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By M. Jawed

Coking coal reserves in India are distributed geographically in Giridih, Raniganj, East Bokaro & Jharia Coalfields (J.C.F.). 97% of prime coking coal in JCF coming through underground mines is credited to Bord & Pillar mining systems inspite of the fact that it results in heavy mining losses. The cost of mining in B & P mines has been much higher due to various factors. In this paper, O.R. model has been discussed with case study for optimizing the cost of production in operational underground mines. Also, a computer algorithm has been discussed using a schematic flowchart, which provides the trend of mining-losses 'in different mining, systems with changing design parameters and finally selects, the optimum mining system for undeveloped seams based on economic appraisal criteria.

Jan 1, 1989

By Glenn L. Krum

Inflation has received much attention due to its effect on capital budgeting, associated cost overruns, and declining real profits. This study focuses on the effects of inflation on the evaluation of a mining investment and the estimation of a mining project's revenues. The study indicates that the best method for estimating future returns is the fore- cast dollar scheme. In this scheme, the metal price was held constant, and the operating costs were "inflated" along a historical regression line. The conclusion was reached by comparing the "actual" performance of a 3000 tpd (tonnes per day) lead mine model with 'its estimated performance during four time periods (1950-1960, 1955-1965, 1960-1970, 1965-1975). The individual data files for each time period and estimating method (6 files by 4 time periods) were pro- cessed by a suite of cash flow computational and investment analysis sub- routines. The analysis presumed that the mine was part of a large corporation which could utilize the expensed, development and exploration costs and any investment tax credits, in the year that they were incurred.

Jan 1, 1979

By T. S. Golosinski

This article reviews current contract mining practices in Australia. Various types of contracts are reviewed, including partnering arrangements and alliances between the contractor and the mine owner. Applicability is also discussed of various types of contracts to specific mining situations, as is their effect on overall mine performance.

Jan 1, 1998

By R. Hemp

This paper describes work carried out to obtain a heat balance in the B3 shaft longwall stope at Blyvooruitzicht gold mine. Recordings were made of the temperature of the air and chilled water entering and leaving the section during three periods, August 1 September 1977, November 1 December 1977 and March 1978. These recordings, together with numerous other measurements were used to determine the rate at which heat was being removed from the section by the various fluids flowing through the section. The rate at which heat was entering the section was then calculated, by considering each source in turn. These two sets of figures made it possible to draw up a heat balance, and also obviously gave vital information on the magnitudes of the various heat sources and on the methods used to remove heat. In general reasonable heat balances were obtained, the errors being in the range -6 per cent to +22 per cent.

Jan 1, 1980

By R. J. Hickson

From 1993 through 1999, Cyprus Amax Minerals successfully completed eight major construction projects around the world. Six greenfield mines were brought into production, an ongoing operation was completely modernized and an environmental issue was appropriately remediated. The projects stretched over three continents: from arctic Russia to the Atacama Desert, from sea level to an elevation of 4,900 m (16,00Oft), from city suburbs to remote wilderness and from a low of US$130 million to more than US$ 1billion. The operations included open-pit and underground mines, mill and leach facilities and involved gold, copper, molybdenum and coal. The diversity of these projects inspired Cyprus Amax to create a "best-practices” project-management protocol to steer corporate expansion in the new millennium. This paper summarizes these best practices, while highlighting the project-management pirfalls to avoid.

Jan 1, 2000

By John A. Dearinger, Fred D. Wright, Robert C. Howell

INTRODUCTION The rock mechanics study of the shortwall mining system at Beth-Elkhorn corporation's Hendrix No. 22 Mine is being conducted under contract with the U.S. Bureau of Mines. The objective of the study is to obtain data on surface subsidence over a portion of the mined area, strata subsidence in the mined area, and underground stress changes and displacements in and near natural support elements of the mining system. This study is currently in progress, and only a portion of the results are being presented at this time. The Hendrix No. 22 Mine is located in the moderately rough mountainous terrain of Letcher County in eastern Kentucky. The nearest mine workings to the shortwall area are approximately 1,900 feet distant. The depth of cover over the mined shortwall area varies from 770 feet at Panel 1 to 170 feet at Panel 5 (Figure 1). The strata in the shortwall area is summarized in the three core logs shown in Figure 2. Hole no. 2 is located in approximately the center of the mined shortwall area (Panel 3, Line C, Figure 1). The coal seam in the shortwall area is approximately 4 feet thick and horizontal, although one major ‘roll’ intersects all panels.

