Articles tagged with: Mining

Mining Project Economics – Simple 1D Model

Date: May 29, 2015 Author: Ken Kuchling Comments: 4 Replies
mining desktop study
In a previous article I outlined my thoughts on the usefulness of early stage financial modelling (“Early Stage “What-if” Mine Economic Analysis – Its Valuable”).     My observation was that it is useful to take a few days to build a simple cashflow model to help your team better understand your project.

By “simple” I mean really simple.

This blog describes one of the techniques that I use to take a super-quick look at any project; whether it is for a client wishing to understand his project at a high level; or whether it is a project that I have read about.  There isn’t any actual study or production schedule available yet.  Maybe there is only a mineral resource estimate available.
It takes about 10 minutes to plug the numbers into my template to get fast results.  The image below is an example of the simple model that I use, but anyone can build one for themselves.

Screenshot of Simple Economic Model

I use the term one dimensional (“1D”) model since it doesn’t use the typical X-Y matrix with years across the top and production data down the page.
The 1D model simply relies simple on life of mine (“LOM”) totals to estimate the total revenue, total operating cost, and total profit.  This determines how much capital expenditure the project can tolerate.
The only caveat is that you need to have some sense for operating and capital costs for similar projects. This analysis can be on both a pre-tax and simple after-tax basis.
Using estimated metal prices and recoveries, the first step is to calculate the incremental revenue generated by each tonne of ore (see a previous article “Ore Value Calculator – What’s My Ore Worth?”).
Next that revenue per tonne is multiplied by the total ore tonnage to arrive at the total revenue over the life of mine.
The second step is to determine the life of mine operating cost, and again this simple calculation is based on estimated unit operating costs multiplied by the total tonnages being handled.
The third step is to calculate the life of mine profit based on total revenue minus total operating cost.
The potential net cashflow would be calculated by deducting an assumed capital cost from the life-of-mine profit.  The average annual cashflow is estimated based on the net cashflow divided by the mine life.  An approximate NPV can be calculated by determining the Present Value of a series of annual payments at a certain discount rate.
The reasonableness of the 1D model will be examined via benchmarking and this will be summarized once completed.  I will include a link to that future blog here.

You need to understand your project

One can easily evaluate the potential impact of changing metal prices, changing recoveries, ore tonnages, operating costs, etc. to see what the economic or operational drivers are for this project.  This can help you understand what you might need in order to make the project viable.

Conclusion

The bottom line is that a 1D economic calculation is very simplistic but still provides a vision for the project.  The next step in the economic modelling process would be a 2D model based on an annual production schedule.  The 1D approach is just a quick first step in looking at the potential.  You can do it even when you only know the head grades and some generalized orebody information.
The two ways you can apply the simple 1-D model are:
  1. evaluate the potential of early stage projects using cost inputs from other studies,
  2. examine a project’s sensitives (units costs, recoveries, prices) by calibrating your simple model to the published study (i.e. use the same parameters and make changes as needed.
The entire blog post library can be found at this LINK with topics ranging from geotechnical, financial modelling, and junior mining investing.

 

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Oil Sands vs Tar Sands – Something I’ve Been Wondering About

Date: May 26, 2015 Author: Ken Kuchling Comments: 1 Reply
tar sand mining
Watching the television news in Canada these days, one sees the environmental opponents of the oil sands parading around with signs that say “Stop the Tar Sands”.  One way to distinguish whether someone is for or against the oil sands is to see what terminology they use.  Do they call them “oil sands” (i.e. pro groups) or “tar sands” (i.e.anti groups)?   Personally raw bitumen seems more tar-like than oil-like so the enviro’s seem to have it right.

