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By LeRoy D. Loy

The coal mining industry must be able to compete with alternate sources of fuel for the utility and industrial customers. If the industry is unable to control transportation costs, either due to government interference, or for other reasons, then mining costs must be kept down. Australia, South Africa, Canada, (and later Colombia) will take larger shares of the export market if mining costs are not kept competitive. The government's environmental regulations must be met without incremental increases in mining costs. Entrepreneurial instincts must be retained by the industry to provide for their investment in the future. What are the Problems with Existing Research? Government funding for coal mining research has been reduced or virtually eliminated. BCR (Bituminous Coal Research) is now a membership- supported organization, but its primary focus has been on health and safety-oriented research. BCR, however, is now attempting to widen its scope and conduct other types of research. There are almost no funds in EPRI's (Electric Power Research Institute) program for coal mining research. Large mining companies do some research for their own purposes and needs, but this is proprietary and therefore results are not shared with the remainder of the industry. The mining industry as a unit is not undertaking productivity (systems) oriented research in any common or cohesive manner.

Jan 1, 1983

By G. T. Lineberry, R. S. Mateer

Often only after years of "technical dormancy" do errors in published literature become apparent and meaningful. To prevent duplication of effort for future generations, the fol¬lowing corrections are offered. These errors were discovered during a recent study in which a computer program for mine hoist rope selection was developed (Lineberry and Mateer, 1988). In order of increasing gravity: Captions for Figs. 3 and 4 are transposed. • Purported to be a more accurate method of rope selection than the process of successive approximation, the direct method assumes linearity between a given rope's minimum breaking strength, T, and unit rope weight, Wv. Because of the sensitive location of the constant, K, in equation (8) for breaking strength, the significance of this nonlinearity is magnified. For a typical 6 x 37 class fiber core wire rope (Wire Rope Corp. of America, 1985), K actually varies from 43,650 to 52,190, depending upon rope diameter. Although the direct solution permits a rapid selection of hoist rope, an indirect (iterative) solution procedure is favored because of its im¬proved accuracy and ease of computerization. • Equation (8) for minimum breaking strength is in error. It should read:

Jan 1, 1989

By G. T. Lineberry, R. S. Mateer

Often only after years of "technical dormancy" do errors in published literature become apparent and meaningful. To prevent duplication of effort for future generations, the following corrections are offered. These errors were discovered during a recent study in which a computer program for mine hoist rope selection was developed (Lineberry and Mateer, 1988). In order of increasing gravity: Captions for Figs. 3 and 4 are transposed. Purported to be a more accurate method of rope selection than the process of successive approximation, the direct method assumes linearity between a given rope's minimum breaking strength, T, and unit rope weight, WV. Because of the sensitive location of the constant, K, in equation (8) for breaking strength, the significance of this nonlinearity is magnified. For a typical 6 x 37 class fiber core wire rope (Wire Rope Corp. of America, 1985), K actually varies from 43,650 to 52,190, depending upon rope diameter. Although the direct solution permits a rapid selection of hoist rope, an indirect (iterative) solution procedure is favored because of its improved accuracy and ease of computerization. Equation (8) for minimum breaking strength is in error. It should read:

Jan 1, 1990

By T. A. McAfoose

As one of the major suppliers of the chestnut Ridge energy center, Rochester and Pittsburgh Coal Company continues the search for more efficient haulage systems. This search is one that is essential in providing coal to the Keystone and Homer City power plants at the most economical cost. These two electrical generating plants located in west central Pennsylvania are part of the energy center which consists of four generating stations. Prior to the time the two stations were put on line, August, 1967 for Keystone and August, 1969 for Homer City, our company made the decision to rely on belt conveyors from the section to the surface to provide for continuous main line haulage. The proximity of these generating stations to proven reserves allow for minimal truck haulage and minemouth setups. With the addition of seven new mines, in the past ten years, revisions have been made on the original setup to interconnect the haulage of several mines to deliver the product by belt to the power plants.

Jan 1, 1979

By E. Farrokh

Estimation of the cutter life and cost is a part of evaluating performance for a hard rock TBM in any project. Various approaches has been proposed for calculation of disc cutter life in various rock types based on machine specifications and rock strength and abrasivity. Cutter change time is a parameter that is used in some of the estimates and is defined as the average time required for changing a cutter on the cutter head and cutter life is the number of cubic meters of excavated rock per each disc cutter. Analysis of cutter life information of several tunnel projects from around the world has revealed that the published models for estimation of cutter consumption require some revisions to offer a more accurate prediction. The preliminary analysis of data shows that the average cutter change time is approximately 66 minutes for different cutter sizes and there is a minimal difference between corresponding cutter change times of the large (e.g. 19 or 20 in) versus smaller cutters (e.g. 15.5 to 17 in). This paper reviews the available and published cutter life data from various projects. It also introduces new models for estimation of cutter life and cutter change time as part of TBM down time and utilization analysis.

