Search Documents

By Joseph M. Pugliese

The Bureau of Mines through its contract research program recently analyzed the mining and environmental requirements in the premining stage for copper mining in the northern highland of Wisconsin. The Critical-Path-Method (CPM) was used in this research. However, a step-by-step derivation of the CPM Diagram was beyond the scope of this effort. The Bureau of Mines objective now is to show, step by step, how the original hand-computed CPM Diagram was constructed. The streamlining (restructuring) of this diagram from the original effort is also summarized. The critical path time (longest time) through the original CPM Diagram was 25.12 yr, excluding public liaison effort. This diagram showed the involvement of the regulatory agency, mining applicant and public in the premining stage. Analysis of this diagram produced a streamlined version which reduced the critical path time by nearly 7 yr. The CPM construction methodology offered here may be applied to mine planning for any mining operation.

Jan 1, 1983

By Anderson Dana

THIS PAPER describing methods and costs of mining and preparing gravel and sand for market at the Port Jefferson plant of the Seaboard Sand and Gravel Corporation, is one of a series of articles on gravel and sand mining, prepared for and published by the U. S. Bureau of Mines, which is designed to disseminate technical information regarding the methods used. The cost tabulations represent operating expenditures only and not total costs, It is recognized that publication of total costs might in many instances cause embarrassment to individual producers, as well as to the industry as a whole. On the other hand, operating costs are essential to the technical [ ]

Jan 1, 1932

By Anthony E. Szczuka

Two facets of surface mining were studied: feasibility of using training simulators to increase productivity of haulage trucks, front-end loaders, and shovels; and improving the efficiency of dragline operations with a computer-aided analysis of dragline usage and the addition of an on-board operator display. Training costs per student were estimated based on current training practices. Training objectives were derived from task: analyses of haulage trucks, front-end loaders, and shovels. The cost effectiveness of training simulators was determined. A computer-aided analysis defined the critical performance parameters. An on-board operator's display is recommended to improve operator efficiency.

Jan 1, 1976

By G. W. Elger

This report describes pilot-plant studies and an economic evaluation of a process developed by the Federal Bureau of Mines, Albany Metallurgy Research Center, to produce synthetic rutile from a rock-type ilmenite concentrate. In this process, ilmenite blended with coke and lime is smelted in an electric arc furnace to separate most of the iron as salable pig iron and to form a titania-enriched slag of low iron content, which is treated with oxygen and titanium pyrophosphate. The titanium oxides are converted to crystalline rutile; the phosphate glass contains most of the associated impurities. The treated slag is ground and leached with sulfuric acid to liberate rutile crystals, which are concentrated by physical methods. In pilot testing conducted to obtain data for a cost estimation, a synthesized product containing about 88 wt-pct TiO2 and less than 2 pct FeO was extracted from a rock-type ilmenite concentrate containing about 45 wt-pct TiO2. The estimated fixed capital cost (on a mid-1975 basis) of a plant producing 500 tpd of synthetic rutile is $28,290,100. Based on 330 operating days per year, the estimated operating cost for this process is $351 per ton of synthetic rutile. The estimated selling price of synthetic rutile made from rock-type ilmenite is $344 per ton, based on a credit of $160 per ton of pig iron and a 20 pct interest rate of return on investment after taxes.

Jan 1, 1976

By B. W. Gandrud

In July 1948, the Bureau of Mines, United States Department of the Interior, in cooperation with the University of Alabama and mine operators, published Report of Investigations 4306, "A Combination Cleaning and Dewatering Process for Treating Fine 'Sizes of Coal, Preliminary Report In this report a new process, referred to as kerosene flotation; was described, and results of experimental work with the process Previous to the fall of 1947 were given, The contents of the report. were summarized on pages 19 and 20' as follows: In coal-preparation plants using wet methods of cleaning, the most difficult problem is the cleaning and dewatering of the "fines" from about 10-Mesh to 0. A combination proceed is now under investigation that shows promise of practically and feasibly solving this problem. The process is similar to froth flotation, but a generous quantity of kerosene is used as one of the reagents, and the feed is from approximately 10-mesh to 0 considerably coarser than the usual froth flotation feed. The kerosene and the coarseness of the reed result in a floated product that, under certain circumstances, can be dewatered satisfactorily by a simple process of mechanical squeezing, Squeezing is accomplished by means of an ordinary conveying' Auger-and trough assembly with a section of pipe easing at the outer end of the trough. The bottom of the trough and. casing is fitted with wedge-wire sections to permit escape of the water freed by the squeezing action of the auger. On account of the important role of the kerosene, the process has been referred to in this report as kerosene flotation. Up to now, the investigative work has been divided about evenly between the laboratory and commercial plants. Nearly all of the work has been done on sludges containing the solids from the underflow of dewatering screens. A few runs have been made on 10-mesh to 0: fines from raw coal, but in some of those runs the dewatering mechanism, failed to function.

