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By Robert C. Cifelli

INTRODUCTION Background and Objectives Underground coal mining is a vital component of West Virginia's economy. However adverse environmental effects including ground subsidence and aquifer dewatering are often associated with such mining activities. Many families in northern West Virginia still rely on private water wells and springs for domestic water needs. In such areas where underground coal extraction and land subsidence have occurred, a disruption of the ground water flow system commonly exists with subsequent drainage of water to lower levels that may extent as deep as the mine workings; this causes loss of water supplies to landowners and represents a nuisance to mining companies 2 This report represents a summary of an M. S. thesis project in geology at West Virginia University by the senior author (3). The intent for this study was to document the effects of underground coal removal on ground water levels at selected mine sites in northern West Virginia, as observed from water wells, springs, and streams. This research should be useful to coal companies and regulatory agencies and aid in recommendations of future water well locations and specifications in areas of existing or proposed underground coal mines.

Jan 1, 1986

By N. S. Tanious

The Nuclear Regulatory Commission (NRC) regulation 10 CFR 60 requires that the ventilation system for the geologic repository be designed to: (1) control the transport of radioactive particulates and gases, (2) assure continued function during normal operations and under accident conditions, and (3) separate the ventilation of excavation and emplacement areas. The ventilation system design should take into account thermal loading; maintenance of the retrieval option and-the separation of the development and emplacement ventilation circuits. An analysis was performed by NRC's contractor, Engineers International on the ventilation system design described in the Department of Energy's conceptual design for Nevada. The ventilation analysis is of a preliminary nature. The conclusions presented in this paper reflect the views of the authors and may not represent the views of the NRC. In this analysis, available Nevada Nuclear Waste Storage Investigation (NNWSI) ventilation design information was reviewed and a ventilation network analysis was performed.

Jan 1, 1988

By J. A. Cole

The mill project at Lone Tree was commissioned in October, 1993, followed by the commissioning of the autoclave pressure oxidation circuit in February, 1994. Discussion of the first year of milling operations at Lone Tree is presented. The mill is currently operating above the design rate of 2,267 mt/d (2,500 st/d). Both phases of the start-up were essentially trouble free. The few problems that were encountered and the respective solutions are addressed.

Jan 1, 1995

By R. W. Reisinger

An historic underground copper mine in Wyoming is discharging neutral but copper-laden water into a pristine creek. The EPA-deferred site qualifies for reclamation by the Wyoming Abandoned Mine Land (AML) program; restoring the discharge so that the creek can eventually support a trout fishery is the cleanup goal. Hydrological and geochemical investigations underground have suggested two sources of mine water: one clean and the other copper-containing. Results of bench-scale and pilot-scale tests support the viability of using low-cost passive treatment techniques to reduce copper concentrations in the near-freezing mine discharge.

Jan 1, 1998

By K. Pietruszka

The article presents the concept of the application of the Finite Element Method (FEM) and ABAQUS software in the global monitoring of changes in the rock mass and on the surface of the area, as a result of backfilling the workings. Waste materials applied for stabilizing old mining workings can have a strong influence on the rock mass and surface. According to the regulations, this process should be carefully monitored, especially in terms of the safety of surface structures and rock mass stability. The article presents the concept of an analytic and graphic presentation of the results of the measurements of old workings, applying the Finite Element Method and ABAQUS software in model studies. The main purpose of such interpretation of the geodetic observations results is the application of methods providing wide possibilities to present the geometry of workings, their changes and the influence of the rock mass and surface.

Jan 1, 2008

By N. Careddu

In recent years, slabs with a rough surface have captured a large share of the ornamental stone market. However, the main technologies used for this type of treatment are based on mechanical shock (bush-hammering) or thermal treatment (flaming or flame-finishing). These traditional technologies are widely used, but have many limitations that decrease their usefulness. The purpose of this study was to develop a technology that enhances the natural colors of the rock and produces a rough surface without compromising its mechanical characteristics, in contrast to traditional technologies. This report shows the technical, economic and aesthetic results obtained with a new water-jet treatment and compares it with competing technologies.

Jul 1, 2010

By W. L. O?Connell

[Patent Issue No. Date Issued To Subject 386,504 July 24, G. Sweanor The separation of quartz from a 1588 metal with a liquid such as CS2 or CHC13 under water by introducing mixture into water layer. Quartz will stay in water layer while metal sinks through organic.]

