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By Thomas M. Barczak

This US. Bureau of Mines report examines the roof and floor contact pressure provided by the interaction of a shield with the surrounding strata. Controlled forces were applied to an 800-ton two-leg shield in the Bureau's mine roof simulator; the distribution of forces acting on the canopy and base of the shield were measured with 24 hydraulic pressure cells. Several influential factors that affect the load distribution were investigated: (1) the magnitude of loading (leg pressure); (2) the profile of the canopy, principally the upward-sloping tip; (3) the base-lifting device; (4) horizontal load acting on the shield; and (5) compliancy of the immediate roof and floor. It was concluded that the shield does not develop full canopy or base contact without deformation of the strata. Maximum contact pressures are developed at the rear of the canopy and on the toes of the base. Less than 10 pct of the available shield capacity is developed at the canopy tip despite the design intention to ensure tip contact. Horizontal loading reduced the toe pressure acting on the base by as much as 75 pct. The base-lifting device exaggerated the inherently high toe loading, increasing the contact pressure by more than 200 pct.

Jan 1, 2010

By Linney, Robert J.

REPUBLIC Steel Corporation's iron-ore properties in the Adirondacks consist of mines, mills, and sintering plants in the Mineville and Port Henry area and at Lyon Mountain. This article will deal with the properties in the vicinity of Mineville and Port Henry. In 1938, when Republic leased the Mineville- Port Henry operations from the Witherbee Sherman Corp., these properties had just come through some hard depression years. As a result, the mine development program was far behind schedule; most of the equipment needed replacement; and above all, the entire system of mining had to be completely changed to reduce operating costs. The concentrator had been in operation for many years; the process was dry and dusty. Machinery and equipment were either badly worn or entirely obsolete. The sintering plant, also long in operation, was badly in need of repairs.

Jan 1, 1943

By C L. Briend, O&apos

This paper presents the main features of coal mining in Japan, as determined by the author while attending the International Coal Conference in October of 1963. The general economy of the country is considered, and the requirements for coking coal are outlined. Statistics and comments on production and consumption are then given, with accompanying cost figures, and the characteristics of Japanese coal mining are compared with those of Canada. Mining methods and underground transportation are covered, with emphasis on undersea mining. Finally, a description is given of a visit to the Miike colliery, the largest in Japan. I T was my privilege to attend the International Coal Conference held in Tokyo in October, 1963, to meet many prominent members of the Japan Coal Association and to visit one of the major coal fields. This is probably the reason why I was asked to present this review of the coal situation in Japan. In doing so, it must be pointed out that I am not an expert in coal mining, that my

Jan 1, 1965

Although not immune from the problems affecting the U.S. economy generally, the mineral industry in 1991 contributed nearly $300 billion in the value of processed materials of mineral origin. Supporting this contribution, the Bureau of Mines continued the research and analytical programs highlighted in this annual review. Featured in 1991 were such relatively new programs as minewide monitoring applications in ground control and advances in processing of ceramics and composites, along with more traditional research into health, safety, and mining technology, minerals and materials science, and environmental technology. Under Bureau sponsorship, a National Minerals Policy Forum brought together some 200 executives from industry and Government concerned with minerals policy to begin a dialogue on developipng a policy statement on current minerals issues. A major feature of the forum was the keynote address by Secretary of the Interior Manuel Lujan, Jr.

Jan 1, 1992

By H. Boghosian

This paper presents the design and construction of a deep basement in a steeply sloping site in glacial till in Glasgow city centre. Existing foundations, adjacent structures and services, in tandem with asymmetric loading, presented particular challenges in the planning, execution and design of the project. The construction methods and temporary works, analysis by the Finite Element method and monitoring carried out are all described.

Jan 1, 2006

By David K. Hylbert

This study investigated stratigraphic and structural causes of roof falls in room-and-pillar drift coal mines in nine mines in eastern Kentucky. A contract modification provided for remote sensing studies in the Dunkard Basin of West Virginia and Pennsylvania. Results of stratigraphic and structural studies of an earlier contract (H0133018) were applied to several new mines. It was found that similar rock sequences contributed to unstable roof conditions. Structure contour and isopach maps were found useful In projecting these trends together with fence diagrams. Using Landsat imagery, a direct relationship was found between lineament direction and the trends of rock jointing, roof fall zones, "snap top" zones and sandstone channels in the examples cited. It was found that, by analyzing lineament intersections, from 50 percent to 65 percent coincided with roof falls.

