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By L. Nahai

An important objective of the Australian Government's policies on resources development is to encourage further processing of raw materials domestically, to the extent that this is economically feasible and consistent with sound industrial development. This Bureau of Mines report examines the extent to which Australia is able to pursue this policy in terms of its own competitive advantages and the implications of such a policy for the United States. Such factors as the impact of other competing producers and their advantages, expected world demand, and infrastructural problem--which may limit pursuit of this policy to the fullest extent--are discussed. After a broad review of the re-source, economic, social, and environmental factors, the perspective for increased processing is examined for a number of mineral commodities.

Jan 1, 1982

Objective To reduce dust generated from soiled floors within enclosed operator cabs. Background Enclosed operator cabs are widely used on mobile excavation equipment in the mining and construction industries. They protect the operator from bad weather, noise, and airborne dusts. The inside cab environment usually must be kept at very low dust concentrations because of quartz dust generated from the excavation of silica-bearing rock. For cabs to be effective in controlling airborne respirable dust, they must have an efficient air filtration system, while providing a positive pressurization of the cab interior. Ideally, the recirculated and exterior makeup air filtration should provide at least 99% capture efficiency for dust particles as small as 0.3-µmaerodynamic diameters. Many of these enclosed cabs use heating units mounted or directed along the floor (see figure 1), which can cause dust entrainment problems. Prior studies by the National Institute for Occupational Safety and Health (NIOSH) of enclosed cabs have shown that these floor heaters can generate notable amounts of dust within the cab enclosure (see Technology News 486). Multiple-shift dust levels measured inside a drill cab increased on average from0.04 mg/m3 during the summer months to 0.68 mg/m3 during the winter months. Additional dust level measurements, made with optical particle counters during a nondrilling time period, verified that dust levels inside the cab increased from 0.03 to 0.26 mg/m3when the floor heater/fan was turned on. Dust levels within the cab also became greater than the ambient air dust levels outside of the cab when the floor heater was turned on during the nondrilling time period. This shows that the floor heater was a notable dust source problem. Cab floors are commonly soiled from operators tracking dirt inside the cab upon entering from the mine or construction site. Interior cab dust levels can be increased by (1) airflow disturbance of the soiled floor or (2) operator disturbance of the soiled floor. Approach During prior NIOSH surveys of surface coal mine drills, several drills with very low cab dust levels (#0.1 mg/m3) were observed to have floor sweeping compound spread out over the cab floor during the working shift. This initial observation led to a more controlled A-B study of the effect of the sweeping compound on the interior cab dust levels. This study involved dust sampling with and without sweeping compound inside the cabs of a bulldozer and two drills. Sweeping compounds commonly use sawdust or cellulose as the main bulk material, with oil or wax added for dust adhesion purposes. Sand is sometimes added to increase bulk density. Sweeping compounds with sand are commonly used to sweep up concrete floors. Those without sand (usually referred to as "gritless") are used to sweep up smooth finished floors. Most of the oils and waxes used for the adhesive ingredient are petroleum-base and can have an irritating odor. People sensitized to petroleum distillates could have allergic reactions to these sweeping compounds. A few companies offer non petroleum-base sweeping compounds, using either a natural oil or chemical additive for dust adhesion. During this study, it was decided that only the gritless sweeping compound (without sand) would be used, eliminating the addition of another potential silica source inside the cab. Since the sweeping compound would be applied on the enclosed cab floor for the duration of the shift, it was decided to use a canola oil-base sweeping compound to eliminate irritating odor from the petroleum-base sweeping compounds. The natural canola oil-base sweeping compound had a slight woody scent. The three pieces of equipment used in this study had notably different cab layouts. The bulldozer had a small cab with vents discharging air-conditioned or heated air from adjustable louvers at operator waist level and floor level. The bulldozer also had a cloth fabric seat and a carpeted floor. Drill A had a large cab with the heat directed from adjustable louvers at operator knee level and the air-conditioned air directed from cabin ceiling louvers. This drill had a vinyl fabric seat and a steel plate floor. Drill B had a small cabin with the heat directed across the floor (see figure 1) and the air-conditioned air directed down from the ceiling. It had a vinyl fabric seat and a worn rubber mat on a steel floor.

