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By Eric K. Albert

The permit generation and review process represents both a time consuming and expensive task for industry and government alike. Changes in regulations and in review procedures cause additional delays. This leads to potentially higher costs of doing business and the extension of time for a project to lie started. This paper describes the motivation and methodology of applying an expert system to function in the role of a permit reviewer. The problems of representing the knowledge of the reviewer and regulatory criteria are illustrated. Futhermore, the selection method for the expert system shell is addressed. Finally, a sample review is demonstrated to show the results of applying this artificial intelligence method to the process of permit review.

Jan 1, 1989

By Wojciech Suwala

The transition from centrally planned to market economy affects methods of economic analysis. The models which were used in the past are riot valid presently, however they we're the seed which initialized the development of methods and applications. There is more than twenty years of experience in modeling of coal mining development. The first attempts were devoted to select the moment of mine construction commencement in order to meet planned output. In Poland significant development of such models began in 1986. Within the Central Research and Development Program there has been a continuous development of models. These models from econometric to optimization ones, were a certain sequence which, in accordance with changing economy system, led to the last version of the model. It is the most suitable one for contemporary problems of coal mining in present Polish circumstances.

Jan 1, 1992

The purpose of this paper is to describe two systems designed to provide estimations in stratigraphic orebodies for the purposes of detailed mine planning. The first is a completely geostatistical approach and the second is a combined geostatistical/deterministic approach. The essential features of both systems are the estimation of stratigraphic ore boundaries and the subsequent use of those boundaries to provide stratigraphic (or zonal) control for block and point grade estimation (kriging). Both systems are illustrated by application to a section of, the Hilton orebodies, Queensland, Australia.

Jan 1, 1989

By D. J. Simbi, T. R. C. Fernandes, M. Nyamhunga

The recovery of P2O5 from a 90-95% minus 45 microns phosphate slimes sample was carried out in a 5.08-cm internal diameter and 549-cm high flotation column cell. The influence of the feed rate, feed percent (%) solids, and frother dosage on the recovery was investigated following a truncated cubic 3 level by 3 variables experimental design. Two three-variable interactions of feed rate (-l)/feed percent solids (+l)/frother dosage (-1) and feed rate (-l)/feed percent solids (-1)/ frother dosage (+I) gave the region of optimum column performance: recovery (52.60-74.50%), mass yield (15.68-18.80%), and concentrate grade (22.87-31.2196). The collector dosage also showed a significant influence on the column performance. The high reagent consumption relative to the current plant levels points to the need for the removal of ultrafine particles (<10 µm).

Jan 1, 1999

By Po-Wei Tun, Kuen-Yuh Wu, Tso-Min Shih, Hsi-Chiang Fang

The purpose of this study is to investgate the coal dust explosion characteristics and to search for the prevention methods of the coal dust explosion as well as the propagation of the explosion flame of the middle-bearing coal formation in Taiwan by an open type coal dust explosion apparatus in laboratory. The coal samples were taken from the typical middle-bearing formations of the Sam-Ming,Tai-Ho and Lee-Fong coal mines The rock dusts, the free water mixture with coal dust samples and the interval clean out the coal dust in the testing chambers were applied for preventing the coal dust explosion and the propagation of the explosion flame.

Jan 1, 1993

By T. P. Weldum, B. J. Mahoski, R. S. Rasmussen

A case study of a systematic approach to grinding circuit steady-state optimization is presented. After an overall review of the flow-sheet, two operating circuits were prepared for detailed testing. Functional performance analysis was chosen as the primary modeling system, and, on this basis, a quality-assurance program for data gathering was implemented. A number of circuit-design and operating variables were investigated. Statistical analysis of plant-test results revealed relationships previously unquantifiable by any other modeling technique. Improvements in the classification system and in mill grinding efficiencies were demonstrated. As a result, there was significant energy cost savings.

Jan 1, 2000

By Margaret Armstrong, Chris Roth

One advantage of kriging is that it provides both an estimate of the block or point grade, and an indication of the local precision via the kriging variance. If one assumes that the estimation errors are normally distributed, then confidence intervals for the grades can be calculated. But in mining, grades are rarely normally distributed; in general, they are skew. This is particularly true for precious metals. In this paper we study confidence intervals for variables with non-normal distributions. Using a non linear geostatistical technique, the grades are transformed into their normally distributed equivalents. Confidence intervals are obtained for these normal variables, and back transformed to give the corresponding confidence intervals for the grades, for either points or blocks. This approach is applied to gold data from the Witwatersrand basin in South Africa.

