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By A. E. Michon

My comments today are directed toward western coal and its impact on Burlington Northern. I will be discussing three major topics. These are: location and extent of mining activities, the flows of this coal traffic into the various market territories, and finally the interaction of this western coal with coals found in the balance of the United States. When we at BN speak of western coal, we refer to those substantial deposits lying in southeastern Montana and north-eastern Wyoming. This territory covers many different coal formations. For the sake of simplicity, I will be referring to this general area as the Powder River Basin (or the "western" coal fields). This slide highlights the area overlayed by a map of the BN rail system. The U.S. Bureau of Mines estimates the demonstrated reserve base of Montana and Wyoming to be approximately 176 billion tons. Of this figure, about 73 billion tons is minable by surface methods. This is roughly 72% of the total strippable reserves in the western united states, BN does not have sole access to this coal for there are deposits in southern Wyoming near the union pacific railroad. I will say more about this later.

Jan 1, 1978

By L. F. Delgado

Environmental and cost pressures sparked renewed interest in gravity separation. Industrial sands in Mexico are generally processed by screening, desliming, and flotation. Gravity separation with spirals was evaluated as an alternative to flotation in order to lower operating costs and decrease water pollution. Outstanding operating results are obtained in glass and foundry sand operations, plus a more competitive position for Mexican producers due to lower operating costs. Coal fines, generally recovered by flotation, have the same cost and environmental advantages when processed with spirals.

Jan 1, 1994

By T. K. Kim

Iron, cobalt, and nickel in waste ferric chloride solutions were separated from each other by solvent extraction. The iron was extracted from the cobalt and nickel by the use of methyl isobutyl ketone, and then the cobalt was separated from the nickel by the use of a high-molecular-weight quaternary amine dissolved in a solvent of high aromatic content.

Jan 1, 1980

By A. K. Sinha

Ever since electricity was introduced, electrical injuries and electrocutions have continued to occur regularly in coal mines. An analysis of the two hundred cases of electrocutions which occurred during 1956 to 1970 indicated that over 50 percent of the incidents were caused by the ineffectiveness or lack of electrical grounding. Research shows that various types of arbitrarily designed ground beds are in use and that the ground resistance and current are often very high and subject to wide seasonal variations. The results of a recent research are discussed in this paper.

Jan 1, 1980

By R. J. Barnes

Consider a typical blast at a surface gold mine in North America. For example, the low-grade area of Bench 4000 at AMAX Gold's Sleeper Mine (Winnemucca, Nevada). Bench 4000 is 20 feet high (=6m) , and blast holes are drilled and sampled on a 14 foot by 14 foot square grid (a4m x 4m). A representative blast includes between 50 and 150 holes, encompassing 15,000 to 45,000 tons of material (w14,000 to 41,000 metric tons).

Jan 1, 1989

By Richard E. Barrett

The relationship between coal characteristics and power plant performance has become a matter of increasing interest to utilities. This relationship can affect the value of coals, decisions as to coal washing, setting penalties for delivery of coal that fails to meet specifications, and justifying buying better coals (at higher costs) before public utility commissions. The study described in this paper was directed to identifying how coal characteristics impact on boilers and related coal and gas handling systems. TVA data for the period 1962-1980 was the basis for the study. Models were developed for boiler efficiency, boiler availability, and maintenance costs as a function of such coal characteristics as ash, sulfur, and moisture content and boiler age. Boiler load and maintenance efforts were considered as variables in some of the models, but were found not to be statistically significant. Although the results of this study are strictly applicable to only the TVA system, they can serve as guides or first approximations for other utilities.

Jan 1, 1983

By Larry Sevenker

On the basis of favorable salt characteristics, primarily compressive strength and impermeability, solution-mined cavities can provide structurally stable isolation chambers for waste. Solution mining techniques are established for storage of hydrocarbons. The proposition of waste isolation in engineered salt cavities is similar to this practice relative to characterization, certification and safeguards. What materials are isolated and how operations are conducted are principle differences. Compatibility of wastes with other wastes must be considered, but hazards can be precluded by avoiding certain mixtures. Waste material characteristics and cavity considerations are discussed.