Feb 27, 2013

By T. Freeman

In the past ten years, the Geotechnical Baseline Report (GBR) has arguably become the key document for tunnel construction. This report not only allocates much of the risk involved with the work, it serves as the basis for bid preparation and is used extensively in resolving disputes during construction. This paper discusses some important issues related to the GBR and presents suggestions for improving these vital reports.

By G. Tapia, R. J. Kelley

Empresa Minera de Mantos Blancos S.A. operates two copper mines in Chile: Mantos Blancos and Mantoverde. Oxide ore is processed by acid leaching followed by SX-EW to produce copper cathodes. In order to define the leach process adequately for each ore, an extensive metallurgical testwork program was carried out during the feasibility study for each of these projects. A combination of heap and dump leaching was selected for Mantoverde, while a modification to the existing vat leach operation was selected for Mantos Blancos.

Jan 1, 1998

By Albert E. Ketler

The techniques for fire monitoring of conveyor belts in underground coal mines have been revolutionized by the advent of sensitive carbon monoxide sensors and computer monitoring systems. These new systems are rapidly replacing the previous thermal (fixed-point temperature) sensors that have been shown to be considerably less sensitive for early fire warning. CO is generally an excellent indicator of spontaneous combustion. However, the most recent non-flammable conveyor belt materials have been shown to "burn" with dense smoke, but without sufficiently high temperatures to produce much carbon monoxide. To cover this fire detection void, a smoke detector was developed to augment CO sensing for these new conveyor materials. However, computer monitoring provides the flexibility for handling this and other additional instrumentation as fire monitoring techniques evolve. CO, smoke and temperature sensing may eventually be advocated for complete fire monitoring.

Jan 1, 1987

By W. N. Brown

One of the seemingly eternal problems with which we are frequently faced is that of providing adequate and economical warehousing facilities to store large quantities of bulk product. Seasonal consumption, transportation, marketing, and other factors very often dictate extensive product warehousing requirements for an operation geared for steady, year-around production of a material requiring weather protection during storage. Fertilizers such as potash and urea are examples of such products; the consumption of these materials is extremely heavy in the early spring at which time the materials must be placed in the soil, whereas, for obvious operating efficiencies, production is more or less constant for a given operation throughout the year.

Jan 1, 1961

By Terry I. Mudder, Michael M. Botz

Discharge regulations for mine waters require relatively low concentrations for cyanide and metals, and the trend is for discharge limits to be lowered. In the event conventional treatment practices are not sufficient to meet discharge limitations, advanced treatment technologies such as ion exchange and reverse osmosis may be considered. Though these technologies will provide discharge quality waters, they also require the disposal of a concentrated brine and are relatively complex and costly to operate. Many mine sites currently using activated carbon in precious metals recovery present the opportunity to economically operate an activated carbon water treatment plant for polishing of effluents. This paper presents summaries of six ( 6) mining operations which have evaluated or use activated carbon for treatment of water and which also use carbon in precious metals recovery processes.

Jan 1, 1997

By Steve Axen

In situ mining is now considered an alternative mining method for some ore bodies. The in situ operation consists of a well field designed from reservoir properties and geological information; the wells for such a field are then drilled, cased, and cemented, using good designs and practices to eliminate future problems. Injection and production (recovery) systems are required to be corrosion resistant. Hand in hand with the mining operation is the metal extraction plant, the entire operation offering an environmentally acceptable method for metal recovery. Great opportunity exists in this field for mineral engineers; presently, they must borrow knowledge from other fields, since the schools have not yet addressed this specialty.

Jan 1, 1979

By H. K. Pelzer

Belt conveyor systems for long-distance haulage are nowadays in a competitive position with conventional methods of transportation such as railways, truck haulage, and also pipelines for solid materials. In a number of cases, the economical use of conveyors is obvious. This is in all those cases where typical features of a conveyor system are showing the outstanding economical position in the very first approach for a certain project. Regarding downhill conveyors, with today's level of belt conveyor techniques nobody would reasonably doubt the justified application of a conveyor system, - as for instance at the Marcona Mining Installation, or at the iron ore mine of Lamco in Liberia.