Is it Oil Sands or Tar Sands

Going back many decades the oil sands were originally called the tar sands.  I’m not sure when the terminology shifted, but in the mid-1960’s the first large scale mining operation was called Great Canadian Oil Sands (GCOS).  I’m not sure why the terminology shift from tar to oil, but maybe it was related to the fact that “tar” was considered something of low perceived value while “oil” was considered something of high economic value.
Jed Clampett and familyLook at what oil did for the economic situation of Jed Clampett on the Beverly Hillbillies.  How about the show “Dallas”? There was also a lot of money and scotch drinking.
Back then we all wanted to discover an oil well in our backyard so perhaps the term “oil” implied some level of elegance and prosperity.
These days when one sees the term “oil” in the news, it tends to be associated with negatives.  We see oil references to rail explosions, pipeline ruptures, tanker spills, job layoffs, fracing, carbon emissions, Middle East wars, and protests.
These days I don’t know if there is any intangible benefit in using the term “oil” to describe your product anymore.  Maybe there is actually some intrinsic harm in doing so.
Tar sand bitumenTar (or bitumen) on the other hand, is a molasses-like substance generally viewed by the public as a material used to repair our streets and patch our roofs. A tar spill is not going to flow anywhere; it will barely flow out of the tank it is held in.  What is there not to like about tar?
So next time there is a protest with signs being held up to “Stop the Tar Sands”, the oil companies should shrug their shoulders, jump on the band wagon, and say “Yeah, tar, that’s us. So what are you worried about?”.
They should try to commandeer the word “tar” back from the protest groups since there really is nothing wrong with tar.  There seems to be a lot wrong with oil.

 

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3D Printing – A Simple Idea

Date: May 25, 2015 Author: Ken Kuchling Comments: 4 Replies
3D models
We hear more and more about 3D printing and what it is able to do. 3D printers have come down in price and can be bought for under $500.   Here is an example of using a 3D printer from a recent project that I consulted on.
The open pit was going to be located in hilly terrain, and issues related to haul road access, waste dump sites, and leach pad location were all important.   The client used a 3D printer to create a small desktop model of the terrain, which was given to each of the consulting firms.
The photo below shows the scale of the model.
3D printed topographyMembers of the engineering team were each given their own 3D model to take back to their offices.  Putting one of these on your desk helps with familiarity of the overall site and allows you to better understand the siting and drainage issues.
Topographic maps may give data on actual elevations and distances, but even a small 3D model gives you a feel for the site.    The model shown above was for undisturbed topography but one could easily print off a similar model once the final pit and dump design is done.
With the current three-dimensional printing capabilities, creating simple 3D topographic models for the engineering team is feasible and I recommend doing so.
At the same time provide the Owner’s team with their own models, helping them understand the site issues that must be dealt with.
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Potash Ore Grades – Check the Units

Date: May 20, 2015 Author: Ken Kuchling Comments: 3 Replies
KCl vs K2O
Having worked with the potash industry for many years, I have reviewed numerous geological reports for projects in Canada, Asia, Russia, and Africa.  One of the curious things that I have seen is the reporting of resource  grades in two different units; either as potassium oxide (K2O) or potassium chloride (KCl).

Is it K2O or KCl ?

Standard practice in the Saskatchewan industry is reporting ore grades using K2O units, with typical head grades in the range of 25% K2O.  Many of the international projects, but not all, have decided to use the KCl units. Therefore when comparing potash resource grades between deposits, one must be vigilant for the units used since there is a significant difference.
The conversion from K2O to KCl is based on the formula K2O = 0.6317 x KCl.   So a grade of 25% K20 is equal to 25/0.6317 = 39.6% KCl.  The KCl grade value is significantly higher.  The unit issue is relevant with low grade deposits, were an actual grade of 15% K2O may be reported as 23.7% KCl.  One might see the ore grade in KCl and assume it is comparable to Saskatchewan potash grades, when in reality they are quite different.

Concentration Ratio is the Key

When looking at different potash projects, particularly those involving underground mining, a key economic factor is the concentration ratio.  This ratio represents the tonnes of potash ore needed to produce a tonne of final saleable product.
Typically the final potash product has a grade of 60% K2O.  Therefore a potash ore with a grade of 25% K2O would have a concentration ratio of about 2.4:1 (60%/25%).  This means that 2.4 tonnes of potash must be processed to produce 1 tonne of product (ignoring the process recovery factor).   For a lower grade ore with a head grade of say 15% K2O, the concentration ratio is 4:1 (60%/15%).