Jan 1, 1963

By J de Cuyper, N. R. Tipman, G. E. Agar, L. Laré, W. Freyberger

The flotation chemistry of the commercial INCO matte separation process was investigated. The slow cooling of Bessemer converter matte forms discrete phases of Cu2S and Ni3S2 and a Cu-Ni alloy. After magnetically removing the alloy, the Cu2S and Ni3S2 are separated by flotation at pH 12.4 (saturated lime) using diphenyl guanidine (DPG) as both collector and frother. DPG has been used exclusively in this flotation process because of its unusual selectivity for copper minerals. The surface product resulting from chemisorption of DPG onto the Cu2S was identified as the double salt Cu(DPG)2SO4,.CU(DPG)2(OH)2. The adsorption followed Langmuir behaviour up to a monolayer coverage. In the absence of DPG, the rapid adsorption of oxygen by Cu2S in flotation pulps was observed. The surface product was identified as the insoluble basic copper sulfate CuSO4.3Cu(OH)2 with the production of sulfate ion. In the presence of DPG, the oxidation reaction appears to be suppressed. The frothing properties of DPG and commercial frothers were compared. DPG is not a powerful frother. Batch flotation tests confirmed that DPG is a highly selective collector when compared to most sulfhydryl collectors.

Jan 1, 1976

By Geo. A. Wells

Abstract The consumption of barytes in certain paints polyurethane foams, seamless, flooring, glass, brake linings, plastisol caskets for food containers and in fluids used for gastrointestinal X-ray examinations rely on tie unique properties of barium sulfate, There are no readily available mineral substitutes. Barytes are also the essential raw material for the manufacture of industrially important barium chemicals. High quality barite ore has become scarce throughout the world. Processing ore into quality end products is both capital and energy intensive. These factors have tended to limit availability and increase prices which have encouraged the use of alternates and restricted market growth.

Jan 1, 1980

By M. T. Ityokumbul

The effect of reaction conditions on the desulphurization of oil sand coke residues has been studied. The variables investigated were temperature, reaction time, heat transfer resistance, and mode of caustic soda addition. The results obtained show that oil sand coke desulphurization increases with temperature, reaction time, and heat transfer rate. In an oxidative environment, coke combustion during molten caustic leaching (MCL) commences at temperatures above 500°C. The mode of caustic addition has no effect on coke desulphurization.

Jan 1, 1995

By Wallace W. Wilson

It scarcely 1s possible to read a new issue of any of the principal mining trade journals without noting some mention of a major new overseas mining venture with which one or more domestic companies are involved. These projects seem to follow a fairly consistant pattern; most are large open pit mines, with relatively low grade ore bodies but huge reserves; the total price tag will be in nine significant figures and around half or more of the total cost will be for infrastructure. West1 noted that nearly $7 billion is being invested annually for new mining projects and the expansion of existing mining ventures, in the free world. He anticipates that by the year 1975 such investments would reach the $10-11 billion annual figure, and that in the five year period 1972-76 total capital requirements can be expected to aggregate around $45 billion. The proportion of this total investment which will be financed in some manner is difficult to estimate because of the variety of available financing arrangements. West estimated that around 75% of the total capital would come from internally generated funds, with the balance from external sources. Conceivably a substantially higher percentage could be attributable to external financing, especially it the trend of recent mineral development in Canada and Australia is any criterion, and of course, including local sales of equity as a part of the package.

Jan 1, 1973

By J. E. deMasi

Over the past 12 years, Exxon Coal U.S.A., Inc. has shipped over 150 million tons of coal from two mines, Rawhide and Caballo, located in the Gillette, Wyoming, area. These mines are operated by The Carter Mining Company, a division of Exxon Coal. Shipments have moved to more than 25 electric utility plants in the west, midwest, southwest, and south. The customer plants have represented a wide variety of configurations, sizes. design criteria, emission standards, and operations in different parts of the country. We have learned a great deal about the performance of Gillette area coals in utility power plants during this period. This paper covers some of the highlights of Exxon's experience with these coals in customer plants. I will focus specifically on things mining engineers may be able to do to make the product better for the customer's use.

Jan 1, 1989

By Francis X. Murray

Synthetic fuels will be the first major development effort to feel the effects of a new set of opposition forces. These confrontations will not be of the same variety as those which occured in the 1970s. Instead the synfuels industry, particularly in the West, will find itself confronting a new coalition of local political, community, and state spokesmen. They will oppose synfuels because the projects will represent a threat to existing lifestyles, political structures, taxes, social life, water rights, economics, and other politically sensitive considerations. In short, they mean change -- usually dynamic, full of unknowns and always threatening. The battles themselves may be fought technically over environmental issues, law and regulations; often these will be the instruments of the opposition. The real underlying problems will likely lie much deeper. In many cases environmental groups will be enlisted as the standard bearers; however, this approach may simply reflect the fact that environmental objections are convenient or at times the only tools at hand.

