Other users include banks and financial institutions with specialist mining industry expertise, minerals industry research businesses, government organizations and labor unions.

You can see a listing of minecost subscribers here.

How reliable are the models?
The models are based on the US Bureau of Mines' Cost Estimation System published in paper form in 1987 and the Bureau's Lotus spreadsheet version of CES developed in 1992 (which is available for purchase on CD-ROM). You can read more about CES by going to the "models" link from "What We Do" on the home page.

We have put a lot of time into updating the routines and re-indexing them to take into account changes in productivity and input costs. The models have also been checked against current mine operating cost estimates prepared by professional cost estimators for a wide range of hypothetical underground and surface operations, and against real mines where costs are disclosed by the operators. Provided the engineering input data is good, the models can produce results within the +/- 10% range expected for a scoping or pre-feasibility study. But usually there are gaps, which is why we offer credits to site users who point out our misconceptions and mistakes.

The model results are audited by having them report the levels of consumables such as diesel fuel, electricity, reagents, explosives, grinding media and so on implied by the cost estimates as well as required labor numbers. This information is always set out in the Flowsheet section of the model. It allows modelled consumables usage to be compared with known or reported fuel and power consumption levels and modelled labor requirements with reported manning levels.

But a model is just a model. In many cases we just do not have complete data for an operation; unexpected ore problems and metallurgical difficulties may not necessarily be captured in a model. But in most cases these problems will be reflected in recovery rates and ore dilution, which should show up in the model results. That's why we offer download credits to site users who alert us to these problems. Our refund policy, the peer review process and feedback from analysts using this site are the best assurance that we are getting it reasonably right.

When it comes to off-site costs such as concentrate shipping and smelting, our estimates become more rubbery. We do not estimate operating costs at smelters and refineries, so we use custom smelting charges calculated according to standard smelter contract terms. These determine the percentage of metal paid in concentrate together with credits for precious metals and other valuable products, less applicable penalties.

Mines that ship to smelters owned by the mine operator clearly do not pay custom TC/RCs and in these cases we may use something other than toll TC/RCs. If we do this then we say so in the Notes section of the model.

Where do you get the data?
Since the models are based on engineering concepts and an accurate understanding of the mine flowsheet, we use technical papers published in the major mining engineering journals and conference proceedings. For production data we use company reports and documents filed with the SEC and other regulatory authorities.

In the interests of model transparency, we list all references used to construct the models in the Notes and References section of each model. An example of this can be seem in the sample model of the Grasberg mine. You can also download the User's Guide to minecost.com Models which is an annotated version of the model with definitions and explanations of each line item.

We also get useful feedback from website users which we incorporate into the models, but for privacy reasons we do not disclose the names of the feedback suppliers.

How can you guarantee model accuracy to +/-10%?
We don't. No-one can. But we do treat the +/- 10% variation as an achievable target for mines where we have good data and for mines where we get good feedback. So it's really up to all site users to help us achieve the magic +/- 10%. That's why we offer the incentive credits.

Naturally we don't expect users to disclose proprietary information about their own operations - but users often have useful insights into operations run by the competition and are happy to share them with us.

Why don't some models have formulas?
Only the "hard-wired" models, such as the sample Grasberg model, do not have formulas. The editable versions of the models do contain formulas to give users complete control over mining and milling rates, milling and concentrate grades, production rates, input costs and exchange rates, product prices, treatment and refining charges, offsite shipping and other offsite costs, plus labour productivity and consumables usage rates. Users can also select which products should be credited as byproducts and which should be co- or main products.

An editable version of the Grasberg model is available free to registered users to play with. The current version has been developed on the basis of feedback from users, and is used to create editable versions of the models for most of the posted mines. Editable models cost more, but we maintain the hard-wired models at round half price.

Remember that you can always upgrade from the cheaper model to the editable version for just the price difference if you do it within 30 days of the initial download.

Registered minecost.com subscribers can also download our User's Guide to minecost.com Models which is an annotated version of a generic model showing all spreadsheet references and formulas with explanations of how they work. This allows registered subscribers to understand just how the models work and exactly what is included in each line item, as well as seeing just how much effort goes into creating the models in the first place.