Jan 1, 1996

By F. L. Pirkle, D. A. Podmeyer

The mineral zircon is mined for use as specialty foundry sands, abrasives, ores of Zr02 and zirco¬nium metal, refractories and zirconium chemicals. It is produced as one of several products from heavy-mineral sand deposits associated with ancient shorelines. Because of its low coefficient of thermal expansion, its high melting point, its high refractive index and its chemical inertness, it is an attractive refractory material. Zircon varies from deposit to deposit in terms of grain size, grain shape and chemical purity. Thus, there is a wide range of commercial zircon products that differ in impurity levels, particle shapes and grain sizes.

Jan 1, 1993

By R. C. Ford

The advent of solvent extraction-electrowinning (SX-EW) technology for recovery of copper from low grade oxide ores has extended the operational lives of many historic mines in the western United States, and made many other orebodies economically viable worldwide. Many of these operations are mature and face closure within the next decade, depending on market conditions. Closure of a large copper heap leach operation has not been undertaken, and differs in some important chemical respects from closure of gold leach pads. Challenges for closure include prediction of solution chemistry and draindown characteristics, determining the benefit of cover placement in semi-arid climates and evaluation of solution management strategies once the economics of copper recovery are no longer favorable. This paper discusses issues pertinent to copper heap closure in semi-arid and arid climates, and strategies for their management.

Jan 1, 2000

By Prasannarao Dontula, Kal V. S. Sastry

Advances are made in the field of mineral processing on a continuing basis both in the industry and the academia. These advances do not always get used fully because of the inherent difficulties in the transfer of knowledge and reduction to practice. In recent years, knowledge engineering is being increasingly employed in other fields to overcome some of these difficulties. This paper presents a vision of how knowledge engineering can be applied to the benefit of the mineral processing industry and includes a discussion of associated principles, techniques, and advantages.

Jan 1, 1993

By J. Kalnejais

Discovered in 1896, the Sons of Gwalia orebody was initially mined by unground methods. Euring the mine&apos;s uderground operations workings reached a vertical depth of 1080 metres. The same orebody is now being mined by open cut methods. The present operation mines a broad envelope of mineralisation surrounding old stopes, whereas the original underground operation concentrated on mining high grade parts of the Gwalia Lode System. Underground mining continued up to 1963 when operations ceased due to high operating costs and the low grade of ore mined. In 1984 a new company, Sons of Gwalia NL, commenced open cut operations.

Jan 1, 1989

By S. Zaman, John Bulter, M. E. Defoe, Franklin T. Davis

This section deals with the carbon minerals and materials: graphite, tar sands, gilsonite, and diamond. as well as sulfur and the sulfides of mercury, arsenic, antimony, and bismuth. Table I contains the production figures for each of these commodities in the United States and in the world. Specifications for concentrates are also summarized as are prices for concentrates at the time the section was written. In each chapter an attempt has teen made to describe the more common commercial mineral involved with the commodity, the processes used to recover and concentrate the minerals, as well as geographical areas where these processes are utilized.

Jan 1, 1985

By J. Iannicelli

High intensity, high gradient magnetic separation can economically remove weakly paramagnetic contaminants down to 0 1 micron from industrial minerals This process is employed by all waterwashed kaolin producers in Georgia where seventeen huge magnetic separators are used to upgrade this product As a result, reserves of kaolin in Georgia have been doubled Design improvements have steadily increased the efficiency of separators and reduced power consumption below 300 KW for a nominal 65 TPH unit Beneficiation of ultrafine minerals is discussed based on pilot plant results on bauxite, ball clay, calcium carbonate, glass sand, talc, and numerous other minerals Operating parameters of the process are reviewed and some alternative equipment configurations discussed

Jan 1, 1983

By Masahiro Lnoue, Kenichi Uchino

Airflow velocity vectors by a forcing auxiliary fan at a heading face were measured in an actual size model gallery and an actual mine. The location of an outlet of ventilation duct gives significant effects on the airflow at the heading in the gallery. It was also found that there were several stagnated regions which may have danger of methane accumulation. The flow were also examined using the visualization technique by laser light in a reduced scale model. The flow in reduced scale model showed similar behavior to those observed in actual size galleries. The air velocity at the outlet has no significant effect on the airflow. It was found that a region to be ventilated by the direct flow of the exhaust fan is limited to a relatively short distance but a secondary flow region is generated near the heading face. CFD ( Computational Fluid Dynamics ) method was also developed to examine the airflow. The calculated results coincides with those measured by actual and reduced scale models. It is concluded that the CFD is useful tool for the analysis of ventilation at the headings.