Jan 1, 1981

By G. Markopoulos

Every year thousands of people from all over the world come to Mount Parnasse, visiting Delphi, the Parnasse ski-resort and other sights in the area of Fokida, available to all ages all year round. This region of Greece, is not only gifted with natural beauty, but also with valuable underground natural wealth: inside Mount Parnasse and the adjoining Ghiona Mountain, there are rich bauxite deposits - the ore from which aluminium is made. In this magnificent part of our country, any mining activities undertaken must be adapted to coexist within such an ecologically sensitive area. This demands an enormous effort, knowledge and the use of technology. This is definitely our Company's primary objective. Our company's (Silver & Baryte Ores Mining Co. S.A.) activities in the area began in 1933, when Euripides Mavrommatis and the two Eliopoulos brothers, Elias and George, established "Bauxite Parnasse SA". Since then, ten thousand people have worked in these ore deposits, and 45 million tons of bauxite have been extracted. The full length of the underground excavations is more than 300 kilometers and 115 million cubic meters of limestone have been extracted on surface mining. In 1996, Bauxite Parnasse merged with Silver & Baryte Ores Mining Co. S.A. Now, the company exports more than 1.500.000 mt per year of bauxite to more than 15 countries around the world, offers a significant amount of job opportunities in the region, and imports valuable exchange into the country.

Jan 1, 2002

By N. Economou

Temporary local seismic networks were installed in western Crete, in central Crete, and on Gavdos, an island south of western Crete, in order to image shallow seismically active zones of the Hellenic subduction zone. Data acquisition was divided in four campaigns through the years 1996 to 2001. More than 4000 events in the magnitude range between 0.5 and 4.8 were detected and localized. The resulting hypocenter distribution allows the localization of seismically active zones in the area of central Crete from the Mediterranean Ridge to the Cretan Sea. The comparison of the hypocenter distribution and the structure has allowed intraplate and interplate seismicity to be distinguished. A southwards dipping zone of high seismicity within the Aegean lithosphere is found south of central Crete in the region of the Ptolemy trench. Between 20 and 40 km depth beneath central Crete, the Aegean lithosphere appears to be seismically inactive. Especially for the year 2001, 1560 events were localized, by the seismic network installed on Messara, central Crete. Most of the seismic events were located, as expected, in the South region of central Crete. National Observatory of Athens (NOA) maintains a permanent seismic network in Greece. In this work a comparison of the earthquake epicenters obtained from both the NOA network and the BOCHUM-TUC network is presented.

Jan 1, 2006

By J. A. Oraniscak

Longwall mining operations continue to increase extraction rates and the potential to generate higher amounts of airborne respirable dust (ARD). The National Institute for Occupational Safety and Health (NIOSH) has gathered data from underground longwall surveys and laboratory crushing tests to identify the important factors influencing the amount of ARD levels generated. Coal-seam characteristics, operational parameters (i.e.,cut sequence, mining height, etc.), extraction rates and dust-control parameters (i.e., airflow, water flow, etc.) were examined to determine their influence on ARD levels measured at longwalls during actual mining operations. ARD generated by a laboratory crusher while crushing bituminous coal samples collected from underground longwalls was also examined to determine if there were cor relations with coal-seam properties. Results from the longwall and laboratory data collected indicated that low-ash, high-volatile coals (low moist fuel ratio or MFR coals) generate higher amounts of ARD. It was found that face ventilation and water application to the coal product are essential elements to controlling longwall ARD levels.

Jan 1, 2000

By Phillip O. Tyree, R. A. Metz, Joseph W. Mussey

Bio-epigenetic sulphur deposits occur in Pecos, Reeves and Culberson counties of far West Texas. Sulfate reducing bacteria, utilizing hydrocarbons as energy, transformed gypsum into replacement limestone and hydrogen sulfide. Hydrogen sulfide, retained in the pores of the replacement limestone, was subsequently oxidized by highly oxygenated groundwaters, and native sulphur precipitated. West Texas sulphur was first recognized at surface exposures by William P. Blake, a geologist attached to the Captain Pope Military/ Scientific Expedition of 1854. Attempts were made in the early 1900's to mine these sulphur vent exposures by a retort method, but the ventures met with little success. In 1967, Duval discovered a large sulphur deposit near some of the old sulphur works in Culberson County. Duval also expanded reserves in a small sulphur deposit in Pecos County. The Frasch process, developed for producing sulphur from Gulf Coast salt domes, proved successful in West Texas type sulphur deposits also. However, modifications of the process were necessary to provide economical and efficient sulphur recovery from the varied ore occurrences. West Texas conditions and logistics require the ultimate in productivity to be competitive in the domestic and foreign sulphur markets. Several companies, in addition to Duval, are producing or have produced sulphur in West Texas. As of June 1, 1984, a total of 29.87 million mt (29.4 million long tons) of sulphur had been produced west of the Pecos River. Duval corporation has produced more than 88 percent of that total.

