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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 James L. Fenton

In its unending search for the raw materials that the affluent society of today requires the mining industry has found it necessary to go to great depths, in many cases, to produce these materials. Inherent with this problem is the insufficient technology relating to improving extreme environments that the mine personnel are exposed to. In this dissertation, the sources of heat flow into a mine along with the various effects that this heat has on the mine personnel are investigated. The object of dissertation is to compile all the available published information pertaining to these underground heat and their effects into one paper. This will provide the mining industry with an available easy-to-use to aid in the determination of mine ventilation requirements as the mines are in the phases of original planning or being extended to depth. Areas of significant, deficiencies it knowledge have been disclosed during this overall appraisal. Recommendations on important basic research needs are out lined for future consideration by Federal or industries sponsorship. This thesis should serve as a stimulus lo, future well-organized research efforts in the area of underground heat sources and their control.

Jan 1, 1973

By Terry Muldoon

In conventional noncoal, room-and-pillar mining, the cutting machine is frequently a major source of airborne dust. Water is often used for dust control. An evaluation of typically used water systems during this program showed that they reduced dust levels by 60 to 70 percent over dry cutting when at least 0.5 gpm of water was applied. These systems, however, are only marginally effective in maintaining compliance levels and the added moisture causes operational problems. During the program, three additional dust control systems were designed, fabricated, and evaluated. The first, a hollow cutter bar, was designed to capture dust in the kerf at the cutting zone. The system was only marginally effective in reducing dust levels due to its lack of control of other sources. Large quantities of material captured by the system made it operationally questionable. The second, a machine mounted exhaust system, was extremely effective in capturing virtually all the dust generated in the heading. The captured dust was ducted out of the heading and exhausted downstream in the crosscut. Exhausting the dust without scrubbing, however, creates problems for personnel working downstream of the cutting machine. Successful application would require changes to the mine ventilation system and mining sequence. The third, foam, injected foam from an onboard generator through a channel to the cutting zone at the tip of the bar. Test results showed that foam, using 1/3 to 1/2 the total fluid quantity, was equally effective when compared to the mine's current water system.

Jan 1, 1983

Commodities statistics and other information are available through the following three systems: Internet Access: To access the USBM Gopher server on Internet, connect to: gopher.usbm.gov port 70, using gopher client software. Or contact the Systems Administrator for technical questions: Matt Klevemann, 412-892-6499 (klevemmc@miner.usbm.gov) These USBM materials are available on Internet, with more to come in the future: Publications and other research findings, including this bimonthly publications list, newsletters, tech transfer updates, environmental technology research, health and safety information. USBM software products Media materials and speeches. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. Mines FaxBack Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644. 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone. 4. After completing your selection, press the start button on your fax machine.

Jan 1, 1995

By M. Carrales

This Bureau of Mines publication presents short-range projections of domestic liquid hydrocarbon production through 1980. Appraisal of future crude oil production was made by evaluating the relationship between primary and enhanced oil recovery and the total crude oil producing trends in each of the oil-producing areas of the United States. Future natural gas liquid production was generally estimated by projecting historical production. Estimates of production were prepared for each of the oil producing areas and summarized for the Petroleum Administration for Defense (PAD) districts and total United States. From 1975 to 1980, crude oil production for the conterminous United States is expected to decline from 7.8 to 6.4 million barrels of oil per day (BOPD), and it is expected to increase from 8.0 to 8.2 million BOPD for the total United States. However, these estimates do not include additional production expected from the Elk Hills field in California and the Yates field in Texas. If included, 1980 production for the conterminous United States would be 6.7 million BOPD and 8.4 million BOPD for the total United States.

Jan 1, 1977

1. Domestic Production and Use: In 1982, 13 companies operated 30 primary aluminum reduction plants, with 3 firms accounting for 55% of production. Washington, Oregon, and Montana accounted for 34% of the production; Texas, Louisiana, Missouri, and Arkansas 18%; Tennessee, Alabama, South Carolina, and North Carolina 14%; other central and eastern States 34%. Based on published producer prices, output of primary metal in 1982 was valued at over $5.5 billion. Aluminum consumption by 25,000 firms was centered in the East Central United States. Packaging accounted for an estimated 39% of domestic consumption in 1982, transportation 20%, building 14%, electrical 8%, consumer durables 8%, and other uses 11%.

