Open Pit Mine - Planning and Design-3rd Edition

Open Pit Mine - Planning and Design-3rd Edition

(Parte 2 de 7)

13.1 Application in prefeasibility work 990

References and bibliography 991 Review questions and exercises 992

Index 995

Preface to the 3rd Edition

The first edition of Open Pit Mine Planning and Design appeared in 1995. Volume 1, the "Fundamentals", consisted of six chapters

1. Mine Planning 2. Mining Revenues and Costs 3. Orebody Description 4. Geometrical Considerations 5. Pit Limits 6. Production Planning totaling 636 pages. Volume 2, the "CSMine Software Package" was written in support of the student- and engineer-friendly CSMine pit generation computer program included on a CD enclosed in a pocket inside the back cover. This volume, which contained six chapters and 200 pages, consisted of (1) a description of a small copper deposit in Arizona to be used for demonstrating and applying the mine planning and design principles, (2) the CSMine tutorial, (3) the CSMine user's manual, and (4) the VarioC tutorial, user's manual and reference guide. The VarioC microcomputer program, also included on the CD, was to be used for the statistical analysis of the drill hole data, calculation of experimental variograms, and interactive modeling involving the variogram. The main purpose of the CSMine software was as a learning tool. Students could learn to run it in a very short time and they could then focus on the pit design principles rather than on the details of the program. CSMine could handle 10,0 blocks which was sufficient to run relatively small problems.

We were very pleased with the response received and it became quite clear that a second edition was in order. In Volume 1, Chapters 1 and 3 through 6 remained largely the same but the reference lists were updated. The costs and prices included in Chapter 2 "Mining Costs and Revenues" were updated. Two new chapters were added to Volume 1:

7. Reporting of Mineral Resources and Ore Reserves 8. Responsible Mining To facilitate the use of this book in the classroom, review questions and exercises were added at the end of Chapters 1 through 8. The "answers" were not, however, provided. There were several reasons for this. First, most of the answers could be found by the careful reading, and perhaps re-reading, of the text material. Secondly, for practicing mining engineers, the answers to the opportunities offered by their operations are seldom provided in advance. The fact that the answers were not given should help introduce the student to the real world of mining problem solving. Finally, for those students using the book under the guidance of a professor, some of the questions will offer discussion possibilities. There is no single "right" answer for some of the included exercises.

xv vin Open pit mine planning and design: Fundamentals

In Volume 2, the CSMine software included in the first edition was written for the

DOS operating system which was current at that time. Although the original program does work in the Windows environment, it is not optimum. Furthermore, with the major advances in computer power that occurred during the intervening ten-year period, many improvements could be incorporated. Of prime importance, however, was to retain the user friendliness of the original CSMine. Its capabilities were expanded to be able to involve 30,0 blocks.

A total of eight drill hole data sets involving three iron properties, two gold properties and three copper properties were included on the distribution CD. Each of these properties was described in some detail. It was intended that, when used in conjunction with the CSMine software, these data sets might form the basis for capstone surface mine designs. It has been the experience of the authors when teaching capstone design courses that a significant problem for the student is obtaining a good drillhole data set. Hopefully the inclusion of these data sets has been of some help in this regard.

The second edition was also well received and the time arrived to address the improvements to be included in this, the 3rd edition. The structure and fundamentals have withstood the passage of time and have been retained. The two-volume presentation has also been maintained.

However, for those of you familiar with the earlier editions, you will quickly notice one major change. A new author, in the form of Randy Martin, has joined the team of Bill Hustrulid and Mark Kuchta in preparing this new offering. Randy is the "Mother and Father" of the very engineer-friendly and widely used MicroMODEL open pit mine design software. As part of the 3rd edition, he has prepared an "academic" version of his software package. It has all of the features of his commercial version but is limited in application to six data sets:

o Ariz_Cu: the same copper deposit used with CSMine (36,0 blocks)

• Andina_Cu: a copper deposit from central Chile (1,547,0 blocks) o Azul: a gold deposit from central Chile (668,150 blocks)

• MMdemo: a gold deposit in Nevada (359,040 blocks) o Norte_Cu: a copper deposit in northern Chile (3,460,800 blocks) o SeamDemo: a thermal coal deposit in New Mexico (90,630 blocks).

