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By W. L. Dare

Tri-axial strains in pillars, created by pillar robbing, were measured in an experiment at the Dysart No. 1 uranium mine near Grants) New Mexico. At this mine, room-and-pillar stoping is used on the advance, and pillars are recovered on the retreat. The are deposit is, for all practical purposes, horizontal. Measuring devices were installed in pillars approximately 90 to 200 feet from the break line, and strains were recorded over a 4-to 6-week period. The measurements indicate that, in general, the algebraic magnitude of vertical strains increased, and the horizontal strains decreased, in turn, indicating that vertical (or near vertical) loads on the instrumented pillars lessened as pillars were recovered.

Jan 1, 1962

By Lance R. Barron

Over the past decade, the U.S. Bureau of Mines (USBM) has studied longwall gate road stability at four mines in the Book Cliffs and Wasatch Plateau Coalfields of Utah. These operations are characterized by multiple-seam mining, abruptly varying cover depths to 914 m (3;000 ft), and massive rigid, sandstone units in the main roof or floor. Such conditions encourage severe bumping, roof instability, and occasional floor heave problems.' Various gate road configurations have been employed to alleviate' these problems. Although the mines have comparable basic conditions, the lithologies and qualities of the immediate roof, floor; and seam ate different in each mine and often vary in a single mine. Gate road systems that mitigate hazards in one mine may prove inappropriate in another or for different areas of the same mine. This report relates the geology of the coalfields; describes the location, geologic setting, specific mining conditions, operating history, and the USBM field study and results or conclusions for each mine; summarizes the relative performance of the gate road systems; and emphasizes the need for site-specific geotechnical data to evaluate gate road conditions and performance.

Jan 1, 1994

By Scott Turner

Within recent years , people have begun to realize the importance and significance of the mining and allied industries . The leading part the engineer plays in civilization is becoming recognized . However , accurate quantitative knowledge of the industrial importance of mining is still seldom possessed except by those close to this business . It is true that there are a few who go to the extreme and represent the whole progress of civilization as a reflection of man's gradual mastery of mineral utilization , but on the whole , the magnitude of the industry is underestimated . The uncertainties of mining , as evidenced by the variable results of prospecting on surface or underground , in an unknown new field or from the bottom levels of a mature mine , the ins and outs of tonnages and metal contents , the possibility of a widespread or even a sudden change between cost and realization-price , add to its picturesqueness and make mining attractive to some . To many , the fact that results are generally more uncertain and less predictable than in other industries lends added charm . The following pages may serve to call attention briefly to the importance of mining relative to other industries in the United States , in Canada , and in the world . Ordinarily , the annual primary mineral production of the United States amounts to about 5 billion dollars . The average for the last five years has been a little over 5 billion dollars . Last year , sadly enough , it was less than 34 billions . Just now , we are on the decline , and have been for the past two years . In Canada , the 5-year average was about 268 million dollars . Last year it was 227 million . Due in part to gold output ( in 1930 , for the first time , Canada's gold production exceeded that of the United States ) , the Canadian average is holding up better than ours . It has been estimated that the average world mineral production over the past five years has amounted to about 12 billion dollars , while in 1931 it was less than 8 billions . The mineral industries are as indispensable for the conduct of modern society as are those of agriculture , but , in the United States at least , they receive far less recognition from the Government . With us , agriculture is fostered by a great department that is maintained by enormous appropriations , while the mineral industries get but little financial support . In the United States , in the calendar year 1930 , the value of production by these two industries were as follows : to 1 . Agriculture ( inclusive of forestry ) 9.9 billion dollars ; mining 4.8 billions ; ratio 2 Direct appropriations by our Federal Government were 109 million dollars to agriculture and 2.8 million to mining , a ratio of 39 to 1. Obviously this is out of balance to the extent of 19 to 1 in favor of agriculture .

Jun 1, 1932

By E. P. Youngman

The basic mining law of Esthonia is the law that was passed by the Parliament (Riigikogu), or State Assembly, on March 17, 1927 (effective Avril 1, 1927), superseding the Russian Mining Law Book VII of the Code) issued in 1912. References in this digest are only to articles of the Law of Merch 17, 1927. However, the law concerning all industrial enterprises (Riigi Teataja No. 28, 1920, Law No. 106) governs not only mills and refineries but also mining operations themselves (arts. 2 and 3). No access was ad to that law. Esthonia is not well supplied with minerals; its industries are primari- ly agriculture and dairy farming. Natural gas, prites, lead, zinc, iron ore, salt, and mineral waters have been found but never as yet in deposits of commer cial size. The production of oil shale is of some importance; and peat, which covers as much as 5 per cent of the total area of the country, is mined in sub- stantial quantities. Cement rock, gypsum, fire clay, and phosphate rock likewise are produced, though only on a small scale.