May 1, 2001

By Thomas A. Milne

As part of the broad program to improve the safety of underground coal mines, the Pittsburgh Mining and Safety Research Center sponsored several detailed studies on the inhibition of coal dust-air explosions. The present study was one of these. The goal of the research was to advance the development of improved coal-dust explosion inhibiting agents by determining, on a laboratory scale, the basic chemical processes involved in the inhibition of coal-dust flames by dry-powder agents. B. Our Approach Neither the basic molecular processes involved in coal combustion, nor the molecular mode of action of dry-powder agents, are known with certainty. Our approach, therefore, involved the direct determination, by sampling techniques, of species behavior in small, aerodynamically simple flames. To further aid in separating behavior of coal and dry-powder inhibitors, the latter were studied in CH4-air flames.

Jan 1, 1976

By Mark S. Sanders

This report presents recommended visibility requirements for continuous miner, shuttle car and scoop operations and details the methodology used to generate them. A task analytic approach was used to define information requirements and visual features which served as sources of information. Information requirements were prioritized and the location of visual features determined. From this analysis, visual attention locations, containing one or more important visual features, were identified. A total of 71 locations-were identified for continuous miners, 54 for shuttle-cars and 54 for scoops. A procedure was developed for assessing whether operators in existing machines could be expected to see the visual attention locations. The procedure makes use of a Human Eye Reference Measurement Instrument (HERMI) designed for this project and an outside-in photographic procedure for documenting compliance with the recommendations. A sample of continuous miners, shuttle cars, and scoops were used to test the procedure. Results are presented in the report.

Jan 1, 1981

By John E. Trombly

System objectives and design criteria for an in-mine visual personnel paging system are discussed. Display technologies are evaluated and tradeoffs leading to display selection are described. The prototype dispatcher's console, battery/receiver box and visual display assemblies are functionally described. The report includes circuit descriptions, schematics, parts lists and equipment cabinet drawings for the three assemblies. The report concludes with an estimate of the manufacturing cost for each assembly.

Jan 1, 1975

By James A. Brierley

Wastewater from uranium mines in the Ambrosia Lake district near. Grants, New Mexico, U.S.A., contains uranium, selenium, radium, and molybdenum. The Kerr-McGee Corporation has a novel treatment process for waters from two mines, sections 35 and 36, to reduce the concentrations of the trace contaminants. Particulates are settled by ponding, and the waters are passed through an ion exchange resin to remove uranium; barium chloride is added to precipitate sulfate and radium from the mine waters. The mine waters are subsequently passed through three consecutive algae ponds prior to discharge. Water, sediment and biological samples were collected over a 4-year period and analyzed to assess the role of biological agents in removal of inorganic trace contaminants from the mine waters.

Jan 1, 1981

By Joseph J. Wallace, William H. Tavenner, D. A. Reynolds, John M. Provost, James J. Dowd, R. F. Abemethy

"CONCLUSIONSThe investigation shows that there are 5 coal beds of major importance in Wyoming County from the standpoint of present production - Pocahontas No. 3, No. 2 Gas, Sewell, Beckley, and Eagle - and 5 beds of minor importance - Pocahontas No. 6, Cedar Grove, Winifrede, Douglas, and Chilton. The Pocahontas No. 3 bed contains the largest remaining known reserves.Known measured and indicated reserves in all beds, based on a minimum thick¬ness of 14 inches and on 1,800 tons per acre-foot of coal in place, are estimated at 2,665 million short tons as of January 1, 1951. Of this total, 2,121 million short 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 make 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.Recoverable reserves of coal have been estimated in beds 28 inches and more thick. This thickness is about the minimum now being mined by hand loading onto conveyors in the Appalachian region. The weighted average recovery for all beds in Wyoming County, as determined by this investigation, is 55.0 percent. This percent¬age is based on the total thickness of coal (less partings 3/8 inch or more thick) in the bed rather than on the thickness of the coal mined. The known recoverable reserves are estimated to be 1,167 million tons as of January 1, 1951.4. Since most of the Wyoming coals are medium- and low-volatile bituminous in rank and expand during carbonization in modern ovens, they are blended with high-volatile contracting coals."