Our intention has been to expose the student to more realistic applications once the fundamentals have been learned via the CSMine software (30,0 block limitation). The MicroMODEL V8.1 Academic version software is included on the CD together with the 6 data sets. The accompanying tutorial has been added as Chapter 16. Our idea is that the student will begin their computer-aided open pit mine design experience using CSMine and the Ariz_Cu data set and then progress to applying MicroMODEL to the same set with help from the tutorial.

The new chapter makeup of Volume 2 is 14. The CSMine Tutorial 15. CSMine User's Guide 16. The MicroMODEL V8.1 Mine Design Software 17. Orebody Case Examples Volume 1, "Fundamentals", has also experienced some noticeable changes. Chapters 1 and 3 through 8 have been retained basically as presented in the second edition. The prices and costs provided in Chapter 2 have been revised to reflect those appropriate for today (2012). The reference list included at the end of each chapter has been revised. In the earlier

Preface to the 3rd Edition xvn editions, no real discussion of the basic unit operations was included. This has now been corrected with the addition of:

9. Blasting 10. Rotary Drilling 1. Shovel Loading 12. Truck Haulage

13. Equipment Availability and Utilization

Each chapter has a set of "Review Questions and Exercises".

The authors would like to acknowledge the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) for permission to include their 'Estimation of Mineral Resources and Mineral Reserves: Best Practices Guidelines' in Chapter 7. The Australasian Institute of Mining and Metallurgy (AusIMM) was very kind to permit our inclusion of the 'JORC- 2004 Code' in Chapter 7. The current commodity prices were kindly supplied by Piatt's Metals Week, the Metal Bulletin, Minerals Price Watch, and Skillings Mining Review. The Engineering News-Record graciously allowed the inclusion of their cost indexes. The CMJ Mining Sourcebook, Equipment Watch (a Penton Media Brand), and InfoMine USA provided updated costs. Thomas Martin kindly permitted the inclusion of materials from the book "Surface Mining Equipment". The authors drew very heavily on the statistics carefully compiled by the U.S. Department of Labor, the U.S. Bureau of Labor Statistics, and the U.S. Geological Survey. Mining equipment suppliers Atlas Copco, Sandvik Mining, Komatsu America Corporation, Terex Inc., Joy Global (P&H), Siemens Industry, Inc., and Varel International have graciously provided us with materials for inclusion in the 3rd edition. Ms. Jane Olivier, Publications Manager, Society for Mining, Metallurgy and Exploration (SME) has graciously allowed inclusion of materials from the 3rd edition, Mining Engineering Handbook. Otto Schumacher performed a very thorough review of the materials included in chapters 9 through 13. Last, but not least, Ms. Arlene Chafe provided us access to the publications of the International Society of Explosive Engineers (ISEE).

The drill hole sets included in Chapter 17 were kindly supplied by Kennecott Barneys

Canyon mine, Newmont Mining Corporation, Minnesota Department of Revenue, Minnesota Division of Minerals (lronton Office), Geneva Steel and Codelco.

Finally, we would like to thank those of you who bought the first and second editions of this book and have provided useful suggestions for improvement.

The result is what you now hold in your hands. We hope that you will find some things of value. In spite of the changes that have taken place in the content of the book over the years, our basic philosophy has remained the same - to produce a book which will form an important instrument in the process of learning/teaching about the engineering principles and application of them involved in the design of open pit mines.

Another important "consistency" with this 3rd edition is the inclusion of the Bingham Pit on the cover. Obviously the pit has also changed over the years but this proud lady which was first mined as an open pit in 1906 is still a remarkable beauty! Kennecott Utah Copper generously provided the beautiful photo of their Bingham Canyon mine for use on the cover.

Important Notice - Please Read

This book has been primarily written for use as a textbook by students studying mining engineering, in general, and surface mining, in particular. The focus has been on presenting the concepts and principles involved in a logical and easily understood way. In spite of great vin Open pit mine planning and design: Fundamentals efforts made to avoid the introduction of mistakes both in understanding and presentation, they may have been inadvertently/unintentionally introduced. The authors would be pleased if you, the reader, would bring such mistakes to their attention so that they may be corrected in subsequent editions.

Neither the authors nor the publisher shall, in any event, be liable for any damages or expenses, including consequential damages and expenses, resulting from the use of the information, methods, or products described in this textbook. Judgments made regarding the suitability of the techniques, procedures, methods, equations, etc. for any particular application are the responsibility of the user, and the user alone. It must be recognized that there is still a great deal of 'art' in successful mining and hence careful evaluation and testing remains an important part of technique and equipment selection at any particular mine.

