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By W. A. Yuill

A process has been developed for increasing the grade of chalcopyrite concentrates from about 25 percent copper to about 60 percent copper. The concentrates are treated with two steps of autoclaving and then by flotation. Because of the lower associated weight, copper in the concentrates could be shipped and smelted at less cost than untreated concentrates. Use of the process can also increase overall yield from an orebody if a lower grade concentrate is sent to enrichment than would be sent to a smelter. Potential applications of the process would be for treating concentrates that must be transported a long distance for smelting or for treating concentrates so as to increase the capacity of a smelter.

Jan 1, 1984

By Frank McKinley

This paper discusses the basic requirements covering the area between the initial discovery of a deposit and a decision as to whether or not the deposit will support an economically sound mining venture. The procedure for gaining the necessary information and the sequence of steps is in .some respects parallel to gaining like information on deposits other than the sand type. For the sake of simplicity the stages and sequence are presented as follow: first, the initial reconnaissance drilling; second, the exploration drilling to permit initial ore body estimates; third, metallurgical testing; fourth, the estimate of plant and operating costs; and last, the economic balance. The objective of the reconnaissance drilling is to collect sufficient information to reach a decision as to the advisability of further exploration or the abandonment of the area. This initial phase will comprise, in addition to some drilling, a thorough reconnaissance of the area, a study of the best geological and topographic maps of the region, and a study of any literature available, all under the guidance of a geologist.

Jan 1, 1958

Mine planners must select a single pit for design with the knowledge that the grades on which this selection is made are uncertain. This uncertainty is often ignored through the use of deterministic models of grade. This makes the mine planner?s job simpler but does not necessarily lead to the ?correct? or ?best? selection. Grade uncertainty is typically modeled with conditional simulation, which generates multiple possible realizations of grade that are equally probable (or improbable). M ethods for incorporating grade uncertainty into mine planning to date have either been perceived as being too complicated, not accessible or too time-consuming. This paper proposes a simple and efficient modeling approach to incorporating conditional simulation into pit optimization, which would be able to be applied in currently commercially available software. An example for R esolute M ining Ltd.?s Syama gold project in M ali shows the range of ore, grade and value outcomes associated with generating pits through a variety of methods.

Jan 1, 2013

By J. Fox, C. Allen, A. Greth, K. Kocsis

"It is the duty of the mine operator to ensure the mine environment is healthy and safe for the mine workers. For deep and hot underground mines, this requires maintaining adequate working temperatures by means of mitigating the heat load generated by strata, auto-compression, mining equipment, explosives, ground water, and human metabolism. The heat load is best reduced by minimizing the amount of heat transferred to the mine air from these sources and through the use of efficient ventilation with effective cooling systems. The heat emitted by mining equipment and vehicles contribute a significant proportion to the combined heat load of an underground mine. This is especially a problem for diesel equipment due to the fact that besides heat, a large amount of water vapor is produced, which increases the humidity in the production workings. Diesel engines have proven advantageous in recent history due to their high power output and reliability. However, as mines continue to become more mechanized and deeper the climatic problems introduced by elevated heat generation will continue to rise. With that, the issue of heat generated by diesel equipment must be addressed. The economic alternative for diesel engine equipment fleets in underground mines is the electric engine. Technological advances in battery technology, increased mechanical output and improved reliability have made the electric engine significantly more competitive in comparison to diesel engines. Because electric engines do not utilize internal combustion, the heat produced by them is significantly less than of the diesel engines. Battery powered mining equipment likewise eliminate diesel particulate matter (DPM) produced by diesel engines. Utilizing battery electric equipment in underground mines provides many advantages, such as: (a) reduced heat load, (b) healthier and safer environment for the mine workers, and (c) reduced mine operating costs due to lower ventilation requirements. This paper will highlight the health and cost benefits of using battery/electric fleets versus diesel fleets in deep and hot underground mines. The study analyzes simulations produced from thermodynamic ventilation models. Early simulations show significant cost reductions in terms of net present value (NPV) when comparing the air volume requirements for battery/electric equipment versus diesel powered equipment for the same production rate. INTRODUCTION The competitiveness of the world mineral market demands that mine operators continue to increase production and decrease costs as commodity prices fluctuate in often unplanned directions. This has forced underground mines to operate at deeper depths and to become more mechanized to remain competitive. Because of these changes, ventilation challenges have continued to increase as the mines combat an enlarged influx of contaminants such as heat and diesel particulate matter (DPM)."