potash mining

This gives a rough sense for the comparable operation size required to meet the same final product production levels.  This also gives a indication for the relative amounts of salt tailings requiring disposal.  Low grade ore can generate significant quantities of tailings, the disposal of which is becoming a larger permitting issue.
In the past gold grades have been reported as “oz/ton” or currently as “g/t”, but most geological reports today are consistent with “g/t”.  Sometimes US based gold projects may use “oz/ton” however the magnitude in reported grades are fairly obvious between grams and ounces.  That isn’t the case with potash grades.
The bottom line is that potash is one commodity that will use different units when reporting ore grades.  Investors and reviewers must be aware of which units are being used.
If you are into potash mining, I have written a couple of blog posts about my brief, but interesting, time working at a potash mine in Saskatchewan.   This was early in my career and I had roles that included mine engineer, chief mine engineer and production foreman.  Each of these roles gave me a different perspective about a mining operation. In this two part blog, I share some stories relating to the uniqueness of potash mining.   If interested, here is the link “Stories from 3000 Feet Down – Part 1“.

 

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Importance of a Study Manager – That’s the Key

Date: May 18, 2015 Author: Ken Kuchling Comments: 1 Reply
project manager
Over my career I have worked as an engineering team member on numerous projects and mining studies.  Some studies went better than others.  Unfortunately some dragged on, ran over budget, and ended up delivering a less than optimal product once all was said and done.
There are numerous factors that will influence the successful completion of a study.   They can be related to the quality of the technical team, the budget, the time window, and direction from the Owner.  However the key factor that I observed is the competency of the Study Manager (or Project Manager).

Study Managers must wear many hats

Study managers are responsible for being the main liaison with the Owner. They must herd a team of geologists and engineers in the same direction. They must ensure that technical quality and consistency is maintained by the entire group.  They are responsible for ensuring that budgets and timelines are being met.  The combination of all of these responsibilities can be an onerous mission, more so depending on the experience of the Owner’s team.
Every technical team has those members that will deliver quality within timelines consistently.  There are also team members that have difficulty meeting targets.  The Study Manager, early on, needs to figure out who fits into which category and then must be able to work with each.

Studies can quickly grind to a halt

An entire study can quickly grind to a halt simply because one key component becomes bogged down. A good Study Manager may occasionally ruffle some feathers but is always appreciated by the team knowing that everyone will be held to account.
The Study Manager also needs to understand the objectives of the Owner and ensure the team is working towards those objectives.
The Study Manager however must also be honest with the Owner, keeping him informed of the actual progress and warn if some target will not be met.
The Study Manager coordinates communication within the team and with the Owner.  Some managers are excellent at this while others fall into the trap of communicating on a “need-to-know” basis or “too late” basis.
Timely and thorough communication is important.  Don’t assume that one is hampering progress by involving the team in frequent communications. They serve a purpose.

Environmental Assessments need engineering input

Often the Environmental Impact Assessment is being conducted concurrently with an engineering study.  The level of internal and external communication now becomes even more critical due to the large number of new technical disciplines involved.
It is not uncommon for EIA’s to make regulatory commitments  that have not been signed off by the engineering side. The Study Manager should be aware when such commitments are being made because the engineering design needs to reflect them.

You should approve the Study Manager

When approving the consultant’s Study Manager, keep in mind that in some instances you may find that different managers within the same organization may have different internal authority.  For example, if technical people are needed on another project, some managers are able to keep their team together.  Other managers may lose team members to the other project if that manager has more internal authority.  Losing manpower doesn’t help a study progress,  so if possible try to get a sense for the authority that the Study Manager has within the organization.

