy” mine or a “hard” mine.
One simple way to explain this is with good geological sections. They help everyone understand any potential issues; i.e. a picture is worth a thousand words. Good cross-sections will describe the following aspects.
  • The complexity (or simplicity) of the ore zones,
  • The width of the ore zones,
  • The vertical extent of geological information,
  • The drill spacing and drilling density,
  • The spatial distribution of assay information,
  • The grade distribution laterally and vertically,
  • The waste distribution throughout the mine,
  • The mining block size in relation of the ore zone dimensions
One can learn a lot just by looking at well presented cross-sections.  The nice thing is that they are generally understood by non-technical people.

Suggestions

I would like to suggest that every technical report includes more focus on the operational aspects of the orebody.
My recommendation is that the following information becomes standard in all technical reports.
  1. At least three to five cross sections through the deposit. Don’t just present a best case typical cross-section.
  2. At least one or two longitudinal sections.
  3. At least three level or bench plans, showing the drill hole pierce points.
Each cross section/bench plan should consist of two parts.
Part 1 shows the drill holes with color coded grade intercepts, ore zone wireframes, and lithology or rock types.
Part 2 should be a block model cross section showing the wireframes, drill holes, and color coded block model grades using the ore/waste cutoff grade as one of the clearly defined grade bins.
It doesn’t really matter if the cross- sections are included in Section 14 or Section 16 of the Technical Report. However if they are included in Section 16 then one should overlay the pit design and/or underground stope shapes onto the sections.
I also recommend NOT incorporating these cross-sections in the appendices since they are too important to be hidden away. They should be described in the main report itself.

Conclusion

Improving the quality of information presented to investors is one key way of maintaining trust with investors. Accordingly we should look to improve the description of the mineable ore body for everyone. In many cases it is the key to the entire project.
I am not suggesting that one needs to remove the statistical plots since they do have their purpose and audience. I am simply suggesting that we should not forget about everyone else try to figured out the viability of the project.
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71. Mineral Processing – Can We Keep It Dry?

It’s common to see mining conferences present their moderated panels discussing “disruption” and Mining 2.0.   The mining industry is always looking for new technologies to improve the way it operates. Disruptive technologies however require making big changes, not tweaks.  True disruption is more than just automating haulage equipment or having new ways to visualize ore bodies in 3D.
Insitu leaching is a game changing technology that will eventually make a big difference.  Read a previous blog at “Is Insitu Leaching the “Green Mining” Future”.  Development of this technology will negate the need to physically mine, process, and dispose of rock.  Now that’s disruptive.
However, if we must continue to mine and process rock, then what else might be a disruptive technology ?

Is dry processing a green technique

Process water supply, water storage and treatment, and safe disposal of fine solids (i.e. tailings) are major concerns at most mining projects.
Recently I read an article titled “Water in Mining: Every Drop Counts”.
That discussion revolved around water use efficiency, minimizing water losses, and closed loop processing.   However another area for consideration is whether a future technology solution might be dry processing.

Dry processing is already being used

By dry processing, I am not referring to pre-concentration ore sorting or concentrate cleanup (X-ray sorting). I’m referring to metal recovery at the mineral liberation particle size.
In Brazil Vale has stated that it will spend large sums of money over the next few years to further study dry iron ore processing. By not using water in the process, no tailings are generated and there is no need for tailings dams.
Currently about 60% of Vale’s production is dry (this was a surprise to me) and their goal is to reach 70% in the next five years.   It would be nice to eventually get to 100% dry processing at all iron ore operations.   The link to the article is here “Vale exploring dry stacking/magnetic separation to eradicate tailings dams”.

Is dry grinding possible

Wet grinding is currently the most common method for particle size reduction and mineral liberation.  However research is being done on the future application of dry grinding.
The current studies indicate that dry grinding consumes higher energy and produces wider particle size distributions than with wet grinding. However it can also significantly decrease the rate of media consumption and liner wear.
Surface roughness, particle agglomeration, and surface oxidation are higher in dry grinding than wet grinding, which can affect flotation performance.
Better understanding and further research is required on the dry grind-float process. However any breakthroughs in this technology could advance the low water consumption agenda.
You can learn more about dry grinding at this link “A comparative study on the effects of dry and wet grinding on mineral flotation separation–a review”.