Jan 1, 1980

By H. W. Busch

In the course of examinations by representatives of the Bureau of Mines of several compressed-air systems in which explosions had occurred, samples were obtained of the carbon deposits that are formed normally in various parts of the systems by decomposition of the compressor lubricating oil. Experimentation with these carbon deposits has demonstrated that they contain a "carbon-oxygen complex" similar to that formed on coal and on other carbonaceous materials and generally recognized as being the cause of spontaneous heating of coal. The exothermic properties exhibited by such a complex are considered significant in relation to the possible initiation of combustion reactions that may lead to explosions or formation of carbon monoxide in compressed-air systems. This report discusses the occurrence of explosions and formation of carbon monoxide in the use of compressed air and presents results of experimentation conducted with carbon deposits from air compressors.

Jan 1, 1949

During the past decade, the miner-al industries have been faced with an increasing shortage of engineers. The point has now been reached where the shortage may be termed critical. This shortage may be attributed directly to declining enrollment in the mineral science programs offered by the universities on this continent. Although the reasons for declining enrollment are undoubtedly many, two major hypotheses may be postulated. The first is that high-school graduates are either unaware of the mineral industries and the opportunities in them or that they are aware of them but have somehow obtained a false image of their true nature. The second is that they are aware of the true nature of these industries and the opportunities they offer but find them exceedingly unattractive. The problem of dwindling enrollments has, in recent years, been subjected to a concerted attack by the industries and professions concerned. However, their efforts to date have been based essentially on the first hypothesis. Sufficient results are now available to suggest that either the methods of attack are inappropriate

Jan 1, 1965

Nearly as impressive as the machines that will be on display at MINExpo are the massive engines and tires that keep the machines moving. As you can imagine, it takes a special tire and special engine to run these machines. The following is a look at some of the exhibitors that will be at MINExpo displaying engines and tires. Cummins Inc. Cummins Inc. will display a lineup engines from 37kW to 2,983 kW (49 hp to 4000 hp) at MINExpo, representing the most extensive ?smallest to largest? range the company has ever put on display.

Jan 1, 2012

By Steve Hubbard, Brad Marchant, Rolando Cuadra

"Triton Mining Corporation acquired the rights to Mina El Limon in Nicaragua in 1993 by international bid. The bid included the gold operations at Limon and an exploration concession of approximately 4000 km2. Triton assumed control of operations and exploration in May 1994.The Limon mine is located in west-central Nicaragua, approximately 100 kilometers northwest of Managua. The climate is tropical, characterized by a wet season from May through October, and a dry season November through April. Gold at Limon is associated with both banded quartz and silicified breccia veins in Tertiary volcanic rocks, belonging to the lower Coyol Group. Mining is from two open pits and one mechanized underground operation. A second underground mine is currently under development for production during 1997.This paper describes the expansion of the milling facility at El Limon from a nominal capacity of 400 tonnes/day, producing approximately 20,000 ounces of gold annually, to the existing 900 tonne per day mill operation. Engineering of the new mill facility was initiated in September 1994 and construction was completed a year later."

Jan 1, 1997

By P. R. Thomas

The Bureau of Mines determined the costs associated with the production of chromium, in the form of chromite and high-carbon ferrochomium, from the demonstated resources of 10 market economy nations. The analyses evaluated the relative geologic and economic position of these chromite resources contained within 80 producing or potential mining operations. This report presents cost evaluations of a demonstrated resource of chromite, contained within the nations studied, of appoximately 1.2 billion metric tons (t). Of this total, 70 pct is contained within the southern African nations of Zimbabwe and the Republic of South Africa. The majority of current chromium mining and smelting capacity is contained within these two countries as well. India and the Philippines have recently demonstrated greatly increased chromite resources and hold the most promise for expanding both chomite and ferrochromium production outside southern Africa. Their demonstrated resources represent approximately 7 and 16 pet, respectively, of the cost evaluated total tonnage. Chromite resources, on an identified or hypothetical basis worldwide, are highly concentrated within Zimbabwe and South Africa, with these two nations containing in excess of 95 pet of the total. Given the present market structure, a majority of chromium contained within the demonstrated chromite resources of the nations studied is economically recoverable; but from a long-term resource and economic perspective, South Africa should inceasingly dominate the markets for both chromite and high-carbon ferrochromium. In addition, it is anticipated that an increasing percentage of chromium traded on the world market in the future will be in the form of high-carbon ferrochromium as opposed to chromite, as this additional processing stage continues to relocate from the industrial nations that account for a majority of chromium consumption to those nations that mine chromite.

