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By K. Kavouridis

The energy and climate protection policy of European Union (EU), and its Member States adopted in 2007 bridges security of supply, environmental protection and competitiveness. The objectives of the EU energy and environmental strategy cover the foreseeable period till 2020. It assumes all sources of energy will be needed. The objectives for renewable and improved efficiency are ambitious; it must be established if they are also realistic. Coal can continue to make valuable contribution to the security of supply and low price of electricity, only with technologies allowing for drastic reduction of the CO2 emitted of its combustion. The aimed at -20% reduction of green-house gases (GHG) of EU-27 by 2020 is an objective limited in time and content. Europe produces less than 15% of global CO2 and this will be reduced to 10% in 2030. Emissions Trading (ET) is to remain the central instrument for CO2 management, especially in the power sector. ET scheme (ETS) or other mechanisms need designing to create an incentive for investment in higher efficiency and technologies and to Carbon Capture & Storage (CCS). The ETS as the climate protection instrument of the EU can become a heavy burden (high fuel and electricity prices, less security of supply) or it can create a climate for modernization of fossil fuel power plants. The suggestion in this paper of fuel-specific benchmark system for CO2 allocation after 2012 can combine the emission levels to be reached with a strong drive to invest, the necessary investment security, transparency and the principle of proportionality. A Benchmark System as recommended by coal industry could adapt to the different circumstances in the long term and comply with EU energy and environmental policy objectives.

Jan 1, 2008

By D. B. RUSHhIORE

I. INTRODUCTION. OF primary importance in mine-installations is the hoist, which has a very direct bearing on the successful operation of a mine. Conditions vary greatly with different mines, and especially in different localities. Such factors as depth, incline, the number of levels, permissible or desirable speeds, conditions of ore, etc., are always more or less special in each case. Veins of ore are never exactly duplicated, and the nature of the ground through which shafts are sunk may considerably modify permissible values. As mining-laws are made by the different States, they necessarily vary somewhat, and, even when not fully observed, they introduce factors which qualify the conditions of hoisting men and ore. The amount of timbering required is often of importance as relating to hoisting-conditions. Methods of loading ore affect the time required, as also does the question of the use of cars or skips. Safety-precautions must be very carefully considered, and the number of men in each mine, the number of compartments, and often the method of removing water from the mine, must. have careful consideration. While a general discussion of the subject. of hoisting is possible, most cases are entirely special, and can be considered only in connection with the peculiar conditions pertaining to that particular installation. The cost of installation of the hoisting-plant may be an appreciable amount, while the cost of raising the ore may be but a small part of the total operating-charge. In many cases, however, the output of the mine is limited by the capacity of the hoist, and the latter thus becomes of the first importance. * Presented also, by mutual agreement, at the meeting of the American Institute of Electrical Engineers, New York, N. Y., Mar. 11, 1910.

May 1, 1910

By G. S. Beaumont

This report presents a programme of work to demonstrate the use of a surface-based centralised computer control system for the remote monitoring and control of underground conveyors in a US coal mine. The system selected for demonstration was the 'Dynalink' Micro MINOS system which is manufactured by Hawker Siddeley Dynamics Engineering Limited. The site selected was Barnes S Tucker Lancashire No. 20 Mine located near Carrolltown, Cambria County, Pennsylvania. The system concept, operating and application software was designed and developed by the. British National Coal Board. The report describes the selection of the site, specification of the system requirements, commissioning, operation and evaluation of the system under typical US mine operating conditions. Experience with the system, based primarily on the system reliability and performance of conveyor control, was favourable. Mine management personnel felt that the system had successfully achieved its objectives and were keen to expand monitoring and control to other activities.

Jan 1, 1986

By Yi Luo

Bolting the mine roof is one of the noisiest underground mining operations. The main contribution to the noise is the drilling of the roof bolt holes, especially drilling in hard rock. Previous research shows that the specific energy consumed in drilling bolt holes is inversely proportional to the bite depth (i.e., penetration per drill revolution). Less specific energy at a reasonably high bite depth means less energy is wasted in the drilling process for producing heat, bit wear and noise. Therefore, proper control of the drilling operation to achieve a reasonably higher bite depth can reduce drilling noise from its sources as a proactive noise control approach. In order to explore the feasibility and develop the proactive technology for reducing drilling noise, drilling tests have been conducted in laboratory settings. The preliminary results show that significant reduction in noise dose can be achieved by drilling in medium hard rock with uniaxial compressive strength of about 276 bars (4,000 psi) and at a reasonably high bite depth of about 4.6 mm/rev (0.18 in./rev). This paper presents the findings from laboratory experimental studies.

