Search Documents

This report contains the papers presented at the Technology Transfer Seminar on Ground Control Aspects of Coal Mine Design held by the Bureau of Mines on March 6, 1973, in Lexington, Ky. Seminar attendance consisted of representatives from the coal mining industry, universities, mining consultants, instrument manufacturers, and local, State, and Federal Government. The purpose of this meeting, one of a series of Technology Transfer seminars, was to provide the coal mining industry with detailed information about recently developed techniques, equipment, and instruments which can be used in the solution of coal mine design problems and to discuss results and direction of research in mine design. The report includes opening remarks by Joseph J. Yancik, Acting Assistant Director--Mining; an overview of the Federal Bureau of mines approach to mine design; three papers an problems associated with the design of panels; five papers on coal mine roof problems; three papers on long wall problems; and the comments made by- the participants on the Bureau-industry panel discussion.

Jan 1, 1974

By Curt D. Edgerton

This study was made to determine trends in fresh water usage by California petroleum refineries, to forecast fresh water requirements to 1975, and to evaluate water conservation practices. Statistical data used in the study were obtained largely from published sources and from records of selected companies. An adequate sampling of the State's refining capacity was obtained, and the data were extrapolated to the total California refining capacity. A breakdown of the data was then made on the basis of the following refining regions: (1) the Los Angeles Basin and Southern Coastal region, (2) the Southern San Joaquin Valley, and (3) the San Francisco Bay area. An unpublished forecast of crude oil input to refineries by a major oil company operating on the West Coast was used as a basis for predicting fresh-water usage. The 1963 fresh water intake by California petroleum refineries was 84 million gallons per day. This is expected to increase to 128 million gallons per day by 1975. The fresh-water to crude-oil ratio is increasing in all regions except the Southern San Joaquin Valley. At present, the supply of fresh water available to almost all of the State's petroleum refineries, mostly from surface sources and company-owned wells, is adequate, although shortages may develop within the foreseeable future. Present conservation methods are centered around the following four objectives: (1) minimum intake of fresh water of the lowest possible quality commensurate with sound technologic practice; (2) optimum recirculation; (3) proper treatment before discharge; and (4) substitution of air cooling for water cooling.

Jan 1, 1965

By D. G. F. Hedley, F. Grant

"In 1958, the Ontario Department of Mines appointed a committee to study the accident situation and mining methods used in the uranium mines in the E1liot Lake district. This committee reviewed the existing knowledge on mine design, pillar support and roof spans and came to the conclusion that scientific knowledge had not yet reached the stage of producing rational design procedures which would reduce the dependence on trial-and-error methods. Since that time, the Mining Research Centre has made numerous stress measurements in two mines to define the pre-mining and pillar stresses. A comprehensive series of tests has been done in the laboratory to measure the compressive strength of the rock; a geological survey of the region has been made to evaluate tectonic stresses; and a survey was done on mining conditions with regard to stable and unstable pillar configurations. This information has been used to evaluate pillar design as effected by pillar width and height, depth below surface, extraction and pre-mining stress fields. The resultant design of pillar widths and corresponding extraction as the depth increased is in line with past and present experience in these mines. The information available on roof stability is still insufficient to design stable stope spans with the same degree of confidence; experience and trial-and-error methods are still required."

