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By J. W. Merks

Spreadsheet software is used to convert test results for drill core samples into borehole statistics such as volumes and masses of in-situ ore, metal contents and variances of metal contents. The properties of variances and the sampling variogram play a pivotal role, The additive of property of variances gives a sound scientific basis to the calculation of confidence limits for metal contents and grades as a measure of the risks associated with estimating reserves and resources.

Jan 1, 2000

By C. W. Benjamin

The paper covers the development of an efficient, "state-of-the-art" design approach encapsulating extensive research and development by Gulf on soft loading, low impact, zero spillage transfer chutes. The development, which interacts and interfaces the comprehensive methodologies for transfer chute design, allows Gulf to deliver detailed designs within 8-24 hours rather than the norm which is weeks or months. Outputs include 3D models of completed transfers and support structures along with rendered 3D representations of the design which can be fully manipulated around all axis in 3D.

Jan 1, 2000

By Y. David

In 1990, the United States became only the second country (after China) to produce more than 900 Mt (1 billion st) of coal in a single year. US production of bituminous and subbituminous coal, lignite and anthracite totaled 933.5 Mt (1.029 billion st) in 1990, 5% more than in 1989. The production gains were largely due to the rebuilding of depleted coal stockpiles by electric utilities and a surge in US coal exports. Domestic coal consumption essentially remained at its 1989 level. A slight increase in electric utility coal consumption was partly offset by a decline in metallurgical coal use. The use of coal in other industries and in the residential-commercial sector remained virtually flat.

Jan 1, 1991

By Vitaly T. Borisovich

Mining economics courses have been taught in Europe for more than two centuries and in the United States for most of this century. They are the mineral industry's version of engineering economics offered by industrial engineering departments. In the 1930s, mineral economics first appeared in American mining schools. This subject goes beyond the deposit and the mine. It examines the economic aspects of mineral resources in general and the individual mineral industries in particular. In 1947, the first degrees in mineral economics were granted in the United States. There are mining and geological engineers who specialize in mining economics. But it has rarely become a separate degree program. Rather, in this country and several others, a graduate student in a mining department or school will include economics in his course work. Then the person writes a thesis or dissertation on a mining economics topic. One exception is found in Moscow at the Department of Geoeconomics of the Moscow Geological and Prospecting Institute (MGPI). To place this program in perspective, some background is needed on education in the Soviet Union.

Jan 1, 1991

By Gary J. Goldberg

Through the early 1980s, surveying at Bingham Canyon required a great deal of repetitive and manual work. The advent of total station surveying equipment provided an opportunity to improve the speed and accuracy of surveying work while reducing manpower needs. An evaluation was made of total station systems and their ability to meet the surveying requirements of Bingham Canyon. This culminated in the purchase of a total station system as the mine reopened in 1986. The surveying department at Bingham Canyon during the early 1980s consisted of three, four-man crews using theodolites and self-leveling levels to perform the majority of the field work. Office work involved data reduction and hand plotting. Although hand-held programmable calculators were used, a great deal of time was spent manually transferring field notes to final calculations. After shutting down in early 1985, plans for start-up of mining operations in 1986 included a review of all aspects of the operation for cost and productivity improvement. Applying total station survey capabilities offered the potential to improve surveying accuracy and speed while reducing manpower needs.

Jan 1, 1990

By Bruce A. McKinstry

For many major mining projects the time frame from initial planning to production can be measured in terms of decades. Hecla's Silver Shaft project, which is scheduled to go into production by the end of this year and includes a complete surface facility, shaft with an ultimate depth of 2,348 meters (7,700 feet), complete ore pass and loading pocket system, and 610 meters (2,000 feet) of development drifting and stope preparation, was initially concieved in the Fall of 1979. This duration of a mere four years from conceptual engineering to production is a testimonial to what can be accomplished when a progressive mining company and an innovative contractor work together as a team rather than developing into two warring camps as often happens.

