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Geological and Natural History Survey of Wisconsin, The University of Wisconsin, Madison, Wis - E. F Bean, State Geologist. A complete list of publications of this Survey will be sent upon request Only a portion of the Bulletins and Maps fall within the scope of this directory, and most of them are available They are: Bulletin 4, Building and ornamental stones of Wisconsin (1898), $2 50, 6, Preliminary report on the copper-bearing rocks of Douglas County, and parts of Washburn and Bayfield counties (1901), 50 cents, 7, The clays and clay industries of Wisconsin (pt 1) (1901), 50 cents; 14, Report on lead and zinc deposits of Wisconsin (the report is out of print but the 18 maps which accompanied it can still be had) (1906), 20 cents (a series of six maps, supplementary to these (1909), may be had for 6 cents), 15, The clays of Wisconsin and their uses (1906), 50 cents; 16, The geology of north-central Wisconsin (1907), $2, 17, The abandoned shore lines of eastern Wisconsin (1907), 50 cents, 19, Zinc and lead deposits of the Upper Mississippi Valley (1907), 25 cents; 34, The limestone road materials of Wisconsin (1914), 50 cents, 35, Underground and surface water supplies of Wisconsin (1915), $150, 36, The physiography of Wisconsin (new edition now in press) (1916), $125, 41, A study of methods of mine assessments and valuation (1914), 50 cents; 44, Mineral land classification in parts of northwestern Wisconsin (1915), $5, 45, The peat resources of Wisconsin (1915), 50 cents, 46, Mineral

Jan 1, 1933

By James A. Barclay, Ralph C. Kirby

The US minerals posture will be increasingly dominated by three interrelated factors. First, when viewed over the long range, the US supply situation can be expected to steadily deteriorate as demand increases. Domestic high-grade ores have been used up, and other nations compete with the US for world supplies. Second, as environmental awareness becomes more acute, an aroused citizenry is demanding that minerals industries conform their operations to rigorous new standards. Finally, the changing energy situation that confronts the US is forcing an appraisal of energy-use patterns on operations previously guided solely by economic principles and not by national priorities. While future US mineral production and consumption patterns are unclear at this time, it is certain that US demand for minerals will continue to outrun domestic supply. Thus, the US is faced with a challenge of producing more minerals and metals from lower grade resources. Meeting this challenge means a strengthening of US research and development efforts, coupled with their application in the remaining leadtimes available. Some specific examples of how the US Bureau of Mines (USBM) is assisting in the processing of low-grade resources follow.

Jan 6, 1975

By W. C. Krumbein

Geological problems are approached from a geometrical (space relations) viewpoint, a kinematical (time sequence) viewpoint, or a dynamical viewpoint. The first two require sound training in conventional geology and in field methods. The third approach requires a solid foundation of chemistry, physics, and mathematics. Modern training for geologists should include close integrltion of basic sciences with geological principles. Introduction Our knowledge of the earth has increased tremendously during the last half century. We know more about its surface configuration, the distribution of its natural resources, the proccssion of living forms that inhabited it in the past, the chemical composition of its oceans, the areal distribution of its surface rocks, the movements of its atmosphere, and so on. Not only do we know more facts about the earth, but we have a better understanding of the processes that take place on and within it, such as the nature of earthquakes, the thermodynamics of the atmosphere, the chemical equilibria involved in the formation of igneous rocks, the mechanics of stream flow, the dynamics of the earth's origin, and so on. Many sciences contributed to the sum total of this knowledge, including such established disciplines as geology, geography, physics, chemistry, astronomy, biology. Out of this accumulation of new knowledge grew also a group of new sciences, such as seismology, oceanography, meteorology, volcanology, hydrology. Collectively these latter are known as the geophysical and geochemical sciences, and to a large extent they began as branches of geology. Until the turn of the century, for example, the study of earthquakes (seismology) was a part of geology, although as early as 1846 Mallet, a physicist, had suggested that the subject could be investigated by elastic-wave theory. Comparatively little progress was made along these lines until the seismograph was developed near the turn of the century; since then, additional earthquake data have accurnul~ted rapidly, but more important, the interpretation of these data essentially has kept pace with their accumulation. In similar fashion, meteorology was generally considered a branch of geology as recently as one or two decades ago. Considerable progress had been made in such aspects as weather forecasting, but the science dates its recent rapid rise from the year 1911, when Bjerknes first applied the principles of dynamics to the analysis of air masses. The rapid development of such disciplines as oceanography, volcanology and hydrology was due in part to the application of principles of chemical equilibrium, of dynamics, and of thermodynamics to earth problems, by men who were essentially physicists or chemists by training. The last half century, therefore, and particularly the last two decades, saw the influx of numerous chemists and physicists into the realm of the earth sciences. In the meantime the main body of geology itself showed a marked growth, and