Jan 1, 1972

By M. B. Shongwe

Pt-based alloys are being developed for high-temperature applications with the aim of replacing some of the currently used Ni-based superalloys (NBSAs) in the highest temperature applications. The Pt-based alloys have a similar structure to the NBSAs, and since Pt is more chemically inert than nickel and has a higher melting point, they can potentially be used at higher temperatures, up to 1300°C, and in more aggressive environments. Several experimental Pt-based alloys were studied at Mintek, and an optimum composition was found to be Pt84:Ahi:Ru2:Cr3 (at.%). On the basis of hardness and microstructure, a later study identified a new optimum: Ptr8:A111:Ru5:Cr6 (at.%). There are at least two Pt3A1 allotropes, and the high-temperature cubic structure has better properties than the lower temperature tetragonal form, and so needs to be stabilized. This work describes the latest results obtained in transmission electron microscopy (TEM) studies of the quaternary Pt-based superalloys. These results are both interesting and important, because the samples have a higher precipitate density compared to those from earlier work. The precipitate morphology is mainly cubic, with minor areas having irregular-shaped precipitates. The high volume fraction of the precipitates is a major breakthrough, since the objective of this work is to improve the alloys. A prior disadvantage was that the proportion of the precipitates was too low in samples before this work, especially compared with the work from Germany on Pt-Al-Cr-Ni¬-based alloys as well as the NBSAs. TEM -Pt3A1 diffraction patterns were studied, and for each diffraction pattern, many possible lattice point combinations were tried, with the angle between the lattice spots as well as interplanar spacings being calculated for each phase (cubic or tetragonal) to match the measured results. An overall analysis of the diffraction results indicates that the cubic phase fitted the experimental lattice points with much lower errors compared to the tetragonal phase. Thus, with the close match achieved with the cubic structure, the structure of -Pt3A1 precipitates is likely to be cubic. X-ray diffraction has been carried out on selected samples, and the results confirmed the presence of cubic -Pt3A1 and (Pt). Different X¬ray diffractometers were used to further verify the results, and the results were also compared with those from TEM.

Jan 1, 2012

By Christopher Haycocks, Lawrence P. Johnson, George M. Neall, James M. Townsend

No method of roof control yet devised has proven to be universally acceptable for the wide range of strata conditions experienced in U. S. coal mines. However, a relatively new innovation, the roof truss, has proven itself capable of preventing roof failures which both conventional and resin bolting could not. Presently, the economics of roof trusses are not favorable when compared to bolting due primarily to drilling and installation procedures, but this is expected to change with improved truss and equipment designs. To realize the full potential of this new method of roof control, design criteria are needed which can optimize the effect of the truss for varying strata conditions. A review of the literature reveals that some work has been conducted on the roof truss. Cambrell and Haynes1 (1970) showed that the roof truss is superior to angled roofbolts installed through a header. Sheorey, Verma, and Singh2 (1973) used statics to prove that the optimum angle of inclination should be greater than 45°. However, to date, no systematic attempt has been made to establish design criteria. In this paper, the problem was approached in three ways. First, model studies were performed to determine general trends of truss support as a function of a number of variables. This provided a better understanding of the support mechanism involved. Secondly, beam theory was employed to calculate the actual support capacity of a truss, realizing the many simplifications, assumptions, and shortcomings of this approach to such a complicated problem. Last, field testing will be utilized to test the hypotheses previously developed and provide hard data to further synthesize roof truss design criteria. Field testing has recently commenced and should be complete before mid 1977.

Jan 1, 1979

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By W. R. Hardwick

This Information Circular describes copper mining and concentrating methods, practices, and costs at the Silver Bell Unit of American Smelting and Refining Co., Pima County, Ariz. It is one of a series being prepared by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. The Silver Bell mining district, one of the older districts in Arizona, is in the western part of the Silver Bell Mountains in Pima County, about 40 miles west of Tucson and about 20 miles southwest of Red Rock, a station on the main line railroad of the Southern Pacific Co. The Oxide and the El Tiro open-pit mines of the American Smelting and Refining Co. are in the district (fig. 1. The principal ore deposits are in T. 12S., R.8E., Gila and Salt River base line, at an altitude of about 3,000 feet. The present town of Silver Bell, established in 1952, is reached by a paved highway, the Avra Valley road, that turns west from Highway 84 at Plata siding near Rillito and extends westward 25 miles to the townsite (fig. 2). The present town is about 5 miles southeast of the old town of Silver Bell that flourished from 1900 to 1930.

