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By George R. Schottler

The objective of this research is to find the extent of the range of applicability of previously developed statistical methods for determining grade and tonnage of ore to bedded uranium deposits. Uranium assays obtained from gamma-ray logs of exploratory drill holes are used to compute grade and tonnage of ore in the deposit by a standard polygonal method and by statistical analysis. The results obtained by the two methods are compared. The uranium-assay frequency distributions are shown to be lognormal and a simple transformation permits the use of standard normal curve statistics. The effects on the assay frequency distributions of stratified sampling, a required minimum mining thickness, and increased assay-interval length are investigated. The addition of low-grade mineralization to make up the required minimum mining thickness results in a distinct change in the skewness of the assay frequency distribution. Any statistical inference regarding grade-tonnage relationships that will be produced, using the minimum mining thickness, should be made on the basis of this "revised" assay frequency distribution.

Jan 1, 1965

By R. S. Dean

This report, the third of a series of annual reports of the Metallurgical Division to be released in this form, covers the fiscal year July 1, 1936, to June 30, 1937. The technological work of the division is performed by sections. Thus, an efficient organization is provided to prosecute the various problems under investigation, and a logical system is set up for presenting the material contained in this report.

Jan 1, 1937

By R. I. C. Manning

The Old Dominion Co, at Globe, Ariz., like the: Phelps Dodge Corporation with which it is closely allied, considers safety a major operating problem. Safety is fostered by this company in consideration of both the humanitarian and economic aspects; the officials, take pride in promoting the welfare of employees, and the management has found that the safest way is the most eco¬nomical and that unless an organization is operated economically it can not continue to exist successfully. In planning and operating any safety, organization, terry things must be taken into consideration because an Enterprise can not be operated solely for safety any more than it can for any other single part of the operations. All work must be planned and executed for the common interest.

Jan 1, 1931

By Robert R. Perron

The U. S. Bureau of Mines is engaged in many diverse programs for improving mine safety. Of particular interest to the Bureau are new and improved means for minimizing the hazard of fire which can be initiated by prolonged low energy electrical faults on trolley line systems. When a high energy fault occurs on a trolley line, wherein the current exceeds the magnitude normally drawn by legitimate loads, such as locomotives, then the circuit breakers at close-by power rectifier sets trip. Tripping of the breakers not only protects the equipment at the rectifier sets, but also disconnects the energy source from the fault and thereby minimizes the fire risk. However, the fault current is frequently of a level substantially below that required to trip the overload breakers. When the fault is a substantial percentage of the set level of the breakers, the energy dissipated by the fault is frequently sufficient to clear the system by rapidly burning itself clear. Such a fault is often short-lived and does not present as serious a fire risk hazard as a prolonged, much lower energy fault, wherein the energy level is too low to clear the system. The breakdown of a trolley line insulator, in which there was a 15 to 30 ampere fault to ground, would represent such a fault or illegitimate load and a substantial fire risk.

Jan 1, 1975

By Gerald T. Homce

Accidental contact of overhead electrical power lines by mobile equipment is a leading cause of occupational fatalities in the United States, accounting for 20% of on-the-job electrocutions. Overhead electrical power line proximity warning devices (PWDs) are intended to warn personnel if mobile equipment moves within some preselected minimum distance of an energized overhead electrical power line. Two commercially available PWDs were tested at the National Institute for Occupational Safety and Health?s (NIOSH) Pittsburgh Research Laboratory (PRL). The objective of the tests was to document performance capabilities and limitations for these PWDs by identifying factors that can influence their operation. The two PWDs evaluated in this research are the SIGALARM Model 210 marketed by Allied Safety Systems, LLC, and the ASE Model 2100 from Allied Safety Engineering. Both of these devices operate by measuring the electric field present around energized power lines. The PWDs were installed on a government-owned 22-st (20-mt) rough terrain crane. A purpose-built test site used for this research at PRL allowed operation of the crane near a variety of power line configurations operating at up to 25 kV. Most of the tests involved positioning the crane adjacent to one or more overhead power lines, adjusting sensitivities of the PWDs to alarm when the crane boom was approximately 20 ft (6.1 m) from the power lines, swinging the crane boom toward the lines under a wide variety of test conditions, and finally, for each unique set of test conditions, documenting the deviation from 20 ft (6.1 m) for actual alarm activation. Test results show that several factors can adversely affect PWD performance. PWD alarm accuracy generally deteriorated when operating with a boom position significantly different than that used for the device?s last sensitivity adjustment. Another factor that can affect PWD performance is configuration of the overhead power line(s) involved. Accuracy of alarm activa­tion distances was best for simple single-circuit installations, but degraded for multiple circuits on the same poles. This degradation was slightly greater for installations with different voltage levels and/or a combination of vertical and horizontal conductor arrangements. Performance also degraded for crane operation between two intersecting power line installations, especially for intersecting lines at different voltages. An additional aspect of power line configuration shown to influence PWD accuracy was phase sequence on the power line circuit(s). Specific phase con­ductor arrangements and combinations, particularly in multiple circuit installations, resulted in either improved or degraded accuracy.