Jan 1, 1946

By Phil Morriss

During the last 12 months, Sandvik?s Technical Service Group has carried out nine Scoping and Pre-feasibility studies for the application of In-pit crushing and conveying (IPCC) for large mining companies; the majority in conjunction with the Snowden Consulting Group. During these studies several key and recurring drivers have been identified: 1. Mining schedule issues ? there are several issues which crop up repeatedly, including: ?the unnecessary curvature of pit walls, ?very high rates of vertical advance which are (created by schedule optimisers to minimise stripping at all times) which are at the limit of what can be realistically achieved (and which of course make it harder for IPCC to achieve any impact), and ?The allocation of material to semi-mobile systems to maximise the ability for IPCC to be an effective alternative. 2. IPCC productivity issues ? the key issues are the IPCC system operating hours achievable, and the system throughput (both instantaneous and the average). 3. IPCC Risk issues ? there are perceptions about the risks associated with the use of IPCC which are a mix of reality and fiction, but which nonetheless create negativity towards the use of IPCC. In this paper, the authors wish to address specifically the factors affecting the IPCC productivity.

Jan 1, 2008

This paper provides an insight into the current status of risk management practices within our industry, based on an industry wide survey, with deliberate cross-reference to quantitative analysis. This survey showed that quantitative assessments appear to be mainly hampered only by the lack of reliable data and industry expertise to carry out such assessments. A short case study will illustrate some of the necessary basic tools and data types that would enable the industry to tap into an additional range of business improvement dimensions to more effectively manage the diverse and changing risk profile of the mining sector.

Jan 1, 2003

By T. G. Sitharam, P. B. Choudhury

Prediction of ground vibration (peak particle velocity, PPV) and frequency is an important task in geoscience. Till date, many empirical equations are derived from conducting trial blasts in the mines, to arrive at attenuation predictors. These predictors are usually site dependant and hold good for one particular type of rock/strata. These predictors cannot be used for geologically different rocks/strata. This paper presents the application of support vector machine (SVM) model, for predicting blast induced ground vibration and frequency, using a one comprehensive model for three different types of rock. Inputs to the SVM model formulation involve twenty one parameters consisting of geotechnical properties of the rock mass, blast design geometry and explosive properties, and the output of the formulated model is peak particle velocity and its associated frequency. The data has been acquired from eight limestone mine, five coal mine and two manganese mines. The comprehensive SVM model is formulated using 400 datasets and tested with 143 datasets. The performance indicators to the model not only justify its formulation but also the advantages it has over site specific predictor models. The SVM model not only predicts PPV, with higher correlation coefficients as compared to predictor equations, but also the associated frequency.

Jan 1, 2010

By P. J. Adams

Environmental regulations require means for controlling emissions of SO2 NOx and particulate when burning coal. The combustion of coal in limestone fluidized beds is one of the most promising techniques for the necessary reduction in emissions. Fluidized-bed firing, furthermore, offers potential economies in capital equipment. The world's largest steam generator applying fluidized-bed techniques was built under the sponsorship of ERDA and installed in Rivesville, West Virginia. This paper describes the design and discusses the start-up and development difficulties which were experienced during the period from initial operation to current readiness for commercial operation. Other developments leading to utility and industrial fluidized-bed steam generating equipment are reviewed. The future potential of this promising technique is discussed.