Jan 1, 1983

By W. W. Stephens

As part of the Bureau of Mines program directed toward more effective utilization of the mineral resources of the United States, a number of processes for production of sponge iron have been investigated. The use of sponge iron as a raw material for production of steels and other ferrous alloys offers several possible advantages over the conventional pig-iron and scrap process, especially for utilization of the smeller, widely distributed iron-ore deposits of the western United States. Although considerable information has been made available on various processes for production of sponge iron, little information 118.6 been published heretofore on the problems and costs involved in melting the sponge iron for production of steel. The present Paper reports the results of tests conducted at the Bureau of Nines pilot plant at Redding, Calif. in which several different types of sponge iron Were used as charge material for production of steel in a 4-ton-capacity basic arc furnace.

Jan 1, 1949

By Lowell B. Moon

Concern over possible wartime shortages finally resulted in passage of the Strategic Materials Act in 1939. As authorized by one section of this legislation, the Bureau of Mines proceeded to investigate deposits of seven strategic minerals with the objective of developing tonnages of low-grade material that could be mined in an emergency. During the war, the size of the program and the number of strategic minerals were increased, and the objective was the more immediate one of aiding production. Since the war, the size of the program has been reduced, but the number of minerals on the strategic list continues to be large. The objective has returned to that of 1939. In the course of the program, more than 10,000 examinations were made and about 1,300 projects were run on deposits of 33 different commodities. A considerable contribution to war production was made in six of the commodities investigated, and a minor contribution was made in twelve others. Substantial reserves have been indicated in 19 minerals. Private interest is currently active in some of the deposits developed in 14 commodities.

Jan 1, 1950

By Edward L. McHugh

The appraisal of mineral resources of the Challis National Forest, Idaho, by the U.S. Bureau of Mines, was made so that the mineral resources of the forest could be appropiately considered in land use planning. Information from this study is intended to tip the U.S. Forest Service to incorporate mineral resource data into forest plans The study was done in conjunction with the U.S. Geological Survey, which released a companion report on the geology and mineral potential of the Challis National Forest in 1989. This summary report is derived from a more detailed USBM Open-File Report (MLA 6-91) that includes descriptions of mines and prospects, commodity profiles, and development cost models. Since the 1860's mines within the Challis National Forest have produced mineral commodities worth more than $590 million at current (1989) commodity prices. Identified mineral resources have a gross value of about $2 billion at current prices, including 8 strategic or critical minerals. The U.S. Bureau of Mines study identified and described 723 active and inactive mineral properties within the forest. Mineral properties with identified resources were evaluate to determine their economic significance, and an assessment was made of the feasibility of mineral development. Of the 2,516,191 acres in the Challis National Forest, about 390,000 acres were classified as having mining development interest. Commercially important mineral production, mainly of molybdenum, gold, and silver from the Challis National Forest is likely for the foreseeable future.

Jan 1, 1991

By Charles L. Kimbell

Virtually every available measure of total world mineral industry activity demonstrated that 1982 was little, if any, better for the industry than 1981 had been. Levels of production, trade, and consumption for virtually every major commodity declined; unit prices for most commodities fell, particularly in terms of constant dollars, and as a result of cutbacks in output and lower prices, capital available for investment within the industry was reduced. These conditions, coupled with the existence of considerable idle capacity, tended to retard investment, although there was an upturn in U.S. oil industry investment overseas. Despite the overall depressed situation of the world's mineral industry, there were indications of possible improvements in market economy countries near yearend, as output of some materials increased marginally and as prices for some mineral commodities reversed their downward trends. The downturns in total world mineral industry activity were not universal from the viewpoint of individual countries. Indeed, output of a number of commodities increased in centrally planned economy countries, and these gains were insufficient to offset declines in market economy countries, thereby sharply altering the proportion of total world output accounted for by each of these two groups of countries. There was a similar shift in consumption on a percentage basis.

Jan 1, 1984

This summary of State laws on explosives was compiled primarily to ascertain what subjects relating to their control have been acted upon by each State legislature and, in general, how they have been treated. It does not include any legislation passed after 1942, or any proclamations, regulations, or administrative orders. It does not purport or attempt to be authoritative. If any problem arises involving interpretation of the statutes of any particular State, the original source must be consulted for the exact words used by the legislature. This summary, however, will be useful in determining whether relevant statutes exist and in locating them quickly, with a minimum of effort. It will be of value also in comparing statutes in one State with similar statutes in other States to determine what construction has been placed upon them by the courts of those jurisdictions or to contrast the varying provisions of many States upon a single subject. To make these comparisons easier, the statutory provisions for each State have been grouped under several major topics in outline form. Although