Jan 1, 1997

By R. W. Barbaro, R. V. Ramani, K. V. K. Prasad, P. T. Luckie

The limitation of sulfur dioxide in power plant In this study, the following quality parameters of the coal emissions dictates that sulfur in coal be reduced to the lowest possible level before combustion to not aggravate the emission control problem at the stack. For coal-fired power plants, the methods in practice to achieve low-sulfur coal include mining areas with relatively low sulfur, reducing sulfur in the mined coal through preparation techniques and blending high- and low-sulfur coals. A prerequisite to the successful implementation of any of these practices is the knowledge of the spatial distribution of sulfur and the capability to predict its value in mining blocks. In this paper, the results of a study conducted to evaluate the applicability of geostatistics for describing the short scale variability of sulfur in a coal seam are presented. Four sides of a block of coal to be mined by the longwall method were extensively sampled at closely spaced intervals. The details of the longwall sampling plan and analysis procedures are discussed. The results of the statistical and geostatistical analysis are presented. The implications of these for prediction of sulfur for control purposes are examined.

Jan 1, 1991

By R. Gong, R. Bhaskar

A coal mine study was conducted to evaluate the effectiveness of a compressed-air, foam spray system installed under a continuous miner boom and directed to cover the pan and the gathering arm. The study&apos;s objectives were to evaluate the foam, underboom sprays&apos; effect on: • the respirable dust concentration in the ambient air, and • the quartz concentration in the airborne, respirable dust. The foam generation and delivery system&apos;s engineering design is described in the paper, followed by descriptions of the mine and the dust sampling strategy. The data were analyzed to study the foam&apos;s effects on respirable dust and quartz concentrations at the continuous miner cab, the face return and the intake. The data indicate reductions in the dust&apos;s quartz content, ranging from 19.7% to 64.6%, in eight of 11 comparisons of the foam vs. no foam cuts. In addition, airborne intake dust reductions were observed in eight of 11 comparisons.

Jan 1, 1993

The declining grades of surface deposits have re-confirmed the need for greater production rates. Large scale production requires increased investments in expensive and sophisticated equipment. The key to successful operations can depend entirely on proper equipment utilisation and in this program of research at the Department of Mining and Metallurgical Engineering, University of Queensland, much emphasis has been placed on the analysis and improvement of this aspect of a load-haul-dump operation. For a model to be successfully integrated into a mine engineering function and readily accepted by mine operating personnel, it has to offer more than just results. The concepts used in its design and construction must include sufficient detail to enable engineers to apply it usefully and with confidence.

Jan 1, 1979

By A. I. Kalugin, A. A. Abramov, D. E. Kozlov

As a result of thermodynamic analysis of a mineral-sodium, oleate-water system, flotation and adsorption tests at various pH values, and sodium oleate concentrations, it has been established that due to regularities of phosphate-containing minerals (fluorapatite, hydroxyapatite, carbonatapatite) flotation cannot be explained by the formation of alkali-earth metal oleates on their surface. This paper presents a novel theory that connects optimal conditions for mineral flotation with zero charge of its surface, which can explain the regularity of minerals flotation observed. The quantitative physicochemical flotation models developed based on the theory are suitable for improving industrial processes, conditioning of recycling waters, and application in automatic control systems at the plants. Key words: apatite, oleate, flotation, modeling, control, and regulation.

Jan 1, 1999

By LeEtta M. Shaffner, John R. Marks

The Homestake Gold Mine in Lead, South Dakota, commenced operations in 1876. As is the case with old, deep, continuously developing mines, a ventilation improvement is periodically required to maintain acceptable underground environmental conditions. Recent historical improvements at Homestake include a 5.2m diameter air shaft driven in the 1960&apos;s and a 2.1 MWR (580 ton) chilled water plant installed in 1978. By 1983, it became apparent that yet another ventilation upgrade would be needed to keep pace with accelerated development in the deepest mining sections. A study was therefore undertaken to project ventilation requirements for the next ten years and to select the method(s) most suitable to meet those requirements. The study called for a two-phase approach in which air flow and air conditioning were carefully balanced. Phase I, the installation of a new 2240 kW surface fan and several underground circuit changes, was completed in 1986. This paper describes Phase 11: the planning, design, installation and initial performance of the air-conditioning portion of the upgrade.

Jan 1, 1989

By Dorothy A. Canter

Three Federal programs exist for identifying significant environmental chemicals, including minerals, that should be tested for toxicological effects. Two programs are mandated by law and can lead to industry-funded studies; they are administered by the Environmental Protection Agency and the Agency for Toxic Substances and Disease Registry, respectively. The third is the National Toxicology Program, a Federally-funded testing initiative. This paper summarizes the three programs, describes their similarities and differences, and discusses their applicability to minerals.

Jan 1, 1991