Search Documents

By Steven E. Mischler

The exposure of mine workers to diesel particulate matter (DPM) and gases is an issue of great concern to the underground mining community in the United States. Approximately 30,000 underground miners are potentially exposed to high concentrations of DPM. In January of 2001, the U.S. Mine Safety and Health Administration (MSHA) promulgated rules setting compliance standards for both underground coal and metal / nonmetal mine workers. As industry works to achieve compliance with these standards, mine operators are looking for feasible methods for reducing DPM concentrations in their mines. In addition, the industry needs methods to accurately measure DPM to ensure that the control strategies they adopt are working successfully. The Pittsburgh Research Laboratory (PRL) of the National Institute for Occupational Safety and Health (NIOSH) conducts research to evaluate control technologies and monitoring instrumentation that can be used to reduce the diesel particulate matter (DPM) exposure of mine workers. An overview of the strategies being utilized in underground US mines to reduce DPM concentrations will be presented. Also, updates on the development of diesel monitoring instruments such as the continuous elemental carbon monitor or the Personal Dust Monitor for DPM measurement will be provided.

Jan 1, 2010

By Madgwick J. C

A novel, microaerobic, heterotrophic microbial leaching system for manganese dioxide is described. Mixed natural microflora were enriched by addition of sugars and crude plant nutrItIOnal supplements. Between 84 and 104 mg MnH was solubilized per gram sugar at I per cent (w/v) concentrations for fructose and galactose in the presence of 0.03 per cent w/v dried microalgae (a Chlamydomonas species). Some 42 per cent soluble manganese was dissolved by microbial action on MnO, (3 per cent (w/v) pulp density) using a 10 per cent (w/v) molasses growth substrate.

Jan 1, 1983

By Charles A. Anderson

Arizona and western New Mexico contain 17 of the 25 leading copper mines in the United States. Production of molybdenite, lead, zinc, and by-product gold and silver is important. Precambrian ore deposits are largely limited to the Yavapai Series in central Arizona and most of the metal production has come from massive sulfide deposits, dominantly pyritic but containing different amounts of chalcopyrite, tennantite, sphalerite, and galena. Their origin has been interpreted by some geologists as hydrothermal replacement of schist, and by others as syngenetic deposits later metamorphosed. Most of the important ore deposits are of Mesozoic and early Tertiary age, dominated by the porphyry copper deposits spatially related to stocks, plugs, sills, or dikes of quartzbearing porphyritic to granular rocks. Host rocks for these deposits include the associated intrusive rocks, Precambrian schist and granitic rocks, Paleozoic limestones, Mesozoic(?) porphyritic andesite, and Mesozoic arkose and siltstone. Chalcopyrite and pyrite are the dominant hypogene sulfide minerals in the porphyry copper deposits, accompanied by minor molybdenite. The Questa deposit in New Mexico is largely molybdenite. Supergene sulfide minerals are chalcocite and minor covellite. Some ore bodies consist largely of hypogene sulfides, some are dominantly supergene sulfides, and others are mixed hypogene-supergene sulfides. Supergene oxide-copper minerals locally are important. Intense hydrothermal alteration accompanied the metallization in all of the porphyry copper deposits; five types are recognized, ( 1) propylitic, (2) argillic, (3) potassic, ( 4) quartz-sericite (without clay), and (5) lime silicate. The origin of the closely spaced fractures that contain ore minerals in intersecting veinlets is debatable; some geologists favor tectonic forces and others suggest cooling of magma or shrinkage due to alteration. Breccia pipes, veins, and limestone replacements account for some important deposits of Mesozoic and early Tertiary age, and presumably these are genetically related to the various intrusive rocks of this age. The St. Anthony deposit of Cenozoic age in southeastern Arizona is unique, consisting of a lead-zinc vein associated with later molybdenum and vanadium oxide-minerals. Cenozoic manganese deposits in western Arizona are an important resource in the Artillery Mountains, but the extent to which they may be exploited is a metallurgical and economic problem.

