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By J. Iannicelli

A variety of domestic bauxites have been beneficiated to meet refractory grade standards by use of high intensity, high gradient, wet magnetic separation. Besides reducing the iron content to less than 2%, the Ti02 content of the bauxite was also reduced. The beneficiation can be accomplished by means of a simplified wet process flow sheet with an estimated cost comparable to that of water washed, filler grade kaolin. The process has been carried out on a small pilot plant and then scaled to produce 25 tonnes of calcined refractory bauxite meeting National Stockpile Specifications.

Jan 1, 1984

By Isiah M. Warner, Philip Oldham, John Kennedy, Bennett D. Lass

A new method for determination of residual flotation oils on beneficiated kaolin clays has been developed The method, which yields qualitative information, is based on fluorescence measurements employing a spatially resolved, polychromatic illumination source for excitation, and a two-dimensional detection scheme using a silicon-intensified, video imaging device The method was used to identify residual oils on a beneficiated, Washington County, Georgia, crude clay The results were compared to a similar qualitative analysis performed via capillary column gas chromatography using a flame ionization detector The video fluorometry was the preferred method of analysis

Jan 1, 1983

By John Turner, David Carey

The Robbins Mobile Miner demonstrates the successful combination of hard rock excavation technology and the latest electronic control technology. The mobile miner, a partial face hard rock tunneling machine, features a fully integrated control system relying on a Programmable Logic Controller (PLC). This PLC controls all functions: tramming, steering, boom swing, cutting depth, conveyor operation, air scrubbers, hopper loading and unloading, etc. The machine is fully instrumented allowing the PLC to monitor the results of all commands on a continuous basis, to record data, to evaluate developing problems, or to shut the machine down if necessary. The paper describes the development of the Robbins - Pasminco automated mobile miner and early testing at Pasminco Mining's Broken Hill Southern Operations, New South Wales, Australia.

Jan 1, 1993

By John M. Anderson

This paper examines the methods available to improve climatic conditions around a deep, high production longwall district of a British coal mine using results from a computer model. Such methods include the provision of increased ventilation quantities, the application of refrigeration, the reduction of heat input at source and the use of alternative ventilation systems. An approach to the solution of a climatic problem is explained with reference to other coal mine contaminants and a cooling strategy for deep high production British coal mines is described.

Jan 1, 1987

By Qiang Ji, Richard L. Sanford

A laboratory-scale microcomputer-based autonomous excavation system has been developed that moves a pile of fragmented rock to a designated location using a shovel attachment on a robot arm. Navigation and excavation sub- systems interactively direct a robot excavator to move the shovel to the rock pile, intelligently load its bucket using a video camera, and dump the rocks to a designated area. Although research was conducted on a laboratory scale model, the system can serve as the basis for further work on a full-scale, robust excavation system.

Jan 1, 1993

By E. G. Kelly, D. E. Walsh

The behavior of gold particles on a spiral was studied using radioactive gold tracers. The method allowed the effects of particle size, particle shape, pulp density, feed rate and splitter settings to be studied. Although the method has been successfully applied to other gravity concentrators, it was found that reliable results were more difficult to obtain on the spiral. However, these preliminary results show that, with suitable precautions, the technique is capable of providing valuable information, unobtainable from conventional studies, that could be used to better optimize spiral performance.

Jan 1, 1993

By R. J. Matetic, Peter G. Kovalchik, Jeffrey Shawn Peterson

The National Institute for Occupational Safety and Health (NIOSH) has initiated a study of a roof bolter to reduce noise exposure to mine roof bolter operators. An important segment of this research entails determining the affect of various drilling configurations on the performance (penetration rate) and sound power emissions when drilling into granite. Test conditions included various combinations of rotational speeds and thrusts; hex and round drill steels of one inch (1.) and one and three-eighths inch (1 3/8.) diameters; vacuum and wet conditions; and using drill media of differing compressive strengths. This paper will detail the affects of each of these on the performance and sound power level emission. When drilling into granite, it was found that wet drilling generated lower sound power levels and performed better than vacuum drilling.

Jan 1, 2005

By J. A. Organiscak

The National Institute for Occupational Safety and Health (NIOSH) has investigated various factor effects on cab air filtration system performance. Factors experimentally investigated were intake filter efficiency, intake air leakage, intake filter loading (filter flow resistance), recirculation filter use, and wind penetration. Adding an intake pressurizer fan to the filtration system was also investigated. Results indicate that the intake filter efficiency and recirculation filter were the two most influential factors on cab protection performance. Use of a recirculation filter significantly reduced cab penetration over the intake air filter by itself due to the multiplicable filtration of the cab interior air. Cab penetration was also affected to a lesser extent by intake filter loading and air leakage. Adding an intake pressurizer fan notably increased intake airflow and cab pressure while providing only minor changes to cab penetration.

Jan 1, 2008

By D. Papacharalampos

A combination of decision- theoretic and knowledge-based methods can be used to classify rock-types from satellite data both efficiently and accurately. An expert system utilizes knowledge-based rules, as a field geologist does, to produce results that make geological sense. Our expert system (GEMS), first processes background information from preexisting knowledge and develops a plan, then classifies individual pixels, and finally generalizes the results using geological rules and plots a map. The system is implemented on a microcomputer and is inexpensive enough to be a part of the standard equipment of any geologist who prepares reconnaissance maps.