Electrostatic separation

Electrostatic separation is a dry processing technique in which a mixture of minerals may be separated according to their electrical conductivity. The potash industry has studied this technology for decades.
Potash minerals, which are not naturally conductive, are conditioned to induce the minerals to carry electrostatic charges of different magnitude and different polarity.
In Germany, researchers have developed a process for dry beneficiation of complex potash ores. Particle size, conditioning agents and relative humidity are used to separate ore.
This process consumes less energy than conventional wet separation, avoiding the need to dry out the beneficiated potash and the associated tailings disposal issue.
Further research is on-going.

 

Eddy current separators

The recovery of non-ferrous metals is the economic basis of every metal recycling system. There is worldwide use of eddy separators.
The non-ferrous metal separators are used when processing shredded scrap, demolition waste, municipal solid waste, packaging waste, ashes from waste incineration, aluminium salt slags, e-waste, and wood chips.
The non-ferrous metal separator facilitates the recovery of non-ferrous metals such as aluminium, copper, zinc or brass.
This technology might warrant further research in conjunction with dry grinding research to see if an entirely dry process plant is possible for base metals or precious metals.  Learn more at the Steinert website.

Conclusion

Given the contentious nature of water supply and slurried solids at many mining operations, industry research into dry processing might be money well spent.
Real disruptive technologies require making large step changes in the industry. In my opinion, insitu leaching and dry processing are two technologies that we will see more of over the next 20 years.
Ultimately the industry may be forced to move towards them due to environmental constraints.  Therefore let’s get ahead of the curve and continue researching them.

 

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70. 43-101 and the Shrinking Feasibility Study

There is current sense that advanced mining studies are suffering from a lack of credibility with investors. Curiously it seems to me that many feasibility study documents are getting smaller at the same time. Might there be some link between the two?
My personal exposure to feasibility studies extends from managing them, participating in them, and undertaking due diligence reviews of them. Earlier in my career mining feasibility studies typically consisted of comprehensive documents, often contained in several binders of information. The study could generate a lot of paper. However currently it seems that often (not always) the 43-101 Technical Report can be the “final” feasibility study document.
In the past there would be binders with detailed calculations and backup for the different parts of the study. Typically there was a binder for the Executive Summary and separate sections (i.e. binders) for Geology, Mining, Processing, Infrastructure, Capital Cost, Operating Cost, Environmental, Project Execution, and Economic Analysis, etc.
The comprehensive report normally had both the report text and the details of the work done. This might include hand sketches, haul cycles, vendor price quotes, spec sheets, email correspondences, the WBS cost estimate detail, and so on.
The section appendices also included 3rd party reports like pit slope geotechnical studies, hydrogeological analysis, tailings dam designs, etc. The feasibility document might have included CD’s with the entire study in electronic format.
Generally all the supporting information for the study was in that comprehensive document. They were great. You knew you were somebody if you were given a personal copy of the entire report for your office.

43-101 Technical Report

The original intent of the 43-101 Technical Report was for it to be a summary document, only about 80-150 pages in length. The intent was to simplify all the technical work for the benefit of non-technical investors. Currently I have noticed that in many cases the 43-101 report is now the entire feasibility study document.
These 43-101 reports contain a fair amount of detail and they can exceed 400 pages in length. I’m not sure how many non-technical people actually read them beyond the Executive Summary or even read them at all.
Unfortunately if one is undertaking a due diligence review of a project, the 400 page Technical Report won’t contain the detail needed for a proper technical review. When more detail is requested, we are usually provided with a series of production and cost spreadsheets that need to be deciphered.  Furthermore the spreadsheets themselves don’t give the sources or basis for all the input data.
In my view the 400 page Technical Report is too confusing for the investing public and not detailed enough for technical review, thereby really satisfying no one.
Why aren’t the comprehensive feasibility study documents being completed all the time? I would suggest it is because of the effort and cost. It takes time to properly document all aspects of a study, creating legible tables, scanning files, and merging it all into a single PDF document. Preparing a 43-101 Technical Report can be a chore, as many of us have experienced in trying to meet the 45 day deadline. So who wants to take on the task of preparing an even larger document?

Recommendation

My recommendation is that, where budgets permit, mining companies return to the days of preparing the comprehensive feasibility study document. It’s the right thing to do.
One doesn’t need to print the entire report on paper since PDF files will work fine. Scanning of some sketches, vendor quotes may add an extra step, but that is hardly a momentous chore. Most 3rd party documents are already been submitted in PDF format so coordinating and merging will be the main task.
The 43-101 Technical Report could return to being a more investor friendly summary style document rater than a full study report.
This comprehensive document approach would apply to both pre-feasibility and feasibility studies that are used for advanced financing purposes.  The re-adoption of the comprehensive report format should be consistent among both large miners and juniors.

