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During the period 1979 thru 1982, Multi Mineral Corporation conducted a mining research program at the United States Department of the Interior's Bureau of Mines Oil Shale Mining Environmental Research Facility in the Central Piceance Creek Basin, Rio Blanco County, Colorado. The program consisted of mining, environmental and geotechnical research data and, the results are described in this report.

Jan 1, 1983

By Edgar Carlos García Flores

El presente texto señala al Perú como modelo de sistemas de explotación minera para Bolivia -en tanto desarrolle, prepare y explote las minas con calidad y así incrementar la producción de sus operaciones mineras. Asimismo, describe los procedimientos idóneos para seleccionar las tablas geomecánicas, la ingeniería de explosivos, equipos de acarreo y los elementos de sostenimiento adecuados para las excavaciones subterráneas con el objetivo de tener operaciones de calidad, seguras y óptimas.

Feb 1, 2015

By William F. Riggs

Inspiration Consolidated Copper Company, located in a semi-arid climate in Arizona, continually struggles with a water problem. This applies to quality as well as quantity. When the EPA considered installing a new centralized sewage plant to handle the combined waste from the municipalities of Globe and Miami, Arizona, they automatically assumed that He could use the sewage effluent for process water in flotation. The treatment plant was to be a tertiary system producing 1600 gpm of sewage effluent. Inspiration decided that this could possibly be a source of additional process water. It was decided to test sewage effluent from Miami Treatment Plant at the rate of 400 gpm since it was only a primary treatment plant. The 400 gpm was combined with the 5000 gpm of process water going to the Concentrator. After one week the results were disastrous. The recovery and final grade had each dropped approximately 5%. With the results from this brief run, it was concluded that sewage effluent from a primary treatment plant could not be used. Research was then brought into the problem to begin an evaluation of sewage effluent in flotation.

Jan 1, 1977

By Charles L. Ross

A successful placer mine is being operated by the E. T. Fisher Co. on Rock Creek in the South Pass mining district at Atlantic City, Wyo. About 2,800 cubic yards of gravel is dug daily by a gasoline-driven dragline shovel with a 1 1/4-yard bucket and washed in a movable plant with a gold-dredge trommel and standard-dredge sluice boxes; the total cost is about 12 cents per cubic yard. The gold-bearing gravel occupies a narrow valley between two low ranges, of hills. The ground is covered by brush and willows, which are cleared of in the fall by burning after the leaves have dried. The elevation at the mine is 7,600 feet above sea level.

Jan 1, 1935

By L. R. MURPHY

This paper gives a general description of mining operations at the Rosebery Mine and a brief account of the older Hercules Mine. The more unusual aspects of the operations, such as the sinking of the inclined shaft, blast-hole experiments, diamond drilling practice, and proposed future developments are described in detail.The following main heads are used:Roseberry- General production Data.General Description of Ore-body, and Characteristics of Ore and Country Rock.Layout of MineMining Methods, Filling, etc.Blast Hole Stoping.Sinking Main Inclined Shaft.Mining Timber. Contract System.Diamond Drilling and Sampling.Surveying.Labour Force.New Developments, Sand Filling and Pumping.Hercules-Situation of Mine.Transport-Haulage and Aerial.Ore Bodies.Stoping Methods.Ore Handling.

Jan 1, 1949

By M. Hajian Heidary

In this investigation, effect of pressure depth on the globulizations of AZ91 magnesium alloy was studied. Cylindrical samples of AZ91 alloy with 1 cm and 2cm in height and 2.5cm in diameter (H/D = 0.4 and 0.8) were prepared, then the samples were hot pressed at 10 and 30% strain at a constant temperature of 200°C; subsequently reheated at 555°C in different times. Results obtained from optical microscopy (OM) showed that the thickness of the samples and consequently, depth of strain affected regions have remarkable effect on the degree of globulization. In addition, it was found that at a constant strain and holding time, structure of thinner samples is more globular than thicker ones.

