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By B. C. Litzinger

Minerações Brasileiras Reunidas S.A. - MBR is a brazilian iron ore mining company geared for the export market. It is controlled by Companhia Auxiliar de Empresas de Minerações - CAEMI through its subsidiary Empreendimentos Brasi leiros de Minerações - EBM which holds 51% in MBR and is formed by CAEMI, the six major japanese steelmills and five japanese trading companies, Universe Tankships, Inc., and Indústria e Comércio de Minérios S.A. - ICOMI. The remaining 49% of MBR's capital are held by St. John del Rey Mining Company, a subsidiary of The Hanna Mining Company. MBR iron ore reserves exceed 1.5 billion tons of high grade ore distributed in 36 deposits located in the so-called IRON QUADRANGLE in the State of Minas Gerais. The Aguas Claras Mine is the largest presently known and highest grade deposit owned by MBR. Other mines such as Pico, Mutuca and Jangada are in operation at a combined rate of production of about 2 to 2. 5 million tons per year. The project consists of mine, railroad and marine terminal (slide). The Aguas Claras deposit, which is located about six kilometers southeast of Belo Horizonte the Capital of Minas Gerais, was selected for initial development. The Sistema Regional Centro of the Rede Ferroviária Federal, through its 6th Division known as the "Central " is responsible for the transportation of MBR ore, and provided the necessary railway construction to connect Mine and Terminal. The Terminal is located on Guaiba Island near the entrance to Sepetiba Bay, at about 120 kilometers west of Rio de Janeiro.

Jan 1, 1974

By David A. Rice, Scott A. Shuey, William K. Tolley

The U.S. Bureau of Mines (USBM) is developing new dewatering technology to permit the recycling of iron values contained in wet steel plant sludges. In laboratory tests, Q-BOP fume sludge was dewatered to 12% moisture by displacing water with acetone in a plate-and-frame pressure filter. Acetone is reclaimed through distillation at lower cost than conventional thermal drying of the sludge. The projected additional energy requirement for acetone treatment of the sludge, including acetone recovery, is $5 to $7 per dry ton.

Jan 1, 1995

By P. Tanaskovic

This is presentation of a model which simplifies application of project management in control of the construction procedure of industrial units (mines, power stations etc). The model is made for further referrence of investors. The most demanding problem in large units is to find the best way of locating all activities within a network. The model uses term "line" (which refers to a construction unit) for a serie of activities which are to be sequentially executed (up to 1000 lines, each with 10-20 activities). The lines are coded in advance. Each line is described by a competent expert. Team of experts provide liason between lines on the basis of computer drawings. The method proved to be extremely effective. In order to provide smooth monitoring at all management levels, graphic documentation is given at 4 levels. The initial level is the third one, made based on input data (more than lo listings per one drawing). By condensation of activities along one line, another level is obtainable. Grouping of lines gives the first level (1-2 listing) for the highest management level. More detailed information is given for a limited (shorter) period at the forth level for the purposes of operational management. Each activity has three phases: prior to contracting, post contracting and accomplishment. All phases are presented at all levels, which enables investor to be continually well informed about construction advancement. Model is written in FORTRAN language. Programs comprise: maintenance of data base, calculation of time and costs and elaboration of graphic and other documentation.

Jan 1, 1986

By Harald Ulrik Sverdrup, Anna Hulda Olafsdottir

The long-term supply of nickel to society was assessed with theWORLD7 model for the global nickel cycle, using new estimates of nickel reserves and resources, indicating that the best estimate of the ultimately recoverable resources for nickel is in the range of 650–720 million ton. This is significantly larger than earlier estimates. The extractable amounts were stratified by extraction cost and ore grade in the model, making them extractable only after price increases and cost reductions. The model simulated extraction, supply, ore grades, and market prices. The assessment predicts future scarcity and supply problems after 2100 for nickel. The model reconstructs observed extraction, supply and market prices for the period 1850–2020, and is used to simulate development for the period 2020–2200. The quality of nickel ore has decreased significantly from 1850 to 2020 and will continue to do so in the future according to the simulated predictions from the WORLD7 model. For nickel, extraction rates are suggested to reach their maximum value in 2050, and that most primary nickel resources will have been exhausted by 2130. After 2100, the supply per capita for nickel will decline towards exhaustion if business-as-usual is continuing. This will be manifested as reduced supply and increased prices. The peak year can be delayed by a maximum of 100 years if recycling rates are improved significantly and long before scarcity is visible.