By J. H. East, D. Harrington

"INTRODUCTION The tremendous expansion of industry during the war and the unprecedented demands for metals and minerals are reflected in the production and use of explosives during that period. The increased use of explosives brought added safety problems to industry because of the necessity of using men as blasters who were not entirely familiar with and some who were totally unfamiliar with the characteristics of some or all of the various explosives. A discussion of the characteristics of the ordinary types of explosives used in: industry should assist in giving a better understanding of the hazards attending their use. Explosives are compounded so they may be used with reasonable safety provided the user understands and follows the procedure recognized as standard safety practice. Short cuts and the failure to understand and use recognized safe practices, as well as the selection of explosives unstited for the work at hand, are all part of the safety problem,The extent to which explosives are used in the United States is shown by a study of the statistics compiled by the Bureau of Mines 4/ regarding them. Some of these statistics are shown below and serve as an indicator of the tremendous number of men engaged in the transportation, storage, and use of explosives. Theme men are exposed to the inherent hazards attending this occupation and they should be familiar with the recognized safe practices relative to explosives."

Sep 1, 1946

To develop a conceptual design for an automated longwall mining system, one should know what has been done, what is being done today and what is being planned for tomorrow. The bibliography referenced and discussed in this report provides a good source for that knowledge. To scientifically determine where attention should be focused to up-grade a system, the system must be quantized as far as possible. The Mechanization Profile of Appendix A-I is discussed in this report and has been used to analyze and determine the degree of mechanization currently in use and/or described in the literature for all three major elements of the long-wall system, namely, Winning, Roof Support and Haulage. The charted profiles make it self-evident where attention and design effort is needed to remove human operators from the face of the mine.

Jan 1, 1975

By Klaus L. Cappel

In 1972, the Bureau of Mines of the U. S. Department of the Interior commissioned the development and design of a Simulator for research and testing of mine roof supports used in long-wall mining. The purpose of the Simulator is to reproduce forces and displacements of a section of a mine roof in contact with one or more supports. This report is an account of the design process that resulted in the final configuration of the Simulator presented here. It includes discussions of engineering considerations that led to major changes in important details of the Simulator. These changes, however, did not substantially alter the basic design originally proposed, except for the elimination of certain originally-specified features that were adjudged as insufficiently cost-effective by both the Bureau of Mines and the design agent at an intermediate stage of the design.

Jan 1, 1974

By Edwin Higgins

SINCE the "Days of Forty-nine" California has been the premier gold producing state of the union. The greatest production was recorded in 1.852, during which year the state's placer and lode deposits yielded over 81 millions. This peak was followed by a steady decline to about 12 millions during the years 1888 to 189.3, a period marked by the cessation of gravel mining. After 1893, production increased to a new peak of over 22 million in 1915, thereafter decreasing steadily to something over 13 million in 1923. Today; California's gold production shows a decrease of 84 per cent. as compared with the output of 1852, and a decrease of 41 per cent, as compared with 1915. It is not a difficult matter to find the causes of this more recent decline. In 1916 there began an upward swing in the cost of labor, which represents approximately 60 per cent. of the cost of mining, and in the price of supplies, representing the remaining, 40 per cent. This rise continued until 1922 and since that year there has been no decided tendency either upward or downward. The increase in the cost of mining since 1916 is variously estimated at from 50 to 75 per cent.; the price of gold has remained fixed at $20.67 per oz. This condition resulted in wiping out the profits of the low-grade operations which, in recent years, have constituted California's main source of supply of gold ore. It is now predicted that there will be renewed activity in California- gold mining. What are chances for the materialization of this forecast? A boom or even a revival of gold mining must of necessity be brought about or accompanied by one or more of the following factors: 1. A decrease in the cost of mining. 2. An increase in the price of gold. 3. New capital for development. 4. The discovery of new deposits. 5. The revival of hydraulic mining.