Jan 1, 2008

By Shelby Z. Palya

"The Bureau of Mines was established in the public interest to conduct inquiries and scientific and technologic investigations concerning mining and the preparation, treatment, and utilization of mining-substances; to promote health and safety, in the mineral industries; to conserve Material resources , and prevent their waste; to further economic development; to increase efficiency in the mining, metallurgical, quarrying, and other Mineral industries; and to inquire into the economic conditions affecting those industries. The organic act of the Bureau, as amended by Congress and approved February 25, 1913, made it the province and duty of the Bureau to ""disseminate information concerning these subjects in such manner as will best carry out the purposes of this Act.""In accordance with this directive, the Bureau reports the findings of its research and investigations in its own series of publications and also in articles that appear in scientific, technical, and trade journals; in proceedings of conventions and seminars; in reference books; and in other non-Bureau publications. The number of these reports, the wide range of subjects they cover, and the variety of mediums in which they appear make the kind of list and index presented in this special publication both necessary and valuable. This issue describes reports and articles published during the period January 1, 1975, to December 31, 1979. It supplements the 50-year list of Bureau publications issued from July 1, 1910, to January 1, 1960; 2 the 50-year list, of articles by Bureau authors published outside the Bureau from July 1, 1910, to January 1, 1960; 3 the 5-year lists of publications and articles, from January 1, 1960, to December 31, 1964,, from January 1, .1965, to December 31, 1969,5 'and from January '1, 1970, to December 31, 1974; and the annual ,lists of Bureau publications and articles from January, 1 to December 31, 1975,7 from January 1, to December 31, 1976,8 from January 1 to December 31, 1977, and from January 1 to December 31, 1978."

Jan 1, 1981

By E. P. Carman

1. CARMAN, EVERETT P., OPPERMAN, MARTHA, NISHIYANA, SALLY, AND RACOOSIN, LEE. Bibliography of Bureau of Mines Investigations of Coal and Its Products, 1945 to 1950. B. 528, 1954, 60 pp. 40 cents. 2. ROSE, HAROLD J. Industry-Sponsored Coal Research in the United States. Chap. in Proceedings: Fifth International Conference of Directors of Mine Safety Research. B. 489, 1950, pp. 9-12. $1.25. Minerals Yearbook 3. STRINER, HERBERT E., CARMAN, E. P., AND GOODING, RICHARD M. Review of the Mineral-Fuel Industries in 1952. Minerals Yearbook 1952, Fuels, vol. 2 (pub. 1954), pp. 1-28.

Jan 1, 1958

The mineral Industry, following the economy as a whole, experienced little growth in 1992. However, with modernized plants, efficient workforces, and lower operating costs, the industry is well positioned to take advantage of possible improvement in the national economy during 1993. In addition to the significant 1992 events highlighted below, important events, trends, and issues within individual mineral industries are addressed in the commodity sections that follow. The value of processed materials of mineral origin is estimated to have been about $310 billion in 1992. The value of U.S. raw nonfuel minerals production in 1992 is estimated at approximately $32 billion, a 3% increase over 1991. The value of domestic minerals production has increased in all but 4 of the last 32 years.

