Articles tagged with: Mine Engineering

56. Does the Mining Industry Employ Interns?

Over the last year or so I have been working on a side project I founded within the tech industry.   One of the things that recently came to the forefront was the use of interns, unpaid interns, that is.   I know that  interns have been used for years in other industries including legal, politics, journalism, and marketing; however I have never come across the use of interns within the mining industry.
Intern
I was recently speaking with a marketing consultant about how to undertake tech marketing and one of the suggestions she made was to hire an intern to do much of the legwork of finding contacts and making contact with them.  My first question was why would anyone work for free?  I was told there were three reasons:
  1. For credit; as part of a course credit in college or university where an internship is part of the programme requirement.
  2. For experience; one can’t get a real job without experience and so the internship teaches something, builds up experience, and creates a portfolio of work.
  3. Networking; building up network connections can possibly lead to permanent work.
At first I was taken aback at the thought of asking someone to work for me for free.  Are we that cheap?   On the other hand if you are paying someone a salary, the expectation is that they should be relatively skilled at their job.  Giving it some further thought, , I have come to realize that the internship may actually be a win-win for both parties.
The company gets to better know potential employees and also gets some productive service from them at no cost.  The intern grows their employment experience and learns about the realities of the business world.  The students are paying the schools to teach them, and now businesses can help teach them as well, but at no cost.   It’s a win-win.
So how did our intern search go?  We posted a free ad on indeed.ca.  Within 48 hours we received eight replies, of which only 2 came close to meeting the qualifications.  Some of the applicants had no relevant experience at all.   Possibly in today’s job market people are willing to work for free on the chance they can get some experience on their resumes which will hopefully lead to a job in the future.  We’ll maintain the job ad for a couple more weeks and see what the overall response will be.
My bottom line is asking whether the mining industry can make use of interns in the areas of geology, engineering, marketing, graphics, etc?  There may be a lot of young students out there looking for opportunity and willing to do whatever it takes to help advance their careers.   Even if your payroll budget cannot afford the cost of another person, you still may be able to help out someone within the industry.
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55. Underground Feasibility Forecasts vs Actuals

I recently attended a CIM Management and Economics Society presentation discussing the differences between actual underground production versus the forecast used in the feasibility study. The presenter was Paul Tim Whillans from Vancouver Canada. His topic is interesting and relevant to today’s mining industry and Paul raised many thoughtful points supported by data. The abstract for his paper is copied below and the entire paper can be downloaded at this LINK and here are the presentation slides.
ABSTRACT
An underground mining study that is done in accordance with NI43-101, JORC or similar reporting code is generally assumed by the public to be representative, independent and impartial. However, it has been well documented by academics and professionals in our industry that there is a sharp difference between the forecasts presented in these underground studies and the actual costs when a mine is put into production.
For underground mines, the risks associated with obtaining representative information are much greater than for surface mining and the cost of accessing underground ore is also proportionally much greater. There is a pressing need to align expectations, by improving the accuracy of projections. This will result in reduced risk to mining companies and investors and provide more reliable information to government agencies, the public, and more importantly, the communities in which the proposed mine will operate.
The objective of this article and an article currently being written titled “Mining Dilution and Mineral Losses” is to:
– Discuss the dynamics of intention that lead to over-optimism;
– Provide simple tools to identify which studies are likely to be more closely aligned with reality;
– Identify some specific points where underground mining studies are generally weak;
– Discuss practices currently in use in our industry that lead to a composite or aggregate effect of over optimism;
– Describe the effects of overly optimistic studies;
– Outline specific changes that are necessary to overcome these challenges; and
– Stimulate discussion and awareness that will lead to better standards.

Headframe

In my opinion, I agree with many of the points raised by Paul. The mining industry has some credibility issues based on recent performance and therefore understanding the causes and then repairing that credibility will be important for the future of the industry. Credibility impacts on shareholder returns, government returns, local community benefits, and worker health and safety; so having a well designed mine will realize benefits for many parties.
If you need more information Paul’s website is at http://www.whillansminestudies.com/
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53. Ore Stockpiling – Why are we doing this again?