What about the PEA

The preliminary economic assessment (PEA) likely does not warrant a comprehensive report. The PEA is not definitive. I have also heard that the PEA is losing some credibility with investors, with some people referring to it as mainly a sales document. I don’t necessarily agree with that sentiment, but I understand why some see it that way.
As an aside, an interesting panel discussion might be whether the PEA has actually lost credibility, and if so, how can we restore credibility. My thoughts on PEA’s were summarized in a previous blog “Not All PEA’s Are Created Equal”.

Conclusion

If any mining industry credibility has been lost, re-establishing it should be important. One way to start doing this is to focus on creating the type of reports that best serve the needs of the industry stakeholders.
Some may say returning to comprehensive reports are a step backwards while mining needs to move forward. In my opinion, moving forward is going from less documented studies towards well documented studies.
One of the most technically detailed feasibility studies that I worked on was for the Diavik diamond project. This was a one-of-a-kind project operated by a well run risk-averse company (Rio Tinto). Every aspect of the project was documented to the upmost extent, although the company had the deep pockets to do that.  Funny thing though, as part of the internal Rio Tinto engineering team I don’t recall ever producing a final report document there (perhaps my recollections have been blurred since 20 years ago).
Once you have established the type of report you want, make sure your consultants clearly understand the expected deliverable. I recommend that someone on your team prepares an RFP document to lay out your wish list, even if sole sourcing the study. A previous blog was written on this topic at Request For Proposal (“RFP”) – Always Prepare One
As an aside, it would be interesting to know if those undertaking due diligence’s in the UK or Australia (i.e. not under 43-101 domain) have seen any changes in the quality of feasibility study documentation.
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69. Power Generation & Desalinization – An Idea that Floats

Access to a fresh water supply and a power supply are issues that must be addressed by many mining projects. Mining operations may be in competition with local water users for the available clean water resources. In addition, the greenhouse gas emissions from mine site power plants are also an industry concern. If your project has both water and power supply issues and it is close to tidewater, then there might be a new solution available.
I recently attended a presentation for an oil & gas related technology that is now being introduced to the mining industry. It is an innovative approach that addresses both water and power issues at the same time.
The technology consists of a floating LNG (liquefied natural gas) turbine power plant combined with high capacity seawater desalinization capabilities. MODEC is offering the FSRWP® (Floating Storage Regasification Water-Desalination & Power-Generation) system.
MODEC also has associated systems for power only (FSR-Power®) and water only (FSR-Water®)

FSRWP capabilities

The technology is geared towards large capacity operations that have access to tidewater. It provides many tangible and intangible operational and environmental benefits.  It can:
  • Generate fresh water supply (10,000 – 600,000 m3 /day)
  • Generate electrical power (80 to 1000 MW) using LNG
  • Can provide power inland (>100 km) from a tidewater based floating power plant
  • Can provide natural gas distribution on land via on-board re-gasification systems
  • Has LNG storage capacity of 135,000 cu.m
  • Has a refueling autonomy of 20 to 150 days
  • Allows low cost marine delivery of bulk LNG supply

Procurement & Application

The equipment can be procured in several ways. For instance it can be contracted as an IPP (Independent Power Producer), purchased as an EPCI (Engineering, Procurement, Construction and Installation), BOO (Build, Own and Operate) or BOOT (Build, Own, Operate and Transfer).
Typically it takes 18-24 months of contract award to deliver to the project site, although temporary power solutions can be provided within 60-90 days.
From a green mining perspective, the FSRWP produces clean power with the highest thermal efficiency and lowest carbon foot-print.
See the table for a comparison of different power generation efficiencies and carbon emissions per kW.
Gas turbines are not new technology to MODEC.  They currently own & operate 42 such generators, which can produce roughly 43 MW (each) in combined-cycle mode.

Mooring options

Currently there are three mooring options for the floating system that should fit most any tidewater situation.
Jetty or Dolphin mooring is suitable for protected areas or near-shore applications where the water depth is in the range of 7 to 20 meters.
Tower Yoke mooring is ideal for relatively calm waters where the water depth is between 20 to 50 meters.
External Turret mooring is similar to a Tower-Yoke and is ideal for water depths exceeding 50 meters or where the seabed drops off steeply into the ocean.