Jan 1, 1993

The goal of the Bureau of Mines diesel engine research program is to reduce exhaust emissions and minimize the risk of fires and explosions caused by the use of diesel- powered equipment in underground mines. This program has led to a fundamental understanding of the problems and to solutions that allow diesel equipment to be used safely and effectively. This volume contains reports of the presentations made at the Bureau Technology Transfer Seminar on Diesels in Underground &fines given in Louisville, KY, and Denver, CO, on April 21 and April 23, 1987. It also contains three reports of related research, not presented at the seminar, which highlight the significant achievements of a joint US.-Canadian research program on diesel emission control technology for underground mines. Topics covered in this volume include discussions of industrial hygiene problems associated with the use of diesels, accident statistics, fire and explosion control systems, measurement of diesel pollutants, emission control techniques including engine maintenance, fuel additives, diesel particulate filters, and ventilation of diesel sections. An alternative to diesel power, the hydrogen-powered mine vehicle, is also described.

Jan 1, 1987

By Alfred Weiss

These volumes report on the study initiated by the U. S. Bureau of Mines to develop and apply a methodology to quantitatively assess the probability and potential benefits of technological innovation over the next twenty-five years. The potential was recognized for new technology to solve copper industry problems in the United States. Objectives of the study were to: (1) Develop a methodology to obtain the opinions of mineral experts about future events -their likelihood of occurrence, and, conditional on occurrence, when and to what extent they are likely to occur; (2) Identify, select, and describe potential technological innovations which would have significant impact on copper production; (3) Implement the methodology and obtain the opinions of the mineral experts regarding selected copper technologies; and (4) Analyze the expected future benefits of successful technological innovations :n the copper industry. Although individual technologies are continuously examined throughout the copper 'community', this study is the first known comprehensive forecast of future copper technology. This study is also believed to be unique 1n that it represents the consensus opinion of over sixty expert copper technologists on the expected use of innovative technology in the industry over the next 25 years. The report is contained in three volumes.

Jan 1, 1983

By S. R. Zimmerley

[In the course of a flotation investi~ntion, a siliceous gold ore was ground ir, R 'ball mill to ~inils 300-mesh. It mas found that the small mount of zlus 300-~esh mnterial had a go12 assw approximately twice that of the oricinal ors, md thst this oversize ~roduct also contained much abra?.ed iron. >!oreover, the gold assay of the abraded iron, which was separated ma~etic-dl:;, wno ei::ht tiaes tkat of the ore. These facts sug,~estsd th~t sone r3laticnshin existed between the abnormally high .gold content and the preseace of abrade4 iron. It was ciecided, therefore, to investl~ate furtkor ths acsoclation of the ;old nith the iron abraded from the balls durir-g grincing. As a nrelininary ex?rr>hent, a samy?le of siliceous gold ore 786 grolznd for 1-1/2 hours i;l 3 ball mill and the nuln was divided into two products electri~mag-etically. The racult s follow: ]

Jan 1, 1937

By S. R. Zimmerley

[In the course of a flotation investi£ation, a siliceous gold ore was ground in a'ball mill to ':1inns 300-meeh. It wa. found that the small amotIDt of _Ius 300-mesh material had a gole.. assay approximately twice that of the oriGinal ore, &~d that this overs.ize nroduct also contained much abrac..ed iron. .,Joreove I the gold assay of the abraded iron t which was !1epnrated ma§metically', ~iVFl.£ eight ti;nes that of the are. These facts suggested that some r31aticnship ex?...,ted between the abnorma11y high gold content an the prese:1ce of brA-cit)" iron. It was decided, therefore, to investigate furt~er th~ Fl.Gsociation of the bold ~ith the iron abraded from the balls during sri~Qing ]

Jan 1, 1937

By W. G. Diamond

Lightweight aggregates have become increasingly important to the construction industry. From 1953 to 1960, the quantity of the aggregates used in concrete block, precast and prestressed concrete, and monolithic structures increased about 92 percent. The present study was conducted in Bureau of Mines Area IV which encompasses the South-Central States of Arkansas, Kansas, Louisiana, Mississippi, Missouri, Oklahoma, and Texas. This is an administrative area and does not delimit a market area or imply an economic unit. Because of the increasing importance of metropolitan areas in evaluating economic growth, significant data showing relationships between growth of the metropolitan areas and the lightweight aggregate industry are included.

