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By Richard E. Ray, George N. Aul, Fred Garcia, William P. Diamond

Increasing longwall panel dimensions, particularly face width in gassy coalbeds, may result in unexpected increases in methane emissions. To investigate this problem, continuous longwall face emission monitoring studies were conducted at two adjacent mines operating in the Pocahontas No. 3 Coalbed, where longwall faces were to be extended from 229 to 305 m (750 to 1,000 ft). It was predicted by regression analysis of methane emissions data from 229 m (750 ft) wide longwall faces that extending faces to 305 m (1,000 ft) would increase methane emission rates by only 7 percent (0.6 m3/min (20 cfm)), to 8.6 m3/min (304 cfm) at the VP-1 Mine. In contrast, it was predicted that extending faces at the VP-3 Mine could increase methane emissions by as much as 13 percent (1.8 m3/min (65 cfm)) to 16.1 m3/min (567 cfm). The geologic and mine design factors influencing the variation in face emissions between the two mines will be discussed.

By Boden A

A procedure was developed for recovering metal values from copper-smelter fume. The fume is first leached to neutrality with dilute sulphuric acid to obtain a solution of zinc sulphate containing a low level of impurities. The tailings from this leach are treated with hydrochloric acid in two stages, in which tin and zinc are quantitatively leached and recovered as a tin concentrate and a zinc sulphatelzinc chloride solution.About 80 per cent of the lead sulphate is converted into lead chloride, which can be recovered as a pure product.Data on the effect of temperature, acid concentration, aeration, and solid/liquid ratios on the hydrochloric acid leach are presented, and the fate of the most important metals during the recovery process is described. Alternative treatments of the tailings from the neutral sulphuric acid leach were briefly investigated.

Jan 1, 1977

By V. C. Petersen

The titanium-rich end of the titanium-germanium system was investigated by x-ray and metallographic methods and verified by resistivity and dilatometer measurements. A constitution diagram is proposed. The titanium-rich portion of the phase diagram is characterized by eutectic and peritectic reactions. The eutectic composition is 19 percent germanium, and the eutectic temperature 1,360° C. The peritectic reaction occurs at 905° C. and 4 percent germanium. Germanium is soluble in alpha titanium to a maximum of 4 percent at 905° C. and in beta titanium to a maximum of 12.5 percent at 1,360° C. Both limits of solubility decrease with decreasing temperatures. Although substantial quantities of germanium are soluble in beta titanium, beta is not retained on quenching. The beta phase probably transforms to alpha by a martensitic reaction.

Jan 1, 1957

By James F. Lewis

THE hematite iron ore mines east of the Hudson River are confined to a strip of country ten to fifteen miles wide, commencing on the south, near Fishkill, running northeast through Dutchess County, and striking the southeast corner of Columbia County, extending into Litchfield County, Conn., known there as the Salisbury mines, cropping out again at and near West Stockbridge, Lanesboro, and Cheshire, Mass., also in Bennington County, Vermont. The ores are found in beds or deposits and in veins, with a limestone ledge on one side and slate on the other, from six to thirty feet from the surface. Portions of it are quite solid, called rock ore, but

Jan 1, 1877

By Robert B. Parsons

"The Province of Manitoba tabled a Budget on March 11, 1992, which contains some important new initiatives designed to improve the fiscal environment for mining in the province. In addition, the Minister of Energy and Mines has released details of the Mineral Exploration Incentive Program which was originally announced in the 1991 Budget.Introduction""We recognize the important contribution o f mining to the economic activity of our province, including direct and service jobs and export earnings. We are determined to secure its future."" - The Honourable Clayton Manness, Minister of Finance, Province of Manitoba, March 11, 1992.With these words of introduction, Manitoba Finance Minister Clayton Manness announced a number of significant measures aimed at improving the fiscal regime for exploration and mining in Manitoba. At the same time, details of the Manitoba Mineral Exploration Incentive Program (MEIP) were released."

Jan 1, 1992

By Sean Gallagher, Christopher A. Hamrick, Arnold C. Love

Twelve subjects participated in an investigation of the biomechanical stresses of asymmetric lifting in stooped and kneeling postures. Three factors were manipulated in this study: Posture (stooped or kneeling), height of lift (35 or 70 cm), and weight of lift (15, 20, or 25 kg). Subjects were required to lift or lower a box every 10 seconds for a period of 2 minutes. Electromyography (PIG) of eight trunk muscles was collected during a lift in this period. The PIG data, normalized to maximum extension and flexion exertions in each posture, were input to a biomechanical model and used to predict compression and shear forces at the L, level of the lumbar spine. Results from the EMG-driven biomechanical model indicated that compression was greater when lifting to a higher shelf (p < 0.001), and indicated a significant interaction between posture and the weight of the lifting box (p < 0.01). Peak lateral shear was not significantly affected by any main effects or interactions (p < 0.05). Anterior shear was increased with increasing height of lift (p < 0.001), and also by the posture x weight interaction (p c 0.01). A multivariate analysis of variance (MANOVA) indicated a complex relationship for recruitment of the eight trunk muscles, with the triple interaction being significant (p < 0.001). The results of this investigation will be used to evaluate safe loads for lifting in these restricted postures.