May 1, 1930

By Michael Mancuso

This report summarizes the problems of topsail handling as related to present requirements of law and current equipment availability. The most prevalent topsoiling systems are reviewed along with a listing of advantages/disadvantages and best features of each system. Seven mining regions are included, along with an analysis of prevailing land use, types of soils and attendant physical, chemical am biological characteristics. There are several probable areas of future research "lined which can benefit mining, minimize the social impact of mined lands and speed the return of mined lands to more productive long-term use.

Jan 1, 1981

By Robert W. Geehan

"INTRODUCTION The Bureau of Mines has been investigating deposits of critical and essential minerals in the United States since 1939. Many of the mines were developed.A preliminary examination of the Sultan mine was made in January 1945 by the author, who recommended investigation by drifting and crosscutting. The Bureau conducted a project at the mine from April to June 1946. Claims investigated are in sec. 20, T. 25 S., R. 58E., Mount Diablo base and meridian, in southern Clark County, Nev., about 7 miles southwest of Good-springs.The Sultan mine has been an intermittent producer of zinc-lead-silver ore since 1910. During World War II, ore was shipped to the Government stock pile at Jean, Nev., and to the International Smelting& Refining Co.'s smelter near Salt Lake City, Utah. Throughout the past year, ore has been milled and the concentrates have been shipped to the smelter."

Sep 1, 1947

By Sidney Katell

This report is the fourth in the series, Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants. The initial work, Bureau of Mines In- formation Circular 7516, was published in October 1949 in conjunction with the synthetic liquid fuels program authorized by Public Law 290, 78th Congress. It included references to and abstracts of publications appearing from 1930 to September 1948 on all processes in general use in the petroleum refining and chemical industries. A supplemental bibliography, Bureau of Mines Information Circular 7705, was published in January 1955 to cover the period September 1948 through June 1952; and Supplement 2, Information Circular 7751, published in September 1956, covered the period June 1952 through June 1954. The present supplement covers the period July 1954 through December 1956.21 The information in this paper was obtained from the following sources: 1. Bureau of Mines Information Circulars. 2. Bureau of Mines Reports of Investigations. 3. Chemical Engineering. 4. Chemical Engineering Progress. 5. Chemical Engineering Costs Quarterly (Cost Engineering).

Jan 1, 1958

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Jan 1, 1979

By Frank G. Horino

Drill cores from 18 exploratory holes that were drilled into the unleached saline beds were tested for mechanical properties by the Bureau of Mines. Test cores were primarily selected from zones L4B, R4B, L3, and R3A in the Piceance Creek Basin, Rio Blanco County, Colo. Regression analysis techniques were tried in an attempt to relate kerogen yield or apparent specific gravity to the parameters compressive strength, Young's modulus, and Poisson's ratio. Correlation coefficients were very poor, indicating that this type of analysis was not amenable to these data. Analysis of variance techniques were tried using a division of either greater than or less than 10% nahcolite together with the requirement of less than 3% dawsonite. Results showed that a larger percentage of nahcolite tended to lower the compressive strength and to increase Young's modulus. A second analysis was made using a division of less than 3% dawsonite and greater than 3% dawsonite together with the requirement of less than 1% nahcolite. For this analysis, a larger per-centage of dawsonite tended to increase compressive strength, Young's modulus, and Poisson's ratio. Mean compressive strength values were determined for the mining horizons of interest. Average physical properties for design purposes were also determined for the horizons of interest and for a proposed adit based only on logged geologic depths to these horizons. No consideration was given to percentages of nahcolite and dawsonite. Creep data obtained from nahcolite-and dawsonite-rich oil shales provides a best fit to a modified power equation.

Jan 1, 1978

By E. K. Stanek

This research study was performed on a case study basis and can be divided into two parallel thrusts: electrical and thermal energy conservation. Energy consumed annually in mining and refining operations represents about 6% of the 80 quadrillion Btu's consumed nationally. In the electrical portion of the study, five areas were addressed: optimal dispatching of on-site generation, high-efficiency motors, conductor selection, power factor correction, and high efficacy lighting. In the case study mine which has a multiple unit on-site generation system, optimally dispatching units can save significant energy. The other four methods are difficult to justify on a retrofit basis due to capital costs. In the thermal portion of the study, a thermodynamic analysis was performed on the reverberatory smelting process possible areas of energy conservation were identified as radiation and convection heat losses from the furnace arch and the dumping of high energy content smelting slag. It has been shown that materials currently available can provide the means of reducing heat loss from the reverberatory furnace. It has also been shown that a significant amount of energy may be recovered from the slag. However, these are both subject to further study and validation.