Jan 1, 1981

By William H. Lehr

In recent years, we have witnessed many innovations in the equipment used in handling bulk materials. Not too long ago, any sizeable stockpile of coal or iron ore was attended by one or more material handling bridges. More recently, large stockpiles have been built with mobile equipment of' the earth moving type with bulldozers and front end Loaders being utilized in reclaiming operations. The most recent stocking and reclaiming device is the rotary bucket wheel machine. The early bucket wheel machines built in the United States were developed for the strip mining of coal. We understand that the first American machine was built in the Midwest in 1944. This type of unit was developed in an effort to reduce the cost of removing overburden and to provide satisfactory spoil disposal. As the available coal reserves under shallow cover were exhausted, the cost of removing the deeper overburden with conventional equipment became too great for these operations to continue profitably. The first machine has now been followed by six or seven additional units, the largest of which can handle material at a rate of more than 7000 cubic yards per hour.

Jan 1, 1965

By C. E. Jordan

The fundamental characteristics of ultrafine chalcopyrite flotation were investigated by the Bureau of Mines to establish techniques to improve recovery of ultrafine chalcopyrite. Intense agitation during conditioning was found to improve flotation recovery of the ultrafine chalcopyrite. A split-circuit flotation design, treating the plus 38-µm-size ore by the conventional method and treating the minus 38-µm-size ore with intense agitation conditioning followed by flotation, recovered 95.6 pct of the copper in a 28.3-pct-copper concentrate, This was a 5-pct increase in copper recovery over the conventional chalcopyrite flotation method.

Jan 1, 1986

By Josef J. Schwegel

The first vertical shaft lime kiln operating according to the parallel-flow regenerative principle was developed and built in the nineteen-fifties by Schmid-Hofer in Austria. Upon proving this concept of calcining or "burning" limestone to be very energy efficient for the production of good quality lime, Maerz Ofenbau AG of Zurich, Switzerland was in 1965 licensed for the design detailing and construction of these kilns. The first regenerative shaft type lime kiln outside of Austria was built in 1966 and through close co-operation with customers and their operating personnel, the advanced technical developments of today's kiln designs were accomplished. At present approximately 190 kilns of this type in capacities ranging from 60 to 700 short tons per day have been built or are under construction throughout the world in highly industrialized as well as less developed countries.

Jan 1, 1981

By Jerry F. Fountain

Variations in ore grade, mineralogy, and copper pricing structures over the life of the Inspiration mine have mandated many modifications to the treatment methods to maximize process economics. In the 1970's, copper prices generally declined, while inflation, wages, and interest rates increased. A metallurgical treatment route had to be developed for this continuing economic climate which would be capable of minimizing labor, energy, and capital cost requirements. After many years of development, the patented "Ferric Cure" process was introduced to satisfy these requirements. This dump leach process for treatment of mixed oxide/sulfide ore includes: strict mineralogical control of ore placed for leaching, controlled leach pad construction, solution saturation and curing of the pads with higher acid concentrations, and, finally, rinsing of the cured pads for removal of dissolved copper. Leach solutions, high in sulfuric acid during the cure application and low in sulfuric acid during the rinse, contain sufficient ferric iron to enhance the leaching of chalcocitic sulfide minerals.

Jan 1, 1983

By D. Butler

Lateral density changes in the subsurface cause a change in the vertical pull of gravity at the surface. By very accurate measurement of gravity and the practical application of common sense, a microgravity survey can sometimes detect natural or man-made voids, bedrock profiles, and geologic structures of engineering interest. This paper will give some practical guidelines for the application of microgravity surveying. Emphasis in many papers (Blizkovsky, 1979, Fajklewicz, 1983) has been on the anomaly size: herein emphasis will be placed on detectability and signal-to-noise ratios. First, some easy to use curves for anomaly valuation are adapted from Arzi (1974). Secondly, the predictable noise sources are discussed. Thirdly, representative models of abandoned underground workings are evaluated for microgravity surveying given the probable noise in the survey results.