In many of the past mining studies that I have worked, stockpiling strategies were discussed and eventually implemented. Sometimes study team members were surprised at the size of the stockpiles that were generated by the production plan. It became apparent that not all members of the team were clear on the purpose of the stockpiling strategy or else they had preconceived ideas on the rationale. To them stockpiling may have seemed to be 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 but will focus simply on the reasons for stockpiling and why stockpiles may get large or numerous .
In my experience there are four main reasons why stockpiling might be done at an operation. They are:
1. Campaigning: For metallurgical reasons, there may be certain ore type(s) that can cause process difficulties if mixed in with other ores. Therefore the problematic ore(s) might be stockpiled until sufficient inventory is built up until it makes sense to process that ore (i.e. campaign) through the mill. Such stockpiles will only grow as large as the operator allows them to, before processing the material and eliminating the stockpile. Be aware that if the mine operations are still delivering different ore types to the crusher area, then those ores may need to be stockpiled during the campaigning period.  More different ore types may mean more stockpiles.
2. Grade Maximization: This stockpiling approach is used in situations where the mine delivers more ore than is required by the plant, thereby allowing the best material to be processed directly and the lower grade material to be stockpiled for a future date. Possibly one or more low grade stockpiles may be used, for example a low grade and a medium-low grade stockpile. Such stockpiles may not be processed for years, possibly remaining in place until the mine is depleted or until the mined head grades are lower than those in the stockpile. Such stockpiles can grow to enormous size if accumulated over many years.
3. Surge Control: stockpiling 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 and provide a steady primary crusher feed rate. These stockpiles are also available as short term emergency feed 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 mainly used for operational 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 consistent and uniform. Such stockpiles may not be large individually; however there could be several of them depending on the orebody character.
There may be other stockpiling strategies beyond the four listed above but those four capture the bulk of the situations.
Using today’s automated production scheduling software, one can test multiple stockpiling strategies by applying different cutoff grades or using multiple grade stockpiles. The scheduling software will have algorithms to determine whether one should be adding to the stockpile or drawing from it. It will track the 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).
Stockpiling in most cases will provide some potential benefits to an operation and the project economics. Even if metallurgical blending or campaigning is not required, one should always test the production schedule and project economics with a few grade stockpiling scenarios. Unfortunately these are not simple to undertake when using a manual scheduling approach and so are another reason to move towards automated scheduling software. Also 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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50. Landslide Blog – If You Like Failures

For those of you with a geotechnical background or have a general interest in learning 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. Their website screenshot is shown below.
Landslide Blog screenshot

Landslide Blog web page 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.
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.
Landslide
The following links are a few examples of the type of discussion that they have on the website.
Here is a description of a small water dam failure in Greece.
Here is some video of the Samarco tailings runout in Brazil.
Here is some video of boulders raining down on some buses along the Karakorum Highway in Pakistan.
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 and cities. Some of their videos are quite fascinating, illustrating the forces behind some of earth’s natural erosion processes. Check it out for yourself.
My bottom line on all of this is that the less the mining industry is mentioned in the Landslide Blog, the better it is for all of us.
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49. Remote Sensing of Ore Grades

The mining industry must continually find ways to improve and modernize. The most likely avenue for improvement will be using new technologies as they become available. One of the new players on the scene is a start-up company called “MineSense Technologies Ltd.”  They are a British Columbia company looking to improve ore extraction and recovery processes based on the sensing and sorting of low-grade ore (pre-concentration in other words). They hope their pre-concentration methods will improve mine economics by reducing the consumption of energy, water, and reagents.