Jan 1, 2007

The mining industry worldwide is currently facing a significant restructuring process. In most underground mines, widespread mechanization of the mining processes increases production while reducing staff numbers. At the same time, mining depths as well as the lateral spread of the mine workings are increasing. This ever-changing mining environment requires sophisticated solutions for the design and operation of underground mines. In fact, a reduced number of mining engineers is taking responsibility for everincreasing mine operations. This applies not only to the excavation of the minerals, but also to all other aspects of the mining operation, including health and safety, disaster management, and mine rescue organization. Most mining engineering graduates entering the industry lack experience in mine emergency management. Young engineer trainees must learn mine emergency management and rescue work in addition to their normal training experience on the job. Often, and unfortunately, emergency and rescue training at different mining companies is not carried out to the highest level and standard and with the best possible training outcomes. The tasks and challenges a young engineer faces while being trained in a new position do not leave much room for additional training in mine rescue and emergency management. At the same time, experienced, ?old hands? are retiring and cannot easily be replaced due to limited graduation numbers. Strategies are being developed at mining universities worldwide to train mining engineering students in handling mine emergency situations and to provide hands-on experience for managing potential accident and disaster scenarios underground. Two of these strategies, from the USA and from Central Europe, are presented in this paper. These specific strategies have to be seen under special consideration of the local and regional boundary conditions, but might serve as case studies for mining schools and universities in other countries.

Jan 1, 2014

By David White

This paper is the result of a comparative study of ultimate coal analyses made and published by the United States Geological Survey. This study, at first casually undertaken to devise an acceptable classification of coals based on chemical analyses, was continued in connection with a microscopic examination of a number of the coals. The initial comparisons, made from a relatively small number of analyses, not only confirmed a previous conviction that the elimina- tion of oxygen incident to the development of a coal is economically far more important than has been generally suspected, but also showed that oxygen is very nearly as harmful as ash in coal. The immediate purposes of the present study were: (a) To deter- mine more definitely, from a comparative examination of a large number of ultimate analyses, the relative importance of oxygen as an impurity in various coals; (b) to illustrate the transition between various grades of coal of similar origin-transition mainly due to progressive devolatilization, brought about more or less directly by dynamic influences; (c) to ascertain the relative proportions of oxygen, hydrogen, and carbon in coking coals, especially with refer- ence to a theory tentatively framed to explain the coking quality; and (d) to forecast the probabilities of successfully treating a large number of coals so as to render them amenable, in a softened condition, to satisfactory study under the microscope. Although the hypothesis as to coking quality finds but partial support in the chemical analyses, its consideration has led to a method of predicting from an analysis with a fair degree of certainty whether any given coal will coke by the ordinary process. The unbroken transition between coals originally similar but now classed in widely different groups, whether of the same age or of different ages, as a result of dynamochemical action, appears demonstrated by the analyses as well as by field observation. This subject will not be

Jan 1, 1911

By W. M. Snoddy

The Montana Tunnels diatreme is a low-grade polymetallic ore body containing economically mineable quantities of gold, silver, lead, and zinc. Widely varying gold grades combined with the general erratic nature of the mineralization create a complex sampling, assaying, and ore control problem. In order to maximize productivity and profitability, a variety of procedures have been used. These include differing sample size, frequency and method. In addition, assay techniques have been adjusted and refined to fit specific requirements, the result of which is an accurate, functional sampling and ore control system.

Jan 1, 1991

By A. Sand

A 2-dimensional computational model based on the discrete element method (DEM) is utilized for modeling of stamp-charged coke making. In this process, a large volume of coal is compacted to one single coal cake before entering the coke oven. Cake densification and mechanical strength development are key factors for the subsequent production of a high-quality coke. An approach is introduced for model calibration utilizing multiple control parameters obtained from a laboratory-scale stamping device. Experimental data on stamper rebound amplitude, attenuation and peak force are compared with simulation output in a pairwise manner by constructing a criteria space, which allows identification of model settings best satisfying the control parameters. The calibration procedure carried out by multiple criteria comparison aided model parameter selection for reproducing stamper behavior in response to the properties of the cake subjected to compaction. This modeling and calibration procedure offers possibilities for numerically studying the densification and mechanical strength development of coal cakes. However, the approach is also more widely applicable to other compaction processes.

Feb 27, 2013

By F. R. Lee

This publication lists permissible equipment approved by the Bureau of Mines during 1965 and 1966 (calendar years), except for breathing apparatus and explosives. The purpose of this publication is to inform the public about approved equipment for safe use in underground mines.

Jan 1, 1968

By J. E. Hipp

Three electrostatic field sensing proximity warning devices were tested using full-scale cranes and power line systems, a scaled model facility, environmental testing facilities, and theoretical/numerical analysis. The design objective of each device is to assist in safe crane operation near overhead power lines. Several design deficiencies (varying from device to device) were observed, including inadequate overlap in sensitivity ranges, utilization of vacuum tubes and electro-mechanical parts, temperature sensitivity and inaudible alarms. In addition, the testing showed major device limitations including sensitivity to boom orientations and length, polarization dependent responses, and unreliable operation in the presence of multiple power line circuits. The multiple power line circuit problem is intrinsic to electrostatic sensing devices. The remaining deficiencies and limitations are correctable within a state-of-the-art design. This investigation is not intended to evaluate the safety aspects or policy of utilizing proximity warning devices. Rather, the purpose is to determine the performance characteristics of such devices in relation to the criteria specified in proposed MSHA regulation 77.805-4 (i. e., the devices must alarm at a distance of 10 feet from the power line).