Jan 1, 1988

Mining was the first economic activity carried out in Cuba, by the colonial conquerous, i.e. gold extraction from rivers and use of asphalt to calk their ships; however, due to different historic reasons only a limited development took place in this field during the colonial domination. During the republican period beginning early in this century, other interests lead to a larger scale exploitation of some known deposits. From the beginning of the century up to the triumph of the Revolution in 1959, not less than the following figures were extracted of some Cuban minerals: Refractory Chromium 3,300,000t Manganese 7,650,000 t Copper 9,000,000 t Iron 22,000,000 t Nickel 150,000 t (Ni oxide and sulphide These productions were practically directed to cover the demands of the U.S., industry and some-times these Cuban ores were almost the sole suppliers of the market.

Jan 1, 1978

By Clement K. Chase

Although flotation is the generally accepted process employed to recover gold and silver as well as copper, lead, and zinc from primary sulfide ores, the metallurgical requirements for the treatment of massive sulfide ore deposits differ markedly in many respects from those employed for the more common disseminated porphyry deposits. In Arizona, some properties classified as other then massive sulfide deposits because of mining and geological characteristics have produced mill-feeds similar to those from massive deposits. Several such occurrences are noted. The process requirements for massive sulfide deposits and unique mill-design implications are discussed in the perspective of world-wide economic considerations and the individual regional metallurgical and economic constraints in the United States.

Jan 1, 1986

By R. E. Blair

The mining and minerals industry has been, and continues to be, at the cutting edge of high technology. Iron and steel built the Industrial Revolution/copper electrified the world/coal tars and petroleum and gas feedstocks developed the organic chemical industry. Industrial minerals now carry forward this tradition. Two, of hundreds of examples of hi-tech industrial minerals are quartz crystal and rare earths. Both demonstrate the international market aspects of mining, processing and finished product trade.

Jan 1, 1988

By B. A. Wills

Much research effort has been spent in attempting to reduce the high energy costs in grinding, but relatively little in developing methods to enhance the liberation of the minerals from each other. This paper presents some ideas on the nature and role of grain boundaries in mineral assemblies, and their influence on the propagation of cracks through the rock. It is argued that if the mechanisms of fracture are more clearly understood, crack propagation may be controlled in such a way that intergranular fracture dominates breakage, producing less fines and a higher degree of liberation.

Jan 1, 1995

By D. Sinha

Mine investment decisions involve both objective and subjective criteria. The subjective criteria are efficiently decided by interaction with company experts. The Expert System approach can incorporate knowledge of experts and interact with conventional computer programs on mine evaluation. Artificial intelligence offers considerable opportunities in comprehensive mine investment decision making process.

Jan 1, 1998

By C. L. McKenzie, R. A. Heig

The design and operation of metallurgical laboratories is discussed. Laboratory size, general laboratory equipment and metallurgical staffing are discussed from a standpoint of desired laboratory results.

Jan 1, 1986

By R. C. Bunge

The selective flotation of semi-soluble salts with fatty acids is often negatively affected by the interaction of the potential determining cation with the ionic surfactant in bulk solution. This problem can be avoided by floating at low pH which involves the emulsification of the collector. The research presented here focuses on the influence of the Ca2+ ion on the flotation of fluorite with palmitic acid at low pH. Our results show that the surfaces of collector emulsions are dominated by precipitation phenomena similar to those encountered in bulk. In turn, fluorite in palmitic solution at intermediate pH displays surface properties similar to those of the collector by itself. This may be due to two alternative mechanisms (i) adsorption of bulk precipitate on the fluorite surface or (ii) the formation of a bilayer of surfactant ions on fluorite. Possibly, both mechanisms occur simultaneously.

Jan 1, 1993

By F. Habashi

It has been estimated that about 45 tonnes of mercury are emitted annually in the USA in the atmosphere as a result of burning coal in power-generating plants. A similar situation had existed in the metallurgical industry particularly in zinc production plants but this problem has been solved long ago by introducing scrubbing systems. Methods of mercury removal and recovery are discussed.

Jan 1, 2010