Jan 1, 1950

Advances were made during 19b5 in many phases of a broad program designed to increase efficiency in the mining, preparation, and utilization of coal. Also recorded were achievements in activities devoted to mine health and safety, coal resources, and mine explosives. Featured in this report is a review of progress in environmental studies relating to coal mining and utilization. Environmental projects comprise a comprehensive program to facilitate mine reclamation and reduce air and water pollution associated with extraction and use of coal. Publications cited throughout this report present results of the coal program in greater detail. Organizations, institutions, and companies contributing to the program are listed in appendix A. Centers and laboratories conducting the coal research and related investigations appear in appendix B.

Jan 1, 1966

Advances were made during 19b5 in many phases of a broad program designed to increase efficiency in the mining, preparation, and utilization of coal. Also recorded were achievements in activities devoted to mine health and safety, coal resources, and mine explosives. Featured in this report is a review of progress in environmental studies relating to coal mining and utilization. Environmental projects comprise a comprehensive program to facilitate mine reclamation and reduce air and water pollution associated with extraction and use of coal. Publications cited throughout this report present results of the coal program in greater detail. Organizations, institutions, and companies contributing to the program are listed in appendix A. Centers and laboratories conducting the coal research and related investigations appear in appendix B.

Jan 1, 1966

By David A. Monaghan

This report describes the results of a 2-year investigation of extensible face ventilation techniques and systems for use at the working face in underground coal mines. The goal was to provide a safe and convenient method of maintaining the extensible system within 10 feet of the face, thereby ensuring good ventilation. A summary of approximately 20 extensible ventilation systems proposed or tried in the past is included for reference, together with a detailed description of the design, construction, and underground testing of a new extensible brattice panel and a new fiberglass duct system. The extensible brattice system utilized a special panel which could be pushed forward as the miner advanced. Brief testing in three mines revealed some conflict with the mining cycle and led to recommendations for two improved designs. The extensible duct system was designed for a Goodman borer and utilized a telescoping tube on the left side of the roof, so that it could be extended without interfering with the miner operator. For mine sections with right-hand return ventilation, a special flat tube section is used to cross over the entry. Underground testing showed substantial improvement in face ventilation without interfering with production.

Jan 1, 1976

By F. E. Block

The reaction between calcined dolomite and ferrosilicon has been studies with the aim of developing a continuous process for magnesium production. Small-scale tests were made in vacuum retorts similar to those used in the vacuum retort process as developed by Pidgeon (1)2/ and operated during the period of World War II in several Government-owned plants. Factors investigated with respect to the silicon efficiency were the reaction temperature, reaction time, amount of excess dolomite in the charge, and effect of adding sodium silicate to the charge to serve as a binder. Additional laboratory tests were made to study the reaction at elevated temperature but at atmospheric pressure. Silicon efficiencies exceeding 80 percent were found to result when operating in the temperature range from 1,750° to 1,800° C. for periods of 20 to 30 minutes.

Jan 1, 1956

Chromium, a critical mineral for which the United States is largely dependent on foreign sources, is the subject of a new report just issued by the Interior Department's Bureau of Mines. The report is the first in a new series called "Mineral Commodity Profiles" (MCP's). Designed to give an updated review of important events affecting critical minerals, it also presents a comprehensive description of industry structure, supply-demand relationships, technology, and outlook for the future.

