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By Thomas S. Kovach

In today's competitive energy market, every effort must be made to assure the lowest possible production cost. 'rhi s. paper describes the cooperative effort between the coal producer and the utility customer to develop and install a fully integrated mine information management system at a 2.5 million tpy lignite mine in east Texas. A description of each item of the modules is included along with the problems encountered during development and how they were corrected. The system configuration is also described.

Jan 1, 1989

By M. S. Vernon, J. J. Kellar, W. M. Cross, R. M. Winter, F. J. Johnson, A. G. Pommer

Three substrates (MgO crystal, CaF2 crystal and Mg plate) were used to construct thin layers of Mg(OH)2. Various routes were used to modify these substrates, including surface hydration and sol-gel coating. In each case, it was found (by using Fourier transform infrared spectroscopy) that thin layers of Mg(OH)2 could be produced. In the case of hydrated layers, the surface morphology of the Mg(OH)2 resembles the bulk platelet shape of precipitated Mg(OH)2.

Jan 1, 2000

By Robert E. Haun

Retech's Plasma Arc Centrifugal Treatment (PACT) system is a thermal technology that uses heat generated by a plasma torch to treat hazardous waste containing metals and/or organics. Metal bearing solids and soil are melted by the process, and organic contaminants are thermally destroyed. The molten material forms a hard, glass-like leach resistant mass after cooling in a mold. This paper discusses plasma processing in general and presents some results of treating mineral processing wastes using the plasma arc centrifugal treatment process.

Jan 1, 1995

By James A. Everts

Calcined bauxites are classified by their major end uses - abrasives and refractories. Target properties are dictated by application and processing requirements. The chemical and physical properties of premium grade calcined bauxites are far more stringent than metallurgical bauxite and this limits the sources and availability. Premium grade calcined bauxites are considered to be strategically critical to the industrialized countries of the world. Subject to disruptions in the key source countries, adequate supplies of premium grade calcined bauxites are anticipated in the foreseeable future.

Jan 1, 1984

By P. Sanchez-Mejorada

Quimica del Rey, SA, a subsidiary of Industrias Peñoles, SA de CV, produces sodium sulfate from brines extracted from a playa of Laguna del Rey, located in the State of Coahuila in northern Mexico. The spent brine is used as raw material for the production of magnesium oxide. The brine, which contains ions of sodium, magnesium, sulfate, and chlorine, occurs filling intercrystalline voids of a lenticular evaporite deposit whose main constituents are glauberite (sodium-calcium sulfate) and blöedite (sodium-magnesium sulfate).

Jan 1, 1987

By Don Stainbrook

Over a period of many years a highly automated computerized system of ore control has been developed at the Newmont Gold Company, (NGC). It is the purpose of this paper to review the development of this system, describe the setting in which it functions and to mention some of the future developments and enhancements. Discussion of the evolution of the system in a historical perspective helps to understand its present status and illuminate some thinking about future directions of development.

Jan 1, 1989

By S. R. Clifford

Organic contaminants can be removed from river sediment using conventional flotation methods. Organic contamination in sediments is one of the most significant pollution problems facing the Great Lakes region. Using conventional flotation, the majority of the organic contamination can be collected in a concentrate, leaving a "clean" tailings. This provides a cost savings by reducing the amount of material requiring further treatment. The concentrate can then undergo additional flotation stages, or other contamination removal procedures, to further remove the organic contaminants.

Jan 1, 1994

By Gordon R. Wicker, Willem P. C. Duyvesteyn, Robert E. Doane

A versatile acid leach process has been developed which is applicable to a broad range of oxide nickel ores. Inherent in this process are high recoveries of nickel and cobalt, as well as a relatively low energy consumption. These features extend the range of economic exploitation of laterite deposits to low grade limonites and to garnieritic ores not suitable for pyrometallurgical processing. Particular advantages can be realized in treating orebodies containing both limonite and garnierite and ores containing significant amounts of cobalt.

Jan 1, 1979

By Lawrence A. Ph. D. Hansen, J. David Deatherage

Laboratory testing programs were conducted to investigate the performance under compression loading of several types of geomembranes and geotextiles proposed for use in heap and dump leach projects. Synthetic liners of several thicknesses were sandwiched between representative subgrade soils and cover materials, thus modeling in the laboratory the actual installation conditions expected. Performance was evaluated by visual inspection and vacuum testing. Several testing procedures and equipment were used to investigate the effect of these testing parameters on the predicted performance.

Jan 1, 1987

By R. Debkowski

The current underground infrastructure of an old monumental salt mine along with using it as a tourist, museum, nature, resort, conference and cultural events place is presented in the paper. At present, mainly in the monumental part of mine, only a small part of the historical chambers, which together with galleries form a tourist route available to visitors. Moreover, the essential activities aimed to make the tourist route more attractive and to change the decor of the underground sites are discussed.