Jan 1, 1968

By P. Bevilacqua, G. Vallebuona

Empirical models are now used for predicting the performance of hydrocyclones in terms of capacity. cut size (d50.c), water split and partition curve. These models (such as the model by Lynch and Rao and the model he Plitt) were developed and checked for hydrocylones with diameters larger than 4 in. However, for smaller-diameter hydrocyclones, little empirical modeling has been done. This paper reports on an extended experimental research program on small hydrocyclones. For these cyclones, the suitability of existing empirical models was investigated and their accuracy was compared. To improve the predictive capability of these models to small cyclones modifications to the equations are proposed.

Jan 1, 1996

By James L. Crowe

Electric-power-generating plants fired by fossil fuels are faced with increasingly stringent requirements for control of sulfur emissions. Several approaches for limiting these emissions, or for operating such facilities in an environmentally acceptable manner, are being pursued. Some of the approaches are based on the use of naturally occurring carbonate rocks or of materials derived from them. This paper discusses primarily the carbonate-rock-based processes being developed for control of sulfur dioxide emissions from fossil-fueled electric-power-generating plants. It includes a discussion of the role of carbonate rock materials in removal of sulfur dioxide from stack gases after combustion, capture of gaseous SO2 during the combustion process, and removal of sulfur from fuel prior to complete combustion. Materials derived from carbon- ate rocks are generally used in processes which convert the sulfur to a throwaway product, but there are also proposed processes in which the sulfur is converted to a useful product and the absorbent is regenerated for reuse.

Jan 1, 1974

By Gene R. Block

The most economical method of reclaiming land that has been mined, whether it be in urban areas or in rural areas, is when the final configuration of the mining area is that which is required by the subsequent use. Surprisingly, there are a number of examples of this situation. In the arid southwest where water production for the expanding population is a problem, many urban sand & gravel excavation areas subsequently serve as holding basins for ground water recharge. In other areas of the county where water is not in short supply, sand and gravel excavations can be planned in such a way that subsequent land uses such as parks and homesites can be enhanced by utilizing the excavated areas as a water amenity. Reclaiming land for agriculture is another example of utilizing the excavated area for a subsequent use providing the excavated area has not been mined too deep. Other than replacing the layer of topsoil on the excavated area, the final configuration of the mining area is in many cases ready for the subsequent agricultural use.

Jan 1, 1984

By James A. Brierley, Rong Yu Wan

Bacterial pretreatment was evaluated as a process for enhancing gold recovery from a refractory ore from Newmont Cold's Cold Quarry deposit. This ore is refractory due to sulfide locking of the gold and preg-robbing carbon. The microbe Thiobacillus ferrooxidans effectively oxidized the sulfide component of the ore, but the preg-robbing carbon continued to be active. Thiourea was examined as an alternative to cyanide for extraction of the gold from the biooxidized ore. The thiourea, coupled with CIL, was effective for gold extraction resulting in up to 89% gold recovery for the sulfidic-carbonaceous refractory ore. The thiourea gold complex appears not to be bound by the preg- robbing carbon of the ore when in the presence of recovery carbon (CIL)

Jan 1, 1990

By T. B. Whitmoyer, J. E. Sneckenberger, M. A. Jerabek, C. F. Stanley

The measurement of acoustic impedance at frequencies up to 6,400 Hz has been proposed as a diagnostic tool to yield more detailed information about lung condition. A three generation branching system of plastic Y-tubes has been constructed. The impedance of the branched system is measured by an impedance tube using the two-microphone technique. The impedance spectrum is used to calculate the reflection coefficient spectrum, which is converted to an impulse response by an inverse FFT. The area function is extracted from the impulse response by the Ware-Aki algorithm. Measurements of acoustic impedance of the branched system were made for several different end conditions of the eight terminal outlets. The outlets were either blocked with modeling clay, plastic packing material, or aluminum blocks or were unblocked. Six measurements were made of each configuration. In general, the more outlets blocked, the larger the shift to the right of the impedance magnitude peaks for frequencies above 3000 Hz. The impedance magnitude peaks for the plastic packing material were shifted in frequency to the right relative to the peaks of the other system terminations. The impedance magnitude peaks for the clay and aluminum system terminations were significantly different in magnitude but not shifted in frequency. The area functions at the end of the branched system were significantly different (a > 99%) for most of the end conditions. Area functions for the modeled branched lung systems between the end of the impedance tube and the termination outlets of the branched system were similar but distinctively different for the various end conditions. These results indicate that the two-microphone technique can sense small changes in the terminating end conditions of a rigid system of branched tubes and thus may sense impedance changes due to lung disease in the conducting airways. Keywords: acoustic impedance, lung model, area function.