Jan 1, 1925

By C. A. Young

In-situ Fourier transform infrared/internal reflection spectroscopy (FT ?IR/IRS) has been extended to study oleate adsorption at a calcite surface. The birefringent and transmission limitations of calcite were overcome by using an appropriately designed optical setup and a near-infrared (NIR) spectrometer. An adsorption isotherm was determined at pH 9.2 and room temperature. Comparison with the fluorite/oleate adsorption isotherm determined by the same technique indicates that oleate abstraction by calcite can be as much as one order of magnitude larger than that by fluorite. Nevertheless, the hydrophobicity of the fluorite/oleate surface is greater for equivalent adsorption densities as indicated by contact angle measurements and flotation results. The monolayer region has been confirmed to be chemisorbed oleate at both calcite and fluorite surfaces. Furthermore, multichannel laser Raman spectroscopy (MLRS) showed that chemisorbed oleate at the fluorite surface undergoes a double-bond reaction with oxygen to form an epoxide/polyether complex. Such a reaction, however, could not be detected at the calcite surface. These phenomena are discussed in terms of the intrinsic surface properties of the mineral systems as well as the adsorption density and the cross-linking/polymerization reaction of the adsorbed oleate film.

Jan 1, 1993

By C. A. Geffen-Fowler

This report, sponsored by the Bureau of Mines, presents the results of an examination of the safety of the Blind Shaft Borer (BSB) shaft sinking system and an alternative modified BSB design concept in comparison to conventional shaft sinking technology. Detailed study of the two systems was also performed to identify and recommend design changes for optimum safety conditions. A comparison of the BSB systems with conventional shaft sinking was made on the basis of relative risk levels. Risk incorporates both the frequency and the potential consequence of accidents. A safety evaluation of the component operations of the two BSB systems was performed using a Failure Modes and Effects Analysis (FMEA) methodology. The results of this analysis show generally that both BSB systems are safer than conventional shaft sinking. The potential risk of conventional shaft Sinking operations could be reduced by over 30%, on the average with the use of the original BSB system, and by an average of about 10% with the modified BSB. Design change recommendations to further improve the safety of these systems include a better fire suppression system, improved man haulage systems and more compact hydraulics. An operational safety manual was also developed for the modified BSB system.

Jan 1, 1981

By FREDERICW K. BRADLE

I HAVE been puzzled by two lines of thought'; one emanating from Washington, D. C., to the effect that we must all cheer up, that in a very short time, measured in terms of months, prices would begin to recover, business would become normal, and prosperity would continue on its way just as before the interruption of a year ago; and a second, coming from certain industrialists and economists, expressing fears that all commodity prices were in for a long downward trend, which would cause much unemployment, eventually drag down wages and so restrict purchasing power as to further aggravate the situation. One basis for the fear of a downward trend in commodity prices' is that ifter great wars a depression could last for something like 40 years-the downward trend to such a depression after our recent World War having been postponed for some reason or other; and the basis for another fear was that the production of gold was becoming less. I had 'also been trying for some time past to refresh my recollection as to how my ow11 particular lead interest climbed out of the depression of 1893; and as all the metals have had, and still have. relative values and prices, I can best express what I have in mind by talking principally about lead.

Jan 1, 1930

By Michael L. Wayman

Archaeological and ethnographic work during the last century has shown clearly that metals have played a small but important role in prehistoric Arctic cultures. For at least the past several millenia both iron and copper have been used in the North, primarily for blades, projectile points, knives, awls, engraving tools, fishhooks, scrapers and axes. In addition they were used for joining purposes as staples and rivets. It is of great interest to enquire into the origins of these metals. In this connection one begins with the observation that to date there has been no clear evidence for the smelting or melting of metals in the Arctic prior to the arrival of Europeans. This can be explained partly by the absence of traditional pyrotechnologies such as the high-temperature firing of ceramics and the heat treatment of bone and wood. Another factor which surely inhibited the development of smelting/ melting operations is the relative absence of wood in the region. The production of charcoal for smelting requires large quantities of wood, to the extent that the desertification of a number of areas in the Old World is believed by some to have been at least partly caused by charcoal production. In the North this was obviously not possible. Thus the Arctic peoples were restricted to using native (naturally occurring) metals and metals obtained by various direct and indirect forms of contact with areas of the world where smelting was practiced. Both of these sources were important in the case of iron; we know that meteoritic iron, telluric (native) iron and smelted wrought iron were all used in the Arctic. These three types of iron will be considered in tum.