Conclusion

The bottom line is that when a project Owner has received proposals for a study and is in the process of awarding that job, the most important consideration is who will be the Study Manager.  If possible meet or chat about how they will manage the study and what their experience is.  Check references if possible.
The voluminous proposals provided by consulting firms contain a lot of information like Gantt charts, organizational charts, cost estimates, team resumes, safety plan, and corporate project experience.  Focus on the Study Manager. Don’t assume they are simply an administrator scheduling meetings and issuing monthly reports. They are the key to success.
A good Study Manager can make a poor engineering team perform, while a poor Study Manager can bog down a great technical team.
One thing to be aware of is that with some firms, a Study Manager is not the same role as a Project Manager.  The SM may undertake more clerical duties, such as weekly or monthly reports, manhour tracking, distributing documents, and coordinating the logistics of the study rather than the technical aspects that a Project Manager may look after.
Another blog post discusses undertaking studies using multiple engineering teams and the pitfalls to watch out for.  That blog post is at “Multi-Company Mining Studies Can Work Well…or Not“.
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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Directional Drilling Open Pit Dewatering Wells – Great Idea

Date: May 16, 2015 Author: Ken Kuchling Comments: 4 Replies
open pit dewatering
I read an interesting article in the Mining Magazine May 2015 edition called “Top 10 Technologies”.  One of the new technologies that jumped out at me is the capability to directionally drill open pit dewatering wells.   This is an oil field technology from Schlumberger Water Services that was now going to be applied to mining.
One of my past roles was as a mine engineer on the Diavik diamond mine team. Pit geotechnical and hydrogeology were under my domain during project design and permitting from 1997 to 2000.
The granitic rock mass was geotechnically very competent with a limited amount of jointing and fracturing.  The pits were going to be located within a lake bed.
It was anticipated that groundwater seepage coming from a partly permafrost pit wall could create a host of operational problems in winter. Most of the groundwater flows were predicted to be along a few major structures or along single open joints.
Generally these major structures were near vertical, which created a problem when trying to intercept them with vertically drilled depressurization wells.  Either you hit one or you didn’t.

The use of directional drilling of pumping wells is a great innovation

Directional drilling of dewatering wells gives the opportunity to angle a pumping well to an orientation that allows the well bore to cut across vertical structures rather than paralleling them.   In addition, one could drill pumping wells near the pit crest targeting towards the ultimate pit bottom.  This may help improve drainage near the operating benches as the pit deepens and could eliminate the need to install inpit pumping wells if water becomes a problem.
Some open pits have constructed underground drainage galleries around the pit circumference to help intercept deep groundwater seepage.  Possibly directionally drilling aligned parallel to the pit wall can replace such high cost drainage galleries.
The bottom line is that the directional drilling innovation makes a lot of sense and mine operators should take a look at it.  It might help improve their pit dewatering systems.
If anyone has experience with directionally drilled dewatering wells, please let us know.
The hydrogeology at Diavik was unique in that the ground consisted of both permafrost and unfrozen ground.  It was likely that unfrozen ground would eventually form permafrost over time once exposed to the cold winter climate.  To read more about the hydrogeology at Diavik, check out this link “Hydrogeology At Diavik – Its Complicated“.
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 Data Rooms – Help!

Date: May 13, 2015 Author: Ken Kuchling Comments: 3 Replies
Mining reviews
Many of us have heard the statement “Have a look in the data room, it’s all in there”. This can bring a cold sweat to even the most experienced engineer who undertaking a due diligence review.  How many of you can recall being given FTP access to a data room that is full of highly disorganized folders and sub-folders, files with cryptic names, different updates of the same file in different folders?

It’s like looking for a needle in a haystack.

It can be difficult to impossible to determine which files are important and relevant and which files have been simply dumped into the data room. There is nothing worse than spending a day reviewing an Excel financial model only to find out that it wasn’t the latest version and a different un-related folder had the correct version.
Data rooms are typically created for due diligence exercises, or during advanced an engineering stage. Regardless of the purpose, it is helpful for all involved  to have a document control person who understands what is in the data room, what is important, and what is non-essential.
Large projects often have an dedicated document control person to manage the data room.  However smaller companies in a due diligence phase may tend to use a team approach.  Everyone dumps all their electronic files into the data room, including email transcripts, using some type of sensible folder structure (hopefully).
It’s then up to the user to dig through the files to locate what they need.  This can be an onerous task, costing everyone money in wasted time.