Jan 1, 1984

By Reinhardt Thiessen

"INTRODUCTION Coal is a complex substance consisting of many different constituents representing many chemical compounds, very few of which are known. It is homo genetic, however, in that it is derived almost entirely from plants. But plants as a whole are complex, being composed of a large number of tissues, each consisting of a large number of cells in a great number of arrangements and composed of a number of chemical compounds in great variety of proportions, and enclosing a large number of waste products representing a large number of' chemical compounds as cell contents. Coal should therefore be expected to be a very complex substance.That coals are formed from plants is no longer debated, but the manner in which coal was formed from the plants leaves many problems still unsolved. However, in general it is now conceded that all coals of all ranks and ages had their origin in deposits completely analogous to our peat deposits of today and that coal formation is a process that runs through the whole series, beginning with peat, and through, the various ranks of lignite, subbituminous, high-, medium-, and low-volatile bituminous, semianthracite, and anthracite in a related chain. In the study of coal, it is therefore of the utmost importance to study and to know not only the plants contributing but .also the manner in which they are transformed into the substances forming the deposits. It is therefore of the greatest value to review briefly the formation of :,eat as it is known today, and to inquire into the facts as to what plants contribute to peat, what parts and products prevail, what are the chemical compounds that enter and which prevail."

Jun 1, 1947

By Charles E. Locke

CONTINUED expansion of gold mining in 1935 led to further developments in treatment methods. In base metals and non-metallics progress is also noted, coincident with greater activity. Statistics are not available yet for 1935 but the trend is shown by 1934 when nonferrous ore mined in the United States was 35,840,737 tons, or 45 per cent more than in 1933. The amount concentrated was 27,167,530 tons or 75.80 per cent of the ore mined, and flotation was used in whole or part on over 96 per cent of the ore subjected to concentration. In the crushing field a new model of the Fahrenwald crusher is promised soon. The Symons fine-reduction cone crusher and Traylor secondary crusher continue to gain as intermediate crushers. A new book entitled "Crushers for Stone and Ore" by William T. W. Miller appeared. The Hadsel mill has been improved still further and a number of installations are in satisfactory operation showing economical power consumption and low wear. An attempt in a

Jan 1, 1936

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. Rd., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. I. B. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 158, Ataturk Bulvari-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 8 Howard-Canfleld Bldg. Santa Barbara, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction 1-18th St. S. W. B'ham, Ala., Phone 56-5566]

Jan 1, 1952

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. d., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. I. R. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 156, Ataturk Bulvarl-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 8 Howard-Canfield Bldg. Santa Barbers, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I. 18th St. S. W. Wham, Ale., Phone 56-5566]

Jan 1, 1952

[RALPH ADAIR Ore Dressing Consultant Bull Mtn. Rd., Asheville, N. C. Phone 4-1693 JAMES A. BARR Consulting Engineer Mt. Pleasant, Tennessee Washington, D.C. BEHRE DOLBEAR & COMPANY Consulting Mining Engineers and Geologists 11 Broadway New York 4, N. Y. I. R. BERENT Engineering Consultants and Contractors Mineral Exploration, Mine Evaluation, Mine Designs and Mine Management 156, Ataturk Bulvarl-Ankara, Turkey BLANDFORD C. BURGESS Registered Professional Engineer Mining Consultant Monticello, Georgia GLENVILLE A. COLLINS Mining Engineer Uranium examinations Cable "Coins" 8 Howard-Canfleld Bldg. Santa Barbara, Calif. COWIN & CO. Mining Engineers and Contractors Consulting Shaft & Slope Sinking Appraisal Mine Development Reports Mine Plant Construction I- 18th St. S. W. B'ham, Ala., Phone 56-5566]

Jan 1, 1952

By NORA Mining Sector Council

The National Occupational Research Agenda (NORA) is a partnership program to stimulate innovative research and workplace interventions. In combination with other initiatives, the products of this program are expected to reduce the occurrence of injuries and illnesses at work. Unveiled in 1996, NORA has become a research framework for the National Institute for Occupational Safety and Health (NIOSH) and the United States. Diverse parties collaborate to identify the most critical issues in workplace safety and health and develop research objectives for addressing those issues. NORA entered its third decade in 2016 with an enhanced structure. The 10 sectors formed for the second decade will continue to prioritize occupational safety and health research by major areas of the U.S. economy. In addition, NORA’s seven cross-sectors will continue to focus on the major health and safety issues affecting the U.S. working population. While NIOSH serves as the steward to move this effort forward, it is truly a national effort. NORA is carried out through councils comprised of members with many diverse interests that are developing and implementing research agendas for the occupational safety and health community over the third decade (2016-2026) of NORA. Councils address objectives through information exchange, partnership building, and enhanced dissemination and implementation of evidenced-based solutions. NORA groups industries into 10 sectors using North American Industry Classification System (NAICS) codes. The Mining Sector encompasses NAICS code grouping 21xxxx where “xxxx” represents the different subcodes of the mining “21” classification. Mining encompasses the extraction of solid mineral and mineral-like substances from their place in the Earth’s crust and supplies them to processing industries that produce economically valuable materials. It does not include oil and gas extraction. The Mine Safety and Health Administration, MSHA separates mining into coal, underground and surface, and metal and nonmetal, underground and surface.