Jan 1, 1979

By Lyle D. Randen

With the environmental movement beginning in the late 1960's came a deluge of permit requirements for the mining industry. Coal mining has been one of, if not the most, severely impacted of the mineral industries as a result of the passage of the Federal Surface Mining Control and Reclamation Act of 1977. Numerous provisions of this Act and numerous regulations developed under authority of the Act are being challenged in differing levels of the judicial system across the United States. Such court cases have had varied success. Numerous other regulatory programs that are not quite as dramatic as the SMCRA have presented an unending regulatory problem for mining operators. My comments in this presentation relate primarily to the major Federal and State agencies and their legal responsibilities which we in the coal mining industry must address in order to receive authority to construct and operate surface coal mines in the State of Wyoming. A list of the Federal and State agencies one could deal with in an application is as follows: 1. Bureau of Land Management (BLM). BLM is responsible for deciding where and when to lease federally owned coal and for establishing terms and conditions for leases. BLM also has some control over surface reclamation on federal land, i.e. regrading to eliminate highwalls, covering of spoils, maximum extraction of coal to limit future disturbance, contemporaneous reclamation, etc. BLM is also responsible for designation of federal lands unsuitable for all or certain types of surface coal mining operations. 2. Geological Survey (USGS). USGS coal mining responsibilities apply only to Federal and Indian lands and concern compliance with production requirements including diligent development, minimum production levels, royalty payments and resource protection, and

Jan 1, 1983

By J. Y. Tian

In view of the fact that many domestic iron ore-dressing plant applying flotation cells in the re-verse flotation, to improve the technical level of magnetite reverse flotation, we apply such a technological process of one stage rougher and two stages scavenger flotation column respectively. The middling from the two stage scavenger process are returned to magnetic separation for condensing. By contrast, the technological process of one stage rougher and one stage cleaning flotation cells is made up of by multi-magnetic separation and magnetic middling regrinding separations. It has been proved that the flotation column we offer can simplify the technological process structure, obtain advanced technical indexes, run the system smoothly, reduce energy consumption, and be environ-mental friendly.

Jan 1, 2014

By J. M. Dahl, L. H. Van Vlack

STAFF: Editor, Gerhard Derge Associate Editor, Paul G. Shewman Carnegie lnstitute of Technology Schenley Park Pittsburgh, Pa. 15213 Editorial Assistant, M. A. Redmerski Production Editor, Otto T. Johnson THE METALLURGICAL SOCIETY: Jack H. Scoff, President; Richard C. Cole, Post-President; Harold B. Emerick, President-Elect; Ralph L. Hennebach, Treasurer; Robert W. Shearman, Secretary; Donald A. Parks, Assistant Secretary; Leslie S. Wilcoxson, Assistant Secretary. PUBLICATIONS COMMITTEE OF THE METALLURGICAL SOCIETY: R. E. Lund, Chairman; T. E. Dancy, H. B. Emerick, P. R. Gouwens, R. E. Grace, J. H. Jackson, H. H. Johnson, A. E. Lee, Jr., R. R. Nosh, R. D. Pehlke, and Paul Queneau. Review and selection of monuscripts is under the supervision of the following Publications Committees: Extractive Metollurgy Division: R. E. Grace, Chairman; G. M. Bell, D. W. Bridges, J. M. Cigon, G. W. Healy, T. A. Henrie, R. D. Holli-day, C. E. O'Neill, C. S. Sami s, A. W. Schlech-ten, and Charles Shull . Iron and Steel Division: R. D. Pehlke, Chairman; T. P. Floridis, Arnulf Muon, G. R. St. Pierre, E. T. Tuckdogon, L. H.Von Vlack, and J. M. Uys. Institute of Metals Division: H. H. Johnson, Jr., Chairman; J. B. Clark, Vice Chairman; M. R. Achter, G. F. Bolling, J. O. Brittain, G. P. Conard, II, L. A. Girifolco. G. T. Hahn, J.P. Hirth, L. Himmel, G. T. Horne, George Krauss, C. F. Leitton, Jr., J. D. Livingston, R. D. Monning, H. M. Otte, S. V. Radcliffe, R. E. Reed-Hill, H. C. Rogers, O. Sherby, M. T. Simnod, G. R. Speich, E. A. Steigerwold, R. A. Swolin, W. A. Tiller, W. R. Upthegrove, J. B. Wagner, Jr., Derek Walton, H. W. Weart, W. W. Webb, and D. WiIsdorf. Published monthly by the American lnstitute of Mining, Metollurgicol, and Petroleum Engineers, Inc., 345 East 47th Street, New York, N. Y. 10017. Telephone PLAZA 2-6800. Subscription $30 per year for non-AIME members in United States and North, South, and Central America; $32, foreign; $7.50 for AlME members. Single copies, $6.00, single copies foreign, $6.50. The AlME is not responsible for any statement mode or opinion expressed in its publications . . . Copyright 1965 by the American Institute of Mining, Metallurgical, and Petroleum Engineers, Inc. . . . Registered cable address, AlME New York . . . Indexed in Engineering Index, lndustrial Arts Index, and Chemical Abstracts . . Second class postage paid at New York, N. Y., and Ann Arbor, Mich. Volume 233, Number 1.