Jan 1, 1963

By K. B. Lindsey

Geologically, the Williston Basin is a large structural depression of sedimentary rock in Montana, North Dakota, and South Dakota and Manitoba and Saskatchewan, Canada. The approximate It-mite of the basin are shown on figure 1; it is roughly circular with a diameter of about 400 miles and contains approximately 120,000 square miles. Although the petroleum potentialities in this area had long been recognized, it had not been vigorously prospected by the petroleum industry because of its geographic location, rigorous winters, depths to possibly productive zones, difficult geological problems, and the fact that more seemingly favorable areas were available for prospecting. With the discovery of oil near Edmonton, Alberta, in the prolific Devonian reefs, an incentive was given to explore for oil in the southeast extension of the same sedimentary trough, the Williston Basin. The Virden field discovery in southwestern Manitoba in January 1951 was a direct result of this southeastward movement. Discovery of this shallow field was followed soon after by discovery of' deep production on the Nesson anticline in North Dakota at Clarence Iverson No. 1 well. North Dakota then became the twenty-seventh petroleum-producing State.

Jan 1, 1954

By M. W. BERNEWITZ

IT is 27 years since I last visited Broken Hill, New South Wales, one of the world's greatest lead-silver-zinc districts. Then, the flota¬tion of ores was in its infancy. The Minerals Separation process had its birth as a practicability in the Central Mill, which is still operating and yielding high recoveries. The average Australian knows that Broken Hill is an important mining center in a "corner" of New South Wales, but he does not know what a factor it is in the lead, silver, and zinc production of the world. Nor does he realize that among the ramifications arising from metal production at Broken Hill are the great lead smelter at Port Pirie, South Australia, 254 miles southeast; the electrolytic zinc works at Risdon, and the limestone mine at Davenport, Tasmania; the acid works at Cockle Creek, New

Jan 1, 1935

By John D. VandeKraats

Yielding rock bolt support systems have been developed to accommodate ground movement in shifting ground such as in coal operations; in creeping ground such as salt, trona, and potash; and in swelling ground associated with some clays. These systems, designed to remain intact despite ground movement, should enhance mine safety and help contain costs in areas where rebolting of rigid non-yielding systems is typically required. Four such systems were tested in straight tensile pulls in the laboratory. They include the Slip Nut System from Dywidag Systems International USA, Inc., Ischebeck's bolt mounted Titan Load Indicator, Rocky Mountain Bolt Company's Yielding Cable Bolt, and a rock bolt installed variation of the yielding steel post developed by RE/SPEC Inc. The first two systems are currently marketed products and the latter two are prototype systems. Each system responds to load and displacement by yielding in a unique manner. All are designed to yield at predetermined loads. A description of each system and its yield function is provided. Each system was tested over its prescribed yield range in a test machine. At least five tests were performed on each system. Each system yielded and continued to provide support according to its design. Each shows promise for ground control use in shifting or creeping rock. This work helps to illustrate the comparative differences in performance between these specialized systems and the applications where they may be most useful.

Jan 1, 1996

The Ocean Drilling Program (ODP) is the largest international geoscience project in the world, and the state-of-the-art drill ship, the JOIDES Resolution, is permanently at sea. Each year there are six scientific cruises (legs) which each last approximately two months. These legs are designed by geoscientists from the nineteen countries that subscribe to ODP.Australia and Canada presently share ODP membership under the banner of the AUSCAN Consortium. The benefits of Australia's involvement in ODP include internationalisation of Australian geoscience, advanced graduate training, and unique scientific investigations of the ocean floors in the Australasian region. In addition, visits to Australian ports by the ODP drill ship, the JOIDES Resolution, contribute up to $2 million per visit to the local economy. Amongst the many other aspects of ten years of scientific drilling, OOP has significantly contributed to our understanding of hydrothermal processes on the seafloor. To date, three hydrothermal sites have been drilled to date by the OOP, Snakepit (MAR), Middle Valley (Juan de Fuca Ridge) and TAG (MAR). Two more hydrothermal sites are scheduled for 1996.