Jan 1, 2018

Geostatistical literature has been dealing with recoverable reserve estimation techniques for the last 30 years. There have been well established support correction techniques (Le. affine correction, indirect log-normal correction, etc.) to deal with volume -variance relationship globally in determining what will be the reserves above a cutoff grade during mining. Kriging has become the accepted technique in the mining industry for ore reserve estimation. Many large companies are using this method for gold and copper deposit modeling. In general, the estimates coming from kriging are smooth. The variances of the block grades estimated by kriging are often lower than the material that will be mined selectively. As a result, kriging tends to under estimate reserves at high cutoff grades and overestimates them in low cutoff grades. It is necessary to perform additional steps after kriging if the goal is to determine recoverable reserves at some cutoff and not the in situ resources. In the mining industry, it is becoming more and more common for the low grade heap leach projects to consider whether the higher grade portion of a deposit may be processed by a mill at higher profits. Similarly, a concentrator -refinery operations are implementing heap leach -SX-EW option for the lower grade portion of their deposit. These options are making it very critical to estimate the low and high end of the grade distributions more accurately. Ore reserve estimation is normally done by using widely spaced exploration data which has very small size support (Le. core samples). Selective mining is carried out on ore control that is based on closely spaced blasthole data normally averaged into larger polygons based on some cutoff grade. Estimated grades from exploration data need to reflect the variability of the grades of the selectively mined units if they are used without further adjustments to predict recoverable reserves.

Jan 1, 1997

"The National Mining Hall of Fame and Museum (NMHFM) announced the 2017 National Mining Hall of Fame inductees. This year’s inductees, selected by the National Mining Hall of Fame’s Board of Governors, represent exploration and extraction of new frontiers, environmental stewardship, leadership in formulating U.S. mineral policy, education, and research and development, including the use of computers in planning, designing and managing mineral industry operations. The contributions of these individuals have undoubtedly had a significant and lasting impact on the mineral and mining industry. These individuals were selected for being visionary leaders, innovators, authors, pioneers in corporate social responsibility, and long-standing advocates for the U.S. mining industry.Dr. Thomas V. Falkie, Leonard Harris, Dr. Vincent E. McKelvey, and Gordon R. Parker will join 236 other mining industry luminaries when formally inducted into the National Mining Hall of Fame on Sept. 23, 2017. The 30th Annual Induction Banquet and Ceremony will be held at the Pinnacle Club, Grand Hyatt Hotel in Denver, CO.2017 National Mining Hall of Fame inductees:Dr. Thomas V. Falkie — In a career spanning six decades, Falkie’s accomplishments in industry, academia, government and professional societies demonstrate a pattern of integrity and sustained excellence. His gravitas and management style left highly favorable impressions in every position he held. He was the chairman and president of Berwind Natural Resources Corp.; President of SME; President of the American Institute of Mining, Metallurgy and Petroleum Engineers; Director of the U.S. Bureau of Mines and head of the Department of Mineral Engineering at the Pennsylvania State University. He played major leadership roles in the American Mining Congress, National Coal Association, Mining and Metallurgical Society of America, and the National Mining Association. He served on the board of directors of Foote Minerals and Cyprus-Amax and was very active in the National Academy of Engineering, the SME Foundation and the National Mining Hall of Fame and Museum.Leonard Harris — A highly regarded metallurgist and business executive, Leonard (Len) Harris may be most remembered for the heart he has for the people whose lives were touched by his career. For more than six decades, Harris has been a true pioneer in corporate social responsibility, leading companies to understand that doing the right thing for the local people is also the best path to business success. After an early career in Australia and Ghana, Harris moved to Peru in 1955 to join Cerro de Pasco Corp., owner of several mines with one of the most complex metallurgical operations in the world. Harris was quickly promoted through multiple positions and was ultimately named director of metallurgy."