Organization of the mining data room is key

Comprehensive searchable document management systems such as Ansarada, Aconex, SharePoint, and others are available.  They can be pricey and will require a team mindset to function, organize, and catalog the information.  However a properly implemented system can make it easier to search for files, keywords, and the latest versions of files. “Properly implemented” means that the entire team takes time when putting information in to ensure it is properly tagged meta-data.  Its is not uncommon for such systems to become repositories for hundreds or thousands of different files.
When using a cloud-based data room or FTP site, try to select one that allows bulk downloading of documents rather than only allowing one file download at a time.
Some data rooms, for security and tracking purposes, require users to be online in order to open a document, even documents downloaded onto your computer.  This makes it difficult to work when one doesn’t have internet access (like on an airplane).
Some data rooms limit the cut & pasting ability from the documents.  This can make it difficult to prepare your own summary  report if you want to include pasted images from the documents.

Conclusion

The bottom line is that management of a mining data room is critically important, although I don’t know if there is any single magic solution.
Small mining companies may have tight budgets and a limited management team so organizing data properly isn’t high on the priority list.   I suggest to anyone organizing a data room, please take the time to properly set up the folder structure, develop a single bibliography of what files are in there, and assign a person to be familiar with the general contents of the data room.
Unless its a legal case involving lawyers, don’t just dump in everything. Avoid unnecessary data files or “work in progress” files that are not actually required by anyone.

Read More on the Subject

Another aspect of data rooms that can help make a due diligence taxing is the way the spreadsheet models are built.  Models can either be made simple and user friendly, or can be complex showing how clever the model creator is.   You can read some thoughts on this at the following link “Mine Financial Modelling – Please Think of Others“.
For more discussion on the topic of mining due diligence, another blog post discusses the help that a technical checklist can deliver.  There are many aspects of a mining project, from legal, social, to technical and a checklist helps to avoid missing things.  You can read more about the checklist on this at “Mining Due Diligence Checklist“. You can even request a free copy of my Excel checklist if interested.

 

Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Follow us on Twitter at @KJKLtd for updates and insights.
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Junior Miners – Get Your Own Independent Consultant

Date: May 12, 2015 Author: Ken Kuchling Comments: 1 Reply
PEA consultants
Over the past few years I have worked in different consulting roles; as an independent consultant; as a member of a large consulting team; and as owner’s representative managing consultants.   I have learned that there is a role for both the independent consultant and larger consulting firms.  Read on for more in this self-serving article.

Independents have a role

A previous blog (“9. Large Consulting Firms or Small Firms – Any Difference?”) discusses where large and small consultants fit into the overall picture.   Large technical teams are required where there are broader scopes of work, significant effort levels, and where multiple skills sets are needed.
Independent consultants are a different thing.  They are best suited for assisting the Owner directly, either independently or as part of an overall corporate advisory team.  Non-technical junior mining management teams should always have access to in-house engineering capability for brainstorming or technical direction.
Even if some of the management are technically oriented, having independent thought is valuable. The question is whether the engineer should be a cheerleader or a true independent observer.
Independent consultants will differentiate themselves from large engineering firms in several ways.
  • They don’t bring a lot of extra personnel onto a job.  They focus only on what is needed and can draw in other expertise when needed.
  • They can provide unbiased advice.  Larger firm sometimes have business development conflicts. The independent consultant does not have the motivation to win a feasibility study or EPCM contract.
  • A company can develop a long term working relationship with an independent consultant.  Everyone gets familiar with each other’s objectives and goals.  Large engineering firms can be revolving doors with people moving on to other firms.
  • Independents can work efficiently at a pace of their own choosing.  This can result in lower costs and faster deliverables.  I know many independent consultants will work evenings and weekends to meet client targets.
  • Independents can provide long term stability since they won’t have any employee turnover.  Personally I was involved for over 15 years with a mining operating in Suriname.  The expat staff at the mine site experienced significant turnover.  This was partly due to them being promised personal development relocations.  I ended up being the only constant for the mine site.  I knew the history and why things were done they way they were.  I even had copies of old study reports they could no longer find in their files on site.  I knew what was done previously, thereby avoiding re-inventing the wheel each time there was a new technical manager was brought in.