Jan 1, 1983

By C. Peppin, H. McLoren, D. Bayer

Hecla Mining Company and Master Builders Inc. conducted a study to evaluate the use of admixtures in reducing backfill binder concentrations. Additionally, admixtures were evaluated to help mitigate the occurrence of cold joints in the fill. Initial results demonstrated a 20% reduction of cement was possible while maintaining critical strength and flowability criteria. Admixtures also helped to control the formation of cold joints in backfilled areas.

Jan 1, 2001

By S. Liu

A general account of nitrogen-generating systems, including the surface fixed, surface-mobile and underground-mobile types is presented. These systems have recently been adopted in coal mines in China to prevent and extinguish fires. The paper stresses nitrogen -injection technology and relevant systems of monitoring and stopping air leakage.

Jan 1, 1998

By Michael D. Zuber

This paper discusses the use of a coalbed methane simulator that has been modified to account for the removal of grid blocks as a function of time to estimate gas emission and production for a variety of mine-associated problems. The specialized features of the simulator are presented. Example applications illustrate the models' use in estimating methane emission rates during mine roadway development, and estimation of longwall panel degasification by horizontal boreholes.

Jan 1, 1997

By John T. Crawford

Various open pit limit-analysis techniques have been utilized for many years to design pit limit surfaces. In the last 15 years there have been many advances in developing sophisticated computer methods to aid this process. The extensive capability of the digital computer has led to effective utilization of multiple alternative approaches to problem solving. Computerized open pit limit analysis methods can be applied to a broad scope of long range and intermediate range mine planning and design needs. This paper provides an overview of some of the more important of these applications. While not covered in detail, they are meant to indicate the flexibility and adaptability of open pit limit analysis methods and to stimulate thought.

Jan 1, 1979

By W. Kennedy Gauger, Tim Oolman, Debra L. Bisson

Radian Corporation (Radian) has developed a process for treating Cr(V1)-contaminated soils that involves: 1) soil washing using an alkaline extractant, 2) biological reduction of Cr(V1) to Cr(II1) in the soil wash effluent, and 3) separation of Cr(II1) from the biologically treated effluent. Biological treatment has been demonstrated for immobilized cells in fluidized bed bioreactors and suspended cells in slurry bioreactors for Cr(V1) levels ranging from 30 to 600 mg/L which have been reduced to non-detectable levels (< 0.05 mg/L; method detection limit [MDL]) during hydraulic residence times as short as 12 hours. The resulting Cr(II1)-containing effluent stream was chemically treated to precipitate chromium hydroxide for removal by physical separation.

Jan 1, 1995

By Leif A. Nordell, Philip E. Freeland

A paper discussing specification, methods, situations and results encountered in underground phase construction of the Rocky Mountain Pumped Storage Project near Rome, Georgia. The scope of work included excavation, rockbolt/shotcrete/wire mesh primary support and cast-in-place concrete lining of the (1) 216 m, top flared shaft, connecting 1.57 radian elbow, and 590 m tunnel to a 10.67 m finished diameter; (2) complex double bifurcation section; (3) excavation, support, installation and backfill concrete for three parallel, 135 m steel penstocks of 5.79 m finished diameter; (4) construction of a 43 m diameter reinforced concrete intake/discharge structure atop the shaft.

Jan 1, 1985

By G. Markopoulos

Thracean Gold Mining is a Greek Company specialized in gold exploration and exploitation. It is focused on the development of the advanced Perama Hill gold project, which is currently waiting approval of the environmental terms of reference from the Ministry of Environment. We have designed a mine operation that is completely safe environmentally. The mine design exceeds all the standards environmental safety set by the European Union. We are currently negotiating lasting relationships with the communities which surround the mine by creating sustainable projects within the area that will provide sources of income to the region long after the mine is exhausted.

Jan 1, 2007

By A. Vargiu, R. Ciccu, G. Massacci

Based on the current results of field practice and on experimental data obtained in the laboratory with a suitable testing apparatus, the industrial operation of diamond wire cutting can be simulated by means of a mathematical model capable of predicting the cutting velocity and the wear rate of the tool, and thence the cost figures, achievable for a variety of conditions (kind of rock, size and shape of the cut, position of the equipment) according to a predetermined setting strategy (peripheral velocity, pull- back force). The paper gives a short outline of the model and discusses the simulation results obtained in a number of cases aiming at singling out the most favourable conditions for a cost-effective use of diamond wire.