Power transmission

Twenty years ago it was impractical to transmit AC power long-distances and subsea power cable technology was not as advanced as it is today. Hence an offshore power plant like a FSRWP was not technically viable. Due to R&D efforts over the last 15 years it is now possible to economically transmit AC. For example it is possible to transmit up to 100 MW over 100 miles through a single subsea cable. In addition, it is also viable to transit 200 MW at 145 kV from a vessel to shore.

Water treatment

Modern FSRWP’s use reverse osmosis membrane technology to produce industrial or potable water.  This is similar to most conventional onshore desalination plants.
The main benefits of floating offshore desalination are increased overall thermal efficiency if both power and water production are combined on a single vessel. In addition, seawater sourced offshore and rejected brine discharged offshore minimizes risk to coastal marine life.

Conclusion

The bottom line is that if your mining project is near shore, and has both water supply and power issues, take a look at the FSRWP technology. One might say it is greener technology by using LNG (rather than coal, heavy fuel oil, or diesel) to generate power.  At the same time it avoids competition with locals for access to fresh water.
This technology won’t be suitable for all mining situations, but perhaps your mine site fits the model. Reportedly rough costs for power are in the range of $0.10-$0.14/kwh with a capital cost of $1M-$1.5M per MW.
There will be minimal closure costs associated with dismantling the power plant.  One just floats it away at the end of the mine life.
Check out the MODEC website if you wish to learn more: https://www.modec.com/fps/fsrwp/index.html
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68. Global Risks – Our Fears Are Evolving

Recently I wrote a blog about how the adoption of new technology in the mining industry will increase the risk of cyber crime. However this is just one of many risks the industry faces today.  This raises the question as to what are the main risks impacting all global businesses.  Luckily for us, the World Economic Forum undertakes an annual survey on exactly this subject.
Each year business leaders are queried about what they view as their major risks. The survey results are summarized in the Global Risk Report.
The 2019 report can be downloaded at this link. http://www3.weforum.org/docs/WEF_Global_Risks_Report_2019.pdf.
The study rates risks according to the categories “likelihood” and “impact”. A risk could have a high likelihood of occurring but have a low economic impact. One might not lose sleep over these ones.
Another interesting feature in the report is seeing how the top risks change from year to year.  Some risks from 10 years ago are no longer viewed as key risks today.

2019 risk situation

In 2019 environmental related risks dominate the survey results. They account for 4 of the top 5 risks by “impact” and 3 of the top 5 by “likelihood”. Technology related concerns about data fraud and cyber-attacks were also viewed as highly likely (#4 and #5). See the image below for the top 5 risks in each category.
Although the Global Risk survey wasn’t specifically directed at the mining industry, all of the identified risks do pertain to mining.

 

10 year risk trend

It is also interesting to look at the detailed 10 year  table in the report to see how the risk perceptions have changed over the last decade.
None of the top five “Impact” risks from ten years ago are still in the top five now and only two from 2014 still exist. In the “likelihood” category, a similar situation exists.
It will be interesting to compare the 2024 list with 2019 list to see how risks will continue to evolve.

How about the mining industry

EY Global Mining & Metals also undertake a risk survey, focused on mining only. You can read their article at this link “The Top Risks Facing Mining and Metals”.  Their top 10 risks are listed below, many are different than those from the World Economic Forum ranks. You must read the EY article to fully understand the details around their risk items.
  1. License to operate (difficulty to acquire)
  2. Digital effectiveness (lack thereof)
  3. Maximizing portfolio returns (can this be done)
  4. Cyber security (increasing risk of attack)
  5. Rising costs (can costs be controlled)
  6. Energy mix (acceptable power sources)
  7. Future of workforce (lack of interest in the sector)
  8. Disruption (falling behind competitors)
  9. Fraud (increasing sophistication)
  10. New world commodities (versus reduced demand for some commodities)

Conclusion

My bottom line is that the Global Risk Report is something that we should all read. Download it and then compare with what your company sees as its greatest risks. The only way to mitigate your risks is to know what they are.  The only way to work with others is to know what their issues are.
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65. Flawed 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?
Perhaps this is one reason we are seeing the flight of investment capital from mining into software/cannabis businesses. The risk/reward profile may be viewed more favorably in these investments.
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64. 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.