Apr 1, 1953

By L. G. Marshall

This report presents a cross section of the sand and gravel operations in the Minneapolis-St. Paul area. The study covers individual operations, economic problems peculiar to the industry, glacial geology of the area and its effect upon the grades and types of products, and past, present, and future trends of the expanding population and its effect upon the industry.

Jan 1, 1963

By L. G. Marshall

This report presents a cross section of the sand and gravel operations in the Minneapolis-St. Paul area. The study covers individual operations, economic problems peculiar to the industry, glacial geology of the area and its effect upon the grades and types of products, and past, present, and future trends of the expanding population and its effect upon the industry.

Jan 1, 1963

By V. F. Parry, W. S. Landers, John B. Goodman

"INTRODUCTION The object of this investigation was to demonstrate a satisfactory method of storing slack subbituminous coal in open pits in a manner,that would minimize the cause of the physical deterioration and would have a practical application.The storage of coal by industrial plants is to their advantage, since an adequate operating supplying of fuel is available at all times as insurance against transportation delays, shortages, and strikes. Furthermore, it is possible to participate in low seasonal freight rates and mine costs by permitting the railroads to utilize idle equipment and by taking advantage of the off-peak production at the mines. For a number of years, one of the larger beet-sugar companies operating in the Rocky Mountain region has taken advantage of the lower prices and seasonal production of subbituminous slack coal during the summer months and purchased a large proportion of its requirements for the annual winter campaign. This company, operating sugar-refining plants in the 1943 campaign, used 256,613 tons of subbituminous coal. Of this quantity, 166,636 tons was purchased during the off-peak season and stored for use during the winter. It is the practice of this concern to place coal purchased through the months of January to October in underwater storage for use in the beet-sugar campaign, which lasts from October to as late as, January. The beet-sugar refining ""campaign"" period starts immediately after the beginning of the beet harvest and lasts 60 to 70 days."

Aug 1, 1946

By M. Mahan, D. D. Blue, O. C. Garst, F. Fraas, L. Fink

"Early in World War II it became apparent that the known bauxite re- serves might not be adequate to supply the demands of the American aluminum-producing industry, as the transportation of bauxite from abroad to this country might easily be interfered with by hostile action. Consequently, the Bureau of Mines set up an intensive, well-integrated program for the production of cell-grade alumina from low-grade domestic ores. This pro-gram of investigation covered the production of alumina from clay, alumite, red mud, and other low- and marginal-grade ores. In line with the Bureau's usual policy of conservation of natural resources, it was decided that the investigation should be extended to cover the production of alumina and other valuable byproducts from aluminum dross.Statistical information showed that during the year 1943-44, an average of 2,900 tons of aluminum dross was generated monthly. This dross, after partial removal of free metal, had an average metallic aluminum content of approximately 9 percent. Some of this dross was produced by the melting of alloyed aluminum; but a large proportion 1,700 out of 2,900 tons - was generated by two producers of primary aluminum, and the dross did not contain an great proportion of alloying metals. Compared with dross from other sources, this 60 percent of the country's capacity can be assumed to have relatively uniform composition. Moreovcr, the problem of collection and distribution can be minimized because of the relatively small number of plants included in the organization of these two producers of virgin metal.Except for large pieces of metallic aluminum that easily can be mechanically separated for remelting, this dross has been discarded and scrapped. Inasmuch as chemical analyses show that the alumina content of dross is far higher-than ordinary ores - 111 percent alumina equivalent in dross compared to 57 percent alumina in bauxite - aluminum dross is a far richer source of aluminum than any known naturally occurring ores. The discard, of this waste material during the war and reconversion periods would be unsound economically. The work reported herein describes tests at the College Park Station of the Bureau of Mines on the recovery of metal, alumina, ammonia, methane, and abrasive-grade corundum from dross."