Minesense

 It’s not entirely clear to me how developed their technology is, but MineSense is relying on a combination of ground-penetrating sensors with other sensor technology in order to measure and report the grade of ore in real time. Existing ore sorting technologies seem to focus on distinguishing mineralized material from gangue, but MineSense seems to be targeting using actual ore grades as the defining factor. They hope to be able to eventually integrate their technology into equipment such as shovels, scooptrams, conveyors, feeders, and transfer chutes.
More specifically their proprietary technology is based on High Frequency Electromagnetic Spectrometry and High Speed X-Ray Fluorescence sensors. Reportedly these can deliver better sensitivity and operate at high speeds. They plan to develop two distinct product lines; shovel-based systems; and conveyor belt-based systems.
Their ShovelSense system would be a real-time mineral telemetry and decision system and used for measurement of ore quality while material is being scooped into the dipper, then reporting the ore quality and type to the grade control/ore routing system, and then enabling real-time online ore/waste dispatch decisions. Additional features may include tramp metal and missing tooth detection.
Their belt conveyor systems (SortOre and BeltSense) will use high-speed multi-channel sensing to characterize conveyed ore and waste in real time, allowing grades and tonnages to be reported and allowing ore to be diverted to correct destinations based on the sensor responses. MineSense say that pilot units are operating at 20 tph and systems of up to 2000 tph are in the development stages. Ore sorting has been around for a long time, with companies like Tomra (www.tomra.com), but possibly the MineSense technical approach will be different.
My bottom line is that we should all keep an eye on the continued development of this technology, especially as MineSense completes larger field trials. Hopefully they will readily share the results with us since it will be critical for industry players to see more actual case study performance data on their website. I recognize that developing new technology will have its successes and failures. Setbacks should not necessarily be viewed as fatal flaws since it takes time to work out all the kinks. Hopefully after being able to fine tune their technology they can advance to their next stage which will be to convince the mining industry to adopt it.
P.S. Unfortunately it appears MineSense don’t have a newsletter sign-up form on their website to help us in following their progress.
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48. Online Collaboration and Management Tools (Part 2)

This blog is the Part 2 continuation of the post from last week regarding software tools that the mining people should take a look at. Here are a few more ideas that I would like to share, having found that these are also great to have in your toolbox.
Google Sheets and Google Docs: When undertaking group reviews of spreadsheets or text documents don’t many of us have frustrations? We typically end up with different versions of the same document floating around and nobody knows which one is the most recent version and which one they should be editing. With Google Sheets and Google Docs you can create online spreadsheets and documents and then allow people on your team to review and edit them in real-time online. Writing reports gets simpler since there is only one version of the document with which everyone is working. A “track changes” option is still there (called “Suggesting”) and everyone can see the edits as they are being made. No more asking “who has the most current version?” it’s always there on-line. This type of collaborative editing is also great for certain types of spreadsheets as well as for Design Criteria Documents that are regularly being updated by different team members.
Foxit Reader:  This is an alternative to Adobe Reader and can be used for reviewing PDF documents, whether text documents or drawings. Foxit provides great editing and commenting tools like highlighting text, adding comments, drawing lines and boxes, adding comment balloons, cut & pasting images into the PDF file, and then saving the commented version. For the most part I have stopped using Adobe Reader and have now switched over to Foxit.
Foxit Reader screenshot

Foxit Reader screenshot

UberConference:  This is an online application for team conference calling that allows screen sharing, online conversations, sends out meeting reminders, and it will call participants at the require time. Watch the video on their website to gain a better understanding; it’s entertaining and true to life.
Uber Conference screenshot

Uber Conference screenshot

Those are a few of the software tools that I have found useful and so now you’re probably wondering “what else is out there for me?” The website The Freelance Stack lists many of different tools that exist. Check them out and some of the others may be of value to you. :
One of the key marketing approaches used by most of the tech companies is to provide a fully functional product for free and then charge money to access the enhanced features. The objective is to get future users familiarized and trained on the system, and then they will decide that they wish to upgrade their capability and so pay for the full product suite. I’m not sure if any geology or mining software  is available in a basic functional format enabling optional upgrading. By functional, I don’t mean simply providing a “viewer” to view the work of others or a 30-day trial period, I mean actual software that provides some actual useful capability for free in order to get you hooked.
My bottom line is that there is a lot of good stuff out there, readily available, much of it free, and it can make managing your project teams easier. Just because it’s related to the tech industry, don’t assume it wouldn’t have an application in the mining industry.
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47. Online Collaboration and Management Tools (Part 1)

