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By Robert S. Ondrey, Robert A. Haney, David J. Atchison

The Mine Safety and Health Administration has conducted tests to determine the effectiveness of two methods for reducing diesel particulate emissions in underground coal mines. Both methods involved collection of the particulate material before being released into the environment. One method utilized a disposable pleated paper filter attached to the tail pipe; the other utilized a reusable wire mesh screen attached to the tail pipe. This paper describes the instrumentation and testing used to evaluate both control methods. Results of respirable dust and diesel particulate measurements made underground are presented and analyzed.

Jan 1, 1992

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 Richard R. Klimpel

In this paper, the old and the new commercially available reagent chemistries for the improved flotation of sulfide minerals will be summarized. The reagent classes discussed are those that meet three criteria: 1) they are being commercially used and/or large scale plant tested in North America in the last few years; 2) they are clearly different in chemical structure than commonly used commercial reagents of the last few decades and are not simply mixtures of existing reagents and/or simple changes in cation, alkyl group size, etc. and 3) the structural formulae are clearly specified in the public literature.

Jan 1, 1994

By P. K. Sims

Extensive mineralization in the basal part of the Duluth Complex of Middle Proterozoic (Keweenawan) age in northeast Minnesota has been explored during the past 30 years as a potential source of copper and nickel from sulfide-bearing assemblages. Very large resources of low grade and marginal material have been delineated by drilling and by test shafts sunk by at least five private mining companies, but none of the properties has yet been mined. With few exceptions, grade and tonnage figures for specific properties have not been released, but the magnitude of the resources has been estimated by the Minnesota Geological Survey and the Minnesota Dept. of Natural Resources as constituting several billion tons of low grade and marginal copper- and nickel-bearing material - a major combined copper-nickel resource of international importance.

Jan 1, 1991

By P. K. Naik, S. C. Das

Leaching studies of low-grade manganese ore containing 31.77% Mn and 23.71 % Fe from Nishikhal, India, were carried out using pyritiferous lignite as a reductant in sulfuric acid medium. The variables studied were quantity of lignite, sulfuric acid concentration and temperature. Regression equations for the extraction of manganese and potassium were determined from 23 full factorial design data. The experimental conditions for the extraction of manganese were optimized using the steepest-ascent method. It was found that 99.03% of the manganese could be extracted in three hours with an ore to lignite ratio of 1:1.8, a sulfuric acid concentration of 1.9 M and a temperature of 99°C. Key words: Leaching, Manganese ore, Lignite, Statistical design

Jan 1, 2003

By O. A. Bascur

Based on current sedimentation theory an on-line thickener model was developed and coupled with an extended Kalman Filter to obtain additional information such as the compression zone level and concentration, a corrected underflow concentration, the inventory, and some rheological information. The on-line model was installed and tested for robustness for periods up to three days in an industrial environment giving good results. Emphasis was given to signal processing and selecting the appropriate input variables for filtering. The analysis of the thickener from a phenomenlogical point of view provides for better operation, establishes the limiting operating conditions, and assists in the design of control strategies.

Jan 1, 1986

By R. A. Metz, Ted H. Eyde, Dan T. Eyde

Industrial minerals deposits present sampling and grade control problems not normally encountered in metal mining operations. No longer are industrial minerals simply crude ground mineral products but are in fact high purity chemical raw materials. Operators of industrial minerals mines and processing plants now must meet increasingly stringent specifications established by the consumer of the final products. Meeting these stringent specifications requires not only sophisticated processing techniques but equally important careful sampling and grade or quality control at the mine. A well-trained geological staff can assure an adequate supply of uniformily high quality feed to the processing plant. In the final analysis this results in significantly higher operating profits.

Jan 1, 1992

By Donald W. Peters

The 191 million acres of public lands that are managed as National Forest System Lands contain extensive geologic habitat for over 40 industrial minerals. The Forest Service actively encourages exploration for and development of industrial mineral deposits within the National Forests. However, due to competing interests, the Forest Service may not always be able to accommodate industry needs. In order to successfully compete with ever-increasing demands for all resources in the 1990's, industry needs to become more active in public involvement and education and in communicating its contributions and needs to public land managers.

Jan 1, 1991

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 Pamela J. Nebgen

Surface mine planning and watershed management requires the manipulation of a massive volume of data. The processes of collecting, examining, selecting, and generalizing information for the production of maps and sediment structure designs are a major part of mine planning and evaluation. Computer aided design graphics systems are becoming increasingly more important to the surface mining industry. This paper illustrates the applications of a digitizer and plotter interfaced to an IBM PC-XT microcomputer, which form the hardware elements in the new University of Kentucky hydrology, sedimentology, and structure design package called SEDCAD.

Jan 1, 1986

By Myles P. Reilly, Randall A. Snowdon, John Temporal, O&apos

The paper describes studies made at the Transport and Road Research Laboratory, UK, of the mechanical cutting characteristics using disc cutters, of rocks with compressive strengths up to 340 MPa. These studies have been performed in both the single pass mode, where interactive breakout occurs between adjacent grooves on every pass of the tool, and the multiple pass mode, where several passes may be required to cause breakout. In addition, experiments to determine the effect on cutting performance of the hydraulic stiffness of tunnelling machines are described. The results of these tests are analysed and discussed in the context of the design of full-face tunnelling machines.

Jan 1, 1983

By M. E. Poad, W. G. Pariseau, M. A. Laurenti

In 1986, a cooperative effort by Homestake Mining Co., the US Bureau of Mines and the University of Utah was initiated to determine shaft stability while recovering high-grade ore in a nearby pillar. Premining finite element simulations indicated the shaft would remain in elastic ground. Six years have elapsed and, despite some initial concern during the first lifts, it appears that the bulk of the original reserve will he safely and profitably recovered. An integrated application of rock mechanics tools from laboratory testing through numerical modeling to mine measurements and observations contributed substantially to the operational success of the project.