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.
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62. AI versus the Geologists

We likely have all seen recent articles about how Artificial Intelligence (AI) is going to change the mining industry.   I have been wondering if AI is a real solution or just a great buzzword.   My original skepticism has diminished somewhat and let me explain why.
At a booth at the 2019 PDAC I had a chance to speak with a publicly traded company called Albert Mining (referencing Albert Einstein’s intelligence).  They are providing exploration consulting services by applying a form of AI and have been doing so for many years.  The company has been around since 2005 but were not using the term AI to describe their methods.
These days the term “AI” has become very trendy.  Currently IBM Canada and Goldcorp are using Watson and AI to further their exploration efforts on the Red Lake property. GoldSpot Discoveries is another recent player in the mining AI field.  It appears Goldspot offers something similar to Albert Mining but they extend their platform to include picking projects, picking teams, and picking investments. That’s a lot of analysis to undertake.  Albert Mining is focused solely on mineral exploration.

Here is what I learned

Albert Mining’s system, called CARDS (Computer Aided Resource Detection System) uses pattern recognition and multi-variate analysis to examine a mineral property to look for targets.     The system requires that the property has some known mineralization hits and assay samples.  These are used to “teach” the software.   Both positive hits and negative hits are valuable in this teaching step.
The exploration property is sub-divided into cells and data are assigned to each cell.  These data attributes could be derived from geophysics, geochemistry, topography, soil samples, indicator minerals, assayed samples, geological maps, etc.  I was told that a cell could contain over 700 different data attributes.
The algorithm then examines the cell data to teach itself which attributes correlate to known mineralization and which attributes correlate with barren areas. It essentially determines a geological “signature” for each mineralization type.    There could be millions of data points and combinations of attributes.  Correlation patterns may be invisible to the naked eye, but not to the computer algorithm.
Once the geological signatures are determined, the remainder of the property is examined to look for similar signature hits.  Geological biases are eliminated since it is all data driven.   The newly defined exploration targets are given a ranking score based on the extent of correlation.
Some things to note are that the system works best for shallow deposits, unless one has some deep penetrating geophysical surveys.  The system works best if there is fairly uniform data coverage across the entire property.  The property should also have generally similar geological conditions and as mentioned before, the property needs to have some mineralized assay information.
This exploration approach reminds me somewhat of the book Moneyball.  This book is about the Oakland A’s baseball team where unconventional statistics were used to rank players in order to find hidden gems.

Are geologists becoming obsolete?

I was told that many in the geological community tend to discount the AI approach.  Either they don’t think it will work or they are fearing for their jobs.  Personally I don’t understand these fears nor can I really see how geologists can ever be eliminated.  Someone still has to collect and prepare the data as well as ultimately make the final decision on the proposed targets.   I don’t see the downside in using AI as another tool in the geologist’s toolbox.
Albert Mining’s stock price has recently gained some traction (note: I am not promoting them)  because junior mining news releases are starting to mention their name more often (Spruce Ridge Resources and Falco Resources are some examples).
Probably years ago if a mining company said their drill targets were generated by an algorithm, they might have gotten strange looks.   Today if a mining company says their drill targets were generated by AI, it gives them a cutting edge persona.  Times have changed.

In conclusion

I suggest we all take a closer looks at the AI technology to better understand what it does.
P.S. I  might also suggest that Albert Mining consider revising their company name to incorporate the term “AI” to stay on trend. (Update: In October 2019, Albert Mining changed their name to Windfall Geotek; I’m not sure it better explains what they do).
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61. 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 and educational.
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/.
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60. Mining Due Diligence Checklist

It doesn’t matter how long you have worked in the mining industry, at some point you will probably have taken 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 sometimes.

I’m a big fan of checklists

Checklists are great and they can be very helpful in a due diligence review. A 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 such times. A screen shot of it is shown below. The list is mainly tailored for an undeveloped project but it still has over 230 items that might need to be considered.

Each 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 in the end; however that requires a longer review period and greater cost.
You a create your own checklist but if you would like a copy of mine just email me at KJKLTD@rogers.com. 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.
Now that we have an idea of what information we need to examine in a due diligence, the next question is where to find it.
Previously I had written a blog titled “Due Diligence Data Rooms – Help!” which discussed how we can be overwhelmed by a poorly set up data room. My request is that when setting up a data room, please consider the people who will be accessing it.

Due Diligence isn’t for everyone

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 understand 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.
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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59. Hydrogeology At Diavik – Its Complicated

About 20 years ago I was involved in the feasibility study and initial engineering for the Diavik open pit mine in the Northwest Territories. As you can see from the current photo, groundwater inflows were going to be a potential issue.
Predictions of mine inflow quantity and quality were required as part of the project design. Also integral to the operating plan were geotechnical issues, wall freezing issues, and methods for handling the seepage water.
This mine is going to be a unique situation. The open pit is located both within Lac de Gras and partly on exposed land (i.e. islands). The exposed land is underlain by permafrost of various depth while the rock mass under the lake was unfrozen. The sub-zero climate meant that pit wall seepage would turn into mega-icicles.  Phreatic pressures could buildup behind frozen pit walls. Many different factors were going to come into play in this mining operation so comprehensive field investigations would be required.