Jan 1, 2006

By Daniel P. Coughlin, Robert C. Thomas, Christopher S. Romanek, Kristian W. Paul

Two separate constructed treatment wetland (CTW) systems receiving the same metal contaminated, acid sulfate water over different lengths of time and at different rates were evaluated for metal attenuation. Both wetlands are the alkalinity generator portion of a succesive alkalinity producing system (SAPS). Sequential extractions are employed to determine phases of metal removal. Results indicate that Fe, Al, Zn, Ni. and Cu accumulate in the organic substrate over time. Manganese accumulates initially, but is not retained in the system over time.

Jan 1, 2000

By P. J. Kientzler, Y. C. Lo

The current study is concerned with the analysis and attempt at simulating the product size distributions obtained from a vibrating ultrasonic device. Systematic experiments of comminution were performed with natural sizes as well as monosizes in order to understand the breakage behavior of the device. A precise analysis of the device's breakage performance in the case of fine grinding of alumina samples will be presented. Initial steps to model the breakage events using a detailed mathematical algorithm will be discussed.

Jan 1, 1992

By Sukumar Bandopadhyay

A present dominant problem is that of high downtime of the longwall shearer used in the coal production process. The means by which this problem can be overcome are many, but one of, the most important ones is that the-use of an expert system can reduce diagnostic and repair time. In this paper, a fault-diagnostic expert system model is presented. Specifically, the diagnostic architecture of the longwall shearer expert system and its use for diagnostic reasoning are discussed.

Jan 1, 1989

By B. D. Nichols, W. S. Gregory

SOLA-DM is a three-dimensional finite-difference computer code designed to model the dynamics of an incompressible fluid and the transport of discrete particulate material around obstacles impervious to flow. The numerical methods used in this code are described. SOLA-DM was used to predict the particle flux sampled by the 10-mm Dorr-Oliver Cyclone and MINIRAM dust monitors. Various geometric and dynamic variations of monitor and airflow combinations were tested. The code predictions are shown in computer-generated graphic plots.

Jan 1, 1987

By W. V. Harper

The travel path of a freed radioactive particle in an aquifer must be estimated from a limited number of available samples. This paper discusses geostatistical methods that minimize the 'uncertainty' associated with the predicted hydrologic surfaces and the predicted travel path. However, any estimation method will produce a single smooth predicted path. This 'sensitivity' will he evaluated using a geostatistical simulation method. The techniques will be illustrated using published data from the Wolfcamp and Pennsylvanian aquifers in the northern Texas Panhandle.

Jan 1, 1990

By G. G. O. O. Uwadiale

A number of Nigerian iron ore deposits have been upgraded to the specifications of concentrates for the blast furnace and the direct reduction iron- and steel-making plants. Depending on the mineralogy of the ore deposits, the techniques of oil agglomeration, magnetizing reduction, washing and scrubbing, gravity concentration, and reverse froth flotation have been utilized. A mode of distributive management of the deposits, in the direction of their technoeconomic utilization in the country's developing iron and steel plants, is presented.

Jan 1, 1990

By D. E. Ranta, M. G. Schulz

Mining of Molybdenum at Questa, New Mexico has been accomplished by block cave methods since August, 1983. As caving progresses, a periodic geologic evaluation is made of the rock types present in finger raises on the Grizzly Level of the mine. The production maturity of the cave can be monitored by relating this data to geologic cross-sections through the orebody. The draw point mapping program is a simple and effective tool that is used in making draw control decisions at Questa.

Jan 1, 1992

By Ernest Peters

To model the zinc pressure leach, equations have been written that describe the rates of individual reactions taking place, including (a) oxygen mass transfer, (b) ferrous oxidation by dissolved oxygen, and (c) ferric reactions with ZnS and other minerals. In the continuous process, at steady-state, these take place at the same rate, and so the equations can be solved simultaneously. Model calculations using simultaneous equations are shown in graphical form to demonstrate the effect of different variables on the leach performance.

Jan 1, 1993

By H. Barry Holt, Charles A. Bischoff

On November 15, 1990, President Bush signed the Clean Air Act Amendments of 1990. The new legislation is sweeping in its demands for cuts in smog, acid deposition, toxic air pollutants and ozone-depleting chemicals. The Amendments will siqnificantly alter air quality permitting and compliance and are estimted to cost billions of dollars to implement. This article provides an overview and summary of each of the eleven titles of the Amendments. It also addresses how the Amendments will be implemented.

Jan 1, 1991

By David J. Kruse

Accurate field measurements are essential when validating a conveyor design. They are fundamental in determining a conveyor's behavior, its long-term maintenance requirements, and the life expectancy/ condition of the installed equipment. Field measurements are also invaluable in forensic engineering, particularly when vital equipment has failed This paper will discuss a wide variety of data acquisition equipment, field measurement techniques and accuracies achieved State-of-the-art, custom designed monitoring equipment, as well as, ''08-the-shely instruments and sensors, will be discussed.

Jan 1, 2004