About the Authors

William Hustrulid studied Minerals Engineering at the University of Minnesota. After obtaining his Ph.D. degree in 1968, his career has included responsible roles in both mining academia and in the mining business itself. He has served as Professor of Mining Engineering at the University of Utah and at the Colorado School of Mines and as a Guest Professor at the Technical University in Lulea, Sweden. In addition, he has held mining R&D positions for companies in the USA, Sweden, and the former Republic of Zaire. He is a Member of the U.S. National Academy of Engineering (NAE) and a Foreign Member of the Swedish Royal Academy of Engineering Sciences (IVA). He currently holds the rank of Professor Emeritus at the University of Utah and manages Hustrulid Mining Services in Spokane, Washington.

Mark Kuchta studied Mining Engineering at the Colorado School of Mines and received his Ph.D. degree from the Technical University in Lulea, Sweden. He has had a wide-ranging career in the mining business. This has included working as a contract miner in the uranium mines of western Colorado and 10 years of experience in various positions with LKAB in northern Sweden. At present, Mark is an Associate Professor of Mining Engineering at the Colorado School of Mines. He is actively involved in the education of future mining engineers at both undergraduate and graduate levels and conducts a very active research program. His professional interests include the use of high-pressure wateijets for rock scaling applications in underground mines, strategic mine planning, advanced mine production scheduling and the development of user-friendly mine software.

Randall K. "Randy" Martin studied Metallurgical Engineering at the Colorado School of Mines and later received a Master of Science in Mineral Economics from the Colorado School of Mines. He has over thirty years of experience as a geologic modeler and mine planner, having worked for Amax Mining, Pincock, Allen & Holt, and Tetratech. Currently he serves as President of R.K. Martin and Associates, Inc. His company performs consulting services, and also markets and supports a variety of software packages which are used in the mining industry. He is the principal author of the MicroMODEL® software included with this textbook.

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CHAPTER 1 Mine planning


1.1.1 The meaning of ore

One of the first things discussed in an Introduction to Mining course and one which students must commit to memory is the definition of 'ore'. One of the more common definitions (USBM, 1967) is given below:

Ore: A metalliferous mineral, or an aggregate of metalliferous minerals, more or less mixed with gangue which from the standpoint of the miner can be mined at a profit or, from the standpoint of a metallurgist can be treated at a profit.

This standard definition is consistent with the custom of dividing mineral deposits into two groups: metallic (ore) and non-metallic. Over the years, the usage of the word 'ore' has been expanded by many to include non-metallics as well. The definition of ore suggested by Banfield (1972) would appear to be more in keeping with the general present day usage.

Ore: A natural aggregate of one or more solid minerals which can be mined, or from which one or more mineral products can be extracted, at a profit.

In this book the following, somewhat simplified, definition will be used: Ore: A natural aggregation of one or more solid minerals that can be mined, processed and sold at a profit.

Although definitions are important to know, it is even more important to know what they mean. To prevent the reader from simply transferring this definition directly to memory without being first processed by the brain, tire 'meaning' of ore will be expanded upon.

The key concept is 'extraction leading to a profit'. For engineers, profits can be expressed in simple equation form as

Profits = Revenues — Costs (1.1)

The revenue portion of the equation can be written as

Revenues = Material sold (units) x Price/unit (1.2)

The costs can be similarly expressed as

Costs = Material sold (units) x Cost/unit (1.3)

Combining the equations yields Profits = Material sold (units) x (Price/unit — Cost/unit) (1.4)

2 Open pit initie planning and design: Fundamentals

As has been the case since the early Phoenician traders, the minerals used by modern man come from deposits scattered around the globe. The price received is more and more being set by world wide supply and demand. Thus, the price component in the equation is largely determined by others. Where the mining engineer can and does enter is in doing something about the unit costs. Although the development of new technology at your property is one answer, new technology easily and quickly spreads around the world and soon all operations have the 'new' technology. Hence to remain profitable over the long term, the mining engineer must continually examine and assess smarter and better site specific ways for reducing costs at the operation. This is done through a better understanding of the deposit itself and the tools/techniques employed or employable in the extraction process. Cost containment/reduction through efficient, safe and environmentally responsive mining practices is serious business today and will be even more important in the future with increasing mining depths and ever more stringent regulations. A failure to keep up is reflected quite simply by the profit equation as

(Parte 2 de 7)