Jan 1, 1980

By Arthur L. Murray

"Oil-shale camps are peculiarly favored, in that before they are establishes it can be ascertained with a degree of certainty, that the life of the project is not limited. Unlike camps at metal mines, where the metal content of a given area is frequently an unknown quantity until after years of development, oil-shale camps should, from the outset, be planned and. built as permanent types of camps. Where this procedure is followed camps will be established which better serve the needs of the industry and the cost of their general care and upkeep will be less.Selection of camp or townsite.The site of the camp or town' whether on company property or not, should be selected with care. It should be separate if possible from the location of the plants of the company so as to be free from noise and fumes and so as to provide a change of environment for employees in going from their work to their homes.The principal features governing the site to be selected are as follows:Drainage. The general contour of the surrounding country should be such that drainage is away from the site. The camp or town should, if practical, be situated on higher ground than that in its immediate vicinity.Soil. The nature of the soil on which the camp or town is located may bear a decided relation to health. A porous, well underdrained top soil of at least four feet in depth insures dryness and facilities the placing of foundations and the laying of water mains and sewer pipes. Such a soil also is an advantage in growing trees, shrubs and grass plots, which are a decided adjunct to making the community attractive.Enviroment. The contiguous territory should afford no unwholesome sur¬roundings such as swamps Or accumulations of stagnant water.General Considerations. The water supply to be provided and the method of disposal of wastes influence to a certain extent the location of the camp or town-site. The means of supplying water, whether by gravity or by pupping, and the disposal of sewage, whether by outfall, system, sewage disposal system through septic tanks, broad irrigation or filter beds, or cesspools will govern the location of the site topographically in relation to source of water and point of disposal of sewage.* This article was prepared as part of the paper ""Use and Supply of Water for the Oil-Shale Industry"" by J. J. Jakowsky, to be published by the Department of Metallurgical Research, University of Utah, in cooperation with the United States Bureau of Mines."

Jul 1, 1921

By J. Gholamnejad

In open pit mine planning and design, push back mine sequencing is widely used for long-term production planning. In push back design, a series of nested pits is generated and then considered as possible push backs with regard to the minimum push back width requirements. These nested pits are produced by parameterizing on one economic parameters like commodity price, mining or processing cost, stripping ratio etc. The most important characterization of these push backs is that the inner most push back has the highest value per ton, the second inner most push back has the second highest value per ton and so on. These nested pits are generated based on the best estimates of grade within a representation of the ore body in a three dimensional matrix form. Therefore, the inherent uncertainty associated with reserve estimation (for our discussion grade uncertainty) is not taken into account when push backs are designed. These methods do not attempt to establish which part of the deposit is likely to be worth most. This paper introduced a new algorithm that incorporates ore grade uncertainty during push back design process. The suggested strategy tries to seek to schedule risky blocks later in the extraction sequence.

Jan 1, 2007

By H. Maleki

This paper recognizes the 100th year of research accomplishments by the mining industry resulting from close cooperation among mining companies, geotechnical consultants and researchers from the former United States Bureau of Mines in stability assessments and development of improved and productive mine designs. The paper provides an overview of dramatic developments in geotechnical instrumentation, and its applications in the U.S. and around the world for enhancing the understanding of ground response to mining-induced changes in stress, resulting in improvements in ground control technologies.

Jan 1, 2010

By Stephen Davies

Mining at Hudson Bay Mining & Smelting's Snow Lake Division is now in the mature stage of the mines' lives. These base metal copper-zinc mines have been operating for more than 30 years. Stopes had small pillars called "crown pillars" left between them. These pillars range up to 100 m (330 ft) long by 40 m (130 ft) wide and 15 m (50 ft) thick. Hudson Bay have been successful in removing these pillars by using cable slings, electric scoops, longhole mining and diesel load-haul-dump equipment. The different shapes and sizes of these pillars has required that many innovative techniques be tried in order to find acceptable economic mining methods. An overview of the different methods will be outlined. Background Hudson Bay Mining & Smelting's Snow Lake Division is located in Manitoba some 800 km (500 miles) north of Winnipeg and 200 km (125 miles) by road from the Hudson Bay smelter complex located in Flin Flon, Manitoba (Fig. I). There are currently three producing underground mines and one open pit operating at the Snow Lake Division, producing copper and zinc concentrates. Pillar recovery is intensive and vital to continued production of these mature mines. The crown pillars are producing more than 50% of the current mine production. This figure will increase in the future. The two mines at which crown pillar recovery is taking place and that will be discussed are the 400 t/d (440 stpd) Rod Mine and the 1000 t/d (1100 stpd) Stall Lake Mine, both five-day-a-week producers. Crown pillar mining has been applied for some time at these mines. However, it was only recently that the crown pillars became vital to production. This has necessitated a number of innovative techniques to recover them.

