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By Walford S. Wright, NORMAN EBBLEY

During the past decade (1937 to 1947), including the war years of heavy demand for metals, the United States realized about one-eighth of its antimony requirements from domestic production, chiefly in Alaska. In World War II, our foreign supply sources became endangered; and uncertainty in our Far Eastern supply made this nation focus on Alaska’s mineral resources with a Production Gear that centered in the Bureau of Mines experimental station at College (Alaska). The development work known as District or central deposits. The strategic mining districts included that of central Alaska was reorganized at Ketchikan Mining Districts. Mines were located here had produced considerable quantities since 1901; but methods for exploration had come from 1936 to spring 1942, some $4 million produced in gold alone. Statistics relating to available ores are those selected by type and exploitation periods with wide variety applied. During the summer of 1941, as part of an extensive Geological Survey program continuing through funds provided by U.S., geological surveys spent six weeks mapping an area approximately two square miles surrounding mines. The mines working both surface & underground work employed these men in mapping exercises.

Jan 1, 1948

By Wilford S. Wright, Harold E. Heide, Robert L. Thorne, Neal M. Muir, Aner W. Erickson, Bruce I. Thomas

A program of investigation of strategic and critical minerals began in 1940 to examine and develop tungsten occurrences in the western United States and Alaska. During the years in which the nation was at war, this work was given special impetus to stimulate domestic production. This report is a compilation of results of the tungsten investigations in Alaska supplemented by certain data made available by the Territorial Department of Mines and is designed to include in its scope descriptions of all known tungsten occurrences in the Territory. Two areas in Alaska warranted special investigation - one at Gilmore Dome, 16 miles northeast of Fairbanks, and the other in the Hyder District, at the head of Portland Canal. Three tungsten properties - the Stepovich, Colbert, and Yellow Pup - are at Gilmore Dome. The Stepovich property, referred to sometimes as the Cleary Hill tungsten deposit, was worked by the Cleary Hill Mines Co. from April 1942 until May 1944 and was first examined by Robert S. Sanford and Norman Ebbley, Jr., engineers of the Bureau of Mines, in September 1942. The Cleary Hill Mines Co. by that time had explored an 800-foot strike length of the ore zone with 10 bulldozer trenches and was sinking an inclined shaft on ore in the central portion of the explored zone. In January 1943, the senior author, in company with Ebbley and Harry C. Doheny, supervising engineer of R.F.C., examined the property. Preliminary work by the Bureau of Mines began in May 1945, but actual exploration did not commence until late in June and continued until the end of October 1943. The deposit was examined by John B. Mortie, Jr., and William C. Overstreet, of the Federal Geological Survey, in 1942, and this study was continued in 1943 by Frank Byors, who also assisted the Bureau’s engineers on geologic problems. A magnetometer survey of this area was undertaken in 1942 by Henry Joosting and Eskil Anderson, engineers of the Territorial Department of Mines, and was completed with Bureau of Mines assistance in 1943. During 1943 the Bureau completed exploratory projects on the Cleary Hill mine and adjacent Colbert prospect. The field work on the Colbert property was begun early in July 1945 and continued intermittently until the end of October 1943, when it was recessed because of subzero weather. During September 1944, the Bureau of Mines established (by means of a few surface trenches) continuity between the Colbert mineralized zone, high on the dome, and the Yellow Pup vein, the lowest known tungsten mineralization in the area. It is generally recognized that any extensive program to develop the area as a whole logically would be carried out from the lower horizon.

Jun 1, 1948

By David S. Brown

What troubles me so often about debates over the environment, which I have heard since I entered government in the late 1960's, is that the issues are so often presented as a false dilemma--the either-or fallacy in logic. The either-or fallacy allows only two possible choices: Either protect the environment or exploit it. In reality, however, there may be a few more options. The diverse, often competing, values that the Earth offers require us to weigh and balance those options through a range of policy options. A quality environment and economic growth and opportunity are not mutually exclusive. First, let me acknowledge that I support a set of resource values recognized in U.S. laws and deemed important down through history for the success of free, progressive, and secure societies: the importance of access to raw materials. Increasingly, however, mineral raw materials have been viewed at best as not particularly relevant to a sophisticated, technologic society, and at worst monstrously destructive of our natural environment. Both perceptions, in my judgment, are wrong.