How do I run your model using my assumptions?
No problem. Download the model of choice and see where you might like to change any of the operating assumptions (these are shown in the Opcost and Flowsheet sections. Email us with your revisions and we will re-model the operation accordingly and return it to you. The cost of re-modelling an operation according to a requested specification is free unless the re-run involves major modifications to the flowsheet. Turnaround time is a couple of days.

If you want to fiddle with various assumptions and test different scenarios, then you should really download the editable model. This will allow you to change just about anything you want.

What is your definition of cash operating costs?
We follow the Gold Institute definition of cash operating costs as adopted by most North American gold producers in 1996. These are:

Direct mining expense
Smelting, refining and transport costs
Byproduct credits
Other
-------------------------
Cash Operating Costs


Royalties (not-profit based)
Production taxes
--------------------
Total Cash Costs


Depreciation
Depletion & Amortization
Reclamation & mine closure
--------------------------------
Total Production Costs

Our models calculate Total Cash Costs only. They do not include depreciation, reclamation, head office expense, selling expense and financing charges. Working capital is not an operating cost.
Cash costs are shown in dollars per day, dollars per ton of ore milled, and in cents per pound of metal paid.

A more formal presentation of cash flows is contained in the DCF sheet. This calculates net cash flow after capital expenditure, working capital and notional tax paid in order to estimate net present values at a range of useful discount rates. In the Editable models users can of course change the capex, working capital and tax assumptions.

How do the models adjust for inflation?
All historical years are shown in nominal or "dollars of the day" terms. Numbers for the current year and all future years are in real or "constant dollar" terms, referenced to the most recent complete year. This means that the numbers for this year and any future years are expressed in latest current year dollars. Prior years (eg 2000) are expressed in historical dollars (eg 2000 dollars). Input costs are adjusted for changes in the relevant cost index, as shown at the top of the Flowsheet section.

In the Editable models, you can change the cost bases for inputs such as labor, fuel and power simply by adjusting the input price escalators in the Edit section of the model so that actual labor, fuel and power costs as shown in the Flowsheet section of the model are consistent with the numbers you want.

Are all the models in US dollars?
Yes! All models use US dollar prices and costs. Models for foreign operations have all their prices and costs converted to US dollar equivalents at the exchange rates shown in the Flowsheet and Revenues sections of the models.

What years do the models cover?
Where possible, we model all years from 2000 (1991 for many of the older models) to the current year plus two, extendible to 2020 in the editable models. This means that years 2000 to 2011 are historical years and are based on reported production numbers. Years 2012 to 2015 (depending on the most recent update) are based on estimated production, incorporating known expansions and/or reductions. Input costs and prices are projected on a constant dollar basis from the latest complete year. Years, of course, are calendar years. On the rare occasion when we are unable to use calendar years we flag this in the Notes & References section of the model. Naturally price and other time-related variables are adjusted to be consistent with the estimation period.

Editable models can be extended out (mostly) to at least 2020 simply by copying the last column in each worksheet to the right. Each year after 2012 will reflect the input assumptions for 2012 unless you change them - which you can. It is just that two or three years out is as far as we can sensibly forecast production rates. And leaving out the future years saves a lot of server space and cuts download times.

How often are the models updated?
All of our models are constantly under review. As new production and other data come in and as we get feedback from site users, the models are re-estimated and posted back onto the site. At the very least, each model is re-estimated twice each year - once when we update input prices and cost indices, and again when actual production data becomes available. You can always check the date the model was last revised by clicking on the mine name on the "Download Mine Models".

Registered users are notified by monthly email bulletins of new models posted and model changes and revisions. If you have just downloaded a model which is then re-posted with changes, we let you know so you can download the revised model for free. The free update is generally available for 90 days after purchase. If we find a mistake, we invite users who have already downloaded the model to collect the corrected version for free.

The whole point of doing this via the internet is that models can be kept current and always available for download - unlike annual (if you are lucky) publications from the research organizations.