Jan 1, 1965

By William H. R. Gibney

Pine Point Mines is located in the Canadian Northwest Territories about 1,200 kilometers north of Edmonton, Alberta, close to the south shore of Great Slave Lake. Originally staked in 1898 by prospectors en route to the Dondike gold rush, it was not until the mid-1940's that large scale exploration was undertaken and Pine Point Mines Limited was formed. Work was suspended in 1954 while studies were made to resolve one of the main problems, transportation. In 1961, under the Canadian Government "Roads to Resources" program, agreement was reached for the construction of the Great Slave Lake Railroad and plans made to put the property into production. A townsite was established in 1963 and plant construction commenced. The first production was in the form of high grade ore which was shipped to Kimberley, B.C. for concentration starting in late 1964. The Pine Point concentrator started up in late 1965 when hydroelectric power became available. Initially designed for 4,540 metric ton per day, facilities were expanded to a designed 7,250 metric ton per day in 1969. Problems associated with mining operations at Pine Point are not unique but are augmented by the isolation, climatic conditions, topography, high water table and spread out nature of the operation. Maintenance of a reasonably stable work force is the number one problem but this is gradually being overcome as more local people are trained and oriented from a nomadic type life to an industrial society. The purpose of this paper is to give a general description of the mining operations of Pine Point Mines Limited and to review some of the problems encountered in the operation along with problems associated with northern operations.

Jan 1, 1970

By J. P. Witherow

The blast-filmace plant of the Crozer Steel and Iron Company was built under contract by Witherow & Gordon, of Pittsburgh, Pa. The furnace is 70 feet high by 16 feet bosh, tunnel-head 12 feet 8 inches, and hearth 9 feet in diameter. The columns are 20 feet high above furnace level, below which they extend 2 feet. The shell is 23 feet diameter at bottom and 19 feet at top. The plate iron is 3/8 inch at bottom, and tapers to 1/4 inch, the top ring being 5/16 inch.