As part of a new side business venture I have been working alongside a team of website and mobile app developers. It has been a good learning experience for me to see how the tech teams do things versus how the mining consulting industry conducts its business. We know there is a lot of private equity money flowing into tech and not mining, so they must be doing something right.
The tech start-up industry has developed its own set of jargon, like agile management, lean start-ups, disruption, minimum viable products, pings, and sprints. Some of their key methodologies would not make sense for the mining industry where one doesn’t have the luxury of trial-and-error and customer feedback to help complete your project. For software development, the attitude is get it out the door fast and your customers will then tell you what fixes they want to see. In mining you need to get it right the first time (hopefully). Having said that, some mining people will say they have seen 43-101 technical reports that follow the “wait for customer feedback” model.
Now where the tech industry can provide us with some useful advice is in the use of project management and collaboration tools. The software developers often work remotely and so make heavy use of the technology that exists or they develop new technology tools to meet their needs. Mining teams are starting to work from remote offices more often these days.
The following is a partial list (Part 1) of free software tools that I have used recently, mainly because I was forced to by the tech teams. Subsequently I have found the tools easy to use and most definitely some can be applied in our own industry, especially with diverse mining study teams. There are a lot more tech tools out there but my list includes the ones that I have personally come in contact with. Most of these are free to use with limited features and enhanced features are available if you subscribe to the full version at minimal cost. However even the free versions are useful and can be used to train your team. Most of them provide both web based and app based access so even when you’re on the road you can still use them and contribute to the team.
Trello: If you want to create a task list for your team, this is the app to use. Imagine a bunch of yellow post-it notes that you can put under various project categories, assign persons to each note, attached a file if you wish, and then have back and forth discussions within each note. Then once a task is done, just drag the note to another category (e.g. “In Progress”, “Completed”). Anyone or selected people can create a note or provide comment. See the image below for an example Trello screenshot.

 

Trello screenshot

Example Trello Screenshot

Slack: If you want to have a running record of group discussions that all or only selected team members can follow and join in on, then Slack is for you. It can replace the long confusing back-and-forth emails that we commonly see, when people sometimes forget to “reply all” so now you’re out of the loop. See the image below for an example Slack screenshot. It’s great for discussions amongst the team and you can have private one-on-one discussions or wide open team discussions and can attached files too. It provides permanent record of discussions or decisions made.
Slack Screenshot

Example Slack Screenshot

Basecamp: is similar program that incorporates features from both the above and some people swear by this tool. I have not personally used it so cannot vouch for it, but some say it is very good. Watch the video on their website describing what it can do.
My bottom line is that there is a lot of good stuff out there, readily available, much of it free, and can facilitate the management of your project teams. Just because its tech industry related, don’t assume it wouldn’t have an application in the mining world. Next week in Part 2 of this blog, I will describe a few more of the tech tools that I have found useful.
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44. Higher Metal Prices – Should We Lower the Cut-Off Grade?

When metals prices are high, we are generally taught that we should lower the cutoff grade. Our cutoff grade versus metal price spreadsheet tells us this is the correct thing do. Our grade-tonnage curve reaffirms this since we will now get more ounces of gold in the mineral reserve. But is lowering the cutoff grade really the right thing to do?
Books have been written on the subject of cutoff grades where readers can get all kinds of detailed logic and calculations using Greek symbols (F = δV* − dV*/dT). Here is one well known book by Ken Lane that sells for $998 on Amazon the last time I checked. You can also download a 38-page abridged sample of this book at THIS LINK and the full version is available for $150 at the COMET Strategy web site.