Jan 26, 2021

By John C. Brower

The purpose of this paper is to examine the Gays in which- the policies of the U.S. government, mining companies and third world countries affect each other with regard to the availability of minerals. The interaction involves U.S. policy towards the mining industry, the policies of the companies themselves, and the policies of third world countries towards the U.S. and multinational companies. It is assumed in this discussion that U.S. policy will continue to be to seek certain minerals from abroad rather than attempt to develop domestic sources for all its requirements. This would seem to make sense both from the standpoint of cost, and for preserving what domestic resources there are so as to maintain some degree of market leverage. In today's jargon, this means greater dependency on the "third world", which, for this discussion, includes virtually all the nations in Africa, South America and Asia. Concern for availability raises the important distinction between dependency and vulnerability, and as the Director of the Bureau of Mines has pointed out, the two are not the same. Dependency is not neccessarily a bad thing; it is vulnerability that counts (Norman, 1980)

Jan 1, 1982

By L. John Minnick

Extraction of crude ores and minerals inevitably produces various by-products either as a result of nonusable residues or as waste by-products from process operations. Thus for each 100 tons of coal extracted in a strip mine operation, one can expect to produce 25 tons, or more, of mine refuse. In addition, the amount of ash produced from the burning of coal will represent 10 to 20 percent of the weight of coal burned. With the advent of lime/limestone scrubbers now being installed on many power plants, an additional by-product is produced that in most instances is equal in volume to the sluiced fly ash. Statistics developed by the National Ash Association have indicated that sluiced waste from power plants in the United States currently exceeds 25 million tons per year (dry basis). Overall mineral industry statistics (copper mines, etc.) indicate better than 200 million tons per year. In the past it was general practice to send most of these waste materials to holding ponds or lagoons simply as a means of disposal or "throwaway" of unwanted by-products. Unfortunately modern society has reached a stage where these large quantities of waste materials are creating monumental environmental and economic problems that need urgent attention. Among these problems are concern for loss of future usable land, pollution of ground water, loss of potential mineral reserves, and loss of opportunities to recycle or use these by-products for the benefit of future generations. An example of the latter is the serious shortages of construction quality aggregates that can be replaced with some of the by-products produced from waste materials from the extractive and chemical industries.

Jan 1, 1975

By Bernard Scheiner

A number of wells were drilled at two phosphogypsum stacks, one at P-21 owned by IMC and the other at Agrico's South Pierce Stack. Each well was sampled, and composites representing 5-ft increments were leached with synthetic rainwater to determine the extent of metal and nonmetal migration. To simulate what was occurring in the stack, composite samples were placed in a column, so that the column represented the stack in miniature form. Leaching experiments showed that both metals and nonmetals moved down the column when water was added to the top of the column. Data obtained from P-21 showed that with time the concentration of metals and nonmetals reached equilibrium values. The concentration of Ca, SO4, F, Si, and PO4 were -600 ppm,~1,500 ppm, 32 ppm, 14 ppm, and 22 ppm, respectively. Column leaching of South Pierce material, representing 0 to 55 ft of stack, showed that after 355 in. of water, the stack was near equilibrium values down to the 33-ft level. With continued addition of water, the portion of the stack at equilibrium would continue to increase and eventually reach the values observed for P-21. The test showed that the sulfate concentration of the effluent from the stack would never reach the USEPA standard value of 250 ppm. During the leaching test, it was determined that the permeability of the phosphogypsum in the columns was 0.000103 cm/sec. This number was used in the modeling. The data obtained from the leaching experiments cast some doubt on the practice of entombment now being practiced for closure of phosphogypsum stacks. The data clearly shows that with time, the amount of material leaching from the stack is low in concentration, with only the calcium and sulfate at higher levels. When a stack is closed at an existing operating plant, allowing rainwater to fall on the stack and capturing the solution in the existing pond system would eliminate the need for covering the stack, since with time the closed stack would continue to leach and at some point reach the equilibrium values of the P-21 stack. Entombment means that the leachable material in the stack will always be there and will require monitoring forever. Allowing rainwater to decontaminate the stack may be the best environmental solution to the problem.