Jan 1, 1995

By Gerald T. Homce, James C. Cawley

Problem: CFOI and SOII data show that 2,287 U.S. workers died and 32,807 workers sustained days away from work due to electrical shock or electrical burn injuries between 1992 and 1998. Method: The narrative, work activity, job title, source of injury, location, and industry for each fatal electrical accident were examined. A primary causal factor was identified for each fatality. Results: Electrical fatalities were categorized into five major groups. Overall, 44% of electrical fatalities occurred in the construction industry. Contact with overhead power lines caused 41 % of all electrical fatalities. Discussion: Electrical shock caused 99% of fatal and 62% of nonfatal electrical accidents. Comprising about 7% of the U.S. workforce, construction workers sustain 44% of electrical fatalities. Power line contact by mobile equipment occurs in many industries and should be the subject of focused research. Other problem areas are identified and opportunities for research are proposed. Impact on Industry: Improvements in electrical safety in one industry often have application in other industries.

Who's Who in Mineral Engineering - The 1978 Membership Directory of the Society of Mining Engineers of AIME

Jan 7, 1978

"Horizontal grinding mills have been used in the mining industry for more than a century, and due to their operational and maintenance simplicity they remain a widely used technology for various stages of comminution. The relative ‘efficiency’ of horizontal grinding mills compared to other comminution equipment is often debated, and efforts to improve the energy efficiency of these mills is an on-going area of attention for process engineers.The discharge arrangement design affects the material transport characteristics within a horizontal grinding mill. Material transport plays a significant role on efficiency of horizontal grinding mills. The magnitude of benefits that can be achieved with efficient material transport in AG/SAG mills has been demonstrated in a Greenfield milling operation at Mirabela Mineração’s SantaRita Nickel operation in Brazil. This grinding circuit was commissioned in October 2009, which was designed as a typical SABC circuit to grind 4.6 mtpa (575tph) to produce a P80 of 125um with 10-12% ball charge in SAG mill. The nameplate design capacity has been achieved in few days in ABC circuit without grinding media in SAG mill, and has been operating in ABC mode. The through has gradually increased to an average of 800 tph and recently 7% ball charge has been introduced to increase the throughput to +900tph.This paper investigates improved material transport using Outotec’s TPL™ (Turbo Pulp Lifter) technology and the opportunities this technology presents when designing horizontal grinding mills. Operational data, with particular reference to energy and throughput optimization, is presented."

Jan 1, 2013

By K. C. Garner

The visit reported was made with support from the 1997 J.C. Boyle travelling scholarship. The management and control of hazardous gases released into the underground environment are an integral part of coal mining. The power-generations stations at Appin and Tower collieries, with a combined electrical output of 94 MW, have been operating for some time and have demonstrated a technology that is able to exploit the available gas fully. Contributory factors have been the development and introduction of directional drilling techniques, pre- and post-drainage of coal, relatively high seam permeability, a high gas content of the worked seam, high production rates and a willingness to embrace new ideas and technology

Jun 21, 1905

By E. McCullough, D. Preece, M. Ortel

Geophysical explosive charges are used in mineral resource exploration. They are detonated subsurface and radiate sonic waves into ground monitors, which detect the vibration waves and their interaction with underlying geologic strata. Geophysicists perform computer analyses of the waves reflected from the strata to determine their depth and thickness (Strobel, Berger & Schaefer, 2012). The purpose of this research is to determine how the detonating explosive charge interacts with the adjacent ground and how the induced waves propagate through the surrounding medium. Furthermore, it is necessary to optimize the location of the initiation point within the charge. Establishing both the direction and intensity of the waves will allow geoscientists to refine and optimize geophysical studies that employ explosive charges.

Jan 1, 2013

It has been suggested that it would be a desirable feature in connection with the Chicago meeting of the, Institute in September to arrange for a return trip for the fuel men through the coal fields of Illinois, Ohio and Pennsylvania, stopping at various points and possibly touching also Kentucky. Perhaps the petroleum men would be interested in a similar trip and might join them stopping off at different points to visit these oil fields. If the members who would-be interested in such a trip will advise the Secretary before the first of June, indicating their desired stopping points, steps will be taken to perfect arrangements accordingly.