Theory of COG

Recently we have seen higher production cash costs at operating mines when commodity prices are high. Why is this? It may be due to higher operating costs inputs caused by increasing labour rates or supplies costs. It also may be partly due to the lowering of cutoff grades, thereby lowering the milled head grade, which then requires more tonnes to be milled to produce the same quantity of metal.
A mining construction manager once said to me that he never understood us mining guys who lower the cutoff grade when gold prices increase. His rationale was that, since the plant throughput rate is fixed, when gold prices are high you suddenly decide to lower the head grade and produce fewer ounces of gold and at a higher cash cost. His point was that we should be doing the opposite; when prices are high you should produce more ounces of gold, not fewer. In essence, in times when supply is low (or demand is high) may not be the right time to further cut back on supply by lowering head grades.
Now this is the point where the grade-tonnage curve comes into play. Certainly one can lower the cutoff grade, lower the head grade and produce fewer ounces now with the upside being extending the mine life. By doing this a company is able to report more ounces in their mineral reserve and the overall snapshot of the company looks better if it is being valued on reserve ounces.
The problem with this is that there is no assurance that metal prices will remain where they are or that the new lower cutoff grade will remain where it is. If the metal prices dip back down next year, the cutoff grade will be increased and the mineral reserve is back to where it was. All that was really done was accept a year of lower metal production for no real benefit. Such a trade-off essentially contrasts a short term vision (i.e. annual production) against a long term vision (i.e. mineral reserves).
My bottom line is that there is no simple answer on what to do with the cutoff grades, hence the need to write books about it. Different companies have different corporate objectives and each mining project will be unique with regards to the impacts of cutoff grade adjustments on their orebody. I would like to caution that one should be careful when taking your cutoff grade spreadsheet, plugging in new metal prices, and then running off to the mine operations department with the result. You need to fully understand the long term and short term impacts of that decision.
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43. Mining Fads and the Herd Mentality

Have worked in the mining industry for over the last 30 years it is always interesting to see the herd mentality that exists and how we all can easily get caught up in fads.  All it takes is a short term spike in a commodity price or a big discovery somewhere and then off we go running in that direction.  It doesn’t matter the rationale driving the event, all we know is that we need to be there and our investors want to be there too.
Based on my experience, the fads that grab us can include specific commodities, locations, or technologies. The industry is very flexible in that regard. I’ll give a few examples below and you probably have more examples from your own experience.

Commodity Fads

It seems that as soon as there is a price spike or positive market narrative, any commodity can take a life of its own.  The following are a few examples and when you think about them ask how many actually came into production or successful production.
  • Potash – a few years ago potash prices spiked and potash properties were all the fad no matter where they were located around the globe, be it Canada, Russia, Ethiopia, Thailand, Brazil, etc.
  • Lithium / Graphite – as soon as green technology started to be promoted in the news, miners couldn’t run fast enough to pick up the lithium properties, same idea hold for the graphite and vanadium and rare earth categories.
  • Uranium – years ago uranium prices spiked and Ur properties were hot everywhere.
  • Nickel; a spike in nickel caused a surge in nickel properties being it sulphide nickel, laterite nickel, or other forms.
  • Iron Ore – in conjunction with the Chinese construction boom, iron ore properties were hot around the globe, in high cost or low cost jurisdictions, it didn’t matter where the property was.
  • Diamonds – in conjunction with the first diamond discoveries in Canada, quickly diamond properties because hot, whether in the Canada or around the globe.  If you couldn’t get a property in Canada’s boom area, anywhere else was fine.
  • China in general – whereby every base metal project was thought of as either a potential supplier to China or a potential acquisition for Chinese companies.  As long as it could meet Chinese investor interest it was good.

Location Fads

We have all seen the staking rushes that occur when a world class prospect is discovered.  I’m sure we can all recall getting the large claim maps (as shown below) with their multicolored graphics showing the patchwork of acquisitions around a discovery. PDAC was great for distributing these and they were well done and interesting to study.
Mineral claim map example
Picking up properties in hot areas became the fad and share prices would move upwards regardless of whether there was any favorable geology on the property.  Who recalls the following?
  • Voisey Bay; with a mad staking rush around there, with nothing else really paying off in the long run.
  • Saskatchewan;  and the potash staking rush where almost every inch of the potash band was staked with only a couple of companies eventually moving forward and only one going into production.
  • Indonesia; during Bre-X people could get properties in Indonesia fast enough.
  • NWT;  where the diamond property staking rush was crazing in the mid 1990’s.