Jan 1, 1989

By Peter Swanson, John Rettkowski

As part of a research program to reduce injuries and fatalities in the U.S. mining workforce, NIOSH is investigating the potential use of noncontact vibration measurements to identify hazardous ground fall conditions. In the present study, the effectiveness of remote vibration sources in exciting resonant responses in damaged structures is examined. Initial experiments were performed on a damaged concrete slab in a controlled environment. Vibration response was measured with a laser Doppler vibrometer using both single-point and two-dimensional array recordings. Excitation sources included direct mechanical impacts to remote portions of the slab and a remotely located industrial demolition hammer. Surficial damage was effectively delineated with both sources through visualization of vibration response in spectral bands selected to discriminate wave propagation from large-scale slab resonance effects.

By Eric S. Weiss, Deno M. Pappas, Timothy M. Barton

During the past few years, the Pittsburgh Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) has been evaluating developments in sealant support systems from a ground control perspective. The proper selection and use of a sealant material can significantly enhance ground control which may result in a decrease in worker related injuries due to ground falls. The purpose of this paper is threefold: to briefly review the current state-of-the-art technology in shotcrete and membrane developments, to evaluate the preliminary findings of a long-term underground study of various types of sealant materials, and to examine installation practices that are critical for an effective sealant material. The underground study utilizes NIOSH’s Lake Lynn Laboratory Experimental Mine to evaluate the long-term performance of several types of shotcrete and membrane materials. Sealant performance to date have been evaluated on a regular basis over a two year period. Although the study is still ongoing, critical mining practices were identified that may seriously effect the bond of the sealant materials to the mine roof and rib; most notably, the importance of scaling and thorough cleaning of the rib prior to application. Also, results froman extensive series of Schmidt Hammer tests found that the shotcrete increased in strength by 70% during the humid summer months.

By L. McWilliams, L. D. Patts, J. D. Noll, S. E. Mischler

Elemental carbon (EC) is currently used as a surrogate for diesel particulate matter (DPM) in underground mines since it can be accurately measured at low concentrations and diesels are the only source of submicrometer EC in underground mines. A disadvantage of using EC as a surrogate for DPM is that the fraction of EC in DPM is a function of various engine parameters and fuel formulations, etc. In order to evaluate how EC predicts DPM in the underground mining atmosphere, measurements of total carbon (TC; representing over 80% of the DPM) and EC were taken away from potential interferences in four underground metal/non-metal mines during actual production. In a controlled atmosphere, DPM mass, TC, and EC measurements were also collected while several different types of vehicles simulated production with and without different types of control technologies. When diesel particulate filters (DPFs) were not used, both studies showed that EC could be used to predict DPM mass or TC. The variability of the data started to increase at TC concentrations below 230, µg/m3 and was high (>+20%) at TC concentrations below 160 µg/m3, probably due to the problem with sampling organic carbon (OC) at these concentrations. It was also discovered that when certain DPFs were used, the relationship between DPM and EC changed at lower DPM concentrations.

By R. A. Franks, J. C. Edwards, L. Yuan

To determine the critical air velocity for preventing smoke rollback, diesel-fuel fire experiments were conducted in the National Institute for Occupational Safety and Health’s (NIOSH) Pittsburgh Research Laboratory’s Safety Research Coal Mine. Such information is necessary for preplanning and implementation of ventilation changes during mine fire fighting and rescue operations. The fire intensity varied from 50 to 300 kW depending on the fuel tray area. Airflow in the 2-m- (6.6-ft-) high, 2.9-m- (9.5-ft-) wide coal mine entry was regulated during the course of each experiment. The airflow was measured upwind from the fire as an average over the entry cross-section with an ultrasonic airflow sensor and was recorded dynamically with a mine monitoring system. The extent of smoke reversal was monitored with light-obscuration monitors, ionization smoke sensors and visual observations. Experimental results for the critical air velocity for smoke reversal as a function of fire intensity compared very well with model predictions based upon a computational fluid dynamics fire dynamics simulator.