Jan 5, 1919

By K. G. Chipman

IN 1936, the Department of Mines and Resources was formed by the amalgamation of the former Departments of Mines, Interior, Indian Affairs, and Immigration. In the amalgamation, the Geological Survey and the Topographical Survey became the major divisions of the Bureau of Geology and Topography, which is a part of the Mines and Geology Branch which, in turn, is a part of the Department of Mines and Resources. The Topographical Survey was formed by combining the former Topographical Division of the Geological Survey and the air and ground mapping sections of the former Topographical and Air Survey Bureau of the Department of the Interior. The latter organization, previous to 1933, had been known as the Topographical Surveys Branch of the Department of the Interior. The amalgamation of 1936 definitely placed on the Topographical Survey the responsibility for the original mapping required for the development of our natural resources. The war has brought upon us the situation where all work has had to be in the furtherance of the war effort. With decreased staff and limited appropriations, the mapping on those scales which are directly concerned with the natural resources has been confined to the search for oil and strategic minerals. The reconstruction period will produce a different situation, with different problems. The past is behind us and it is necessary to prepare for the future. First, we should consider briefly a few general principles in the making and using of maps, then take stock of what we have, see what the needs are, and consider how we are to meet these needs.

Jan 1, 1944

By W. L. Saunders

(Wilkes-Barre Meeting, June, 1911.) I. INTRODUCTION. IT is now generally admitted by experts that at least so far as rapid progress is concerned the Alpine system of tunnel-driving is superior to any other. This is perhaps natural in view of the record of experience in driving tunnels through the Alps. These great mountain-chains cannot be treated in the ordinary way by shaft-sinking and driving headings, thus multiplying the points of attack. The work must be done from the ends only, hence speed in driving is of the utmost importance; and, as necessity is the mother of invention, the concentration of effort to make progress has resulted in an organization and in mechanical appliances that have produced results so much in excess of the usual practice, even in America, that a discussion of the subject in detail should be of much value to the engineer and contractor. The first Alpine tunnel was the Mont Cenis, length 7.5 miles, driven with a progress that averaged about 7.75 ft. per day. Next came the Saint Gothard, 9.5 miles long, 18 ft. per day; Arlberg, 6.5 miles long, 27.25 ft. per day; Simplon, 12.25 miles long, 36 ft. per day. The figures represent progress when driving from two headings, so that by dividing them in two we get the daily single-heading progress. The latest of the Alpine tunnels is the Loetschberg, now being driven. In this work the world's record has been beaten by a single day's record in one heading of 36 ft. and by an average daily record in. one heading of 29.5 feet. The Alpine range forms a natural barrier between a large section of northern and southern Europe. This range extends from the southeast of France to the frontier of Hungary, between Italy and the plains of southern Germany. The contour

Jul 1, 1911

By James F. Archibald, H. Jame Hackwood

"Research was performed to assess the feasibility of barrier membrane substances, for use within mining or associated high risk environments, in restricting the diffusion transport of radon gas. Specific tests were conducted, both within laboratory and in situ environments, to determine radon gas concentration ratios across a barrier of interest and emanation rate variation resulting from application of such materials. Several materials have been demonstrated to be effective in restricting the emanation of radon gas into initially radon-free environments. One liquid material shows particularly good promise upon consideration of ideal radon barrier criteria.IntroductionIt has long been known (I.2.3) that inhalation of the short-lived, alpha particle-emitting daughters of radon gas can result in irradiation of lung tissue with the potential for causing lung cancer. Control measures are necessary to maintain concentrations of airborne contamination at a minimum to protect miner health and safety. Typical control practices in mines have been through the application of systematic ventilation and backfilling of excavated opening. As mines become deeper, however, and additional workings become exposed, increased ventilation capacity requirements are needed. As an alternative to other radiation control measures, the use of sealants to prevent radon migration from walls into mine atmospheres may provide a suitable engineering alternative."

Jan 1, 1987