Jan 1, 1977

By I. Iwasaki, K. A. Smith, X. Cheng

The reaction mechanism for the cathodic decomposition of pyrrhotite in deoxygenated solutions at natural, near neutral pH levels was studied using potential and cyclic voltammetric measurements. Reaction products on the pyrrhotite surfaces were examined by Auger Electron Spectroscopy (AES), by X-ray photoelectron spectroscopy (XPS) and by analyzing the voltammograms for the electron balance of the reactions. Surface properties of the pyrrhotite/solution interface were characterized using an ac impedance technique. The parameters of an equivalent circuit were determined by the nonlinear least-squares fit (NLLSF) technique. The effect of cathodic polarization on floatability was investigated by performing microflotation tests. Possible implications to the flotation separation of chalcopyrite-pyrrhotite ores are discussed.

Jan 1, 1995

By J. M. Dean, R. L. Grayson, R. D. Begley, G. L. Winn

Evidence has accumulated indicating that cultural change toward safer workplace behaviors is beginning to occur systematically in the coal industry. Through a range of programmatic mining company successes, enforcement and litigative actions, economic responses to competition and integrated efforts by federal and state agencies, a broader participation of safety and training professionals is being achieved to address prioritized workplace problems at mines. Small steps in workplace-related improvements have been realized already, but the trends in industry safety statistics, coupled with focused programmatic initiatives, indicate that more definitive and systematic steps are occurring to improve safe behavior in the workplace routinely.

Jan 1, 1998

By S. Chander

Neutralization of acidity by addition of alkaline materials is a commonly used method to treat acid mine drainage. However, this procedure requires large amounts of reagents based on acid-base accounting. The potential use of organic additives in preventing or ameliorating acid mine drainage was investigated in this research. The tests were conducted in weathering columns using refuse samples from a coal cleaning plant. Both cationic and anionic compounds were tested. For a comparison, tests were made in the presence of limestone and lime. The results show that some of the reagents substantially retarded the rate of oxidation whereas others even enhanced it. The suppression of the rate of pyrite oxidation was ascribed to surface chelation. Formation of surface compounds prevented the pyrite particles from further oxidation. Such a treatment required only small quantities of reagents since the reaction was confined to the surface.

Jan 1, 1992

?Energy-related systems: wind, solar, electric are typically materials intensive. As new technologies are widely deployed, significant quantities of the elements required to manufacture them will be needed. However, many of these unfamiliar elements are not presently mined, refined or traded in large quantities, and, as a result, their availability might be constrained by many complex factors. A shortage of these ?energy-critical elements? could significantly inhibit the adoption of otherwise game-changing energy technologies. This, in turn, would limit the competitiveness of the U.S. industries and the domestic scientific enterprises and, eventually, diminish the quality of life in the US.? -Energy Critical Elements: Securing Materials for Emerging Technologies?- American Physical Society, 2011.

Jan 1, 2012

By R. J. Wesely, Corby G. Anderson, L. Ernest Krys, John B. Ackerman, A. D. Zunkel, Suzzann M. Nordwick

Processing of the refractory precious metal ore from the Sunshine Mine is done in a fully integrated hydrometallurgical facility. This operating philosophy began with the construction of an antimony plant during World War 11, and it continued with the construction of a silver-copper refinery in 1984. The antimony plant relies on an alkaline sulfide ambient pressure leach combined with antimony electrowinning and antimony compound production. This plant is the largest producer of antimony metal in the United States. The one-of-a-kind silver- copper refinery uses a nitrogen species catalyzed sulfuric acid pressure leach system. The plant contains innovative downstream silver recovery processes as well as copper solvent extraction and electrowinning. This paper presents the pertinent process chemistries and flow sheets for the two unique hydrometallurgical processing plants.