Jan 1, 1992

By William G. Doepken

GENERAL DESCRIPTION The Henderson mine utilizes a highly mechanized, continuous panel-caving system to extract ore from a deep, massive, molybdenum deposit. The mine site, lo¬cated 80.5 km (50 miles) west of Denver, is situated at 3170 m (10,400 ft) above sea level in a steep valley on the eastern side of the Continental Divide. The mill site, located on the western side of the divide, is linked to the mine via a 15.5-km (9.6-mile) railroad tunnel. Mine production is scheduled to reach 27 215 t/ d (30,000 stpd) from the uppermost production level. This pro¬duction rate will have been reached within the four years following an intensive ten-year preproduction development program. A second production level, due to come on stream in later years, will expand production capabilities to 31 751 t/d (35,000 stpd). The mine, which employs approximately 2000, has blocked-out ore reserves of 220 Mt (242 million st) at an average grade of 0.42% MoS2. Geology The Henderson deposit is composed of two partially overlapping ore bodies that lie 1080 m (3600 ft) beneath the peak of Red Mountain. The ore bodies are entirely within a Tertiary rhyolite porphyry intrusive complex that has intruded Precambrian granite. The de¬posit is elliptical in plan with overall dimensions of 670 x 910 m (2200 x 3000 ft). In section it is arcuate with an average thickness of 185 m (600 ft). The top of the deposit is at an elevation of 2610 m (8700 ft) while the lower limits range from 2340 m (7800 ft) on the west to below 2100 m (7000 ft) on the east. The mineralization is relatively continuous in the ore bodies and consists of molybdenite and quartz in random to subrandom, intersecting, closely spaced veinlets. Cavability RQD (rock quality designation) * values measured from Henderson drill core and compared with the RQD values from the Climax and Urad block-cave mines in¬dicated that the Henderson ore would cave but with difficulty and that a high percentage of the cave ma¬terial would be blocky. Initial caving experience shows the Henderson ore caves easier and with greater frag¬mentation than was indicated by the RQD values. Pos¬sible reasons for this are: 1) The greater lithostatic load at the Henderson has a greater effect on caving and fragmentation than anticipated. 2) The relief of confining pressure due to caving action and brittleness of the rock is enhancing breakage. Mine Layout The Henderson mine layout was designed from its inception for a large-scale, rubber-tired, continuous panel-caving mining system. The ore body is vertically divided into three major mine levels (Fig. 1). The top¬most level (8100 level), which is 2469 m (8100 ft) above sea level, is the current mine production level. The intermediate or 7700 level, which is in the initial

Jan 1, 1982

By F. L. Wilke, J. Fabian, D. Oravec

The task of production planning in ore mining is primarily con¬cerned with the removal of ore blocks within planning periods spread over the life of the mining operation. The investigation of this problem in the past resulted in the introduction of computer based optimizing techniques for production scheduling and se¬quencing. Although these techniques succeed in computing an "optimal" mine output for one planning period, they usually fail in composing a practical and feasible mine plan over the periods in concern. This paper describes conventional production planning based on operations research and the capabilities of a knowledge-based approach. An example of a planning system for the Slovak under¬ground iron ore mine Nizna Slana will be presented. By combina¬tion of these two techniques this system should improve the qual¬ity of planning procedures.

Jan 1, 1996

By C. Strachan

This paper presents an evaluation of tailings dam incidents from the 1994 USCOLD Tailings Dam Committee report. Comparisons are also made with water storage dam incidents from USCOLD reports and recent tailings dam incidents. The evaluation results show that tailings dam incidents are due to a number of factors including overtopping, static and seismic instability, seepage and internal erosion, and foundation conditions, and that no particular type of tailings dam or operational condition is more susceptible to incidents. In addition, the results confirm that tailings dams should be located, designed, operated, and reclaimed with a thorough knowledge of site conditions, mill operation, site monitoring, and tailings characteristics.

Jan 1, 1999