The STATE MINERAL SUMMARIES publication provides estimated data and summaries of mineral activities at the State level for 1989. Most of the estimates are based on nine months data. These summaries have been prepared in cooperation with State geological surveys or related agencies. Individual State summaries are published separately as State Mineral Industry Surveys and copies can be obtained from the appropriate State Activities field office.

Jan 1, 1990

By A. C. Fieldner

ONE of the important functions of the Bureau of Mines is the, analysis of coal from every coal-mining State and Alaska. These analyses are being published for use of Government officials and the public. In connection with analytical data showing composition and quality of coals of the States, consumers, Producers, and the general public will be interested in a brief description of the geologic structure of the coal basins, typical mining conditions in the several districts, and the principal economic data of the industry. These publications have therefore heel) designed to include such features to present concisely the principal facts regarding occurrence, reserves, duality, characteristics, production, and uses of coals of each producing State.

Jan 1, 1952

By David Bendersky

The principal objectives of this study are to: (1) survey electrical practices in metal and non-metal mines, (2) survey electrical practices in metal and non-metal mills, (3) clarify the federal regulations governing electrical practices in metal and non-metal mines/mills, (4) analyze electrical accidents, and (5) make recommendations aimed at improvement of the safety of electrical practices in metal and non-metal mines. Information was obtained from literature searches, accident reports, visits to 27 mines and 12 mills, and discussions with knowledgeable industry and government people. The various electrical power systems and practices at the mines and mills visited are described. Similarities and differences based on the type of mining and the minerals being mined or milled are presented. The federal regulations governing metal/non-metal mine/mill electrical practices (Code of Federal Regulations, Title 30, Sections 55.12, 56.12, and 57.12) are presented and discussed. Explanations of each regulation are provided in an appendix. The attitudes of mine/mill operators towards the federal regulations are described. An analysis of the electrical accidents in metal/non-metal mines and mills during the period 1972-1978 is presented. Recommendations, including specific research and development activities, aimed at improvement of electrical safety in metal/non-metal mines are submitted.

Jan 1, 1980

By ALBERT E. HALL, Arno C. Fieldner, Alexander L. Field

As a safeguard against excessive clinker troubles, specifications for the purchase of coal can be drawn to include the "softening" or "fusing" temperature of the ash. The value of such information has been recognized by the Bureau of Mines and has induced the bureau to investigab~ laboratory methods of determining the fUSIbility of coal ash, and the bearing of the results on clinker formation in fuel beds. The bureau realized that the fusibility of a mixture of oxides and silicates snch as is comprised in coal ash ,'aries according to the conditions under which tests are made, and that in the absence of any generally accepted method, no agreement is to be expected among tests made in differ«:-nt laboratories. Indeed, Marks a has recently called attention to differences as great as 3900 C. that were obtained with the same sample of ash by two different laboratories. Therefore if a fusion-temperature clause is to have any place in specifications for coal, a standard m('thod of t('sting should be adopted in order to insure comparable results by different laboratories and to obtain the softening or fusing temperature of the ash unde:'r conditions similar to those of a fuel bed. After a consistent method has been devised for obtaining comparable:' results at different laboratories, there will remain the correlation of these results with those from the burning of coal in furnaces before the value of fusibility tests in coal specifications can hE' finally determined.

Jan 1, 1918

By H. C. George

This bulletin deals with prime movers, power-transmitting machinery, and the surface equipment and methods used to pump oil wells. It does not discuss geological problems nor the methods and equipment used in drilling or at flowing oil wells. Much of the presentation is by photographs and drawings which are described in the text. Underground equipment and methods for pumping oil wells will be discussed in a later publication of the Bureau of Mines.