Jan 8, 2017

By Paul G. Mahoney

The original Radum aggregate plant, built by Henry Kaiser in 1931, is the oldest of the nearly 200 individual operations established by the Kaiser companies. Since that time it has been producing aggregate products primarily for the San Francisco Bay Area. Currently, and for many years, this plant has been listed as the Nation's No. One aggregate producer. Early this year a new $10,000,000 facility went on line replacing the old plant. Construction of the facilities was performed under the direction of Kaiser Engineers construction management teams. The existing plant continued to operate without interruption during the entire construction period.

Jan 1, 1970

By J. Kenneth Wittle

The DC Graphite Melter has been shown to be capable of processing radioactive waste materials. The process is characterized by its high temperature capability and operation in a closed system. From an environmental perspective, the control of emissions coupled with destruction for hazardous organic materials is mandatory. These same characteristics may be applicable to the minerals processing industry. Under normal operation, the system reaches temperatures for nominal operation of 1600°C, with an arc temperature in the order of 5000°C. The system temperature is determined by the melt temperature of the material being processed. In testing of a 750 lb/hour unit, temperatures of 2200°C were reached. Current focus is on finding waste treatment and metals recovery opportunities in the metals processing industry for his innovative technology.

Jan 1, 1999

By Richard J. Robbins

This paper is presented with particular reference to the findings of the OECD Advisory Conference on tunneling held last July in Washington D. C. A great deal has been said about the Conference in the past few months, but it may be appropriate to review briefly the background and objectives of the Conference to better understand how the mining community can relate its underground excavation problems to the results of the Conference. OBJECTIVES OF THE OECD CONFERENCE The world demand for tunneling (the term tunneling is used here loosely to include almost all forms of underground excavation) is expected to grow at an in- creasing rate. During the decade of the ?70's, the demand is expected to at least double by comparison with the previous decade. Much of this increase in demand will be due to the rapid growth of urbanization around the world. As urban populations grow larger and denser, the conservation of surface land and the quality of the environment become more important. This aspect of the increasing demand poses a difficult challenge to those who must plan and implement urban development.

Jan 1, 1970

By J. G. Wargo

Disseminated gold deposits are the object of major search and development efforts by many mining companies throughout the world. The invention of more advanced equipment for open pit mining and and use of heap leaching methods, taken together with favorable gold prices has led to rising profits in the gold mining industry.

Jan 1, 1988

By M. J. Virnig, G. A. Kordosky

Throughout time, the mining industry has been very successful in meeting the world's requirements for metals and materials while meeting the challenges of decreasing ore grades and increased emphasis on protection of the environment. This success has been due to the development and implementation of new technologies. A clear example of such a development over the past 25 years is the increasing use of leaching/solvent extraction/electrowinning for the recovery of copper from oxide and sulfide ores. The key to the successful introduction of this technology was the discovery and development of the hydroxyoxime liquid ion exchange reagents by General Mills Chemicals (now Henkel Corporation). An important role was also played by the close working relationships between General Mills Chemicals and Ranchers Exploration which resulted in startup of the first plant in 1968 and between General Mills Chemicals and Bagdad Copper which resulted in the startup of the second copper SX-EW plant in August of 1970. Following on the heels of the hydroxyoxime development came the commercialization of other new chelating reagents based on different chemical functionalities, i.e., beta-diketones, alkylated 8- hydroxyquinolines and sulfonamidoquinolines. This initial spurt of activity was then followed by a slowing of development in terms of new reagent functionalities. Activity has continued in terms of further optimization/improvement of existing reagent functionalities but the commercialization of new reagent functionalities has slackened. This observation reflects the fact that the development of new reagent functionalities for metal recovery has become increasingly more expensive such that the right combination of price and sales volume must exist in order to justify the investment required to bring a new reagent to the market place. Given the dependence of the mining industry on innovation to meet the needs of the future, one can ask how these new developments, particularly in new reagents, will occur. To arrive at an estimate of the costs involved in commercializing a new metal extractant functionality, particularly a chelating type functionality, a case study of the development of LIX ®* 34