Jan 1, 1996

By F. Kennedy

Consolidation Coal Co. (Consol) supports an active research and development effort to improve the safe, productive mining of coal and to use coal in an environmentally acceptable manner: Attention will be focused on degasification of coal seams, continuous coal transport systems, earth sciences activities, and coal combustion. Brief mention will be made regarding the SO2 emissions control programs. The research program constitutes about 1 % of Consol coal sales, which positions Consol as the preeminent coal company supporting broad-based research addressing the full spectrum of the various problems associated with using the nation's abundant reserves of economical, readily available fuel.

Jan 1, 1990

By Michael J. Rinker, R. V. Nicholson

Waste rock and tailings from a proposed nickel-copper mine were evaluated extensively for potential on-land and under water disposal. Standard humidity cell and column tests were conducted over a two year period and underwater tests were conducted for more than one year. Nickel concentrations or release rates from the waste were consistent with nickel to sulphur ratios in the solids. This relationship provided a tool to assess the risk of metal leaching in wastes using nickel and sulphide assays. Nickel release and mobilization was found to occur for both oxidizing leach tests and under water tests even when pH values exceeded 7.0. Geochemical model calculations showed that iron oxyhydroxide solids can scavenge nickel from leachate and that the nickel inventory can be released from solids at relatively lower, but neutral pH values.

Jan 1, 2000

By Vanessa M. Torres, Lafayette C. L. Freitas, Evandeo C. Silva

This paper shows two applications of artificial intelligence models in process development. In the first application, a heuristic fuzzy correlation can predict flotation behavior in bench scale based on feed characteristics for a high variability copper ore, as well as to predict plant performance for a feasibility project evaluation, minimizing its risk. The second case study shows the use of neural networks to model the iron ore sintering, correlating ore characteristics and operational parameters with sinter properties. With this application, CVRD aims to establish a new step on iron ore product evaluation and customer support.

Jan 1, 1998

By A. S. Mallicis, Li Xiawoei, P. W. Weiblen, I. Iwasakl

Platinum group metals (PGM) are often found in close association with arsenide and sulfarsenide minerals in copper-nickel bearing gabbroic rocks. Major losses of platinum in flotation have been attributed to the susceptibilities of the arsenic minerals to oxidation and subsequent losses of their recoveries in cleaner flotation stages. The use of a nitrogen atmosphere in grinding and in flotation, the effectiveness of activation for improving their floatabilities, and the role that electrochemical interactions play not only between grinding media and minerals, but also among different minerals, are discussed.

Jan 1, 1989

By E. B. McNew, J. M. Barnes, A. E. Torma

The applicability of biosorbent materials for the removal of uranium and other heavy metals from synthetic and actual uranium mil 1 tailing (UMT) solutions has been investigated. The biosorbent materials used in this study were barium loaded beads of alginate, alginate-dextran sulfate, alginate-carrageenan, and alginate-xanthan gum. These studies were performed in stirred vessels and packed columns. It was observed that 100 percent of the uranium could be removed from a synthetic solution following 2 hours of contact time in a stirred vessel, and 80-100% of U, V, Mo, Mn, Sr, and Zn could be removed from a UMT effluent solution with a packed column. Kinetic evaluations were performed, using a generalized rate equation, on the biosorption of uranium with these barium loaded beads.

Jan 1, 1992

By William Wraith

The availability of computer resources and data management technology, together with the prudent use of scientific management concepts, has made it possible to achieve important improvements in the control of maintenance and materials activities in the mining and minerals processing organization. The introduction of minicomputers and. the greatly improved efficiency of computer systems in general have put the use of computer technology within the reach of even the smaller mining companies which probably could not have afforded them just five to ten years ago. A number of progressive companies have implemented computer-based maintenance, purchasing, and supply inventory control systems. Using modern safety stock, demand forecasting, parts reliability analysis, and other control concepts, these new systems have helped minimize production losses by reducing the frequency and severity of supply shortages and unplanned repairs. At the same time, these systems are helping to conserve scarce capital resources by better utilization of supply inventory investments, reduced expenditures for maintenance, less frequent equipment replacements due to improved maintenance reliability, and greater capacity utilization of existing facilities.

Jan 1, 1979

By M. S. Klima, M. Fofana

The use of a laboratory-scale magnetic fluid-based separator for coal separations was examined. A Frantz laboratory magnetic separator was modified by fabricating new pole pieces of the appropriate geometry to provide the proper magnetic field gradients. Two separation chambers, which were constructed of Plexiglas, were designed to fit between the pole pieces. A commercially available, water-based, ferromagnetic fluid was used as the separating medium. The separating density was changed by varying the current intensity of the electromagnet coil. Both batch and continuous separations were made using 0.59 x 0.50-mm and 0.18 x 0. 15-mm coal. The results are compared to those obtained using organic liquids.

Jan 1, 1998

By R. H. King, R. E. Cameron

Mine managers need better information to locate new opportunities and then to assess the effect of their decisions. We are developing the Intelligent Decision Support System (IDSS) and its two major modules, the Pattern Recognition System (PRS) and the Knowledge Representation Subsystem (KRS) to automatically provide the information from monitoring system sensors. This paper focuses on the KRS Algorithms that extract key information from lists of time-study type event sequences. Because a static system cannot operate effectively in a dynamic mining environment, we are prototyping an index- based technique that allows the system to adapt itself to this dynamic environment.

Jan 1, 1991