Jan 1, 1996

By R. G. Darmody

Chemical problems associated with surface mining, such as acid generating materials, are important and well documented. However, reclamation research has shown that poor soil physical condition is the most limiting factor to successful row crop production on reclaimed mined land. Critical to success are selection of the best available soil materials used in soil construction and a material handling method that minimizes soil compaction. Excellent corn and soybean yields have been achieved on low strength soils both in high weather stress years as well as low stress years. Total crop failures have occurred on high strength soils in years of weather stress. Some deep tillage practices have been successful in improving compacted soils, but it is preferable to avoid compaction when the soil materials are handled. Soil strength measurements with a cone penetrometer have proven to be a useful tool in evaluating rooting media and reclamation practices. Research has shown that surface mining can be a short term land use that may be followed by productive farmland, if reclamation is done correctly.

Jan 1, 2002

By J. R. Sturgul

A dynamic input-output model for a coal power enterprise that now includes four underground coal mines, three coal washing plants, a power plant and a railway transportation system was developed. The model is applied to analyze investment alternatives for long-term development, including the expansion of existing mines, the opening of new mines, the construction of new coal washing and power plants and the upgrading of the railway system. As a result, the optimal investment strategy with capital schedules and projected sector outputs is obtained. Also, the importance of the new power plant to the strategic development of the company is demonstrated. It is concluded that, without applying a dynamic input-output model, it would be much more difficult or impossible to conduct such a systematic and compete analysis.

Jan 1, 1999

By D. F. Martin

Sustainability is typically understood as having three interrelated dimensions-environmental, economic, and social. However, far less attention has been paid to social sustainability than to the other two forms. The paper argues that one of the difficulties in giving substance to the concept of social sustainability is that it is inherently value-dependent and has major conceptual, definitional and therefore measurement issues. This is particularly the case in complex crosscultural environments such as those found in Australian mine hinterlands with significant Aboriginal populations. Nonetheless, a concept of social sustainability can provide an important counter to the usual focus on environmental and economic sustainability, and can productively guide the minerals industry in its engagement with the Aboriginal people of mine hinterlands. The paper outlines a set of principles for socially sustainable communities, and proposes means by which these principles can be implemented. It further suggests that these principles may have broader applicability than just in the case of Aboriginal people.

Jan 1, 2005

By Robert C. White, Kurt W. Keskimaki

The Henderson Mine is a large underground panel cave molybdenum mine located near Empire, Colorado. Diesel equipment is employed for all development work, as well as production ore handling. Due to fluctuating demand for molybdenum, production rates have varied from 16,000 to 32,000 metric tons per day (18,000 to 36,000 short tons per day) over the last four years. In order to obtain the maximum air flow for minimum power cost the Henderson mine has completed the following modifications to the ventilation system: removal of large intake fans, elimination of underground booster fans, shutdown of tunnel exhaust fans, completion of the number 5 exhaust ventilation shaft, and use of partially debladed main exhaust fans. These changes have reduced the annual cost of mine ventilation at the Henderson Mine by over 80 per cent, a very critical cost savings in today&apos;s competitive molybdenum marketplace.

Jan 1, 1989

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 R. W. Smith, R. K. Mehta, X. P. Zheng, A. M. Raichur, M. Misra

Experimentation was per formed on the flotation of apatite and dolomite separately using anionic collectors in the presence of Mycobacterium phlei. Also, the flotation of mixtures of dolomite and apatite in the presence of anionic collectors and in the absence and presence of the bacterium were studied. It was found that M.phlei functions as a depressant for both minerals. However, it functions as a better depressant for dolomite than for apatite. Experimentation was extended to two different Florida dolomitic phosphate rocks. In this investigation a concentrate grade of less than 1.0% MgO was achieved with a 75% P2O5 recovery.

Jan 1, 1999