Jan 1, 1964

By Alvin Schallis

The. problem of supplying enough magnesia for the American war effort has become highly important. Before hostilities began, only about two-thirds of our, require vents came from domestic sources; now they must supply almost all the magnesia we need. A further burden is placed upon our own supply by the fact that more and more magnesia is being required, not alone to pace the war tempo of general industrial activity, but also to replace chrome ore in refractories and to make magnesium metal. The domestic magnesite and brucite industry is equipping itself to satisfy much of this greater demand for magnesia, but the remainder must be obtained elsewhere. The principal sources of magnesia are magnesite, brucite, dolomite or high-magnesium limestone, natural brines, sea water, salt-works bitterns, magnesium silicates, and magnesium salts. Although dolomite is tae subject of this paper, it should be considered in perspective with all these highly competitive sources of magnesia.

Jan 1, 1943

By A. J. Kauffman

The alluvial deposits of the Pacific Northwest have been investigated and worked with varying degrees of intensity since about the middle of the 19th century. Earlier efforts, of course, were centered about the placer-gold content of the deposits; later, the Oregon beach sands were exploited for their chrome content, and, still more recently, deposits in Idaho were worked for their content of monazite, a rare-earth mineral which also contains significant quantities of thorium. The composition of alluvial deposits seems to depend mainly upon the nature of the source rock from which the detrital material was derived and upon the resistance of the individual mineral grains to the agencies of weathering and transportation. The processes of crushing and concentration used in ore dressing are applied in a leisurely but nonetheless effective manner when exposed rock masses are eroded by natural forces. Weathering effects a continuous disintegration and chemical decomposition, wherein resistant minerals are set free as individual grains and new minerals are formed. Erosion carries these detrital products down the slopes into natural waterways, where a mechanical separation of heavy particles from light is accomplished by the running water. The accumulation of such resistant, heavy particles through the ages has resulted in formation of the black-sand deposits. In addition to the associated gangue minerals, heavy sand deposits in the Pacific Northwest may contain the following constituents of possible economic value: Gold, platinum, chromite, ilmenite, magnetite, garnet, zircon, monazite, columbite-tantalite, and radioactive blacks.

Jan 1, 1956

By Eugene O. Binyon

"Belt and shaker conveyors, used singly or as combined units, have for many years been an integral part of many coal-mine haulage systems. The belt conveyor has also been used extensively as a main haulage unit in open-pit iron-ore mines of the Lake Superior district, particularly on the Mesabi Range. Few underground metal mines, however, either in the ferrous or non-ferrous branches of the mining industry, use the conveyors exclusively or even extensively for underground haulage. At present, only five iron-ore mines in the entire Lake Superior district have belt- or shaker-conveyor installations of any significant size. Of these mines, three are in the Crystal Falls-Iron River district of Michigan on the Menominee Range, one is on the Marquette Range near Ishpeming, Mich., and one is on the Mesabi Range near Keewatin, Minn.Results of the studies of tackless haulage in the Lake Superior district will not permit the establishment of any formula to prove or disprove the advantages of belt or shaker systems at all underground mines. The studies do show that trackless haulage can be used to advantage where the proper conditions exist. Advantages are particularly apparent when development can be planned sufficiently in advance of exploitation to permit installation of belts or shakers as part of the development program and where the systems are extended to include haulage in stopes as well as main entries.During the winter of 1947-48, the Bureau undertook a study of all of the underground ore conveying systems known to be in operation in the Lake Superior district for the purpose of making available to the entire mining industry the technologic data developed in the area. Because conditions that led to the installation of the belt and shaker conveying systems were often a function of the character of the deposit or the method of mining, a brief description of those conditions is included in this report.After a preliminary investigation into the extent to which trackless conveyors were employed in the district, it was found that a detailed study at five bites would result in fair appraisal of that method of haulage in the underground iron-ore mines.Each of the five significant installations is described separately in this report. In one instance, however, company policy does not permit identification of the mine wherein the conveying is done. In that instance the operation is designated as mine ""A"".Unless otherwise specified, all tonnage figures quoted herein are gross.The cooperation of officials of all of the companies operating underground mines in the Lake Superior district permitted successful completion of preliminary studies of mining practices and conveying systems.Special acknowledgment is made to R. D. Satterley, general superintendent, and to operating staffs of the Sherwood and Morris mines of the Inland Steel Co. The assistance given by W. D. Whitman, assistant superintendent, and Douglas Tippett, mine captain at the Morris mine, and P. D. Pearson, superintendent, R. O. Marsten, engineer, and W. Johnson, mine captain, at the Sherwood mine, is acknowledged."