The date of the last substantial model revision is shown on the model download page that comes up after you have clicked on a mine name.

What about mines that are not on the list?
Our aim is to model all significant mines owned by the major listed mining companies. Mines owned by non-listed companies or nationalized companies (with some exceptions such as Codelco) are a second-order priority. It all depends on what people want. We also restrict ourselves to operations where we have a flowsheet and minimum dataset as we are not in the business of making up numbers.

This of course is the reason why we do not model Chinese mines, where the detailed information required for sensible modelling is just not available. People who claim they can "cost" Chines mines are bluffing.

But if you need an operation that is not posted on the list, contact us by email and we will see what we can do.

How do you calculate by-product credits?
Usually we credit 100% of all mine products to the cost of producing the main metal. But with many mines, two main products share costs and credits. In these cases we simply allocate onsite mining and milling joint costs across the two main products according to their net value in concentrate to the mine, and pay them their share of credits. Offsite realization costs such as shipping, smelting and refining are charged to the relevant metal in concentrate. The calculations involved in byproduct crediting are always set out in detail in the Opcost module under "Operating Cost Analysis", and there is a more detailed explanation of the process in the User's Guide to Minecost.com Models. Naturally we are happy to answer email questions on the subject.

In the Editable models, you can select which products should be credited or treated as a main or co-product.

What metals prices do you use?
Our normal procedure is to use annual average prices as reported on the London Metals Exchange for LME-traded metals and London market prices for gold and silver. If a company reports actual realized prices for its mines, then we will use realized prices. The same applies to TC/RCs, in that we will use published toll TC/RCs unless a company reports the TC/RCs actually paid, e.g. Freeport at Grasberg. Again, what we do in each case is stated in the Notes & References section of the model.

Can I see a sample of your mine cost models?
Yes indeed. Follow the free sample link from the home page and download a complete model with cost curves. Or go to the mines download page where any mine marked as being free is downloadable by anyone.

Note that we restrict the free download of the sample editable model and sample cost curve spreadsheets to registered users. And only registered users can download the free Users's Guide to minecost.com Models.

Can I download just the cost curves?
Downloadable cost curves for each industry are added to the website as we build up the models. At present, cost curves for the copper, lead, zinc, nickel, silver, PGM, molybdenum and the manganese and iron ore industries are available for download.

What you get is a set of Excel spreadsheets containing production and cost data for all the mines we have modelled in the industry, a routine that generates a cumulative cash cost curve chart and a routine that generates a nicely formatted table of production and cost data that you can print out. Naturally production rates and costs are identified for each mine on the cost curve. The spreadsheets come for years 2000 to 2013.
And since the spreadsheets are dynamic, you can change the data and even add new mines to the list as required. When you re-sort the data, cost curves and formatted tables are automatically generated. In fact the spreadsheets are so flexible that we restrict the free sample spreadsheets to registered subscribers.

Even better are the "premium" cost curves for all the above industries which contain cost breakdowns into mine, mill, royalties etc, offsite transport and treatment/refining, or alternatively into labor, energy, reagents and offsite costs. Premium cost curves come with charts and data tables showing costs after no byproduct credits, costs after 15% byproduct credits and costs after 100% byproduct credits. Premium cost curves are available for years 2008 to 2013.
All industry cost curves are accessible from the link at the top of the mines download and the data download pages.

What happens when I register?
To register, click on any Register link to see the terms and conditions for becoming a registered subscriber. Then go to and complete the registration form. Once the form has been processed, you will receive by email a user ID and password which allows you to download any of the mine models posted to the site and to access any subscriber-only areas. Registered subscribers can also download the free sample editable model, the User's Guide to minecost.com Models and sample cost curve spreadsheets.

Note that registration is free. There are no user charges or membership fees. Registered users pay only for models they download, at the prices stated for each model on the download lists. Mine model prices vary according to complexity, and range between $280 and $390 per mining operation. Naturally we reserve the right to increase or decrease the list price of the models. Editable models typically cost about double the price for "hard wired" models, but they come with formulas and allow you to change most operating variables, test different assumptions and perform sensitivity analyses. And if you have already bought a "hard-wired" model, you can always upgrade to the editable version of the same model for just the price difference.