Jan 1, 1925

The contribution of minerals to the growth and development of the United States is best demonstrated by the uses which have evolved during the past two centures. During pre-Revolutionary days the colonies were essentially agricultural in character, producing cotton, tobacco, rice, indigo, grains and flour, fish, livestock, dairy products, and timber. Shipbuilding was the major manufacturing industry. In 1763, the total value of exports for Virginia, Maryland, New York, Pennsylvania, and Massachusetts was £2,722,000, of which £55,000, or 2 percent, was for "copper ore, and iron in pigs" (3)1 and £49,000 was for 21,000 barrels or hogsheads of "pot-ash." The value of 75 ships built for sale in 1763 by the colonies was £61,500.

Jan 1, 1976

By Stephen P. Signer, John L. Lewis

This paper presents the results of a case study conducted in a two-entry gateroad in a coal mine where excessive roof deformation and bolt loading resulted in failure of many roof supports. The instruments consisted of 16 fully grouted, strain-gaged resin bolts, load cells on both full and partially grouted cable bolts, and vertical deflection multipoint extensometers. These instruments were installed on-cycle to measure loading on bolts in an existing support pattern and to determine if cable bolts could be used to improve roof stability. Results showed significant amounts of movement within the bolted zone. In some cases, these movements were enough to load the supports past their ultimate strength. Geology appeared to be a significant factor in localized roof degradation; that is, a very weak rock layer in the immediate roof overlain by a very strong rock layer contributed to the development of shear planes. Only one instrumented bolt had a maximum strain of less than 2,000 microstrain, which was the yield point of the steel. The average maximum strain on all bolts was 20,000 microstrain. However, electrical continuity to many gages was lost and a pattern was noted that would indicate possible bolt failure. Wire mesh and concrete cans installed as secondary support performed very effectively.

By Kermit G. Davis, Sean Gallagher, William S. Marras, Kimberly Kovacs

This study evaluated spinal loads associated with lifting and hanging heavy mining cable in a variety of postures. This electrical cable can weigh up to 10 kg per metre and is often lifted in restricted spaces in underground coal mines. Seven male subjects performed eight cable lifting and hanging tasks, while trunk kinematic data and trunk muscle electromyograms (EMGs) were obtained. The eight tasks were combinations of four postures (standing, stooping kneeling on one knee, or kneeling on both knees) and two levels of cable load (0 N or 100 N load added to the existing cable weight). An EMG-assisted model was used to calculate forces and moments acting on the lumbar spine. A two-way split-plot ANOVA showed that increased load (p<0.05) and changes in lifting posture (p<0.05) independently affected trunk muscle recruitment and spinal loading. The increase in cable load resulted in higher EMG activity of all trunk muscles and increased axial and lateral bending moments on the spine (p < 0.05). Changes in posture caused more selective adjustments in muscle recruitment and affected the sagittal plane moment (p < 0.05). Despite the more selective nature of trunk EMG changes due to posture, the magnitude of changes in spinal loading was often quite dramatic. However, average compression values exceeded 3400 N for all cable lifting tasks.

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 appropriately considered in land use planning. Information from this study is intended to help 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. Mineral development activity in and under the Challis National Forest has been of great economic significance to Idaho and the United States. Since the 1960&apos;s, mines within the forest have produced mineral commodities worth more than $590 million A 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 evaluated 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 Clarence A. Wright