Jan 1, 1991

By Guiseppe Bonifazi

This work applies the definition of "separation function" already introduced in the paper presented at the XVIII IMPC. This 'function" (defined for a certain size distribution after comminution of an ore) refers to the recovery distribution of a mineralogical species in a product made up of all the particles having at least a given content of that species. Many tests would be required to determine the liberation function for each mineralogical species, particularly for complex ores. Several stages of comminution would need to be examined and the mineralogical composition of the particles of each grain size class would need to be analyzed for each process step. A quick and dirty method is shown for obtaining the "separation function". It is based on the processing of data from topological maps of polished and/or thin representative sections of ore. By superimposing grids of different sizes over these maps and with appropriate combinations of mesh sizes, it is possible to simulate the grain size distributions linked to different stages of comminution and then evaluate the mineralogical composition of each grain. The procedure is carried out full automatically and can simulate a complete treatment circuit, imposing cut-off grades for the products at each separation phase. It is also possible to predict the results of treatment processes that involve grinding phases. The procedure has been successfully applied to complex ores containing several useful components.

Jan 1, 1995

By James J. Olson

INTRODUCTION The need for Government-sponsored research and development to increase excavation rates and lower costs for tunneling and mining operations in a variety of rock types has been emphasized in a wide range of publications from advisory panels, symposiums on rapid excavation, and individuals. In response to the predicted demands for mining and construction-oriented underground excavations for the next two decades (1970-1989), a comprehensive 10-year, $200-million research program in rapid excavation was proposed by the National Academy of Sciences in 1968 (1). Although the large program recommended by the Academy has not been funded, substantial Government-sponsored research in rapid excavation has been conducted during the past several years. This paper reviews some of the significant research accomplishments obtained under a three-year, $6.6-million research program in rock mechanics and rapid excavation sponsored by the Defense Department's Advanced Research Projects Agency (ARPA) and managed by the Bureau of Mines. In addition to the rock mechanics research, five major phases of excavation; systems analysis, geologic prediction, rock disintegration, ground support, and materials handling were represented by the projects funded under the ARPA program. The brief outline below recapitulates the major research areas and some of the projects summarized by this paper: Excavation Process Modeling by Computer Geologic Prediction Geologic Reconnaissance for Site Selection Longhole Probe Drilling for Hazard Detection

Jan 1, 1974

By Howard L. Hartman

Introduction The federal government's declining role in funding research has created a critical dollar gap for university departments of mining engineering. Industry, too, is affected by the drought. Research is lagging. Hardpressed universities are going to the private sector for funding. Mining companies should not shower universities with philanthropy, but a research partnership should be contracted on a pay-as-you-go basis. A model exists at The University of Alabama (albeit not in mining) that could be adopted by the mining industry. An equal partnership arrangement between a university and an industry for conducting research is proposed. The concept is not that a corporation sponsors and a university performs the research. Nor does it call for educational contributions or giveaways from industry. Rather, the corporation and the educational institution enter into a cooperative research endeavor, a full and equal partnership. Both parties contribute and both share the benefits. A key to the relationship is that it has a single objective: it must generate profits or reduce costs for the company. Working Model Recent literature is replete with examples of proposals for joint research endeavors, involving both contracts and grants, between industry and universities (Bronwell, 1971; Bugliarello, 1978; Branscomb, 1981; Sanford and Holland, 1982). They are all good proposals and offer something to both parties. They are, however, not widely supported. Few have received a favorable nod from the US mining industry. Though it may be logical, for example, to remake the American Mining Congress (or some new consortium) in the mold of umbrella-type industry organizations to fund cooperative research with mining institutions, such proposals have never flown. What model, then, will work? First, look for a model that has worked in industry in general. Second, seek to apply it to mining specifically. There is a model project that satisfies the first of those criteria. It is a project complicated by a third party, in addition to a corporation and a university. In January 1983, the "Factory of the Future Project" was initiated between The University of Alabama (UA) and General Motors Corp. (GM). The United Auto Workers (UAW) is a third party to the agreement. The factory was GM's Rochester Products Division manufacturing plant in Tuscaloosa, AL, also home of UA's main campus (Fig. 1). Saving a Plant The agreement came about at the initiative of GM and the UAW. Faced with having to close the plant because of excessive production costs, company and union officials proposed to the university that an applied research facility be established at the plant. The university would operate the laboratory, dedicated to $470,000 a year cost reductions for the company. The school would lease the 5.1 km2 (55,000 sq ft) space for $470,000 a year for three years. Any savings effected by the university's research effort would be credited toward to the rent. GM said the small factory, which made replacement carburetors

Jan 9, 1984