Remember, the only charges are for model downloads.

Subscribers receive monthly email reports notifying them of new mines added to the download list, plus changes, revisions and updates to the mine models. This monthly email is also our method of keeping track of subscribers, so acceptance of the report is a condition of remaining subscribed. You can always cancel the monthly reports, but this will also cancel your user ID and password. However you can always re-register as required.

Two payment options are available. For corporate users, we simply invoice you monthly for model downloads you have made. For individuals who are unknown to us, we generally require submission of a valid credit card. Once the card has been approved by the card issuer, we charge the card account for model downloads as they are made. These will appear on your card statement. Note that all downloads (for either payment method) are confirmed by our sending you an independent email confirming the download. No charge or billing is made unless we have confirmed the download by email.

Credits are paid to users who point out our mistakes and to users who contribute data or other useful information about the operations we have modelled, and to users who submit data for operations we have not yet modelled. Credits are paid by allowing subscribers to download models for free, as explained below.

How does the credit policy work?
This site is a data exchange and we want to encourage two-way traffic. We therefore invite users to tell us when we get the models wrong. In fact, we will credit you with the full cost of any model download if you can demonstrate that our estimate of onsite cash operating cost per ton of ore milled (as stated in the summary section of the model) is more than ten percent out in any historic year. Awarded credits can be used to download any model currently posted on the site up the value of the credit, and unlike frequent flyer points, our credits never expire. Naturally you can accumulate credits to download the more expensive mine models. Even if you don't catch us out by more than 10%, we will award credits for your contribution, depending on its value. While it is up to us to decide what you get, you will find we are pretty reasonable. After all, we need user contributions and feedback to make the peer review process works. It is in everyone's interests to make the models as accurate as possible.

We also give credits for mine data contributions for operations not posted onto the site. If you have good technical information on a mine in or near production that you believe would be of interest to site users, email us with your proposal. If we accept your contribution, we will credit you with double the download cost for that mine when it goes up onto the list.

We also acknowledge that we can make mistakes and get things wrong. If we have to amend a model to correct a mistake, we notify users who have already downloaded that model and invite them to download the corrected model for free. If we update or revise a model to incorporate new production information or to make a revision that affects the result, we offer a free replacement model to users who have downloaded that model up to ninety days prior to the revision. This means that if you download a model and we change it for any reason within ninety days of your download, you will receive the corrected model for free. It's all part of the service.

Do I have to supply credit card details to register?
NO - only if you are an unincorporated private individual. Users employed by incorporated entities such as banks, stockbrokers, investment institutions, mining companies, mine suppliers etc., or government agencies do not need to submit credit card details. We simply bill them on a monthly basis.

Users from whom we do require credit card details supply their information to us on our secure registration form. To ensure transaction security, all information supplied on the registration form is encrypted using the Secure Sockets Layer protocol. SSL uses encryption keys of up to 128 characters long and is compatible with most browsers, including Netscape and Internet Explorer. As well as encrypting all transmitted information, SSL uses encrypted digital identification certificates issued by Verisign Corporation to guarantee that you are actually dealing with www.minecost.com and no-one else. Verisign issues digital IDs only after a thorough reference check and maintains a register of valid holders of digital IDs which is open to public inspection.

Credit card information supplied to minecost.com is never stored on line or on hard disks. Card details are used only once to establish the card's validity with the credit card issuer. Transactions are then processed according to standard mail/telephone/standing order procedures specified by the card issuer. On this point, mail/telephone/standing order merchant facilities are offered by American Express, Visa and Mastercard only to organizations of good standing.

All model downloads are independently confirmed by email before any claim is made against subscriber accounts.

Remember that most users are accepted on a "Bill my Company" basis and do not supply credit card details at all.