Jan 1, 1968

By F F. Pitard

The comparison between J Visman and C O Ingamells’ works with P M Gy’s works has been the object of intense debates in the past. Such negative debates inevitably resulted in a loss of many good opportunities. The author’s long experience in applying works of these three authors led to the pragmatic conclusion that it is relatively easy to integrate everything Visman and Ingamells created into the Theory of Sampling; therefore, it is suggested that the compatibility has been vastly overlooked, and a correction for such anomaly is recommended. It is important to emphasise that Visman and Ingamells works may be beneficial and provide relevant, harmonious additions in some areas, and ultimately offer attractive possibilities to sampling practitioners. Such additions may enhance our capabilities to predict sampling difficulties by using a stronger strategy and to design better sampling experiments that would allow us to further understand the heterogeneity of minor constituents, and especially trace constituents. Basically, the suggested integration is essential for sampling trace constituents in the environment, in food, in chemicals and in the pharmaceutical industries.CITATION:Pitard, F F, 2017. Integration of Visman and Ingamells’ works into the Theory of Sampling – a necessity to expand possibilities in sampling practices, in Proceedings Eighth World Conference on Sampling and Blending , pp 55–62 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2017

By K. Moxham, R. G. B. Pickering

Over the last few years Lonmin Platinum and Sandvik have embarked on a unique partnership of collaboration through a systematic approach to developing equipment to mechanize and automate narrow reef platinum mining. After the initial design and manufacture of the equipment the key aspect is the integrating equipment, people and method into a mining system. Another key a spec of mechanization is the optimization of equipment utilization and this philosophy has ensured continual evolvement of mining methods. This paper describes the trials and development that have resulted in the mining method described as Lonmin mechanized breast.

Jan 1, 2006

By G. W. Murrie

A geologic study of the Mary Lee Group of coalbeds in the Black Warrior coal basin was undertaken to examine coal stratigraphy and determine regional trends and extent of the coalbeds. The area investigated encompasses 835 square miles in Jefferson, Walker, and Tuscaloosa Counties, Ala. More than 700 core logs were used to construct a structure map, coal, interval, and overburden isopachs, and cross sections. There is evidence that structure affected sedimentation. Coalbed isopachs indicate the Mary Lee Group was deposited in fluvial-deltaic and low-lying coastal plain environments. The Mary Lee coalbed is the only coalbed which is continuous throughout the area, commonly with two benches which have a combined thickness of 2 to 12 feet. The Mary Lee coalbed changes rank in the basin from high-through medium-to low-volatile coal. The methane gas potential of the Mary Lee Group coals is estimated to be greater than 1 trillion cubic feet. There is an excellent correlation between the orientation of surface cleats with those measured underground in the Mary Lee coalbed. The face cleats roughly parallel the axes of the area's folds and trend northeast-southwest.

Jan 1, 1976

Cook Colliery currently mines in the Argo Seam, beneath old workings in an overlying seam. The Argo seam is up to 4.8 m thick and a continuous haulage system behind an ABM25 is used to develop first workings. Current partial secondary extraction utilises floor stripping and pocketing or sumping first working pillars on retreat. The following paper summarises this recent secondary extraction experience, particularly from a geotechnical perspective, but also considering production and ventilation issues. Outcomes and learnings are presented for mining in this challenging and close multi-seam environment. The sealed castor seam workings are within 20 m, and vary from unmined areas to large first working pillars, to partial extraction panels and full extraction panels. High stress remnant pillars and goaf-edges are notable mining considerations. The mining environment is further complicated by faulting, thrust zones and weak laminated roof.

Nov 25, 2010

By R. H. Fernald

In 1900, as far as available records show, there were only two producer-gas power installations in the United States. In June, 1915, the number probably exceeded 1,000. Of this number, some 84.5 per cent comprised small plants using anthracite, and only about 15 per cent of the total number utilized bituminous coal and lignite. In addition to these, two plants used wood, and three or four used oil. In the main, however, the larger sized units are operating on bituminous coal and lignite. During the early years of these plants little success was anticipated from the use of bituminous coals and lignites, but in 1904 and 1905 it was fully demonstrated at the Government testing station at St. Louis that these fuels could be utilized to excellent advantage. However, although many producer-gas plants in daily operation are using bituminous coal and lignite, many power-plant men are still skeptical regarding the successful commercial use of these fuels.