May 1, 1946

By Joseph Daniels

[Adequate supplies of suitable coal and coke are prime requisites in many industries, particularly those dealing with the utilization of mineral resources, recently interest has been focused on the possibilities of using electricity produced at Bonneville and Grand Coulee, Wash., in many electrochemical and electrometallurgical processes, in which core or some form of carbon is necessary in addition, discussion has been revived on the possibility of making iron and steel by the conventional methods employed in blast and open-hearth furnaces. The subject also is important at this time because of its relationship to industrial preparedness for national defense. A supply of coke from local sources on the Pacific coast is necessary in any program of production for strategic sufficiency of certain materials. An anal trio involving tae establishment of such industries should include detailed data on available supplies of coal, the quality and properties of the coke produced, and the technologic and economic factors involved in manufacture of echo and disposal of byproducts.]

Jan 1, 1941

By A. Renton Amell

The rate of dissolution of U02 was measured in acid solutions similar to those used for in situ leaching, with S04 of 10-1.82 to 10-4 M, Fe(III) of 10-2 to 10-4 M and pH's of 1.1 to 2.3. The dependence of dissolution rate on pH was small and inconsistent, probably reflecting the combined effects of a very weakly polar oxidizing complex, probably FeSO4+, and a nearly neutral U02 surface. Differences in the state of the U02 surface may explain this variability as well as contrasts between these results and results reported in other work. Changing either S04 or Fe(III) concentrations significantly affects dissolution rates. Increasing low sulfate concentrations in solutions containing 10 2 M Fe(III) at pH 2 results in formation of FeSO4+. In such solutions, rates increased with (S04)/(Fe(III)) up to 1:30, thereby indicating that the oxidation of U02 by FeSO4 is more rapid than by Fe3+. However, the dissolution rate decreased at higher (SO4)/ (Fe(III)), due either to sorption of SO42- on the UO2 surface or to formation of other less reactive sulfate complexes such as Fe(S04)2 or FeHSO4+ However, Fe(III) concentration is the dominant factor in determining solution rates. The rate was directly proportional to ferric iron concentration, indicating that the rate-determining step of the dissolution reaction is a single-electron oxidation by a ferric complex. Dissolution rates were lower in solutions of 0.1 and 1.0% H202 (0.029 and 0.29 M) than at similar concentrations of ferric iron because of formation of an insoluble surface coating of uranium peroxide, UO4?4H20. This phase may limit the value of hydrogen peroxide as an oxidant in lixiviants, not only by its very low solubility, but perhaps also by filling pores and reducing permeability in the ore body.

Jan 1, 1978

By D. D. Walker

Scheelite, the most abundant tungsten mineral in the Philipsburg region of Montana, is found in replacement deposits and along fissures and cracks in limestone at various distances from contacts with acidic igneous rocks. It also occurs at the limestone-igneous contacts, but typical garnet tactites are developed in only a few places in the region. The most favorable host rocks for scheelite mineralization are the Jefferson, Hasmark, and Madison limestones. Scheelite is exposed in float, outcrops, and surface and mine workings along a 2-mile-wide belt extending southwest from Lost Creek beyond Silver Lake, a distance of 15 miles or more. (See fig. 1.) Some scheelite is found in veins formerly mined for silver. Powellite and molybdenite occasionally are present with the scheelite. Hubnerite occurs in quartz veins in the Black Pine area 10 miles northwest of Philipsburg. These quartz veins occur in the quartzites of the Precambrian Spokane formation. Tungsten production in the region has come almost exclusively from scheelite deposits, both lode and placer. During a 6-year period beginning in 1943 a total of 142.0 tons of 63-percent W03 concentrate was produced by H & H Mines Co. In the early 1950's, the Trigger mine produced 4,000 tons of 1-percent W03 ore and the Tip Top 650 tons of 2.0-percent W03 ore and 2,906 tons of 2.2-percent ore. There has been sporadic production from some of the smaller properties in the area.