Jan 1, 1977

By Secretary of the Interior

"INTRODUCTION The Bureau of Mines Synthetic Liquid Fuels Program again forged ahead during 1952, and important technical advances led the way to improved methods of converting coal and oil shale into liquid fuels. Marking the eighth year of activities under this program, the pact 32 months brought a new domestic industry nearer realization.The increasing demand for gasoline and oil and the rising cost of finding new petroleum, coupled with America's growing dependence on imports and the unsettled international situation, have continued to emphasize the importance of the Bureau's Synthetic Liquid Fuels Program. Oil, the indispensable material of wartime, likewise has critical importance in peacetime, touching as it does the life of every individual. Supplementing petroleum with synthetic liquid fuels will not only conserve this Nation's petroleum reserves but also will bring into greater use its tremendous reserves of coal, as well as the vast deposits of oil shale for which no other practical use has yet been found.The Bureau of Mines Synthetic Liquid Fuels Program is one of the most important and far-reaching of the Government's research projects. Through development of commercial synthetic liquid fuels, the United States can obtain oil products from its great inland reserves of coal and oil shale to supplement petroleum in any quantity that may be necessary, consistent with economic and other requirements, such as national defense. The use of raw materials from such deposits would be of highest importance in wartime, when shipping lanes are menaced by the enemy. The Synthetic Liquid Fuels Program of the Bureau of Mines and research efforts of industry have advanced. American technology to the point where it is now possible to begin the design and construction of prototype plants. Certainly, significant improvements will be made as the program continues, but this prospect in no way alters the fact that the start of prototype plants should be encouraged. These plants, as the first step in the development of a synthetic fuels industry, would serve a threefold purpose:"

Jan 1, 1953

By Sam S. Taylor

In most oil fields, natural gas is the major source of energy causing flow of oil to the well. The amount of gas produced With the oil generally exceeds actual energy requirements, so that in time the gas reserve of the field becomes seriously depleted and the oil production nest be stimulated by some auxiliary means. One of these is to repressure the oil formation with natural gas; or, where a gas supply is not available, often air is used. Although air is a cheap and convenient repressuring medium, its use sometimes is attended with several disadvantages. First, the return air-gas mixture decreases rapidly in fuel value, often until it can be used no longer as a source of power. At the same time, explosive mixtures may result if recycling is used, causing hazards to life and equipment. Second, some fields experience considerable trouble with the formation of emulsions which become increasingly difficult to treat. Although there is no definite proof that air repressuring always causes these emulsions, many operators are convinced that this is the case.

Jan 1, 1934

By Karl R. Becker

A variety of commercial detonators (fuse type and electric instantaneous and delay types) were subjected to impact and thermal stimuli to determine initiation stimulus levels and the dominant parameters in resistance to initiation. In the impact trials the detonators were impacted along their length to find the most sensitive region; threshold initiation limits obtained for these regions ranged from 3.47 to 20.82 joules (2.6 to 15.4 ft-lb). The friction sensitivity of the explosive component was an important parameter in determining sensitivity; various construction features of nonexplosive components played a role as well. In the thermal sensitivity trials, the detonators were heated from ambient to 100° C at an average rate of about 1.0° C/min, and thereafter at 0.5° C/min until they exploded; the explosion temperatures observed ranged from 121° to 188° C. These temperatures correlated quite well with the reaction temperatures of certain characteristic explosive components used by different manufacturers. The data also indicated an effect of confinement on explosion temperatures of detonators.

Jan 1, 1975

By John Paul Gries

This Bureau of Mines report reviews the mineral industry of the Black Hills area, including Butte, Custer, Fall River, Lawrence, Meade, and Penning- ton Counties, S. Dak.; and Crook, Niobrara, and Weston Counties, Wyo. It includes discussion of geological occurrence, processing, and potential of 27 commodities that have been produced from the nine-county area. The value of mineral production exceeds $70 million annually. Gold and petroleum account for two-thirds of the total, followed by clays, cement, sand and gravel, and rock. The combined mineral industries annually consume 268 million kilowatts of electrical energy, 933 million Mcf of gas, and 2 million barrels of fuel oil. Water consumption is about 10,000 gallons per minute. About 2,700 persons are employed on a year-round or significant part-time basis.

Jan 1, 1974

By E. H. Burroughs

This bulletin is the fourth in the series of petroleum bibliographies being published by the Bureau of Mines, the three preceding, Bulletins 149, 165, and 180, being compilations for the years 1915, 1916, and 1917, respectively. In this bulletin the same general plan has been followed in arranging the references, but a few changes and additions have been made in the classification, the more important changes being in the classes "Geology and Origin" and "Refining and Refineries." Dl1'ring the year German periodicals were not available, and, as in the bibliography for 1917, references to articles in foreign journals that were not available have been taken' from other sources and credit given to those sources.