Jan 1, 1994

By Z. Zhang, M. S. Gonzalez, M. de P. Bueno, P. Holopainen, S. Luukkanen

"Despite being a field of study that requires practical knowledge and experience, mining engineering education follows the same pattern in most mining universities around the world, consisting of theoretical courses and laboratory-based practical modules (Mischo, 2015). The possibility of having practical training in real mining conditions on actual mine sites or processing plants is limited, while the only contact that undergraduate students have with mining operations during their time of study is usually through shorttime internships or visits in the context of educational trips. Real integration between universities and the mining industry may be scarce, which does not help students to observe the actual processes and thus understand the whole picture of mining operations.Indirect practical training is now possible since that technology is shifting from mechanical to digital, and the use of virtual reality — in the context of Mining 4.0 — can provide additional experience to the learning process. However, virtual reality is limited to the visual impression and is also limited in actions (Binder et al., 2018). In any case, when there is not a proper pragmatic view of how the different disciplines link to each other, especially if there is a lack of communication, unfortunately the results could be seen at a later stage in the mines as a poor performance of professionals and workers.Another major challenge for educating specialists in the mining sector is that experimental mines suitable for practical education, where the skills and knowhow could be developed and/or enhanced, are rare worldwide. Such research and educational (R&E) facilities are practically former metal ore mines that have been transformed into experimental sites. Besides being limited in number, not all facilities of this kind serve both a research and educational purpose.An early example of asolely experimental mines is the Luossavaara-Kiirunavaara Mine site operated by LKAB in Sweden, where systematic research on rock mechanics and mining engineering was successfully carried out in the 1980s. As a result, the developed underground mining technology was applied in LKAB’s mines at a later stage. There have also been research mines within collieries such as the former Lake Macquarie Mine at New South Wales in Australia and the Zeche Tremonia Mine in Germany), but these are no longer in operation (Mischo, 2015)."

Oct 1, 2019

By R. Kalra

The current paper looks at evaluating the merits of large geared mills versus gearless driven mills by evaluating the following factors: The capability of currently available systems in terms of power and mill diameter Efficiency in terms of overall electrical power consumed vs mechanical output power Capital cost Running costs Cooling requirements in terms of air versus water cooling Installation and delivery time World?s largest geared drive ? 2x8500kW ? Wushan, China (operating) Among the many reasons that geared drives on large SAG mills are not favoured, is due to not having an efficient variable speed drive option (60 to 80% critical speed), which is required for process reasons. As technological advances have occurred quite rapidly in recent years, this paper uses the latest data in applying these comparisons and attempts to dispel some of the myths regarding Slip Energy Recovery (SER) and variable frequency drive technology on twin pinion drive systems. Early attempts to provide load sharing on twin pinion drives used primitive electronics which have since been developed to eliminate the problems encountered in earlier attempts. In particular, torque pulsations between the twin motors have been overcome using a higher number of devices (pulses) and better electronics. With successful operation of 2 x 6.5MW (Phu Kham, Laos) and three 2 x 7MW units under manufacture (Pascu Lama) and a further 40 projects worldwide, energy efficient Hyper Synchronous SER drives are now mature and ready for use on 2 X 10MW dual drive mills. Speed variation required is in the range of +/- 15% of synchronous motor speeds. VVVF drive packages from ABB and Siemens are also available for 2 x 10MW in low and high speed options. Dual hydraulic inching drives provide a much safer and convenient operation with the added advantage of locked charge detection.

Feb 27, 2013

By J. Mark Richardson

The use of an integrated software package to simulate and optimize the performance of mineral processing circuits is illustrated by three examples. Each represents application of the software and associated techniques to optimization of an existing plant. In the first example, a South-western U. S. copper company employs the method to simulate and improve performance in crushing, screening and SAG milling. A second copper producer evaluates equipment changes and flowsheet alternatives in a closed-circuit ball mill-cyclone operation. A Southeastern U. S. aluminum refinery optimizes performance of a dry milling and classification circuit for production of carbon particles used in anode casting. Graphical and tabular data describe the circuits simulated and the results achieved in each example.

Jan 1, 1990

By Earl M. Frizzell

This paper addresses considerations for the use of artificial support of pit walls in surface mines, a new project of the Bureau of Mines. Results to date indicate that a polymer-coated cable with embedded grit could provide good anchorage for stabilizing benches and highwalls, and an electronic method of recording discontinuities in the field is being reviewed and developed for application to mining. The objectives of the work in progress are to define the engineering parameters and evaluate the concepts for artificial supports in order to provide safe working environments when pit slopes are steepened to increase ore recovery and reduce overburden handling.