Jan 1, 1884

By D. A. Flanagan, P. B. Crawford

A study has been made of the feasibility of storing liquid meihane at low pressures in undergrohd caverns. Methane liquefies at — 258°F at atmospheric pressure. It is shown that the methane evaporation rates will rapidly decrease and cool the surrounding rock so that at the end of one month they would be between 50 Mcf/hr for a cavern of 25-ft radius and 700 Mcf/hr for a cavern of 100-ft radius. At the end of 10 years, the evaporation rates would be 18 and 100 Mcf/hr, respectively, for caverns of the same radii. The evaporation rates may be reduced by a factor of 2 to 10 by the application of insulation. The cost for mining the caverns is estimated to be $.75 to $1.25/Mcf of storage. This is substantially less than surface storage; it is believed to be safer and to result in lower maintenance, savings in space and savings in strategic materials. INTRODUCTION During the past few years, there has been an increasing interest in the economic feasibility of liquefying methane. Methane liquefaction is being considered for tanker transport; in addition, liquefaction is being reconsidered for shaving peak gas demands. Several articles have described natural gas liquefaction and the progress of the tanker in making trial runs from the United States to Great Britain to determine the feasibility of tanker transport. At the present time, pipelines are not designed to supply peak gas loads during extremely cold periods such as are oiten encountered in the North and Northeast. Gas is being stored in underground reservoirs en-route to its destination, but in many instances satisfactory storage in porous reservoirs has not been practical, especially along the Eastern seaboard where few petroleum reservoirs have been found. In England and other foreign countries, it is unlikely that satisfactory porous structures could be found, and it may be desirable to mine or excavate the rock to obtain storage. By storing the methane near the consumption point, product availability can be increased during periods of need. Methane liquefies at - 258OF at atmospheric pressure, and 1 cu ft of liquid methane will make about 600 cu ft of gaseous methane. Methane liquefaction for shaving peak gas demands was conducted in Cleveland, Ohio in the early 1940's. The Cleveland plant was designed to liquefy 4 MMcf/D of natural gas.' Development of several low-temperature processes has resulted in some improvements in the design of low-temperature storage vessels. Liquefied-methane storage vessels can be designed for various evaporation rates. The desired rate will depend on the reason for liquefaction. For shaving peak gas demands, the desired evaporation rates would be low, possibly between 0.2 and 1.5 per cent/day. For methane tanker transport and supply, the evaporation rates must be high and must equal the total daily rate of supply. It is apparent that the cost of storage facilities will depend on the objective and will vary appreciably. Surface storage of methane may cost between $3,000 and $20,000/MMscf, depending on the size and design. The failure of the surface storage vessels at Cleveland, with the resulting injury and loss of many lives, has caused considerable emphasis to be placed upon developing new, safer and improved methods of storing liquid methane. Storage of liquefied propane and butane in underground salt domes has been very satisfactory. The per-barrel cost of underground storage for any sizeable capacity is very small compared to the cost of surface storage for LPG mixtures. The larger the capacity of the underground storage, the less is the per-barrel cost. Numerous advantages appear to exist if liquefied methane could be satisfactorily stored underground, the principal advantages being increased safety, lower initial cost, lower maintenance cost, savings in space and savings in strategic materials. The purpose of this paper is to determine the feasibility of storing liquid methane underground in mined caverns. If a large spherical cavern is dug underground and is filled instantaneously with liquid methane, the surface of the sphere may approach the liquid methane temperature almost instantaneously. The temperature distribution for a sphere of radius r. in an infinite medium, initially at one temperature with spherical surface kept at T, from time t = 0, is given by Eq. 1.'

By G. W. Jones

One of the major activities of the Bureau of Mines is the promotion of safety in mining and other industries, In this connection, the Bureau determines the explosion hazards' of combustible gases, vapors, and solids and investigates means of controlling and preventing explosions. Many dangers are likely to confront men who must enter a building immediately after it has been damaged. Rescue workers must watch constantly for common gases and vapors that may be present in dangerous concentrations in and about demolished, buildings. Fuel gas is the most common source of danger, although refrigerants, gases from furnaces, flues, fires, sewers, and industrial processes, and gas from bomb, explosions in confined places also constitute definite hazards. To rescuers and trapped casualties, these gases offer the hazards of (1) explosion, (2) toxic effects, including asphyxiation and death, and (3) displacement of air so that the oxygen content of the atmosphere is reduced to or below the danger level.

Jan 1, 1944

By J. J. Forbes

The Act of Congress authorizing the establishment of the United States Bureau of Mines became effective July 1, 1910. One of the most important duties Congress delegated to the Bureau in this Act was the study of health and safety conditions in the mineral industries. Early investigations of these conditions revealed the need of prompt Care of injured employees, as, under the difficulties inherent in their occupation, seemingly unimportant wounds if not treated promptly might become infected and cause permanent disability or even death. Many seriously injured persons brought out of mines and plants by fellow workers ignorant of approved methods of giving first aid or of safe means of transportation have been caused suffering and have had injuries accentuated to such a degree as to bring about permanent disability or death. The need of general instruction in first aid thus became apparent. BRIEF HISTORY OF FIRST-AID WORK The education of miners in the United States in first aid probably was conducted systematically first by the anthracite industry in Pennsylvania. Subsequently, first-aid training was carried on actively in Alabama and Indiana. Meanwhile, a general training campaign was carried on among industrial workers by the American Red Cross Society; when the Bureau of Mines began its nation-wide campaign of instructing employees of the mineral industries, the Red Cross turned over that part of its industrial training work to the Bureau but continued to cooperate by furnishing surgeons as judges in important first-aid contests and demonstr tions and assisted for a number of years in determining training methods.