A good thing Rio Tinto was a 60% owner and the operator

At no time did the engineering team feel that field budgets were restricted and that technical investigations were going to be limited. Unfortunately in my subsequent career working on other projects I have seen cases where lack of funds does impact the quantity (and quality) of technical data.
The Golder Associates Vancouver hydrogeologcal team was brought on board to help out. Hydrogeological field investigations consisted of packer testing, borehole flowmeter testing, borehole temperature logging, and borehole camera imaging. Most of this work was done from ice level during the winter.
A Calgary based consultant undertook permafrost prediction modelling, which I didn’t even know was a thing.
All of this information was used in developing a three-dimensional groundwater model. MODFLOW and MT3DMS were used to predict groundwater inflow volumes and water quality. The modelling results indicated that open pit inflows were expected to range up to 9,600 m3/day with TDS concentrations gradually increasing in time to maximum levels of about 440 mg/ℓ.
The groundwater modelling also showed that lake water re-circulating through the rock mass would eventually comprise more than 80% of the mine water handled.

Modelling fractured rock masses is not simple

Groundwater modelling of a fractured rock mass is different than modelling a homogeneous aquifer. Discrete structures will have a great impact on seepage rates yet they can be difficult to detect beforehand.
As an example, when Diavik excavated the original bulk sample decline under the lake, water inflows were encountered associated with open joints. However a single open joint was by far the most significant water bearing structure intercepted over the 600-metre decline length.  It resulted in temporary flooding of the decline.

Before (2000) and After (2006) Technical Papers

Interestingly at least two technical papers have been written on Diavik by the project hydrogeologists. They describe the original inflow predictions in one paper and the actual situation in the second.
The 2000 paper describes the field investigations, the 1999 modeling assumptions, and results. You can download that paper here.
The subsequent paper (2006) describes the situation after a few years of mining, describing what was accurate, what was incorrect, and why. This paper can be downloaded here.
In essence, the volume of groundwater inflow was underestimated in the original model.  The hydraulic conductivity of the majority of the rock mass was found to be similar.  However a 30 m wide broken zone, representing less than 10% of the pit wall, resulted in nearly twice as much inflow as was predicted.
The broken zone did not have a uniform permeability but consisted of sparely spaced vertical fractures. This characteristic made it difficult to detect the zone using only core logging and packer tests in individual boreholes.

Groundwater Models Should Not be Static

The original intent was the Diavik groundwater model would not be static.  It continued to evolve over the life of the mine.
Now that Diavik has entered their underground mining stage, it would be interesting to see more updates on their hydrogeologcal performance. If anyone is aware of any subsequent papers on the project, please share.
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58. Ore Dilution Prediction – Its Always an Issue

mining reserve estimation
Over my years of preparing and reviewing mining studies, ore dilution often seems to be a contentious issue.  It is deemed either too low or too high, too optimistic or too pessimistic.  Everyone realizes that project studies can see significant economic impacts depending on what dilution factor is applied.  Hence we need to take the time to think about what dilution is being used and why.

Everyone has a preferred dilution method.

I have seen several different approaches for modelling and applying dilution.   Typically engineers and geologists seem to have their own personal favorites and tend to stick with them.   Here are some common dilution approaches.
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.
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 process will incorporate some waste dilution into the block.  Possibly that could convert some ore blocks to waste once a cutoff grade is applied.   Some engineers may apply additional dilution beyond SMU compositing while others will consider the blocks fully diluted at the end of this step.
3. Diluting Envelope:
This approach assumes that a waste envelope surrounds the ore zone.  One estimates the volume of this waste envelope on different benches, assuming that it is mined with the ore.  The width of the waste envelope may be correlated to the blast hole spacing being used to define the ore and waste mining contacts.  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.  Alternatively, the individual diluted bench tonnes can be used for scheduling purposes.
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.  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 the “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 dilution is being added 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 to apply the cutoff grade 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.  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, otherwise it is simply being viewed as a contingency factor.

Conclusion

My personal experience is that, from a third party review perspective, reviewers tend to focus on the final dilution number used and whether it makes sense to them.   The actual approach used to arrive at that number 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 approaches.
Readers may yet have different dilution methods in their toolbox and I it would be interesting to share them.
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