Jan 1, 1999

By R. L. Guerguerian

Hydrostatic trunnion bearings were recently provided on large Semi-Autogenous Grinding (SAG) mills driven by wraparound motors assembled on the head to shell flanges. A conventional SAG mill would have a ring gear driven through one or two pinions. The effects of the magnetic air gap forces from this new SAG mill drive arrangement on the performance of the bearing are discussed. A step-by-step systematic analytical de-sign of the hydrostatic trunnion bearing is presented, followed by a discussion of grinding mill erection requirements to conform with the design. A brief comparison with other bearing types and their response to the effects of magnetic air gap forces are also presented.

Jan 1, 1992

By R. W. Wittkopp

The Relief Canyon gold deposit is located approximately twenty- four kilometers east of the town of Lovelock in Northwestern Nevada. At Relief Canyon, the Late Triassic Grass Valley Formation has been thrust over the Late Triassic Natchez Pass Formation. The lower plate Natchez Pass Formation is composed of massive gray dolomitic limestone which is locally silty and sandy. The upper plate Grass Valley Formation is composed of shale, siltstone, argillite and quartzite. Gold mineralization at Relief Canyon occurs along the highly brecciated thrust contact between these two formations. Weak gold mineralization often occurs above the thrust in the Grass Valley Formation, however, most of the ore grade mineralization is present below the thrust in the brecciated Natchez Pass Formation or where the two formations are mixed as a result of movement along the thrust. Several types of gold mineralization have been recognized at Relief Canyon. A large amount of the ore is present as a jasperoid breccia, however, significant amounts of ore occur as a mixed breccia composed of upper plate rock, fresh limestone, clay and jasperoid breccia. Gold ore also occurs in a fresh limestone breccia which contains a large amount of clay. Below masses of jasperoid, jasperoid stringers containing gold extend into the fresh limestone. Gold mineralization at Relief Canyon appears to be truly disseminated and has the typically associated trace elements of arsenic, antimony, mercury and fluorine. The Relief Canyon deposit can be classified as a structurally controlled disseminated gold deposit. Other deposits that fit this classification are the Pinson and Dee gold mines.

Jan 1, 1984

By B. K. Mishra

Power draw of the mill has been accepted as an indicator of the performance of the mill, yet the problem of predicting power under a given set of mill operating conditions still remains to be solved. In the literature, this problem of predicting power is attributed to a lack of knowledge with regard to the motion of the charge. Here a DEM based model is used to analyze the motion of the charge. The resulting information is used to predict the power draw of the mill. A 16-ft diameter mill is simulated. A factorial design study of the variables-mill speed, lifter configuration and ball size distribution-as independent variables is taken up. The power draw as a response variable is analyzed to establish the best operating condition of the mill.

Jan 1, 1993

By J. T. Kline

This paper will present a review of the underground leaching of remnant copper mineralization left as a result of the block cave mining operation at the Lakeshore Mine in Casa Grande, Arizona.

Jan 1, 1985

By Turker Hudaverdi, Yasar Agan

This study tries to predict blast-induced flyrock using intelligent modelling techniques. Flyrock is a site-specific phenomenon. Design variables and rock properties highly influence flyrock throw distance. Site investigations were conducted in a sandstone quarry. Fundamental operational parameters, blast dimensions, bench face condition, and rock mass structure were monitored. Stepwise regression technique was applied for variable selection. Burden–hole diameter ratio, in situ block size, and powder factor were determined as the most significant parameters. Considering output of stepwise regression, artificial neural network, ANFIS, and Gaussian process regression techniques were applied to predict flyrock throw. A comprehensive validation was performed using twelve different performance indices. Pre-determination of input parameters supported development of successful soft computing applications. Rock block size was found to be an appropriate input variable for flyrock modelling. In addition to classical performance indices, standardized and symmetric accuracy metrics were quite useful in model validation process. The intelligent models predict flyrock range with an error less than 6 m. The mean percentage errors are lower than 10%. ANFIS seems to be the best model for flyrock prediction. The calculated mean absolute error is 5.36 for ANFIS model.