By J. A. Smith

The topic assigned me by the Chairman of the Institute, "Safety Practices in Franklin and Williamson Counties, Illinois," I fear will necessarily resolve itself into a paper on shale dust, its application and the results obtained. I returned .only last week from a three weeks trip through these counties at which time, through the courtesy extended me by the operators, I had ample opportunity to visit and inspect many of the largest mines in the field, some of which are among the largest in the United States. With the exception of shale dust and ventilation, I see but vary few instances where the Illinois mines are further advanced in safety precautions than the western mines, and in some respects I believe the operators of the West are further advanced in safety methods than their eastern brothers. Great care is exercised in handling of all ventilation currents. This is an aboslute necessity, as this field is quite gaseous, and the peculiar geological structure of the overlying and underlying strata makes airtight seals very

Jan 1, 1924

By K. M. Banks

The hot ductility of in situ melted tensile specimens of micro-alloyed steels having C contents in the range 0.12?0.17% (mass %) have been examined over the 700?1000°C temperature range. An improved testing method for simulating the continuous casting process was used, which takes into account both primary and secondary cooling conditions. Increasing the N content to electric arc furnace levels (0.01% N) was found to cause a serious deterioration in ductility. V-N steel gave better ductility than Nb-containing steels due to less precipitation. From a cracking perspective, low- N steels are generally recommended but, when not feasible, a combination of Nb and V gives even better ductility. However, to be sure of avoiding transverse cracking in higher N steels a small addition of Ti is required. This resulted in a decrease in the fraction of fine particles and in accord with this better ductility. Transverse cracking of industrial slabs was then avoided.

Jan 1, 2011

By W. Langer

Of the 50 or so most often utilized industrial minerals, more than two thirds are, or have been, produced in the western states of Arizona, Colorado, Idaho, Kansas, Montana, Nebraska, New Mexico, North Dakota, Oklahoma, South Dakota, Texas, Utah, and Wyoming. Some commodities, such as natural aggregate, currently are produced in all 13 states; others such as beryllium and iodine are produced in only Utah and Oklahoma, respectively. Together, the 13 western states make a significant contribution to the US industrial minerals industry.

Jan 1, 2007

By Robert J. Morris, John N. Butler

A series of organic collectors has been developed which successfully float synthetic secondary uranium minerals, such as autunite, carnotite, and torbernite. Recoveries up to 97 pct have been obtained. With cleaning of rougher concentrates, ratios of concentration as high as 15:l are possible on head assays of 0.10 to 0.50 pct U308. Additions of certain base metal salts aid in recovery and materially in- crease the rate of flotation and selectivity of the collectors for the synthetic minerals. Flotation tests on natural uranium minerals have not yet equaled results obtained on the synthetics, although these collectors do give better results than conventional collectors for nonsulfide minerals.

Oct 1, 1956

By W. L. Crentz

In Fayette County, the Pittsburgh bed has been the major source of production for almost two centuries. Although historical documentation is not available, there is evidence, that the Pittsburgh bed may have been discovered in Fayette County near Mt. Braddock, Pa., as early as 1753. The earliest known reference to coal in western Pennsylvania was recorded in 1758 by a Quaker trader, James .Kenny, who reported having seen coal in Fayette County. The production of coke from Pittsburgh coal was begun in 1841, when two 10-foot beehive ovens were erected in the Connellsville region to make coke .for shipment by river to the market. The Connellsville, region extends from Latrobe, Pa., in Westmoreland County to South of Uniontown, in Fayette County. Connellsville coke was used with great success in the Clinton furnace in 1859.