Jan 1, 1916

By C. Dixon

The Abandoned Mine by C.C. Woollacott A heap of rocks marks the abandoned mine. The veld's unpitying silence lies around. Those broken stone?a mute and mournful sign Of human enterprise with failure crowned. Time with the slow hands, shall form the scene anew, Repair the gashes in the wounded soil, And cover up the last remaining clue To a poor useless record of men's toil. And this, the mound they built when hopes were high Shall be a grave, where those hopes buried lie. Outline This paper will consider the implications of the mine closure provisions set out in the new Mineral and Petroleum Resources Development Act and draft regulations. A comparison will be made with the existing provisions in the Minerals Act and the mine closure policy of the Department of Minerals and Energy (DME). The paper will consider whether the new provisions have the potential for improving performance as regards mine closure. It will investigate the financial provisions requirements and the implications of these provisions for mines. It will consider the requirements for a social and labour plan and consider the implications of this for mine closure and its funding. It will analyse the provisions relating to the transfer of environmental liabilities to third parties and consider the implications of this in the case of closing mines and non-closing mines. Finally it will consider the issue of residual legal liability of a mining company once a closure certificate has been issued.

Jan 1, 2003

By P. R. Day, W. K. Webster

"The introduction of large boreholes underground initially involved taking the techniques of open-pit bench blasting to the production stope, but with deeper boreholes and narrower stopes more controlled techniques must be developed in order to maintain good stope walls and prevent dilution of ore or structural damage to pillars due to blasting overbreak. The points discussed are drilling accuracy and drill pattern, the relationship between open-pit wall control and underground mining, the varied explosives products and initiation devices available, and some of the many ways that variations in loading, such as deck charging, etc., can produce desirable results.IntroductionThe use of large-diameter blastholes for underground mining began ten years ago and today they are widely employed in a variety of orebodies and stope configurations. These big blastholes, which range in size from 4.5 to 8 inches in diameter, were originally employed in the same manner ' as open-pit bench blasts; that is, the stope was silled out to full width and all holes were drilled vertical and parallel. This was suitable for competent, massive orebodies, however the popularity of the big drills saw their usage in more narrow stopes, often with poor ground conditions. The dipping orebodies and small drill sublevels resulted in inclined drilling.Today, there is full-ring drilling of 4.5-inch holes. Some 6.5-inch holes are drilled up to 350 feet deep. A 350-foot borehole may contain 6000 to 7000 pounds of explosive. The detonation of this size of charge weight within the confines of an underground stope can have considerable effect on the stability of stope walls and adjacent pillars. Obviously, precautions must be taken to minimize the damage which would result from the large charge weights possible with these big boreholes."

Jan 1, 1982

By John B. Goodman

This report summarizes the work done by the Koppers Company, Incorporated, in cooperation with the Bureau of Mines on the commercial evaluation of the primary low-temperature tars produced from Texas lignite in the Rockdale, Tex., plant of the Aluminum Company of America in conjunction with the Texas Power and Light Company. The interest of the Bureau of Mines in this project is twofold. First, through its cooperative agreement with the Texas Power and Light Company the Bureau has assisted in the technical design and practical operation of the prototype, externally heated, entrained-state carbonizer for producing char for electric-power production and for primary low-temperature tar. Second, the first successful operation of the prototype carbonizers employing the Bureau of Mines-Parry process on lignitic coal in 1953-54 led to the production of large quantities of primary lignitic tar, concerning which too little was known or had heretofore been published in this country.

Jan 1, 1959

By Lily Ruíz

El presente texto evalúa el relave minero de SIMSA con el objetivo de obtener un producto ecológico que pueda ser utilizado como mejorador cationico de suelos y restaure el equilibrio de los suelos ácidos de la selva peruana. Para ello, se desarrolló un trabajo a nivel de laboratorio, obteniéndose resultados satisfactorios. Posteriormente se pasó al nivel piloto donde a través de la experimentación se utilizó el relave en diferentes concentraciones para la producción agrícola y forestal, reafirmando los resultados en las mejoras de la productividad en suelos ácidos.