Jan 1, 1982

Illumination hardware developed in conjunction with previous Contracts H024202l, H0242049, and H0242023 had not been adequately tested in actual underground work situations. The purpose of this contract was to install and monitor this equipment on mining machines and in actual working places of coal mines to gain experience with the use of the lamps and support equipment in the abusive and critical environments for which they were intended. The equipment that was to be tested consisted of the following: a. Lamps -A variety of sizes of permissible fluorescent lamps which operate from 12 volts DC power. These include the following sizes: Model 8, (9 watts) 2" diameter; Model 15/2 (14 watts) 2" diameter; Model 15/3 (21 watts) 3" diameter; Model 20 (25 watts) 3" diameter; Model 30, (28 watts) 3" diameter; and Model 40, (39 watts) 311 diameter. Representative photographs of these lamps are shown in Figure 1-1 and 1-2.

Jan 1, 1976

By Oliver C. Ralston

The Nonmetals Division studies problems relating to the use of minerals, many of which are important to national defence for purposes other than the extraction of metals. In fact, virtually all of the work of the division has been diverted to investigations pertaining to better use of the Nation's natural nonmetallic is resources as weapons of defense. The experiment stations of the division are at Norris, Tenn.; Tuscaloosa, Ala.; Seattle, Wash.; and College Park, Md. Studies involving the application of electric power to the nonmetallic minerals are conducted at the Electrotechnical Laboratory at Norris, and investigations on mineral-dressing treatment are conducted mainly at the Southern Experiment Station at Tuscaloosa. The cleaning and preparation of coal are studied at both Tuscaloosa and the Northwest Experiment Station Lit Seattle (other projects relating to utilization of coal are conducted by the Coal Division of the Bureau of Mines). Problems covering the use of minerals and fundamental problems as to their properties are studied at College Park.

Jan 1, 1941

By Jack Touseull

On November 15, 1972, the Bautsch mine, a lead-zinc mine in Paleozoic dolomites, experienced a massive rock failure involving 3 to 5 million tons. Because this failure was large and extended to the surface, it was included in the Federal Bureau of Mines investigations on "Massive Rock Failures." Analysis of the rock mechanics and mode of failure revealed that failure at the Bautsch mine was the result of the interrelationship of many factors. Factors related to the failure were found to be external and internal to the mining environment. Unlike internal factors, external factors were not apparent and, therefore, many external factors were investigated; some of which are not normally considered in rock mechanics analyses. External and internal factors determined to be of significant importance were: (1) precipitation, (2) fractures, (3) plastic clay layer, (4) topography, (5) rock alteration, (6) bedding, and (7) mining zone dimensions. Because of the conditions at the mine, failure could have been predicted without extensive instrumentation. Application of basic geologic and engineering principles to the internal and external factors could have predicted failure. Alternately, failure would, in all probability, have been delayed by years if, after 1962, mining had been curtailed in the area of failure.

Jan 1, 1980

By Robert H. Peters

Groundfall accidents have been the leading cause of fatalities in the underground coal mining industry for many years. Statistics from the Mine Safety and Health Administration (MSHA) indicate that approximately half of the victims of these fatal accidents were in an area where no devices had been installed to support the mine roof. This report was prepared by the U.S. Bureau of Mines to provide guidance to operators of underground mines concerning the use of techniques that may help to keep miners from going under unsupported mine roof. The report is divided into two major sections. The first section reviews the findings from several areas of empirical research pertaining to strategies for convincing employees to avoid unsafe acts and/or adopt self-protective behaviors. The strategies are (1) incentives and feedback, (2) disciplinary actions, (3) training (primarily fear communications and behavioral modeling), and (4) nondirective techniques. This literature review has a broad focus and should be helpful in making decisions about how to encourage a wide variety of types of self-protective behaviors. The second major section of the report presents an analysis of each strategy's potential for keeping miners away from unsupported roof.

Jan 1, 1991

By Wilford S. Wright, Harold E. Heide, Robert S. Sanford

"INTRODUCTION The United States production of tin has always been negligible, and domestic requirements have been met almost entirely by imports. The advent of war in Europe in 1939 brought a threat to our foreign source of supply, and steps were taken by Congress to forestall shortages of tin and other metals. By authority of the Strategic Minerals Act, passed by Congress in 1939, the Bureau of Mines and Geological Survey conducted investigations of domestic tin deposits.An examination of Alaska deposits was undertaken in 1940 and 1941 by J. B. Mertie, Jr., and Robert R. Coats of the Geological Survey.H. B. Heide conducted a preliminary examination of lode and placer-tin deposits at Cape Mountain in 1942, which was followed in 1943 and 1944 by a program of exploration by churn drilling in the placer area and trenching and sampling the lode deposits.Placer tin, found at the head of Goodwin Gulch, Cape Creek, First Chance Creek, and Boulder Creek, indicates that the mineral was derived from the vicinity of lode cassiterite occurrences on Cape Mountain. Placer tin led to the discovery of at least one, cassiterite vein by the Geological Survey and the Bureau of Mines."