Nov 12, 2023

By A. E. Hall

The authors are to be commended for their attempt to provide a convenient piece of software for preliminary drum hoist specification. This field has received little attention in recent years and is eminently suited to calculation by computer. Unfortunately, there appears to be an error in the calculation of the required rope diameter. The 66-mm (2 5/8-in.) rope selected is oversized for this application. Wire rope weight and breaking strength are related to the rope diameter. For a round strand rope

Jan 1, 1988

By K. J. Ashley

Over the last six years I have been involved with the calculation of ore reserves and mine planning using various computer systems and soft- ware packages. This experience has given me a unique perspective from which to view the needs of the engineers and geologists whose job it is to produce geologic and mineable ore reserves. The purpose of this paper is to share that perspective with those who are in this field or are thinking of purchasing computer software to aid in these calculations. My first experience with computers in mining was the creation of a mini-computer based coal reserve and mine planning package written as part of my Easter's thesis. This package took about ten weeks to write, four weeks to document, and two weeks to install at the mine for which it was written. It did what it was designed to do, which was to emulate the hand procedure which had been used prior to its installation. The package was specific to its application which involved several small seams of coal being mined simultaneously and would have required major modification for it to be applied to a mine where, say, one thick seam was mined in two benches.

Jan 1, 1985

By James R. Walpole

Less than 100 years ago the first major federal regulatory agency, the Interstate Commerce Commission was established (in 1887), and since that time literally hundreds of other federal agencies have been created. The regulations set by these agencies tremendously affect the individual citizens of this country as well as U.S. institutions. A few examples of the myriad agencies established include the Food and Drug Administration. (1907), the Bureau of Mines (1910), the Federal Reserve System (1913), the Federal Trade Commission (1914), the Tennessee Valley Authority (1933), the Securities and Exchange Commission (1934), the National Labor Relations Board (1935), the Small Business Administration (1953), the Federal Maritime Commission (1961), the Equal Employment Opportunity Commission (1965), the Farm Credit Administration (1971), etc., etc. Eight years ago, on December 2, 1970, still another federal agency was established by the reorganization plan of President Nixon -- the Environmental Protection Agency (EPA). The Administrator of EPA was given authority to regulate certain activities affecting the environ-ment, which were formerly within the jurisdiction of the Department of Interior, the Department of Health, Education and Welfare, the Federal Radiation Council, the Atomic Energy Commission, the Department of Agriculture, etc. Within weeks after the formation of this Agency, Congress began to enact legislation which would be administered by EPA. Over the last eight years a considerable number of such laws have been passed, a few of which include: the Clean Air Act (1970), the Noise Control Act (1972), the Federal Water Pollution Control Act (1972), the Marine Protection, Research, and Sanctuaries Act (1972), the Federal Insecticide, Fungicide and Rodenticide Act (1973), the Safe Drinking Water Act (1974), the Toxic Substances Control Act (1976), the Resource Conservation and Recovery Act (1976), the Clean Air Act Amendments of 1977, etc. It may be helpful to review, in a summary fashion, the major provisions in some of these statutes, and accompanying regulations, as they relate to water quality control in the mining industry. The Safe Drinking Water Act and the Federal Water Pollution Control Act contain provisions to be examined, as well as the Resource Conservation and Recovery Act and the Toxic Substances Control Act. One other law, the Surface Mining Control and Reclamation Act (1977), is not administered by EPA although it does contain many provisions related to environmental control, and it will also be dis-cussed because of its importance to the mining community.