Sep 9, 2007

By C. H. Riggs

This petroleum-engineering report of the Atlanta oil field in BO them Arkansas reviews reservoir conditions and pressure-production history of one of the important Smackover limestone fields in southern Arkansas. The study of the field was made and the report prepared to aid operators in this and similar fields to increase the efficiency of recovery through the application of better engineering practices. A similar study of the Magnolia field in Arkansas by Carpenter and Schroeder was the first of these reports prepared under a joint agreement between the Arkansas Oil and Can Commission and the Bureau of Mines. The increasing demands for petroleum and its products and the steadily increasing cost of discovering and developing oil field; emphasize the importance of conserving known reserves of oil and gas. In recent years vast improvements have been made in the technique of oil recovery, both by better utilization of the natural energy stored in the reservoir and by improved methods of applying external energy to the reservoir system. This report may aid in oil conservation by careful evaluation of the several factors that did or did not contribute the greater recovery in the Atlanta field and by suggesting improvements in production methods and applications.

Jan 1, 1949

By Marco Sonnenschein

As time is costly, engineering companies have developed methods, procedures and mechanical equipment to tunnel faster. But the best excavation method will not be able to cope with the time pressure if there is not a reliable backup system. Therefore, the application of belt conveyors for tunnel boring machine (TBM) drives as well as for drill-and-blast driven tunnels assure a quick and smooth removal of excavated soil in order to enhance the efficiency of the tunneling equipment. During the last 10 years, belt conveyor systems have achieved ?state-of-the-art? levels and have become the first choice for muck removal systems in both TBM and drill-and-blast driven tunnels. Because time has become such a key criterion in tunneling projects, it is essential that all equipment is operated so as to derive optimum efficiency and minimize costs. Efficiency also means to think about new tasks for existing technologies.

Jan 1, 2012

By Lottrey A. L, Sowerby B. D, Cutmore N. G

On-line monitoring of low rank coal quality during input to a process has the potential to provide benefits through: ò anticipation of coal quality variations prior to utilisation; ò provision of a tool to help determine the influence of coal quality on process behaviour, and ò provide a direct measure of coal quality for pricing. Moisture and ash are the two most significant coal quality parameters for combustion. They determine the energy content which can be derived from the coal and the problems arising from the presence of ash in the process (eg ash fouling, corrosion, erosion, particulate emissions and ash disposal). Extensive pilot-scale testing and full-scale experience has shown that specific coal/ash constituents (eg Na2O/ash ratio, acid-soluble aluminium, silica, sulphur contents, etc) are also important for the behaviour of Latrobe Valley brown coal during combustion, ash formation, deposition and removal of ash in precipitators and furnace ash hoppers. This paper discusses the range of on-line analysis techniques which have been investigated and their application to low rank coal analysis. Preliminary results from a joint SECV/CSIRO project which aims to develop two separate advanced instrument systems are also presented. These systems are based on: ò microwave attenuation and phase shift - for direct determination of moisture content; and ò inelastic neutron scattering - to provide total hydrogen, carbon, chlorine and ash contents, with potential for calculation of moisture content, specific energy, sodium content and Na20/ash ratio using correlations.

Jan 1, 1992

By Richard S. Fowkes

Advanced technology, including automation and computerized information systems, is being adopted in mining at an ever-increasing rate to improve safety and productivity and to decrease overall costs. This U.S. Bureau of Mines report focuses on the human factors issues related to advanced technology. Among the significant facts discovered were the following: Experts studying tile design adoption, and implementation of new technology have stated repeatedly that human factors specialists should be involved from the early planning stages, through design and fabrication, and up to and during production, since human factors has been consistently identified as the biggest obstacle to the efficient utilization of new technology. Also, middle management is generally the greatest obstacle to the adoption of advanced technology, this technology can give rise to worker alienation, boredom, stress, job insecurity, and a sense of isolation; training most of the present work force is more cost effective than hiring new workers; workers are willing to accept new technology if they are given a voice in its implementation; the social and the technical systems should be jointly optimized; and with the intro¬duction of advanced technology, the cognitive or mental, rather than the physical, aspects of human-machine interaction must be emphasized.