Jan 1, 1951

By Denise Weber, Jürgen Kateloe, Marku Papst, Laurenz Preusse, Axel Preusse

"The angle of draw (in Germany, referred to as Limit Angle) plays a significant role in the field of mining subsidence engineering. This applies both to the assessment of the affected area by underground mining activities as well as applied methods for the prediction of ground movements.Recent observations using remote sensing show that ground movements outside the affected area defined by the angle of draw have been detected in German hard coal mining. Since the affected area by underground mining activities also plays an essential role regarding claims of landowners with damages to their houses and infrastructures, possible solutions for limiting the size of the affected area will be presented in this paper.Ground movements which exceed the affected area of an underground coal mine, as defined by the angle of draw will be shown in an exemplary manner. Present knowledge indicates an expectation that ground movements outside the affected area will not cause damage of major significance.This paper outlines the consequences for all affected parties regarding ground movements due to underground coal mining that exceed the extent of the area defined by the currently assumed angle of draw. This will be visualized in a case study.INTRODUCTIONGermany has a long tradition of coal mining, especially in the mining area of the Ruhr district. Following a long period of mining activity, the area is now highly populated and densely developed. In such an environment, it is of utmost importance to calculate and predict ground movements initiated by mining activities; therefore, the research here focused on the prediction of ground movement for the last decades. Special attention was given to the development of accurate ground movement models, which can be utilized in all mining areas. These models are based on different influencing factors such as depth of mining, worked thickness and the angle of draw.Depending on these models, the mining companies calculate the area of land subsidence; the predicted results are used for financial calculations and planning. For structures on top of zones with a high risk of deformation, structural measures can be applied, construction warnings can be given and, in cases of damage, compensation can be planned. The technical and economic planning was performed for all areas of mining subsidence. The most important factor for the outer limits of mining subsidence is the angle of draw (Ger. Grenzwinkel), which plots the border of the area of mining subsidence."

Jan 1, 2015

Roof bolting with resin bonded bolts has been developed extensively in French coal mines. There are three aspects of this development: 1. The reason for and the care used in the development of roof bolting from use as a reinforcement in a classical arched roadway to use as the only support in roadways in ad- vance of the working face (the roadway being reinforced behind the face); 2. The problems encountered and studied, such as choice of boltable roadways and determination of the technical data in designing a roof bolting pattern; 3. Only because roof bolting has been controlled by safety rules, and especially by accurate measurement of strata behaviour, has this system of support been expanded aapidly in France since 1967.

Jan 1, 1971

By D. Bois, F. P. Hassani, M. Hossein

"A growing environmental awareness hos prompted the mineral industry to seek innovations in waste management and technology. It is estimated that over 500 million metric tonnes of solid waste each year are rejected by the Canadian mineral industry. This waste hos to be disposed of in the most environmentally and economically acceptable manner.An extensive study has been conducted to estimate the cost of implementing total tailings fill from a waste disposal point-of-view as an alternative to large-scale surface disposal of tailings. The cost of waste disposal at the surface (tailings pond), and underground (total tailings fill) for three Canadian mines which have taken part in Quebec Mine Survey conducted in 1992 are analyzed. Surface disposal is the most economical and common method of mine waste disposal in Canada. Total tailings backfill as a method of waste disposal is technically feasible but cannot be regarded as more economic than surface disposal in all . It is important to remember that while surface disposal costs are rising, due to tighter legislation and more environmental pressure on governments; the costs of preparing and placing total tailings backfill is still falling as the technology improves."

Jan 1, 1994

By Ulrich Von Stackelber

Deep sea mining of manganese nodules actually will have an environmental impact to the seafloor and to the water column. However, we are far from being able to predict the possible consequences. Therefore, in 1992 environmental studies were conducted with the R/V Sonne in a manganese nodule field of the Peru Basin. The bathymetry of the seafloor was mapped using the hydrosweep system and the distribution and type of sediments were investigated by the parasound system and by collecting surface samples and sediment cores. Deep towing of a side-scan sonar system revealed a Mn encrustation of sediments and a nodule coverage of variable density. Along the tracks of a photo sledge a great variability of bottom fauna and of bioturbation was observed. Bottom-mechanical investigations of surface-near sediments were completed on board. Additionally water samples were collected near the sea floor to determine character and amount of dissolved and suspended particles. Manganese nodules and crusts were collected at 80 locations. In many aspects the nodules differ from those of the Clarion-Clipperton Zone: Big cauliflower-shaped nodules with growth rates up to 160 mm/ Ma may reach a maximum size of 24 cm in diameter, maximum abundance may be 44 kg/m2, the mean size of buried nodules is greater than that of surface nodules. The reason for that difference is due to the relatively high bioproductivity in surface waters and to a Mn redox boundary in the sediment column 10 cm below the seafloor. Histograms of nodules showing the distribution of size and growth type clearly indicate that the growth history is different for basins, slopes and tops of seamounts and ridges. Nodules with diameters >7 cm show mainly diagenetic and to a minor degree hydrogenetic growth. Smaller nodules of the same assemblage are composed mainly of hydrogenetically grown Mn oxide. The optimum diagenetic growth occurs within the sediment immediately above the Mn redox boundary, a level which is not reached by the small nodules.