Jan 1, 1999

By William G. Fischer

This paper attempts to close the gap between extensive rock testing with field measurements and the mine operator's need for safe mine layouts and alternatives. It was found that many of the variables that influence mine geometry and worker safety are relatively unimportant while others are critical. The development of empirical relationships which tie the critical variables to the "safe useful life" of a trona mine layout and observations made in 140 production areas where the variables were researched over a fifteen year period are discussed. The concepts presented may have applicability in mine design for other bedded deposits.

Jan 1, 1984

By E. C. Yeager, E. O. Wagner, A. W. Koth, V. F. Parry, J. B. Goodman, D. G. Gernes, W. L. Patty

"In July 1943, the Bureau of Nines received an appropriation to investigate the beneficiation of Minnesota iron ores through the use of lignite. The broad objective was to find a way to link the large deposits of lignite in North Dakota with the low-grade iron ores of Minnesota. It was proposed that sponge iron might be made through new methods of processing, and one of the objectives was to determine the possibilities of gaseous reduction of fine ore. The problem of obtaining high-hydrogen reducing gases from lignite was assigned to the Subbituminous Coal and Lignite Section of the Bureau of Mines in August 1943.Through the advice of technical consultants and men familiar with the mineral resources of Minnesota and North Dakota, a tentative program of development was outlined. The first proposal was to study the gasification of lignite briquets in a standard water-gas machine. Previous experience with gasification of lignite indicated that the raw fuel would not be suitable for use in the conventional water-gas process on account of degradation, but gasification of lignite briquets appeared possible. Through the cooperation of the Northern State Power Co„ a series of tests was made at the company's plant in Grand Forks, N. Dak., on lignite-char briquets made by the Lehigh Briquetting Co. at Dickinson, Dak. These briquets are made by the Lurgi process, and they have been used satisfactorily as a domestic fuel. The object of the tests was to compare gasification properties of lignite-char briquets with those of gas. coke made from Kentucky coal, normally used in the Grand Forks plant. The tests revealed that the lignite-char briquets were not suitable for gasification, in the standard water-gas process because of disinte-gration and low efficiency caused by loss of fine carbon.While these investigations were underway, a joint Minnesota-North Dakota Development Commission was formed to aid in planning investigations on development of mineral resources of the two States. Some members of this commission were technical men, who with consulting engineers on the Bureau's staff made up an unofficial technical committee, and assisted in solving certain problems connected with gasification of lignite and beneficiation of iron ores. This committee has been of 'real assistance in guiding the investigation.A technical meeting was held in Minneapolis on November 10 and 11, 1943, for further discussion of objectives and certain technical problems. Results of tests on lignite briquets were presented, and several reports analyzing other methods of gasification were discussed. The Reyerson-Gernes process for the continuous gasification of lignite in an externally heated retort was considered from several angles. This process differs from others in that the natural moisture in the coal is utilized to help gasify the coal, and the volatile matter is largely decomposed. Although this process had been carried out successfully in a small steel retort, no definite design for a commercial-scale retort had .been developed. It was first proposed that the process might be carried out in a Glover-West retort. However, it was brought out that a Glover-West retort would require modification to simulate the process correctly, and that good results might not be obtained even then owing to the leakage of gas through the refractory walls and to an anticipated low rate of heat transfer at the gasification temperature suitable for lignite. Further, the probable leakage of inert furnace gas into the water-gas would be adverse to the Objective to obtain a gas that could be purified to 96 percent hydrogen."

Jun 1, 1946

By AIME AIME

T HE 133rd meeting of the A. I. M. E., opening in New York on Feb. 15, promises to be as successful technically and socially as any in the past. The papers submitted for the various technical sessions are unusually excellent and insure something of interest to every group. Tentative programs have already been issued, and a concise resume of the various sessions, arranged chronologically, appears on page 48. Among the many interesting technical sessions arranged, attention is directed to those of the Petroleum Division, embracing the Symposium on Production that has come to be an annual feature, and new ones on refining practice, transportation and economics. The Institute of Metals program is similarly comprehensive. It includes 15 papers, 8 on copper, 4 on aluminum and its alloys, and one each on magnesium, lead, and fatigue of metals. The Coal Committee offers as a leading contribution its report, prepared under the direction of H. N. Eavenson, giving a new analysis of the capacity of the mines and a comparison of coal with other industries. This will be supplemented by a number of other papers of especial interest to operating men, among which are "Data on Use of Loading Machines in Bituminous Mines," by Graham Bright; "Evaluation of Coal," by R. H. Sweetser; "Selection of Coals for the Manufacture of Coke," by H. J. Rose; and "Relation of Origin and State of Carbonization of Coal to Problems of Low Temperature Carbonization," by S. W. Parr. The Iron and Steel Committee has scheduled seven papers, and there will be a special session on open-hearth practice, in which will be presented the first results of the two conferences, held by the sub- committee at Pittsburgh and Cleveland. A symposium on molding sands will be a special feature of the session on non-metallics.