Dec 1, 1946

The compliance sampling method for coal mine dust in the United States has not changed appreciably in the last 30 years. A call for more frequent sampling with immediately available results is leading to new instruments that may supplement or replace the existing sampler. This report discusses two such instruments that provide immediate results of dust levels. The first, called the Respirable Dust Dosimeter (RDD), is designed to supplement the existing U. S. cyclone compliance sampling method. It uses the pressure drop across a filter to provide an inexpensive screening type of measurement. The RDD has been tested in the laboratory and a limited number of coal mines. Side by side testing has compared the RDD performance with personal coal mine samplers in triplicate area sample measurements. Results show that the differential pressure of specific filtration media can be an effective surrogate for respirable mass. Data show that there is a dependence on coal type and an effect of relative humidity. There also appear to be two distinct responses related to coal type. For specific coals the coefficients of determination, R2, are better than 0.9. For general use the detector tube, using laboratory generated calibration curves, can be used to estimate respirable dust levels. However, a calibration to a specific coal type may substantially improve the accuracy. Another sampler in development is called the Personal Dust Monitor (PDM). Designed to give compliance quality accuracy, the PDM uses the frequency change of a vibrating element to measure dust and give immediate feedback of results. Results of laboratory comparison of the prototype PDM sampler to personal gravimetric samplers indicate R2 values of better than 0.99 for three different coal types. Work is in progress to package the components into a person-wearable unit combined with a cap lamp system with a total projected weight of less than 1.4 kg (3 lbs).

On July 1, 1969, the Explosives Research Center merged with the Health and Safety Research and Testing Center to form the Safety Research Center, with facilities at Pittsburgh and Bruceton, Pa. Subsequently, passage in December of the Federal Coal Mine Health and Safety Act of 1969 (Public Law 91-173) had a major influence on the activities of the new center. These activities were conducted under two main programs, Coal Mine Safety Research and Explosives Research. The Coal Mine Safety Research program was concerned primarily with two categories of hazards: health-related hazards associated with the mine environment, due to such factors as respirable dust, toxic gases and vapors, and excessive noise; and accidents due to mine fires, explosions, and roof falls.

Jan 1, 1972

By Sidney Katell

The present report, a continuation of the series of Bibliography of Investment and Operating Costs for Chemical and Petroleum Plants, is concerned with articles published from January 1958 through December 1958. The periods covered in previous reports are as follows: January 1930 - August 1948 I. C. 7516 September 1948 - June 1952 I. C. 7705 July 1952 - June 1954 1. C. 7751 July 1954 - December 1956 I. C. 7847 January 1957 - December 1957 I. C. The following sources were used to obtain the references to and the abstracts of the published articles included in this report: 1. Bureau of Mines Information Circulars. 2. Bureau of Mines Reports of Investigations. 3. Chemical Engineering. 4. Chemical Engineering Progress. 5. Coal Age. 6. Coal Utilization. 7. Cost Engineering. 8. Industrial and Engineering Chemistry. 9. Nucleonics. 10. Oil and Gas Journal. 11. Petroleum Engineering. 12. Petroleum Refiner. 13. World Oil.

Jan 1, 1959

By John R. Benham

The Windigo Theilson RARE II area has a low mineral potential. There are no mines or claims in the area. The only observed results of mining activities were five prospect pits near Tolo Mountain. Samples from these pits contained no significant assays. The study area contains more than 190 million cu yds (145 million m3) of cinders in 17 cones. Development of these cinders is unlikely because their locations are remote, and other sources supply area needs. The Geological Survey has classified the area as prospectively valuable for geothermal resources. However, there has been no geothermal exploration activity.

Jan 1, 1982

By Virginia E. Gleason

In this report, recommendations are made for programs to develop workable techniques to stop or prevent acid mine drainage formation in those underground coal mines where acid production could take place. These recommendations include development of mine closure technology, development of surface water infiltration control procedures, study of the effect of roof collapse on mine water characteristics, evaluation of the long-term effects of flooding underground mines above drainage, investigation of the effectiveness of section sealing in active mines, development of a simple model for predicting mine water quality and quantity, preparation of a manual on mine drainage abatement procedures, and development of a program to disseminate information on mine drainage abatement to the coal industry. These recommendations are based on an in-depth evaluation of information acquired over years of research on acid mine drainage formation, on numerous laboratory and field studies of methods of preventing or minimizing acid mine drainage formation, and on review of the geological, hydrological, and mineralogical factors involved. There are 772 references.

Jan 1, 1978