Jan 1, 1943

By John C. Machisak

INJURY DATA and experience at, coal mines in the United States for 1953 and 1954 are presented in this publication with a minimum of interpretation and comment because of the numerous tables required to afford detailed comparisons between the 2 years. Corresponding tables for 1953 and 1954 follow in consecutive order under the following general sections: (A) General injury experience: Tables 1 to 11: Contain current data on number of fatal and nonfatal injuries, frequency and severity rates, and average severity and time-loss rates. (B) Selected injury data: Tables 12 to 85: Contain current data on causes of injuries, distribution of injuries by part of body injured, days of disability, extent of hand and machine loading, experience by employment and production groups, and various other operating factors and physical conditions related to the occurrence of injuries at the Nation's coal mines.

Jan 1, 1958

By Ralph P. Carter

It is apparent that coal will play an increasingly important role in satisfying the nation's energy requirements for the remainder of this century. Both deep mining and surface mining will be practiced to develop known U.S. coal reserves, but until significant improvements in the productivity of deep mining emerge, surface mining is likely to be predominant. This report addresses the problems of coal extraction and surface mine reclamation in the 11-state Midwestern coal resource region, where surface stripping of high-sulfur, bituminous coal has been a well-developed industry for most of this century. Midwestern coal markets have declined in recent years. In part this is a result of widespread conversions to more convenient and (apparently) economical liquid and gaseous fuels, but the decline in Midwestern coal use is also attributable to the impact of current air pollution control regulations that prohibit emissions of sulfur oxides and particulate matter. A part of the regional demand for Midwestern coal has been transferred to the Northern Great Plains where extensive low-sulfur coal reserves are currently being developed.

Jan 1, 1974

By Michael J. Sapko, Kenneth L. Cashdollar

In This Chapter [Methane ignition as initiation source for much larger secondary coal dust explosions Rock dusting requirements to prevent coal dust explosions Dangers of hybrid mixtures of methane and coal dust] Although methane explosions are dangerous, those that involve coal dust are even more so. If exploding methane disperses and ignites the coal dust that has accumulated on the mine ribs and floor, the burning coal dust immeasurably increases the strength of the explosion. Such methane-dust explosions are prevented by inerting the coal dust in a way that prevents the exploding methane from igniting it. This chapter discusses the dust hazard and how it is pre-vented in U.S. coal mines. METHANE IGNITION AS INITIATION SOURCE FOR MUCH LARGER SECONDARY COAL DUST EXPLOSIONS The typical scenario for coal mine explosions starts with the ignition of a flammable methane-air atmosphere near the face. The turbulent winds from the primary methane explosion then disperse the coal dust. If there is insufficient rock dust (usually limestone), a secondary coal dust explosion then propagates throughout large sections of the mine. These scenarios have been studied extensively at the Bruceton Experimental Mine (BEM) and the Lake Lynn Experimental Mine (LLEM) of the NIOSH Pittsburgh Research Laboratory. The minimum quantity of methane required to initiate a coal dust explosion was studied in 1930 in the BEM [Rice et al. 1933; Nagy 1981] and then later in the LLEM, whose cross-sectional area (130 ft2) is over twice that of the BEM [Sapko et al. 1987a]. Studies conducted in the BEM closely simulated conditions that existed in operating mines in the early 20th century. The later tests in the 20-ft-wide entries of the LLEM simulated the geometries of modern mines with advanced roof support technology. The data from the BEM tests show that 13 ft3 was the minimum quantity of methane at the face that, when ignited, would disperse and ignite coal dust. In the BEM, this amount of methane was mixed with air to form a total flammable volume of about 140 ft3 of a 9% methane-in-air mix-ture. In the wider entries of the LLEM, about 37 ft3 of methane was required to disperse pure coal dust and start a self-sustained coal dust explosion. This amount of methane was mixed with

Jan 6, 2006

By L. B. Pankratz

Heat contents, measured above 298.15° K, and derived entropy increments are presented in tabular and equation form for the two crystalline forms of zinc sulfide (sphalerite and wurtzite) and for four solid solutions of iron and zinc sulfides having the compositions Zno.,,6Fe0.302S, Zno.750Fe0.250S, Zno.650Fe0.3505, and Zno.498Feo.502S.