Jan 1, 1937

By W. R. Evans, H. H. Kaveler, Jack Tarner

The geological features, development history and engineering detail of the Shuler Field and the results of approximately two years of unitized operation of the Shuler Jones Sand Pool, were discussed in a prior publication.' The purpose of this paper is to present the results of pressure maintenance in the Shuler Jones Sand Pool after nine years of unit operation. GENERAL INFORMATION The Shuler Jones Sand Pool is located in and about Section 18, Township 18 South, Range 17 West, Union County, Ark. The pool was discovered .in September, 1937, unitized in February, 1941, and subjected to gas injection operations in July, 1941. Water was first returned to the reservoir in July, 1944. The reservoir is an anticlinal trap covering about 4,000 acres. The 154,000 acre-ft of sandstone initially consisted of approximately 150,000 acre-ft of productive oil zone and 4,000 acre-ft of gas-cap. The average depth of production is 7,400 ft. Maximum closure of the reservoir is 135 ft and the oil column lies between a gas-oil contact at -7,270 ft and a water-oil contact at -7,370 to -7,380 ft. The field is approximately four miles long. east and .west, and one and one-half miles wide. The sand grains are angular and vary from fine to medium size. The porosity of the sandstone averages 20.2 per cent. The specific permeability averages 400 md. Some zones have as high as 30 per cent porosity and specific permeability of 4,000 md. The reservoir rock is not uniform in character but consists of sandstone zones interspersed with shale. The variation in rock characteristics is evident in the electric log and core analyses presented in the original publication. Asphalt present in the pore space of the sandstone limited the reservoir to the southeast and apparently blocked any encroachment of water from that direction. The initial reservoir pressure at a subsea depth of 7,300 ft was 3,520 psi. The reservoir temperature was 198ºF. Initially, the solution gas volume was 765 cu ft per bbl and the reservoir volume factor was 1.45. The gas solubility and formation-volume-factors of the reservoir liquid are related with reservoir pressures above 300 psi as follows: Solution gas, cu ft per cu ft, S = 0.0334 P + 18.65 Formation volume factor of reservoir oil, FVF = 8.0 x 10 -5 P + 1.168 Gas volume factor, standard cu ft of gas equivalent to one cu ft of gas at reservoir conditions of temperature and pressure, F = .062 P - 4 Pressure (P) measured in psia. The equation for the gas volume factor presented above is based on a direct measurement of a sample of the gas and is a correction of that used in the original paper. The gravity of the oil produced is from 32 to 34" API. CALCULATION OF INITIAL OIL IN PLACE The Jones Sand production history is interesting because it lends itself to analysis by material balance. Production statistics from discovery of the Jones Sand through 1949 and material balance calculations of the initial stock tank oil in place are shown in Table I. The usual procedure in testing the application of material balance calculations is to compute the apparent initial volume of oil in place, using production and pressure information obtained at different time periods. If the apparent oil in place volumes computed increase with successive time periods, water encroachment is indicated and approximations must be mads to correct for its influence. The first requirement in utilizing such calculations is reliable reservoir pressure, accumulated gas, oil and water production, and PVT data. Calculations of apparent oil in place in the Jones Pool, based on field data

Jan 1, 1951

By Natalia Konstantinova, Georgy Novikov, Pavel Rekant, Goergy Cherkashov, Olga Bogdanova

The economic interest of oceanic ferromanganese crusts and nodules is determined by high grades of major, rare and earth rare elements in these types of marine minerals [1]. Modern oceanic ferromanganese deposits have a global distribution with the largest fields in the Pacific Ocean. The Arctic Ocean still remains a poorly explored region. The first ferromanganese deposits from the deep part of the Arctic Ocean were recovered almost at the same time in 2012 both in US and Russian cruises to the Chukchi Borderland (1) and Mendeleev Ridge (2). Preliminary results of mineral deposits from the first area were reported at UMI-2012 by James Hein et al. [2]. We present here the data of ferromanganese deposits from the Mendeleev Ridge.