Jan 1, 1993

By Louis L. Sirois, Kwang S. Moon

The flotation mechanisms of various flotation machines are briefly reviewed. The counter current column flotation mechanism is described in more detail. The merits of counter current column flotation include; improved metallurgical performance in terms of grade and recovery, effective cleaning action in the long cleaning zone with a blanket of fresh water, smaller floor space required due to the vertical configuration of a flotation column, low capital, operational, and maintenance costs due to the absence of moving parts and finally, easier flotation control due to the simplified circuit. The results of column flotation studies on various minerals and coal at CANMET are discussed. Some of the industrial experiences with the Canadian flotation column on various sulphides, oxides and coal are also presented.

Jan 1, 1988

By John Clarke Holman

Industrial growth and survival in today's competitive world means both economic efficiency and technological superiority. Superior technology includes not only exploiting the best methodologies and techniques presently available, but also a continuous search for and development of, better ones. In practical terms this translates into an investment of substantial sums of money. Of course, even a relatively small investment will not be justified if the fruits of the project cannot be secured to the investor and the inventor alike. There are at least three ways to protect new or improved technology. If the improvement reaches the height of an invention, "patenting" usually is the preferred mode of protection. If, however, the improvement is novel and valuable but does not satisfy the requirements of the patent laws, one may then consider "trade secret" agreements as a means of obtaining appropriate return for the investment made so long as the improvement is capable of being maintained in secret and cannot be "reverse engineered." If one develops a new and useful organism and seeks immediate protection from infringers, current thinking is that the copyright law may afford such protection simply by publishing the genetic code. Here is one instance where you may publish without perishing! This paper will endeavor to highlight the pros and cons of various legal mechanisms and their applicability to the frontiers of technology.

Jan 1, 1985

By U. E. Paakkinen

Progress in computer control of flotation circuits has developed parallel with advances in reliability of on-stream X-ray analysis (Cooper, 1976). Attainment of acceptable results with X-ray fluorescence analysis over the past ten years has led to application of computer control in more than 30 concentrators. Gains in applying flotation control also have given incentive to improving measurement and control devices for other essential functions in control systems. At the same time, advancing technology has made available computer systems having characteristics practical and economical for the physical environments of concentrators and ore processing plants. Benefits from flotation control have centered on increased efficiency in mineral separations, derived by stabilizing circuit operation subject to changing ore characteristics. The gains have been most evident in processing complex ores for multiple concentrate products. In many cases, particularly when coupled with grinding control, the economic results from on-line control have been substantial compared to investments in monitoring and control equipment.

Jan 1, 1979

By R. A. Jankowski, R. Gong, R. Bhaskar

The control of respirable coal dust in continuous mining sections involves careful analyses of the generation and transport of the dust, including airflow pattern analyses. Potential dust control devices must be evaluated based on their effect on both local dust transport and potential dust exposure of face personnel. The development of larger and more productive continuous miners increases the need for research on dust control and improvement of visibility in the face area. Two studies relating to underboom dust control are discussed. The first study involved the valuation of potential underboom dust control techniques to reduce operator exposure to dust and determining the relationship between the positioning of exhaust ventilation and the exposure of face personnel as a function of face and operating variables. The study involved full-scale laboratory experiments using a state- of-the-art data acquisition system. The second study related to the use of foam under a continuous miner boom and its effect on silica concentration and respirable dust. The foam study was performed in a coal mine. The laboratory studies involved the fabrication of a full-scale test facility and development of a computer based data acquisition system. This was followed by baseline data collection, smoke trace tests, detailed performance testing of various underboom dust control measures and data analyses. The underground foam test involved the design and installation of the foam generation and delivery system, testing, and data evaluation. The results of the studies are summarized in this paper.

Jan 1, 1991

By J. J. Kellar, W. M. Cross, J. D. Miller

Infrared spectroscopy has been one of the most useful experimental techniques for the analysis of surface reactions in flotation systems, including surface alteration and surfactant adsorption reactions. With the advent of Fourier transform infrared (FTIR) spectrometers, many low-energy throughput IR experimental techniques previously unused by flotation researchers have come into greater use. In particular, internal reflection spectroscopy (IRS) is the most often used technique for in-situ studies. To date, three IRS methods have been used for in-situ measurements. These techniques are evaluated for use in characterization of surface reactions in flotation systems. The method using mineral crystals as reactive internal reflection elements (IRE) is of particular interest because it allows surfactant adsorption densities to be calculated directly from in-situ spectral data in real time. Application of in-situ FTIR/IRS with reactive internal reflection elements will be demonstrated for collector adsorption reactions in each of the major flotation systems. The alumina (A1203)/sodium dodecylsulfate system is used as an example for insoluble oxide/silicate flotation, while the fluorite (CaF2)/oleate system serves as a paradigm for semisoluble salt flotation. For sulfide flotation, sphalerite (ZnS) is used as the reactive IRE with potassium amylxanthate and potassium ethylxanthate as collectors. In the case of soluble salt flotation, sylvite (KC1) is used as the IRE with n-octylamine as collector. Finally, the use of reactive IREs in the near-IR spectral region and in spectroelectrochemical research is discussed.