Jan 1, 1986

By A. C. T. Bigg, A. F. Colombo, A. R. MacPherson

The step-by-step study of the Stronsay ores follows the testwork through the initial determination of Bond Rod and Ball mill work indices, the MacPherson Autogenous work indices and the production of a preliminary flowsheet. These results are then used to design a pilot plant program to test the effectiveness of fully autogenous primary and secondary grinding and to determine the feasibility of controlling feed rate by the use of variable speed mill drive and/or varying the mill load. A final flowsheet is recommended with mill sizes and power requirements.

Jan 1, 1992

By S. Bhattacharya, M. M. Singh

The Surface Mining Control and Reclamation Act of 1977 (SMCRA) requires under-ground coal mine operations to prevent "material damage" to renewable resource lands caused by subsidence. However, what constitutes material damage is not defined. This paper discusses the applicable criteria for agricultural lands, forests and grazing lands, surface water bodies, and ground water aquifers. Although data on the subject are limited, an attempt is made to present quantitative guidelines to distinguish between moderate and severe damage due to subsidence.

Jan 1, 1988

By Y. M. Jiang, R. L. Sanford, D. W. Park

Artificial intelligence has emerged over the past two decades as an important problem-solving tool. Techniques include expert systems, neural networks, free classification, fuzzy logic and genetic algorithm. These methods can be employed to solve rock mechanics and ground-control problems associated with the highly complex nature of rock masses and ground conditions. A current study focuses on the development of an artificial-intelligence system for real-time interpretation of data collected from longwall monitoring stations and on the development of an early warning system for the prediction of undesired conditions and the prevention of longwall-mine instability problems. The successful application of these artificial-intelligence techniques will contribute to a safer and healthier mining environment.

Jan 1, 1997

By L. J. Laughlin

The majority of non-drive conveyor pulleys use rotating shafts, and typical idler rolls use non-rotating shafts, even though both products are used to support and guide the conveyor belt and its load. This paper will explore and compare the requirements for rotating and non-rotating shaft designs and the impact of that design on the product. Additionally, it will explore how the “roller” bearing types (deep groove ball, tapered, or spherical) affect these designs.

Jan 1, 2003

By H. Y. Sohn, H. K. Lin

The leaching of primary porphyry chalcopyrite ore under simulated solution-mining conditions was studied using a packed-bed reactor. A mathematical model incorporating the intrinsic leaching kinetics of chalcopyrite and pyrite grains, the pore diffusion of dissolved oxygen within the ore fragments, liquid-solid mass transfer, and the effect of fluid flow and axial dispersion was formulated and tested for the overall leaching process. The dependence of oxygen solubility on ionic strength of the solution was also incorporated into the model. Satisfactory agreement between model pre- dictions and experimental data was obtained. The model can also predict the rate of the leaching process under different temperatures, oxygen pressures, solution flow rates, and different size distributions of ores.

Jan 1, 1991

By Hugh W. Rimmer

The design of comminution circuits and the evaluation of alternatives should be based on state-of-the-art equipment and appropriate design criteria - considerations that are often neglected by today's designers. This paper critically reviews common circuit designs, evaluates various alternatives for difficult-to-treat ores, and discusses the factors that should be considered when developing new plant designs or auditing existing plant performance. Data obtained from laboratory, pilot and plant-scale test work on a wide range of ores and circuits are used to justify the author's conclusions.

Jan 1, 1995

By S. K. Kawatra

Outokumpu Electronics has designed a new on-line coal slurry ash analyzer, based on an instrument developed at Michigan Technological University. The primary goal was to build an accurate instrument at the lowest possible cost. The instrument determines ash content from measurements of X-ray backscatter, iron K, fluorescence, and low-energy y-ray absorption. It is capable of measuring the ash content with a standard error of 1.1% ash over an analysis range of 9-21% ash and 7-22% solids. The analyzer was tested on coals from United States, Poland, Great Britain and the USSR.

Jan 1, 1993

By Alan C. Noble

Ore reserve estimation is a multi- disciplinary process involving not only tonnage and grade estimation (resource estimation), but also consideration of technical and legal aspects such as mining the deposit, beneficiating the ores, and selling the product. This paper provides a background to under- standing resource estimation including geologic modelling, manual estimation methods, conventional computer methods. and geostatistical methods. Mine planning, metallurgical studies, legal/environmental, and marketing considerations are also discussed as they relate to estimating ore reserves.

Jan 1, 1991

By T. H. Dubaniewicz, J. E. Chilton

The U. S. Bureau of Mines is investigating the application of fiber optic technology to methane and carbon monoxide monitoring. A methane monitoring system is described that is based on differential absorption of infrared light. It can detect concentrations as low as 0.2% and as far away as 2 km via fiber optic cable. The upper range is 100% methane. The system requires no electrical power within the mine so it should operate safely under mine disaster conditions. A hybrid carbon monoxide monitoring system is described that combines a low-powered electrochemical cell with fiber optic telemetry. Testing has shown the system can operate maintenance- free for several months.

Jan 1, 1992

By Ross W. Smith, D. L. Taylor, K. A. Altman

Traditional sensitivity analysis of metallurgical data has the potential to overestimate the value of mining projects. Such analyses provide no information about the probability of the results. Simulations that rely on the input of statistical information provide more realistic predictions of the value of future projects and offer additional information regarding the probability of the outcome.

Jan 1, 2003

By William P. Lorenz

The paper describes a uranium by-product recovery plant operating within a copper leach, solvent extraction, and electrowinning circuit. The operation is unique because it is integrated into the main process stream of the copper circuit The plant processes 1408 m3/h of copper solutions containing about 10 mg/L of uranium. An Eluex type process was selected due to its compatibility with the copper leach plant. The paper includes an overview of the copper circuit

Jan 1, 1983