Technology Fads

Even mining or processing technology could get caught up in somewhat of a wave and become a fad for further study, a rationale often driven by suppliers or consultants.  Who can recall…
  • Paste Tailings; with numerous conferences and consultants promoting thickened or paste tailings technology as the panacea leading to numerous studies related to thickening, pumping, and disposal.
  • Block Caving; whereby in order to deliver high tonnages at low cost, bulk underground mining was being promoted.  Everyone wanted their underground project to be a low cost caving style operation.
  • High Pressure Grinding Rolls (HPGR); where process consultants would tout HPGR as the new replacement for conventional grinding mills.  I’m not sure this technology has taken the industry by storm as they were hoping.
  • IPCC; whereby inpit crushing and conveying was being promoted in many articles and global conferences as the solution to operating cost pressures.  I think implementation of IPCC technology isn’t as simple as envisioned.
  • Dot.com; in the early 2000’s many junior miners left exploration behind and transitioned to the dot.com boom, a fad with generally poor results.
  • Medical marijuana; seems to be the hopeful target for some junior miners today. Unfortunately there is only so much marijuana you can sell.
  • Pre-concentration; this seems to be a growing technology fad that may be gaining momentum, with a few consultants pushing for it to be studied more.  This isn’t new technology and will have its benefits but a big stumbling block is how many deposits are actually suitable for its application.
My bottom line is that over the years it has been interesting to watch the mining industry react to events.  Sometimes it seems like we’re passengers on a boat running from one side to other side and then back again.  Unfortunately that doesn’t necessarily make for smooth sailing and can result in upset stomachs.
What’s the next fad? I don’t know but if you could predict it we can probably make a lot of money.

 

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39. Measured vs. Indicated Resources – Do We Treat Them the Same?

One of the first things we look at when examining a resource estimate is how much of the resource is classified as Measured / Indicated (“M&I”) versus the tonnage classified as Inferred.  It’s important to understand the uncertainty in the estimate and to a large degree the Inferred proportion gives us that.   At the same time I think we tend to focus less on the split between the Measured and Indicated tonnages.
We are all aware of the study limitations imposed by Inferred resources.  They are speculative in nature and hence cannot be used in the economic models for feasibility and pre-feasibility studies. However Inferred resource can be used for production planing in Preliminary Economic Assessments (“PEA”).
Inferred resources are also so speculative that one cannot add them to the Measure and Indicated tonnages in a resource statement, although that is what just about everyone does when looking at a project.   I don’t think I fully understand the concerns with a resource statement if it included a row that adds M&I tonnage with Inferred tonnes as long as everything is open and transparent.   When a PEA production schedule is presented, the three resource classifications are combined into a single tonnage number but in the resource statement itself the M&I&I cannot be totaled.  A bit contradictory I feel.
With regards to the M&I tonnage, it appears to me that companies are most interested in what part of their  resource meets the M&I threshold but are not as interested in how the tonnage is split between Measured and Indicated.   It seems that M&I are largely being treated the same.  Since both Measured and Indicated resources can be used in the feasibility economic analysis, does it matter if the split is 100% Measured (Proven) or 100% Indicated (Probable)?   The NI 43-101 and CIM guidelines provide definitions for Measured and Indicated resource but do not specify any different treatment like they do for the Inferred resources.

 

CIM Resources to Mineral Reserves

Relationship between Mineral Reserves and Mineral Resources (CIM Definition Standards).

 

In my past experience with feasibility studies, some people used the rule-of-thumb that the tonnage mined during the payback period must largely consist of Measure resource (i.e. Proven reserve) and then the rest of the production schedule could rely on Indicated tonnage (Probable reserve).  The idea was that a way to reduce project risk was to ensure that the production tonnage providing the capital recovery should be based on the resource with the highest certainty.   Nowadays I generally do not see this same requirement for Measured resources, although I am not aware of what everyone is doing in every study.   I realize there is a cost, and possibly a significant cost, to shift Indicated resource to Measured so there may be some hesitation. Hence it may be simpler for everyone to simply regard the Measured and Indicated tonnages in roughly the same way.
NI 43-101 specifies how the Inferred resource can and cannot be utilized.  Is it a matter of time before the regulators start specifying how Measured and Indicated resources can be used?  I see some potential merit to this idea but adding more regulation and cost to an already burdened industry is not helpful.
Perhaps in the interest of increased transparency, feasibility studies just need to add two rows to the bottom of the production schedule showing how the annual processing tonnages are split between Proven and Probable reserves.  One can get a better sense of the resource risk in the early years of the project.  Given the mining software available today, it likely isn’t difficult to provide such additional detail.
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