Jan 1, 1989

By Robert R. McDougal, Anne E. McCafferty, Bruce D. Smith

Magnetic, electromagnetic, and radiometric airborne survey data have been used in regional and local (drainage basin) scales. In a regional geoenvironmental assessment of the state of Montana, magnetic and radiometric data compiled from airborne surveys were used along with other digital geologic and geochemical data to prioritize mining districts for potential acid water generation. Probability ratio mapping was done in order to integrate the interpretation of many different digital data sets. On a more local scale, the Animas (CO) and Boulder Basin (MT) watersheds have been studied using helicopter geophysical surveys. The airborne geophysical surveys show many more structural features than the geologic maps. Combined interpretation of the geophysical data sets using the probability ratio method has resulted in identification of areas of alteration. Airborne radiometric data in the Boulder Basin area suggests that rocks with high potassium and thorium also have a high acid water buffering capacity.

Jan 1, 2000

By C. Douglas Lee

This case study describes the work done at the University of Arizona on the development of a computer mine model for an irregularly shaped and spotty ore deposit. The purpose of the work was to develop techniques for modeling any highly irregular deposit, for which the regular 3D fixed block model is not well suited. The deposit contained complex geology consisting of sedimentary beds that had been faulted, thrusted, and intruded by igneous rocks (see Fig. 1). The physical dimensions of the modeled ore body were 1067 m (3500 ft) along the N-S direction and 914 m (3000 ft) along the E-W direction. Topographic relief in the modeled area was approximately 274 m (900 ft). The highest grade of ore was found near the surface with mineralization extending down to approximately 152 m (500 ft) below. Using a fixed bench height of 12 m (40 ft), the model required 25 levels with the highest elevation being at 1286 m (4220 ft). Fig. 2 shows a cross section of the developed computer model of the ore deposit. The particular modeling approach selected for this deposit was the 3D irregular block model.* This meant that only the dimension of bench height was fixed at 12 m (40 ft). Irregular size blocks in the form of polygons were adopted in the model to describe the ore zones and geologic contacts. The following sections of this chapter describe some of the techniques used in modeling.

Jan 1, 1979

By Wayne W. Murdy

Since 1993, Newmont Mining has been growing through the development 'q of three major foreign mining operations with a fourth under construction. The first project, Yanacocha in Peru, began operating in October 1993. This occurred at a time when political and business risk in that country was considered high. In 1995, Newmont began operating the Muruntau joint venture in Uzbekistan. It is the first mining project of its kind in the Confederation of Independent States (CIS). In early 1996, Newmont started operating the Minahasa Mine in Indonesia. In early 1997, Newmont began construction of a $1.9-billion project in Indonesia. The company is also completing a feasibility study with its partner for the development of a gold operation in Mexico. All of these projects have been considered "risky" by most standards. Newmont has been successful in all of them through risk mitigation programs. These programs include using strong and successful in-country partners, concentrating on developing a strong national workforce with minimal expatriate employees, using World Bank, European Bank for Reconstruction and Development (EBRD) and International Finance Corp. (IFC) financing and building and maintaining strong ties with host governments.

Jan 1, 1997

By David J. Kruse

The proper modeling of granular flow using discontinuum mechanics has the potential to be one of the most significant scientific advancements in the mining industry today. This paper will examine the status of discrete element technology, specifically focusing on current and future applications. The fundamentals of the Discrete Element Method (DEM) will be briefly introduced, as well as relevant design parameters. Various types of granular flow problems currently being solved using the DEM methodology will be presented. The results and potential benefits of these cases will also be discussed. All simulation results and figures used throughout this paper are from studies and designs preformed by the DEM group at Conveyor Dynamics, Inc. (CDI).

Jan 1, 2000