Feb 1, 2024

By N. A. C. Smith, A. C. Fieldner, R. R. Sayers

Gases and vapors given off by petroleum and its products have long been recognized as somewhat injurious, when inhaled in high enough concentrations. The petroleum industry has recognized these effects and has tried to minimize the possibility of employees encountering dangerous concentrations of the vapors. Petroleum gases and vapors have not, however, been considered as actively poisonous, in the sense that hydrocyanic (prussic) acid and phosgene are poisonous; men have been exposed to them repeatedly, and for long periods, without any marked ill effects. Light Mexican crude oil when first introduced into the United States for refining was handled in much the same way as was customary with other apparently similar crudes; but experience soon showed that some toxic substance escaped from the crude during production and transportation and in most of the refinery operations. After a preliminary investigation several of the larger companies decided that the gases from the petroleum were the source of trouble, and therefore took precautions, wherever possible, to protect the men from exposure to these gases. With the increasing use of Mexican crude, this problem has become important. The present report covers the work done on the subject by the Bureau of Mines and the Public Health Service under a cooperative agreement with the American Petroleum Institute.

Jan 1, 1925

By A. Pellegrino, F. Collin, C. Guiducci, R. Charlier

A numerical approach for modeling coupled Hydro-Mechanical fracture behavior in 2D is presented in this paper. This approach accounts for the strong dependence of the flow characteristics on fracture apertures and offers an anisotropic description of the flow propagation in the fracture. An interface finite element and a constitutive model are developed . In order to validate the applicability of the model to general geomechanic problems, 2D simulations were performed. Results show the good application of the mathematical model and the fundamental hydraulic role played by the fractures. In diesem Beitrag wird ein Stoffgesetz vorgeschlagen um hydromechanisches Kluftverhalten numerisch zu Modellieren. Dieser Vorgang nimmt die starke Abhängigkeit der Fliesseigenschaften von der Kluftöffnung mit in Anbetracht. Ein Interfaceelement und ein Stoffgesetz wurden entwickelt. Zum validieren der Anwendbarkeit dieses Modells wurden 2D Simulationen durchgeführt. Ergebnisse haben gezeigt dass das mathematische Model anwendbar ist und dass Klüfte eine fundamentale hydraulische Rolle spielen. Une approche numérique pour la modélisation du comportement couplé hydro-mécanique des fractures en 2D est présentée dans ce papier. Cette approche prend en compte la forte dépendance des caractéristiques du flux de fluide sur les ouvertures des fractures et présente une description anisotrope de la propagation du flux dans la fracture. Un élément fini d'interface et un modèle constitutif sont développés. Dans le but de valider l'applicabilité du modèle à des problèmes généraux de géomécanique, des simulations 2D ont été réalisées. Les résultats montrent la bonne application du modèle mathématique et le rôle hydraulique fondamental joué par les fractures.

Jan 1, 2003

By Hardwick F. W., O'Shea L. T.

The survey covers: coal-mine lighting prior to the invention of the safety-lamp, including candles, the flint-and-steel Spedding mill, and mirrors; the growth in knowledge of firedamp; the Society in Sunderland for Preventing Accidents in Coal Mines; Dr. Clanny's blast lamps and steam lamps; George Stephenson's tube-and-slider lamp, triple-tube lamp, punched-plate lamp and gauze Stephenson lamp; Sir Humphrey Davy's lamps; the controversy over invention priority, and other early forms of safety-lamp; 1816-1835 developments including the lamps of Upton and Roberts, M.Mueseler, John Martin, Dr. Clanny (new 4th lamp), M. Agre, John Newman, Gossart and Roberts, Francis Ellis, John Dillon and Mr. Wood (refrigerating lamp); 1836-1843 developments, notably of Mueseler lamps; 1844-1866, including lamps of the Davy, Clanny, Boty, Eloin and other types; 1867-1879, including the Gray lamp; 1880-1887, including the Marsaut lamp; and 1888-1913. Detailed reference is made to the findings of various relevant Royal Commissions and appendices include a list of the safety-lamps described in an appendix to the 1886 report and a publications list. The paper was prepared for the International congress of mining, metallurgy, applied mechanics and economic geology to have been held in London in July 1915. Discussion (p.718-724) includes a brief comment by Blackett W.C. and a longer contribution by Ashworth J., with the authors' response

Dec 1, 1916