Jan 1, 1921

By James Westfield

Following is a resume of activities of the Division of Coal-Mine Inspection that have had a favorable effect on health, safety, and the reduction o1 injuries at coal mines: 1. The Federal Mine Safety Code for Bituminous Coal and Lignite Mines of the United States was issued originally by the Director of the Bureau of Mines July 24, 1946, after consultation with management and labor representatives of the coal-mining industry. The code has been used by Federal coal-mine inspectors while inspecting bituminous coal and lignite mines as a basis for determining the existence of unhealthful and unsafe conditions and practices in these mines. A revised code was issued by the Secretary of the Interior October 8, 1953, after further consultations with representatives of management and mine workers and was incorporated by reference in the 1952 and subsequent bituminous coal wage agreements. The agreement of May 29, 1946, between the Secretary of the Interior, acting as Coal Mines Administrator under authority of Executive Order 9728, and the United Mine Workers of America, covering bitumi¬nous coal and lignite mines in Government possession, charged Federal coal-mine inspectors with the responsibility of making periodic investigations of the mines and reporting to the Coal Mines Administrator any violations of the Federal Mine Safety Code. Federal coal-mine inspectors also had temporary authority to close mines found to be imminently dangerous, but such authority (under Executive Order 9728) was removed June 30, 1947, when Government control of the mines was terminated.

Jan 1, 1959

By John R. Duda

The Bureau of Mines is developing estimates of capital investment, operating cost, and selling price for underground mines producing bituminous coal by various mining methods. This study estimates the required capital investment, operating costs, and selling prices for two hypothetical mines designed to produce 1.3 and 2.6 million tons per year (MM tpy)3 by using a longwall system in conjunction with a continuous-mining system. The coal properties being mined are assumed capable of sustaining a 20-year production period. Wages and union welfare payments used in this study are those in effect as of December 6, 1975, as set forth under the National Bituminous Coal Wage Agreement of 1974. Costs of materials and equipment are based on January 1976 indexes. Initial capital investment is $34.6 million for the 1.3-MM-tpy mine and $63.5 million for the 2.6-MM-tpy mine. Capital requirements, including deferred investments, were estimated to be $50.8 and $92.2 million, respectively. These figures translate into total capital investments of $38.51 and $34.91 per ton of annual production. Assuming a desired 15-percent discounted cash flow (DCF) rate of return, with Federal income taxes at 50 percent, the required selling prices would be $13.41 and $12.27 per ton for the 1.3- and 2.6 -MM- tpy mines.

Jan 1, 1976

By Albert L. Toenges

The Grundy coal field is in process of development, and this circular was written to describe the mining methods and practices in use in the mines now being worked in this field. In lieu of man-hour labor data for individual mines a consolidated sheet of mine costs, which includes expenses for labor, material, and power, is given for all mines. The costs are for a working day only, based on average daily production. Because the demand for coal is seasonal, the costs for idle days, which vary at each mine, have not been estimated. Approximate reserves of coal seams have been estimated from data and maps taken from Bulletin XVIII of the Virginia Geological Survey4/.

Jan 1, 1936

By Edward P. Barrett

SPONGE IRON has been defined as the metallic product formed by the reduction (removal of combined oxygen) of iron ore or other iron oxides at temperatures below the fusion point of iron. This product probably derived the name "sponge iron" from its porous nature. When the reduction proceeds at slightly higher temperatures and the particles of metal weld together or finally even melt to yield pellets or balls that lack the porosity and low-density characteristic of sponge iron, the product might more correctly be called "direct iron."

Jan 1, 1954

By Ronald P. Hollenbeck

This study reviews and discusses the fluorspar industry in the Eastern United States, with emphasis on factors controlling the industry such as production, consumption, uses, and transportation. The greatest potential for increased consumption of fluorspar in the immediate future was found to be in the manufacture of fluorine chemicals and steel. Important factors affecting the future domestic industry include imports and the maintenance of adequate domestic fluorspar reserves. Exploration, commercial deposits, mining and milling, reserves, and new developments in the industry are covered.

Jan 1, 1967