Jan 1, 1986

By R. E. Hucko

The goal of the U.S. Department of Energy (DOE) coal preparation R&D program is to develop technology to reduce the ash and sulfur contents of United States coals to levels such that the resultant product can be formulated into a high- quality solid or slurry fuel that could replace oil or natural gas in both new and retrofit applications. The Coal Preparation program is implemented by the Pittsburgh Energy Technology Center (PETC) and is conducted both in-house and by a cross section of industrial organizations, universities, and national laboratories.

Jan 1, 1986

By A. J. Basu

An overview of the evolution of computerized mine planning and design has been given, emphasizing the need for a knowledge-based system for planning and design of underground coal mines. An outline for the development methodology and procedure has been provided. Problem structuring guidelines have been used to incorporate intelligence and integration to the design modules. A skeletal model for a mine planning and design expert system has been prescribed, and the development process has been documented in detail. A feasibility prototype has been developed to test the structure of the skeletal model and to ensure completeness of the design process. The feasibility prototype development and its contribution toward proto typing has been addressed in this paper. At present, prototype development is underway. The prototype is expected to be avail-able for testing and implementation in early 1991.

Jan 1, 1991

As we are all well aware, the demand for coal is increasing very rapidly. This makes the coal industry one of great opportunity for both the miner and the-supplier. Up until the middle 1960's, the price of coal had been one of the most stable of all commodities for the proceeding fifty years. In somewhat oversimplified terms this was because the inflationary tendencies had been offset by improved mine techniques and more efficient, more productive, and more reliable equipment; but, in the last seven years the price of coal has doubled. It is not the intent of this paper to discuss the many reasons for this price increase, but to show how the cost of hauling coal can be sharply decreased with a new truck concept. Not long ago a mining executive stated that all haulage trucks now available are basically the same. They look the same; they cost about the same; they have the same engine, power train, and tires; and, they have about the same operating cost. Truck size has increased which has reduced the number of drivers, but the purchase price and maintenance and repair costs have increased proportionally. Pits must be widened and loading shovels enlarged, out, all this has not reduced the cost of moving coal. Another executive said that he saw no advantage in buying new trucks because his people now know how to maintain and operate the ones they presently have. They have all the right spare parts along with a good maintenance program. Most replaceable parts of the trucks now in operation have been replaced and improved at least once and the trucks are now running better than when they were new. Besides, the trucks are no pretty well written off.

Jan 1, 1972

By W. H. Davitt

One might ask why someone like myself, involved in the determination of taxes, should be speaking at a "cost engineering" session of a national engineering society. While it is true that taxes, especially income taxes, whether they be federal, state, or local, are not usually thought of as a "cost" of doing business, it is equally true that these tax costs do reduce the distributable profits just as much, as the cost of power, supplies, or labor. Therefore, the consideration given to taxes is often as important as that given to other costs. Hopefully yea will recognize that, within certain limits, taxes can be controlled to an economic advantage. That question may then lead to another question: What does the amount of taxes have to do with me? I'm an engineer or manager; not an accountant or a lawyer. If I may take a few minutes of your time, I might be able to present in a brief discussion some interesting facts that will provide the answers to those questions. My discussion will be directed mainly to Federal taxes. However, much of it will be applicable to state and local taxes, also.

Jan 1, 1973

By Jr. Wallace

This paper describes the importance of mine ventilation and air conditioning in the operation of a nuclear waste repository. It discusses the impact of ventilation on determining the number and size of shafts and access drifts to and within a repository horizon. The paper also describes the need to maintain separate ventilation systems for waste emplacement and construction operations. The requirement to have filtration capabilities for exhaust air from waste emplacement areas is discussed. Because radioactive high level waste will induce high temperatures in the emplacement drifts, the ability to cool an emplacement drift for re-entry requirements is important. The paper discusses strategies to cool an emplacement drift and the possibility of using continuous airflow to control temperatures in these drifts.

Jan 1, 1991