What happens when I click on a mine name from the mines page?
When you select a mine for download, you will see a page containing details of the selected mine and the files to be downloaded, the date the model was last updated, and our standard terms and conditions. This gives you the opportunity to confirm or decline the download. If you confirm that you want the model, you will be asked to supply your userid and password. When this is accepted, you will be sent a XXXX.ZIP file which is downloaded onto your computer. You then need to expand this into an XXXX.XLS file by clicking on the XXXX.ZIP file which should appear in the folder you downloaded the XXXX.ZIP file into. Sometimes people have trouble finding the XXXX.XLS file because it appears in a folder they were not expecting, usually because they forgot to tell the browser which folder to download to. If you can't see the XXXX.XLS file, you may need to look for it. If you have successfully downloaded and recovered the GRASBERG.XLS sample model, then you shouldn't have any trouble.

Within a couple of days you will receive an email from us confirming the download. This is done after manually inspecting the www.minecost.com log files to ensure that you have received the complete file. No charges are made prior to the confirmatory email.

The file I downloaded does not work in Excel
All Excel files on minecost.com are supplied in Excel 97. This ensures that they will run on any version of Excel sold since the late 1990s, including Office '97 and later updates.
Problems with running files downloaded off the minecost.com website are invariably because you forgot to unzip the file. All files downloaded from the minecost.com website are in self-extracting compressed binary form. We do this to save space on the minecost.com server and to minimise file download times. The file you receive is in XXX.ZIP form and you need to expand it to create a XXX.XLS file. Expansion is easy - just double click on the XXX.ZIP file and the XXX.XLS file will be automatically created. Open this file in Excel.

If you attempt to open XXX.ZIP in Excel you will get a message saying that XXX.ZIP is not an Excel file - and Excel is right - it isn't! So when you see this message you know that you are trying to open XXX.ZIP in Excel and not XXX.XLS.

Do you have student discounts?
Indeed we do - in fact, we will supply models for free to bona fide students. Students wanting free models should email us with their request. Note that we usually require the student's professor/class instructor to confirm the request.

Privacy Policy & Security Issues
Minecost.com user and subscriber information is never disclosed to third parties. Email address supplied to us are used only to send our monthly email updates. Email addresses are not disclosed or passed on to outside parties. Emails originated from minecost.com are in text form only, not HTML. This means they may be less fancy, but more important this also guarantees that you cannot receive viruses from the minecost.com email server.

All registration information transmitted to minecost.com is via a secure server using encryption. Never supply sensitive information to websites that do not have a secure server! Credit card numbers are not stored online or on computers that connect to the internet.

Models are charged for only after we have manually checked the minecost.com server logs to ensure that the correct userid and password were used to make the download, and that the complete file was transmitted to the user without error. Only then do we send out an email confirming the download and notifying the user that a charge will be made for the download. Read more about our privacy policy here.

Why Do I Get Monthly Emails and How Do I Stop Them
The monthly Subscriber Report not only keeps you informed of developments at minecost, but it also allows us to keep track of you in a non-intrusive way. After all, subscribers have open access to everything on the minecost website and we need to know when subscribers leave their current employment or otherwise disappear. If the monthly email to a subscriber bounces or is otherwise undeliverable, we will cancel that subscriber's user ID and password. So if you change your email address and want to remain subscribed to minecost, please make sure we have your new email address. If you change jobs or your contact details, just re-submit the registration form and we will amend your registration details.

If you do not wish to receive the regular Subscriber Report, just reply to the email with the word "unsubscribe" as the subject. Note that unsubscribing to the minecost Subscriber Report will also unsubscribe you to minecost and your user ID and password will be cancelled. But you can always re-register if you need something.

Copyright and Fair Usage
World Mine Cost Data Inc. retains intellectual property rights to all minecost models, cost curves and other software products downloadable from the minecost website. Fair usage rights pass to the purchasers of minecost products. These rights entitle users to retain minecost products for their own exclusive use for any purpose within their own organisations except for re-sale. Model data and information may be freely published by users in their own documents and reports. All we require is the usual acknowledgement of the source of the data.