Oct 1, 1949

Dry weather since the third week in January has set back any prospects for an early increase in hydroelectric power in the Pacific Northwest, according to The Bonneville Power Administration. The 25% cutback made in July probably will not be restored in March or April. Noranda Aluminum, Inc., increased its price for 99.5% aluminum ingot from 66 cents to 70 cents per pound effective March 1, 1980. Revere Copper & Brass, Inc., also -increased its price for primary aluminum from 66.0 cents to 70.0 cents per pound effective February 1. Kaiser Aluminum & Chemical Corp. raised its international price for 99.5% primary aluminum from 72.6 cents to 82.6 cents per pound, c. i. f., effective February 26 on new orders and on shipments from March 15.

Jan 1, 1980

By Robert E. Hershey

1. This investigation shows that the most important beds in Claiborne County, from the standpoint of present production and reserves, are the Coal Creek and Jellico. Together, they contain 69 percent of the known recoverable reserves in the county. Reserves in five other beds are tabulated in this report; in order of quantity of reserves, they are: Blue Gem, Lower Pioneer, Pewee, Big Mary, and Rex. 2. Known measured and indicated reserves in all beds, based on a minimum thickness of 14 inches and on 1,800 short tons per acre-foot of coal in place, are estimated to be 60 million tons, as of January 1, 1953. Of this total, 55 million tons is in beds 28 inches and more thick. Areas in each bed were omitted from the estimate because available data relative to the bed characteristics are too meager to permit making an estimate that conforms with the definitions of measured and indicated coal adopted for this study. Should future drilling or development prove reserves in these areas, such reserves should be added to the total estimated reserves.

Jan 1, 1956

By W. G. Diamond

Lightweight aggregates have become increasingly important to the construction industry. From 1953 to 1960, the quantity of the aggregates used in concrete block, precast and prestressed concrete, and monolithic structures increased about 92 percent. The present study was conducted in Bureau of Mines Area IV which encompasses the South-Central States of Arkansas, Kansas, Louisiana, Mississippi, Missouri, Oklahoma, and Texas. This is an administrative area and does not delimit a market area or imply an economic unit. Because of the increasing importance of metropolitan areas in evaluating economic growth, significant data showing relationships between growth of the metropolitan areas and the lightweight aggregate industry are included.

Jan 1, 1964

By James A. Wasson

Because of the danger to life and property in a coal mine if an oil or natural gas well should be accidentally intersected during mining operations, certain precautionary measures should be carried out prior to entering previously unmined areas. The locations of all wells both at the surface and at the depth of the coalbed should be accurately determined. The condition of the well should be learned from surface observations, and more importantly, from subsurface examination by geophysical logging devices where possible. It is also desirable to learn the physical properties of the hydrocarbon-bearing rock formation and the hydrocarbon fluids. The major hazard presented by oil or natural gas wells to mining operations is that of explosion and fire due to the rapid release of gas into the mine atmosphere. Wellbore pressure, the principal index of danger, should be determined by one or more of the methods described and by a service company such as those listed in the appendix. Because of high pressures involved and the consequent hazard, much emphasis has been placed on underground storage of natural gas in areas containing minable coalbeds. Maps are shown of the principal coal producing areas and the locations of currently active gas storage reservoirs. A checklist has been included of factors to be considered when mining coal in an area where oil or gas wells exist.

Jan 1, 1973