Consultants and Stocks Options

A point of discussion is whether the independent consultants should receive stock option compensation.  I have worked under both situations.
Awarding stock options might eliminate the “independent” nature of the relationship and hence negated the ability to sign off as an independent QP.  In some circumstances, the company may not require the independent consultant to be a QP since they mainly fulfill an advisory role.
Does one want independent advice, from someone who may not be a significant shareholder or option holder?
One advantage of awarding stock options is that the consultant may become more beholden to the project.  They feel it is their project too, rather than simply acting as an adviser.  They may have a longer term interest in being involved with the project and the company.
Conversely the company may prefer the consultant doesn’t have any direct ownership so that their advice can be viewed as being unbiased. Having a contrarian view of corporate plans is a good thing.
I feel that awarding stock options is a good way to foster long term commitment from the consultant. It can be easier for them to walk away without any such inducement.

Conclusion

The bottom line is that independent consultants have a role to play and should be part of all owner’s teams, whether be on the Board or on an Advisory Panel.   The independent consultants can be selected based on their technical specialization (i.e. exploration, resource modelling, mining, metallurgy, environmental) and provide valuable part time guidance to the company.
The caveat is to ensure that the consultant is technically capable.  I have seen instances where certain members of the advisory panel gave poor advice.  perhaps they weren’t that technically capable but simply friends with some of the management.  Unfortunately other advisors would see these limitations, but not say anything out of professional courtesy.
Lastly, decide whether the engineer should be an honest advisor or a cheerleader.  Companies should want to hear the truth.  If a 3rd party due diligence teams comes in, they will be looking for flaws in the project.  It would be in a company’s self interest to know what those flaws are before the due diligence teams finds them.
One of the things an advisor can help do is decide the study path the company should take.  To learn more about the 4 mining study types, you can check out this blog post “4 Mining Study Types (Concept to Feasibility)“.
Note: You can sign up for the KJK mailing list to get notified when new blogs are posted. Follow me on Twitter at @KJKLtd for updates and insights.
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Pit Wall Angles and Bench Widths – How Do They Relate?

Date: May 10, 2015 Author: Ken Kuchling Comments: 3 Replies
open pit slopes
The wall of an open pit wall will consist of a series of stacked benches.  Geotechnical engineers will normally provide the pit slope design criteria based on the inter-ramp angle (“IRA”) for various sectors around the pit.  The IRA represents the toe-to-toe slope angle, as shown in the diagram below.

Pit Slope Image for post

The inter-ramp angle can be created in many ways, depending on the bench height (“BH”), bench face angle, and the catch bench or berm width.  Different combinations of these can be used to develop the same inter-ramp angle.
Typically the bench face angle (“BFA”) will be dictated by the rock strength, the structural fabric, and whether controlled blasting is used (minimizing damage to the walls).   The BFA may vary around the pit or in different rock types, but it typically is in the range of 60° to 75°.

Open Pit Slope

The catch bench (“CB”) or berm is used to catch spalling rock and prevent it from rolling down the pit wall,  creating a safety hazard.
A rule of thumb is that the catch bench width should be according to the formula 4.5m + 0.2H, where H is the height of the bench.   This means the recommended catch bench width for a 5m high bench should be about 5.5m; for a 10m high bench it should be 6.5m; and for 15m high bench it should be 7.5 metres.
Double benching (or triple benching) is used where the inter-ramp slopes angles are steep enough that single benching would result in an overly flatten slope.
For example if the inter-ramp slope is 50° and the BFA is 70°, then the corresponding calculated catch bench width for a 5m high bench would be 2.4 metres.  However such a small catch bench would be ineffective in catching spalliing rock.
If one double benched (i.e. left a catch bench every 10m instead of every 5m), then the calculated catch bench width would be 4.8 metres.  If one triple benched (i.e. left a catch bench every 15m), then the recommended width would be 7.1 metres.  Hence triple benching would be suggested in this case, assuming the rock mass is of sufficient strength to sustain a 15m high face.
NOTE:  Due to changes with Google security protocols, the online calculators have been take offline until a resolution can be implemented. 
A simple interactive calculator (Bench Slope Calculator) has been prepared to show the relationship between all of these factors.  A screenshot of the calculator is shown below.  It allows one either to calculate the IRA given a set of bench height, BFA, and catch bench criteria; or calculate the catch bench width given the height, BFA, and IRA criteria.  The yellow shaded cells represent input cells.