Sep 1, 2014

Accident control has been a pre occupation of progressive industrial and mining companies for many years but few have attempted more than direct injury control. In recent years, particularly in North America, analyses of accident costs have shown that material damage resulting from accidents is usually of greater economic significance than injuries and this has led to the concept of loss control. Loss control is an attempt to take the emphasis off injury prevention and to concentrate on the basic factors which affect both the health of the individual and of the company. The deterrent to greater acceptance of this philosophy has been the apparent diffi- culties of implementing a loss control programme but Associated Minerals Consolidated Limited has adopted a simple approach. It has had a minimum disturbing effect on normal operations because existing systems have been modified to provide the new information required. It is suggested that the programme outlined is applicable to other mining ventures and is a practical method of providing benefits for both the company and its employees.

Jan 1, 1975

By Ralph M. Hunter

Until recent years, maintenance of surface coal handling facilities was a relatively simple task. Equipment consisted principally of conveyors, screens and crushers of comparatively simple construction. Electrical equipment consisted of motors and starters, with little, if any, interlocking. In most cases failure of any component affected only the grades of coal loaded so that even a prolonged breakdown did not affect mine operation materially. However, with the introduction of modern cleaning plants, the picture has changed. The equipment is much more complex and therefore more difficult to maintain. In many cases failure of any component of the plant prevents loading of coal. Even if provision is made to bypass, the quality of coal loaded is lowered, affecting markets. In the case of plants designed to permit full seam mining, marketable coal cannot be loaded without operation of the cleaning plant. Under these conditions it is apparent that considerable thought and effort toward better maintenance are justified. In order to assure continuous, efficient and economical operation, maintenance should receive consideration, not only after the plant is in operation, but while it is being designed. It is hardly necessary to say that the designer should strive for sturdi-ness and wearing qualities. It is sometimes not realized, however, that even the best parts will sooner or later require replacement or repair. The designer should, there- fore, give consideration to accessibility. Anyone who has had to do with cleaning plant maintenance is familiar with installations where several hours are required to get at a part that can be repaired or replaced in a few minutes, once it is accessible. As in most cases, experience is the best guide. The men who operate and maintain this equipment know the problems encountered. Whenever available, the opinions of these men should be sought and heeded. As an example, we might consider the refuse elevator on a Chance Cone. Our company is now operating three of these cones, the first of which was installed in 1941, and the latest in 1946. Exact records are not available, but well over 50 pct of delays charged to the Chance Cones have been caused by the refuse elevator. This elevator receives refuse from the cone and carries it to a point above the water level of the cone, discharging onto a dewatering and desanding screen. Since the elevator operates under water and necessarily has close clearances in the lower boot, it tends to jam on large pieces of refuse or tramp iron. The chain, buckets and boot are also subjected to the action of water, sand and refuse, which accelerate normal wear. In case of jamming or chain-breakage it is necessary to drain the elevator and the cone so that even a minor fault in the elevator causes a considerable loss of time for the cone. In our new plant, which will contain two Chance Cones, the refuse elevator has been eliminated. This was accomplished by raising the cone so that the refuse gates could discharge directly onto the dewater-

Jan 1, 1949

Removal of As(III) and As(V) in Aqueous Solution There are toxic arsenical species such as As(III) and As(V), and arsenious species have specially strong toxicity. The strong toxicity causes contamination of groundwater and water pollution for the semiconductor production process. This study is concerned with the removal of As(III) and As(V) with various kinds of Mg/Al layered double hydroxides (LDH) containing CO32-, SO42-, Cl- and NO3- as interlayer anionic species. The anion exchange property is different from the kind of layered double hydroxides and the Mg-Al-NO3-LDH is superior in the anion exchange property of As(III) and As(V) due to the nature of nitrate ion existing in the interlayer. The pH condition suitable for As(V) removal is 7.1 or more. If the initial conditions such as 10mg/dm3 of As(V) concentration, 7.1 of pH, 1 m3 of amount of solution and 99 per cent of removal are fixed, the required amount of Mg-Al-NO3-LDH is 0.27kg for two step-batch operations. The As(III) is suitable to oxidize to As(V) before the removal processing.

Sep 13, 2010