Jan 1, 1926

By D. Harrington

When the word "gas"' is mentioned in connection with mining almost invariably it is inferred that the explosive gas, methane, is in mind and that the reference is to coal mining. Although methane is likely to occur in any coal mine the metal mines of the world contain by far a greater variety of gases than do the coal mines. Often the gases in metal mines are as dangerous as the gases likely to be found in coal mines, and sometimes are even more deadly. A coal mine is more likely to contain methane than a metal mine. In rare instances it may contain high percentages of nitrogen or carbon dioxide or it may be deficient in oxygen where the air is confined in a blind end or in a sealed region. Much more rarely relatively small percentages of ethane or other hydrocarbons with an odor of ether, gasoline, or kerosene, or minute percentages of hydrogen sulphide are found in a coal mine. During a coal-mine fire or explosion carbon monoxide content is likely to be high (4 per cent or more), and if the coal contains much sulphur the high fumes may contain some sulphur dioxide.

Jan 1, 1931

By S. H. Ward

An account of a new method of investigating the electrical .properties J the earth's crust is presented. The method, called AFMAG, employs, as a source, natural alternating magnetic fields of audio and sub-audio frequencies. Measurements of the distortion of these fields caused by geological features are made with the aid of search coil detectors at several discrete frequencies. Many results of field surveys made with the method are presented and they illustrate its advantages and limitations when applied to the search for massive sulphide mineralization. The advantages far outweigh the limitations and in fact indicate that a major breakthrough in geophysical exploration technique and instrumentation has been made.

Jan 1, 1958

By Alan M. Jessop

This paper discusses the distribution of frozen ground in the zone of discontinuous permafrost in relation to the pattern of surface temperature. The importance of understanding permafrost in relation to surface construction and open-pit mining operations is stressed.

Jan 1, 1972

By Scott Turner

GOLD AND SILVER, the monetary metals, have presented in the last year a striking contrast; gold has experienced unusual prosperity, while silver has been depressed more severely than ever before. Gold mining has been hailed as the only basic industry that is able to thrive on depression; the new gold produced is thought by many to be the most important material for the reconstruction of prosperity. Silver production, meanwhile, has been sinking to its level of 40 years ago, and its price to a level never before recorded. These factors have reduced the value of silver produced in 1932 to about the value of the average annual production more than a century ago, that of the decade 1801-1810. No other major commodity in world trade appears to have suffered a greater decline during the present depression.

Jan 1, 1933

By F. Rwere, A. Masasire, P. Dzomba, M. Mupa

Accurate determination of platinum group metals (PGMs) and gold (Au) has always proven to be a difficult task, due to their low concentrations in platiniferous ores. The most common preconcentration technique used in analysis of these metals is fire assay with a flux containing nickel or lead. This technique can be improved by using co-collectors. Here we hypothesise that Fe, Co, and Cu can be used as co-collectors to enhance separation and preconcentration of PMGs and gold by fire assay. To test this hypothesis, geological exploration samples from Siyanda Union Mine (Northam, South Africa) were analysed by an inductively coupled plasma-optical emission spectrometer (ICP-OES) for PGMs (Pt, Pd, and Rh) and Au. A control sample (certified reference material AMIS 0426) was also analysed by the same technique. The PGM and Au recoveries from the control sample ranged from 83% to 105% for all three co-collectors, with relative standard deviations less than 10% for the control sample and 7% for the geological samples. The PGM and Au recoveries by Fe and Co co-collectors were modestly higher than that of the Cu-collector. These results indicate that Fe and Co are better co-collectors than Cu, presumably due to the loss of analyte when using Cu. Taken together, Fe and Co co-collectors can be viable alternatives for analysis of PGMs and gold using the fire assay method.

Jan 2, 2022