The Missouri-Kansas-Oklahoma lead and zinc district, better known as the Joplin district, includes the mines in southwest Missouri and in those parts of Kansas and Oklahoma that are directly adjacent. (See PI. I.) This report of investigations carried on by the Bureau of Mines gives the methods used in mining and milling and indicates in some detail the conditions that affect the efficiency of those methods; it does not attempt to discuss the geology of the district, except incidentally, as this has been described in numerous reports by several geologists. Some of the more important recent publications are those of the United States Geological Survey by Smith and Siebenthal, a Bain, b and also those of the Missouri State geological survey by Buckley and Buehler." Other reports are those by Schmidt and Leonard," and Winslow,e of the Missouri geological survey, by Haworth and Crane,! of the Kansas geological survey, and by Jenney.g Although the lead and zinc ores are closely associated, the proportion of zinc ore mined at present is far greater than in former years. For this reason and because the losses in milling zinc ores are proportionately greater than in milling those of lead, the zinc ores are here given most consideration. Only the mines and mills actually examined and tested are discussed in detail, statements of results being restricted to the mines in general, with no special reference to anyone mine. Several mill tests were made to determine in a general way the efficiency of the milling practice in this district and to discover at what stage of the process the losses were greatest. Making these mill tests proved difficult,for, because of the arrangement of the mills and the necessity of estimating the tonnage treated, systematic mill testing and sampling can be done at only a few plants. Many tables giving results of mill tests and screen tests have been omitted because they would serve only to emphasize the important points shown by other data given. The writer has tried to bring out the possibilities of making certain improvements that would effect a greater saving, and has endeavored to avoid the use of technical terms and phrases in order that all statements may be clear and easily understood.

Jan 1, 1918

By Charles T. Baroch

RESEARCH strengthened the position of cesium as the preferred material (commonly but erroneously called "fuel") for ionic propulsion engines. Its use as an element of the plasma thermocouple for generating electricity also seemed more likely. Domestic Production.-No domestic ore of cesium and rubidium was produced. San Antonio Chemicals, Inc., San Antonio, Tex., and Maywood Chemical Works, Maywood, N.J., continued to produce cesium and rubidium compounds including carbonate, chromate, hydroxide, nitrate, sulfate, and all four halides. Rocky Mountain Research, Inc., Denver, Colo., began producing various cesium and rubidium salts. American Potash & Chemical Corp., Los Angeles, Calif., offered cesium and rubidium for sale.

Jan 1, 1960

By K. E. Robinson

This study provides an initial indication that mill tailings produced in the Coeur d&apos;Alene Mining District of Idaho can be placed on floodplain areas in a technically acceptable manner without artificial liners and without seriously contaminating the surrounding area. Tests have shown that landfills on these unused areas can result in returning these areas to productive use. The engineering properties of mill tailings permit construction of stable embankments. Designed slope protection inhibits water erosion. Among the environmental considerations in using tailings for landfill construction are the acid and other contamination produced by tailings and wind erosion of exposed tailings surfaces. The initial results indicate that adverse impacts are not as severe as previously thought, and mitigative measures are feasible. Based on the preliminary data, and in accord with existing Federal and State waste management regulations, a conceptual design has been developed for 23 potential landfill sites in the District, which could reclaim 750 acres of floodplain. A cost analysis of landfill construction with mill tailings indicates that the method would be an economically viable means for increasing the valleywide tailings storage capacity, provided construction with slurried tailings is feasible. A Stage H study is proposed to evaluate slurried tailings as a foundation material, as opposed to hauled tailings used in this present study.

Jan 1, 1981

West Virginia ranks second in the nation in coal production, surpassed only by Wyoming, and usually accounts for 15 to 20percent of the nation&apos;s total annual production. Cod occurs in seams of minable thickness in all but nine of the state&apos;s 55 counties. There are two coal- producing regions, the northern field and the southern field. West Virginia coal is mined by both underground and surface methods. Underground mines in West Virginia account for a major portion of its coal production. Surface mines are generally contour operations and, especially in the southern field, are in steep slope areas, with slopes greater than 20 degrees. Many of the surface mines remove multiple seams. Recoverable reserves in West Virginia total in excess of 55 billion tons of bituminous coal. West Virginia&apos;s regulatory program was conditionally approved on January 19, 198 1. Its Abandoned Mine Land Program was approved February 23,198 1, with emergency authority granted on August 26,1988.

Jan 1, 1992