Jan 1, 1960

By George S. Rice

In 1911 the Director of the United States Bureau of Mines instructed the chief mining engineer of the bureau , during an investigation of coal-mine safety conditions in Europe, to ask the directors of the various mine-experiment stations whether they would favor a European conference . The majority of the officials in immediate charge of experiment stations favored the plan , and Victor Watteyne, inspector general of Belgium, suggested that the United States call such a conference to be held immediately after the Eighth International Congress of Applied Chemistry, which was to assemble in New York on September 3, 1912 . Accordingly, invitations were issued by the United States Government to those countries having mine-experiment stations , namely, Austria-Hungary, Belgium, France, Germany , and Great Britain, and to those that contemplated the establishment of such stations , Canada and Mexico . All but Great Britain and Canada accepted ; Mexico designated a representative , who later found it impossible to come. The Government of Great Britain in declining, expressed regret at its inability to accept ; an informal statement was made that the opening of the experimental gallery at Eskmeals , England , occupied the attention of the officials in charge . Delegates were appointed by their respective Governments as follows: Austria-Hungary, Julian Czaplinski , royal mining engineer. Belgium, Victor Watteyne , inspector general of mines . France, J. Taffanel, director of the Lievin experiment station . Germany, Carl Beyling, bergassessor, director of Dortmund experiment station. United States , Charles E. Munroe, consulting explosives expert and George S. Rice, chief mining engineer of the Bureau of Mines . Subsequently Mr. William O'Connor , a mining engineer and mine operator of Wales , who opportunely appeared at the Pittsburgh station with letters of introduction from the South Wales Institute of Engineers and from prominent mining officials of Great Britain , was unanimously invited to take part in the meeting as an unofficial representative of Great Britain . Messrs . Beyling, Taffanel , and Watteyne were met in New York on September 3, by George S. Rice, who accompanied them to Washington, where they were welcomed by Director J. A. Holmes , of the Bureau of Mines , and where , with the delegates to the Eighth International Congress of Applied Chemistry , they were presented to President Taft . Mr. Taffanel was unfortunately called back to France just before the scheduled time of the conference on account of a mine disaster ; the other delegates , including Mr. Czaplinski , convened at Pittsburgh on the morning of September 14. Mr. Rice, representing the Director of the Bureau of Mines , acted as temporary chairman , and called the meeting to order.

Jan 1, 1914

The Bureau of Mines, through its Minerals Availability Program (MAP), investigates the mineral supply potential of the United States and market economy countries (MEC's) for a number of minerals considered essential to the U.S. industrial base. Major activities include identification of important mines and mineral deposits, estimation of their mineral resources and production costs, and availability and sensitivity analyses. Products include data print-outs of geological and engineering information, discounted- cash-flow rate of return (DCFROR) analyses of individual mining operations, commodity availability appraisals, and analytic services to Government agencies. These products are used in assessing the mineral supply position of the United States: in setting priorities for research aimed at reducing production costs and minimizing adverse environ- mental impacts and regulatory compliance costs of mining and mineral processing operations; and in formulating and evaluating Government policies that affect minerals. Bureau MAP data and analyses have been provided to the executive and legislative branches to aid in consideration of trade, tax, and stockpile policy issues. A study of the economic potential of selected seabed mineral resources supports the regulatory responsibilities of the Department of the Interior in the U.S. Exclusive Economic Zone. Analytic studies of mineral project viability, industry competitiveness, and import dependencies were also undertaken for, or in cooperation with, U.S. and foreign government agencies, industry and trade organizations, and international lending institutions.

Jan 1, 1987

By Oliver Bowles

This paper is the third of a series of reports on asbestos prepared by the Bureau of Mines. The reports already issued contain general information, including descriptions of deposits throughout the world.3/ The present paper deals chiefly with milling and marketing. Many grades of asbestos are marketed, and an important phase of milling is the grading of fiber; these subjects therefore are related so intimately that contiguity in their treatment is fully justified. Although the Bureau of Mines is interested primarily in the mining and preparation of raw materials, the fabrication of asbestos products has attained such importance in the United States that brief reference to processes of manufacture is included. CLASSIFICATION OF FIBER Canadian asbestos fibers are divided into three main groups - crudes, mill fibers, and shorts. The term "crude" is applied to fiber of spinning grade measuring three eighths inch or longer, that is. hand-cobbed and not passed through a mill. Mill fibers are obtained by crushing and beating the fiber-bearing" rock, until the, asbestos is freed and, then removing the fiber from the rock by screening or air separation. Shorts are the lowest grades of mill products.