Jan 1, 1978

By Kenneth A. Grace

Each and every mining operation from a simple sand-and-gravel pit to the largest integrated mine-mill-concentrator-smelter-refining complex has, as its foundation, a quantity of extractable natural resource the reserves. Without reserves, there is no mine, and any concentrating or extracting plant, no matter how sophisticated, is simply so much scrap metal. And, of course, without resources there are no reserves. It is remarkable, therefore, especially in this age of careful planning, high quality engineering, and state-of-the-art financial analysis, that such a fundamental and vital item is so little understood and the subject- of so much confusion. Time and time again it has been the experience of the author, when called in to a mining operation that has run into trouble in reaching projected production targets, to find that the designed-for tons were not reaching the concentrator/extraction plant, and/or the grade of such tonnage was substantially below the forecast and design grade of the plant. The mill blames the mine for delivering below standard tons and/or grade and the mining engineer blames the geologist for overly-optimistic assessment or incorrect interpretation of the deposit. The geologist blames the mining and metallurgy division for wrongly interpreting his data and conclusions, or simply fouling-up a fine orebody.

Jan 1, 1983

By M. P. Hoffman

The U.S. Bureau of Mines is developing a roof bolter with a computer-controlled drill head that will increase the safety of roof bolting in underground coal mines by allowing miners to be relocated to a safe area. To ensure secure anchorage, acceleration and strain data are broadcast from an instrumented drill steel to a data acquisition system. These data are analyzed, correlated, and transformed to pro-vide information about roof strata, then are sent to a supervisory computer executing National Institute of Standards and Technology's real-time control software. The supervisory computer sends setpoint commands to proportional-integral-derivative control loops to control drill thrust, position, revolutions per minute, and torque.

Jan 1, 1994

By Walenty Frydel

The paper deals with highly efficient dust collecting systems of the 10-600 type which constitute new generation installations de- signed to eliminate dust hazard in headings driven with roadheaders. A vortex ventube controlling the air flow in the com- bined ventilation system by means of air vortex generated by the ventube drive unit is also presented. From the results of measurements of under-roof concentrations of methane it appears that the application of the vortex ventube makes it possible to decrease the under-roof accumulation of methane more than 10 times.

Jan 1, 1997

By W. D. Hausel

The Wyoming craton in the western United States is a favorable terrane for diamond deposits. The craton hosts a variety of ultramafic, ultrabasic, and ultrapotassic rocks. Additionally, a few hundred 'kimberlitic' heavy mineral anomalies and some geophysical and remote sensing anomalies indicate the presence of undiscovered, mantle-derived, pipes in the craton. The Wyoming craton is separated into a Wyoming 'archon' known as the Wyoming Province, and the Colorado 'proton' known as the Colorado Province. The 'archon' underlies much of Montana and Wyoming and continues north into Alberta and Saskatchewan; the Colorado 'proton' underlies much of Colorado and a small portion of Wyoming. Although most exploration geologists would consider the 'archon' the most favorable terrane for commercial diamond deposits, the 'proton' has produced more than 120,000 diamonds, while the 'archon' has not been very productive.

Jan 1, 1996

By Qingming Feng, Jinhong Zhang

A study has been carried out to apply fly ash as a high strength, water-resistant precast construction material through geopolymerization. Experiment results show that the working conditions such as water content, the concentration of NaOH, curing temperature, and curing time significantly affect the mechanical property of geopolymermatrix. Through optimization, an above-100MPa compressive strength has been achieved with the geopolymerization products. The optimum working conditions involves 10MNaOH concentration, 14–15% water content, and curing at 90 °C in an oven for 1 day or at ambient condition for 3 weeks. Adding Ca(OH)2 does not help to increase the compressive strength of the specimen.Water soaking tests show that the geopolymerization product has a very high water resistance without losing noticeable compressive strength, even after a 1-month soaking time. To elucidate the geopolymerization mechanism, microscopic techniques such as SEM/EDS (scanning electron microscopy and energy-dispersive X-ray spectroscopy), XRD (X-ray diffraction) and ATR-FTIR (attenuated total reflectance Fourier transform infrared) are also applied to investigate the microstructure, the elemental and phase composition of geopolymerization products. The findings of the present work provide a novel method for applying fly ash as a high-strength water-resistant precast construction material.

Aug 17, 2020