Jan 1, 1994

By W. F. Hazen

This paper describing the mining practices at a 100 per cent mechanized mine working the Pittsburgh or No. 8 coal bed in eastern Ohio is one of a series being prepared by the U. S. Bureau of Mines on mining practices, methods, and costs in the various mining districts of the United States. The purpose of assembling this data is to place before those interested in the mining industry the methods employed and the cost data on the items involved in the winning of the coal and its removal to the railroad car at the tipple. Mining costs are governed by the mining method used, which is selected for its adaptability to local natural physical conditions such as the nature and thickness of the coal, its dip, the character of the roof and floor, and the thickness of the overlying strata.

Jan 1, 1929

By Lorenz E. Sieffert, Lawrence B. Berger, H. H. Sehrenk, Ralph W. Stewar, James A. Gale

"INTRODUCTION The purpose of the investigation discussed in this article was to evaluate the toxic hazard from gases produced when thermosetting plastic materials used for electrical insulating purposes are burned or thermally decomposed in enclosed spaces. For brevity the term ""toxicity"" is used throughout the article to refer to the nature of gases produced under these conditions. A need for immediate study of the problem was created as a re¬sult of the battle damage reports received from various United States Fleet units. These indicated that the fumes emitted when these materials were burned or thermally decomposed had, in several instances, resulted in toxic atmospheres. In attempting to develop a suitable test method for evaluating toxicity, it was recognized that no single test procedure could be expected to duplicate the variety of conditions that might exist in an actual fire aboard ship. In view of the immediate need, however, it was felt that considerable information could be obtained, at least to classify comparatively the several types of materials as to the toxic effect caused by burning or thermal decomposition, through the development of a sound empirical method which could be applied to all of the materials. On this basis, it was decided to modify the Navy flame resistance test for thermosetting plastics to render it applicable to the determination of the toxic, gases evolved when this test was employed. A wide variety of materials was tested, both molded and laminated, to cover the types commonly used by the Navy in electrical applications. Toxicity determinations were conducted at the Bureau of Mines Central Experiment Station, Pittsburgh, Pa. Parallel tests, to determine the flame resistance of the materials, were conducted at the Material Laboratory, U. S. Navy Yard, New York, N. Y."

Oct 1, 1947

This report summarizes the results of several field tests conducted by Collins for the Bureau of Mines under contract S0122076 and contract H0232056. The field projects represent a part of Collins continuing effort on a broad study of coal mine communications. These experiments analyze the propagation characteristics of radio signals in a working coal mine environment. The intent of the program is to provide basic propagation loss characteristics by which we may evaluate various approaches to an integrated mine communications system. The goal of such a system is to satisfy both operational and emergency communications needs in the mine.

Jan 1, 1974

By E. Yigit

Hydrometallurgical production of zinc from concentrates is generally carried out by H2SO4 leaching. For the smooth operation of this process, some harmful components must be removed from the leach solution before the electrolysis stage; MgO is one of these compounds. Zinc concentrate samples from the Mount Isa mines were used in leaching tests. Leaching tests with an aqueous solution of H2SO4 and SO2 gas were carried out at various temperatures, pH levels and leaching durations. While duration and the pH value of the solution were effective parameters in H2SO4 leaching, temperature and pH were more effective in SO2 leaching for the removal of MgCO3 and CaCO3. Removal of MgCO3 and CaCO3 was generally achieved at low pH values. The results show that SO2 gas can be a good alternative to sulfuric acid in the leaching of MgCO3 and CaCO3

Jan 1, 2010

By D. V. Fites

Criteria for deciding when rock should be ripped and what ripping equipment and techniques should be used in given situations are discussed in this article. The relation between ripper performance and seismic wave velocities in various types of rock is also discussed. The ripper is not a new tool. In fact, it dates back as far as the Roman Empire. The Roman&apos;s ripper-mounted on wheels and shaped something like a plow — was pulled by oxen and used to loosen the earth for the shovelers and basket carriers building the Appian Way. There are records of rippers being used in this country in railroad construction between 1860 and 1880. However, the ripper as we know it today did not appear until about 1930. Tractor-drawn models were in use in 1931 on the Hoover Dam project. At that time they weighed about 7500 lb and were pulled by tractors with about 75 flywheel hp and up to 30,000 Ib total weight. The chief shortcomings of trailed

Jan 1, 1969