Jan 1, 1992

By T Hughes

The Gekko InLine Pressure Jig (IPJ) was unleashed on the World gravity separation market in 1996 and has since sold over 150 units in applications including tin, diamonds, silver, coal, garnet and gold. During the past twelve years the knowledgebase of the best applications and capabilities of the IPJ has greatly increased. Improvements to the original IPJ design have included engineered ceramic ragging in specific gravities from 1.6 to 5.0, full automation and improved designs of feed presentation and tailings and concentrate handling systems. The IPJ has been found to be able to handle a wide feed size range and recover mineral at liberation size without significant addition of water to the mass balance. Test work carried out during full-scale operation of the IPJ has shown the IPJ can recover diamonds down to 0.5 mm, sulfides down to 0.3 mm and gold down to 0.1 mm which greatly expands its application in the mineral processing industry. A significant volume of data now supports the symbiotic benefits of an IPJ and flotation circuit combination to pre-concentrate an ore and minimise downstream processing requirements.

Jan 1, 2008

By Ihsan Berk Tulu, Deniz Tuncay, DYKE MARK ALEXANDER VAN, Ted M. Klemetti

Bleeder entries are critically important to longwall mining for the moving of supplies and miners as well as the dilution of mine air contaminants and must stay open for many years. In this study, standing supports in moderate cover bleeder entries were observed, numerically modeled and instrumented by researchers at the U.S. National Institute for Occupational Safety and Health (NIOSH). The measurements of the installed borehole pressure cells (BPCs), standing support load cells and convergence meters, and roof extensometers are presented in addition to the numerical modeling results and visual observations made by the NIOSH researchers in the bleeder entries. The results include the effects of multiple panels being extracted in close proximity to the instrumented site as well as over one and a half years of aging. As expected, standing supports closer to the longwall gob showed the greatest load and convergence. The roof sag appeared generally independent of the proximity to the longwall gob. The BPC readings were driven by both the proximity to the gob and the depth into the pillar. The results of this study demonstrated that the entry roof can respond independently of the pillar and standing support loading. In addition, the rear abutment stress experienced by this bleeder entry design was minimal. The closer the mine development, pillar or supports are to the gob, the greater the applied load due to rear abutment stress.

By Joseph A. Corgan

The river- or dredge-coal industry of Pennsylvania is conducted on many of the rivers and creeks that drain the Pennsylvania anthracite fields. Coal thus recovered found its way into the streams as coal was being prepared for market by the anthracite industry proper, in the northeastern part of the State. The Principal rivers draining; the fields, those where dredging is taking place, are the Susquehanna, Schuylkill, and Lehigh. Several creeks - the Shamokin, Mahanoy, Wiconisco, and Swatara - also are productive sources of river or creek coal. Operations along the streams cover a wide territory, and along the Susquchanna alone; dredges are recovering coal for about 160 miles. Anthracite was a significant factor in the early industrial development of the United States. Industry used it to generate steam, and railroads used it as fuel for locomotives; but it probably was most important industrially in the smelting of iron ore. For more than a hundred years homes have been heated with this fuel. From the beginning of mining in 1807, to 1940, more than 4 billion net tons of anthracite had been prepared and shipped to market. In the preparation process much of the smaller-size coal and refuse found their way into rivers and creeks which carried the material many miles. This study is concerned with the recovery of that anthracite from those rivers and creeks.

Jan 1, 1942

By Lawrence A. Engel

The idea of using apron feeders for in directly feeding crushers is not a new one, it has been used for many years. To the best of our knowledge, the first apron feeder was used for bulk material handling in 1893. Since that time many design innovations have been introduced, with perhaps the most effective one being, the application of crawler tractor components in the feeder construction. This design was first introduced to the mining industry in 1954 by, national iron company. These feeders were used in the handling of run-of-mine iron ore on the Minnesota iron range, at the rate of 1,000 ltph. The material was fed over a grizzly to a jaw type of crusher. The crusher output was also handled by an apron feeder. Today, the apron feeder is being used in hard rock surface mine operations feeding crushers at rates of 5,500 ltph and over.

Jan 1, 1983