Bench Slope Calculator Pic

Single Bench Height (BH):  this is the input height of a single operating bench.
No. of Benches between catch benches:   this is the input for single, double, or triple benching.
Total Height (TH):  this is the calculated total height (# of benches X single bench height)
Bench Face Angle (BFA):  this is the input bench face angle, in degrees
Catch bench (CB):  this is the width of the catch bench, either as an input or a calculated value.
Inter-Ramp Angle (IRA): this is the slope angle in degrees, either as a calculated value or an input.
When double or triple benching, sometimes a small 1-2m drill berm may be left between benches due to the inability of the drill to position itself against the pit wall.  The width of the drill berm can possibly be eliminated by drilling the entire double bench or using smaller drills.
Sometimes one may see the term “geotechnical berm”.   In some pit designs a large bench is introduced periodically, e.g. every 120m-180m in continous wall height, which acts as another measure to catch ravelling rock.

Conclusion

The bottom line is that the inter-ramp angle can be achieved in different ways depending on various components of the slope profile.  Safety is of the utmost importance and therefore the adequate sizing of the catch bench is important, as is the ability to access the benches and clean up the rubble buildup.  Double and triple benching maybe required in some circumstances to achieve the design wall angles yet maintain safety catch bench widths.
For those curious about how mine economics can be impacted by increasing the pit wall angle, a small study we did  indicated that going from 45 deg to 50 deg could reduce waste quantities by 15% This was equivalent to $50 million in savings.  To read more, follow this link.  “Steeper Pit Slopes Can Save Money“.
Note: If you would like to get notified when new blogs are posted, then sign up on the KJK mailing list on the website.  Follow us on Twitter at @KJKLtd for updates and insights.
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Financings – It Helps to Have a Credible Path Forward

Date: May 9, 2015 Author: Ken Kuchling Comments: 1 Reply
mine economics
Update: This blog was initially written in May 2015, however not much as changed to the end of 2018.
Let me say the obvious; the state of the junior mining market is not great these days.  The number of financings is down and it seems there are a lot of companies struggling to get their piece of the financing pie.   People mention to me that there actually is a fair bit of private equity funding available but only for the right projects.
I have heard from geologist colleagues that financing grass-roots exploration is still extremely difficult.  That is unless company management has had past successes or is well connected to the money scene.
I’m told that 43-101 resource estimates alone no longer generate much excitement.  For projects to be “on the radar” they need to be advanced to at least the PEA stage.  It seems that investors want some vision of what the project might eventually look like.
I have be made aware of more junior mining companies that are struggling for cash while others seemed to have no problem in getting at least some funding to continue their operations.  To me, the biggest differences between these two situations are;
  • If there is top notch management in place,
  • The type of project they had,
  • If their path forward and development plan made sense.

You don’t want to always change management

Management is what it is.  Companies attempt to bring on experienced people to the executive level or to the Board level.   Experienced management can hopefully establish if their project will have a high probability of success or if the project is going to be a hard sell.  This will provide guidance on whether to continue spending money on the project or look for a new project.
From my experience in undertaking due diligence, when a company is looking for financing it is important that  management have the capability to present an orderly, practical, and realistic path forward.  It is important to demonstrate where they will spend the money.
I have participated in due diligence meetings listening to management teams explain that they will have a resource estimate this year and be in production in two years.  Those around the table glance at one another, knowing that they will be lucky to have a feasibility study completed by that time and even more lucky to have their environmental permits in place.   This makes investors nervous.

Keep plans realistic and achievable

It does not help the perception of a management team (or the project itself) if the path forward is unrealistic and unattainable.  The exception being if the management team have done it before.   Similarly low-balling cost estimates and presenting great NPV’s will usually fool no one that has experience. It ultimately may do more harm to credibility than good.
The bottom line is that in order for a project (and the management team) to get serious attention from potential investors is to make sure there is a realistic view of the project itself and have a realistic path forward.
Even a good property can be tarnished by making the technical aspects look over-promotional rather than real.  Make sure the right technical people are involved in the entire process and that company management are listening to them.
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