Jan 1, 1994

By Noel N. Moebs

This report summarizes a Bureau of Mines study on the use of geotechnology to identify and reduce ground control hazards at slate quarry operations in eastern Pennsylvania. The major ground control hazard is falling rock, attributed to weathered bedding plane faults, which weaken quarry highwalls. It was demonstrated that these faults can be detected outside of the quarry perimeter using surface resistivity measurements. Falls of ice from quarry highwalls constitute a second major hazard, which requires water diversion as a basic control method. In situ stresses seemingly cause only minor problems in slate extraction although they could interact with developed stresses and lead to failure of barriers between quarries. Pull tests showed that rockbolts anchor firmly in slate and should prove effective in securing loose rock.

Jan 1, 1986

By W. R. Hardwick

This paper describes mining methods and practices of the Morenci Branch, Phelps Dodge Corp., Greenlee County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts in the United States. A similar program, conducted from 1928 to 1939, was generally conceded to have contributed substantially to improving the efficiency of mining operations. The morenci open-pit mine (see photograph, fig. 1) is in southeastern [zona] (fig. 2), on U.S. Highway 666 about 5 miles north of Clifton, county at of Greenlee County. The concentrator and smelter are near the mine at an altitude of about 4,400 feet. Figure 3 is a map of the mine and plant.

Jan 1, 1959

By J. J. Bouillon

"Located in the northwestern portion of the Abitibi greenstone belt, Les Mines Selbaie is a copper-zinc (silver and gold) producer. Felsic tuffs host three are zones. Composed of sulphide veins and breccias, they are not exhalative massive sulphide deposits, except, probably, for the massive pyrite (fragments and lenses) localized close to the top of the volcanic sequence.The total of all (mineable and mined) ore in the three zones presently outlined on the property, is of the order of 29.9 x 106 tonnes with average grade of 0.63 g/t Au, 37.02 g/t Ag, 1.21% Cu, 1.91% Zn.The ore reserve calculations and the daily production procedures are computerized to various degrees. The data handling process is highly computerized.Various geophysical methods are, and have in the past, been successfully used on the property. The ""mise-à-la-masse"" surveys were used to perform the geological interpretation of an underground deposit (A-2 zone). Presently the PULSE-EM surveys are performed in all surface and underground exploration drill holes."

Jan 1, 1990

By R. P. Singh

A mine fire model gallery has been designed and constructed on the premises of the Central Mining Research Institute, Dhanbad, India to perform systematic in-depth studies on various aspects of mine fires. The gallery is 65.5 m long and 5.86 m2in cross-section and it is divided into firing and non-firing zones. It is equipped with a computer-aided online telemonitoring system that has 130 sensors, two data loggers and computer peripherals for continuous recording of various fire parameters. A fan to generate airflow through the gallery has been installed at its end. Two sliding doors and one rolling shutter were also provided for sealing and regulation of airflow. Two sets of experiments have been carried out in the model gallery maintaining air velocity of 1 and 1.5 m/s through it. In the experiments, the inner sides of the firing zone, 22 m in length, were lined with a thin layer (8?10 cm thick) of coal slabs. Two fire suppression techniques viz. flushing of liquid nitrogen (LN2) and infusion of high pressure high stability (HPHS) nitrogen foam were tried to quantify their effectiveness under dynamic fire conditions. The paper addresses important design features of the gallery, its instrumentation system, the experimental procedure adopted and important findings from the experiments. It has been observed that the intensity of the fire was very high after one hour of its initiation and continued for 3?4 hours. During the period, frequent backlash with smoke and flame was noticed. The efficacy of the fire suppression techniques has been assessed interms of reduction in temperature, generation rate of CO2and CO, and heat release rate. The study reveals that high pressure high stability (HPHS) nitrogen foam is more effective in controlling open fires than liquid nitrogen is. Keywords: Model gallery, telemonitoring system, velocity, temperature, pressure, gas concentration, intensity, liquid nitrogen, high pressure high stability nitrogen foam.

Jan 1, 2004