Jan 1, 1935

By S. L. Windes

"INTRODUCTION For a number of years, the Bureau of Mines conducted tests on various types of structures to ascertain the effect of seismic vibrations emanating from quarry blasting in an effort to determine an index of damage. Associat¬ed with these tests, occasional records were made of the characteristics of the air blast or concussion from the explosions. Although the importance of the air-blast problem was recognized, the equipment was not designed for airblast measurements, nor was the early research program concerned with the problem. After the ground-vibration tests had been completed, attention was turned to study of the air blast and its effect. The program was modified, however, in certain aspects by the imminence of war and the final entry of the United States into the conflict. These modifications were made to supply information pertaining to military and civilian defense problems.Detailed discussion of these problems is beyond the scope of this report, which attempts to present preliminary results of factual and fundamental character. However, it may be noted that airblast data are urgently needed for intelligent design of both Government and non-Government buildings, which must withstand the air blast from bombs and afford maximum protection for the occupants. The safety of vital equipment above and below ground necessitates consideration of damage from air blast. Protection against use of dynamite by saboteurs, moreover, hinges largely on the effect of air blast. Identification of a planned ""accident"" involving dynamite often entails knowledge of the characteristics and power of the airblast.The peacetime problem of damage from air blast resulting from quarry and mining blasting activities is of course exaggerated by the wartime requirements of increased production accelerated operation, and enlarged development."

Jun 1, 1943

By David A. Hall

We present an analysis of the propagation in a uniform tunnel of semi -circular cross section that contains two axial conductors. In particular, we show that, even if one of these conductors has high ohmic loss, one of the two propagating modes has relatively low attenuation. This corresponds to the situation where an unloaded dedicated wire is used to improve radio frequency communication in a mine tunnel that contains a heavily loaded trolley wire.

Jan 1, 1978

By Donald F. MacDonald

This report aims to discuss, from the viewpoint of the mining geologist, the bearing of topographic and geologic conditions on cer- tain problems that arose in the construction of the Panama Canal. T+ is published by the Bureau of Mines as a contribution to engineer- ing liters ure because it presents information that shows how geology and topography must be considered by the mining engineer in plan- ning excavations and in removing loose material and solid rock in the safest and most efficient manner. The printing of this bulletin has been approved by the governor of the Panama Canal, as it was impracticable for the Panama Canal to give this information to the general public in any of its publications. The "sword cut" of Goethals and his men did not sever the Isth- mian barrier; it merely clove the hills to a depth of 40 feet above sea level. This cut and the great areas of low valleys at both ends of it have been covered with fresh water to the 85-foot level. This high-level lake held by dams at either end, the 85-foot locks, by which ships enter it, and the dredged approaches from the two oceans constitute the Panama Canal. In the preparation of accurate estimates concerning the cost of large excavations information regarding the geologic conditions, as obtained by a study of natural features, is necessary. Drill holes and test pits will furnish supplementary geologic information, but without a gen- eral knowledge of the geologic conditions it will not be possible for the constructing engineer to answer such questions as the following: (1) What rock units will be encountered in the excavation and in what proportion? (2) What will be the cost of drilling each for blasting (3) How far apart and how deep must the drill holes be to efficiently break the rock of each to the proper size-not too fine nor yet too coarse? In this connection jointing, fissuring, bedding, toughness, and other physical characteristics must be considered (4) How steep will the slopes of the excavation stand, and to what extent will they wash and trench on exposure to the atmosphere? (5) What proportion of the material to be excavated is of such physical character that it may be utilized in any other part of the project, such as in concrete construction, road making, wharves, breakwaters, riprap work, etc.

Jan 1, 1915