Jan 1, 1965

By David C. Grant

A laboratory technique for simulating in-situ uranium mining was developed and used to determine the effects of leaching variables on permeability, uranium recovery, leach solution interaction with the ore-aquifer environment, and post-leach chemical leakage. In particular, ammonium bicarbonate, the commonly-used leach solution, was examined in great detail. Agitation leach tests were conducted to examine the effect on ammonium sorption and desorption of clay content, solution and clay ammonium levels, pH, and the type and concentration of other anions and cations in solution. Initial column tests were performed to determine the degree of ore-aquifer interaction that could be expected for various leach solutions; sulfuric acid, and ammonium, sodium, and potassium bi-carbonates. Subsequent tests examined various methods to restore the ores by lowering the post-leach chemical leakage. The restoration tests examined the use of reducing agents (e.g., ammonium bisulfite, sodium bisulfite; and sodium sulfite), ore blocking and stabilizing agents (e.g., sodium silicate, aluminum chloride, and magnesium-calcium salt).and ammonium displacement agents (e.g., aluminum chloride and lanthanum chloride-sulfate)

Jan 1, 1980

By R. D. Leitch

The work of the United States Bureau of Mines on stream pollution3 by coal-mine drainage has included a study of seasonal variations in acidity and volume of several streams in Pennsylvania. The acidity of these streams has been determined during the two or three years prior to 1930 and the results may be considered to represent "normal" low water conditions. The summer of 1930, however, was unusually dry and represents what may be termed "extreme" low water conditions on these streams. This report is a comparison of the results obtained for extreme low water of 1930 and for other years. The streams investigated were Buffalo Creek in Somerset County, Indian Creek (lower 5 miles) in Westmoreland County, Little Toby Creek in Elk and Jefferson Counties, Daguscahonda Run in Elk County and West Creek in Elk and Cameron Counties. These will be treated separately in the order given. Most of the descriptive matter and physical data pertinent to the streams and drainage basins are taken from published reports of the Pennsylvania State Water Supply Commission, 1917.4

Jan 1, 1931

By R. F. Selden

The material in this paper is intended simply, to be an inquiry into some of the theoretical aspects of the occurrence of methane and carbon dioxide in coal, with a brief resume of the more recent literature. Several discussions on various phases of the subject have been published, a few of which (4, 20, 25, 88, 90)4/ have more or less extensive bibliographies of tie earlier literature. In large measure the pertinent literature deals with the unusual aspects of the subject, and in consequence it might appear that the normal aspects have not been given due consideration here. The latter information is largely a matter of practical field experience, and since that which is normal to one locality is often abnormal to another no sharp differentiation appears to be necessary or, in fact, possible. No attempt will be made to present a critical discussion of the relations between the presence of gases in coal and pertinent geologic features or mining practice. Although the presence of foreign gases in the ventilating air of many mines is not particularly noticeable, in many others the evolution of methane and perhaps small amounts of carbon dioxide (or sometimes the reverse - large amounts of carbon. dioxide with perhaps sore methane) is quite apparent.

Jan 1, 1934

By C. W. Owings

The Bureau of Mines has conducted a survey to determine potential exposure of mine workers to dust produced in connection with intermittent rock drilling in coal mines. Eighteen mines in 3 states were visited, and 30 different operations were observed, as follows: 10 drilling in draw slate, 8 drilling top rock for brushing or grading, 2 drilling in the coal face, 4 drilling in the bottom, 2 drilling top rock for overcasts, 2 drilling in faults or boulders, 1 drilling for roof bolting, and 1 drilling for trolley hangers. Dust respirators were worn by drilling crews during 16 of the 30 operations. Three hundred thirty-two samples of air-borne dust were collected during the survey. ACKNOWLEDGMENTS The information in this report is based on samples collected and observations made in bituminous-coal mines. Operating officials at these mines have contributed to this study, and their cooperation is gratefully acknowledged. All samples were counted by Thomas B. Kirby, chemist, and Dominick A. Ambrosia, scientific aid, and were analyzed by Gretta S. Baur, physicist, and Patricia M. Gussey, scientific aid, of the Health Branch of the Bureau of Mines.

Jan 1, 1953

By Albert L. Brautigam, Michael R. Yenchek, Jeffrey Shawn Peterson, James C. Cawley

The National Institute for Occupational Safety and Health investigated how the starting of induction motors may cause nuisance tripping of short-circuit protection on coal mine power systems. This research had a dual purpose: 1) to identify how motor-start waveforms differ from those for short circuits and 2) to devise a method to provide short-circuit protection without intentional time delays to account for motor starts. This technology will help ensure that surface temperatures of energized electrical apparatus will not exceed gas or dust ignition thresholds when short circuits occur.