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By Larman J. Heath

Wellbore enlargement was tested using hydrazine hydrate in a gas-storage well in Ohio to increase the well productivity. The wellbore was to be enlarged by chemical disaggregation of the sandstone adjacent to the wellbore. Productivity immediately declined 49.1 percent and gradually declined to zero in 7 months. A down-hole camera survey showed a white-to-gray precipitate covering the entire wellbore surface. The precipitate was chemically analyzed and identified as mostly carbazic acid, a hydrazine derivative of carbonic acid. Formation of this precipitate was not anticipated; this viscous sub-stance caused the gradual loss in productivity of the well. The wellbore was not enlarged. Laboratory tests were run to determine what clay stabilization measures could be taken in sandstone cores to prevent clay swelling and particle migration caused by hydrazine hydrate. Normal clay stabilization methods did not prevent the virtually complete loss in permeability to hydrazine hydrate. Other laboratory tests using natural gas diluted with small amounts of carbon dioxide confirmed the ease with which carbazic acid could be formed in a hydrazine hydrate-saturated environment within and adjacent to the wellbore.

Jan 1, 1970

The 1963 Lignite Symposium was held on the University of North Dakota campus, Grand Forks, N. Dak., April 30-May 1, 1963, under the cosponsorship of the University of North Dakota and the Bureau of Mines. This symposium, the third in a series, had as a general objective the dissemination of information concerning advances in technology and utilization of solid fuels, with emphasis on lignitic coals. Approximately 150 representatives of industry, government, and educational institutions from 21 states and 3 Canadian provinces were present at the symposium. Those attending were welcomed by Marling J. Ankeny, Director of the Bureau of Mines, representing the Bureau, and Dean T. H. Clifford, Vice President of the University, representing the University.

Jan 1, 1964

The 1963 Lignite Symposium was held on the University of North Dakota campus, Grand Forks, N. Dak., April 30-May 1, 1963, under the cosponsorship of the University of North Dakota and the Bureau of Mines. This symposium, the third in a series, had as a general objective the dissemination of information concerning advances in technology and utilization of solid fuels, with emphasis on lignitic coals. Approximately 150 representatives of industry, government, and educational institutions from 21 states and 3 Canadian provinces were present at the symposium. Those attending were welcomed by Marling J. Ankeny, Director of the Bureau of Mines, representing the Bureau, and Dean T. H. Clifford, Vice President of the University, representing the University.

Jan 1, 1964

By G. H. Keith

Electrowon tungsten powders were investigated with respect to consolidation, fabrication, and mechanical properties. Sheet, 0.03 inch thick, was produced and its tensile strength measured between 250° and 1,935° C. The large particle size of electrowon tungsten effectively precluded sintering to a density sufficient to allow hot working to sheet or bar. The powders were consolidated by die pressing to 70-percent density, sheathing in molybdenum, and high-energy-rate extruding to either round or sheet bar of 100-percent density. The material was then rolled conventionally to sheet. The mechanical properties of the sheet prepared from the electrowon powders compared favorably with those reported in the literature for sheet prepared from commercially produced hydrogen-reduced powder.

Jan 1, 1970

By A. M. Ouchi

Existing empirical design tools have been developed from fair-to-good quality rock masses (RMR76 >50). This paper presents a focus of ground control research presently being conducted by the Rock Mechanics Group in the UBC Mining Department in incorporating weak rock masses (RMR76 <50) into existing empirical design relationships. An emphasis is being placed upon the updated span design curve/critical span graph originally developed at UBC. The original database has been augmented with over 450 weak rock data points from mines such as the Stillwater mine (Montana), the Eskay Creek Mine (BC) and several mines in the Carlin Trend and other parts of Nevada. The original database is comprised of spans supported with ?traditional? mechanical bolting. In weak rock environments however, this type of support has been found for the most part, ineffective. This paper presents the span and weak rock RMR76 relationship for four different support categories. This work attempts to provide rock mechanic tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment.

Jan 1, 2008

By Xintan Chang

MFIRE is a computer simulation program that performs normal ventilation network planning calculations and dynamic transient-state simulation of ventilation networks under a variety of conditions. The program is useful for the analysis of ventilation networks under the influence of natural ventilation, fans, fires, or any combination of these. MFIRE simulates a mine&apos;s ventilation system and its response to altered ventilation parameters such as the development of new mine workings or changes in ventilation control structures, external influences (varying outside temperatures), and internal influences (fires). Extensive output enables detailed, quantitative analysis of the effects that the alteration will cause to the ventilation system. The program was developed at Michigan Technological University (MTU), Houghton, MI, with support from the Bureau of Mines. A personal computer (PC) version of the program was completed under contract for the Bureau by MTU. The purpose of this report is to document the installation and use of the PC version of the program MFIRE.

Jan 1, 1990

By T. T. Tomimatsu

[This Bureau of Mines paper investigates explores, and analyses the Corporate structure dynamics and Rancid role to evaluate the economic health of the U.S. copper producers. It highlights the Corporate policy options and measures of corporate profitability and suggests that a competitive domestic copper industry will exist in the future. The study highlights the activities of 14 selected major copper-producing companies, including their subsidiaries o affiliates, that were responsible for more than 95 percent of the total U.S. production in each of the years since 1969. The selected firms are hot all primarily in the business of producing copper. Several of the large producers are classified by the financial institutions as integrated oil and gas enterprises.]

Jan 1, 1980

By R. R. Sayers

The hazards connected with work under abnormal air conditions are becoming of increasing importance from a financial as well as a physiological stand- point, due to the extension of compensation laws to include diseases caused by dusts, toxic gases, and abnormal temperatures and humidities. The United States, with the excention of California, North Dakota, Wiscon- sin, Massachusetts, and Connecticut, is the only English-speaking country to-day where silicosis is not compensated.3 Cases of permenent total disability or death due to silicosis mar aprear in common-law courts, particularly in the States that have not recognized silicosis as an occupational disease for which compensation should be provided. Such cases have recently been tried in one State, according to a magazine editorial, not providing scheduled commensation for employees affected by silicosis, with results favorable to the claimant. Clearly established cases definitely linked with occupation as the cause may be expected to be recognized as deserving by juries and courts, and awards will be made. In one Atlantic Coast State, according to this editorial, 108 claims for silicosis, including 21 deaths therefrom, are said to have been filed against two small plants engaged in finely pulverizing quartz sand.

Sep 1, 1932

This report is the first in a "final" series of publications on the Juneau Mining District (JMD). This volume summarizes the results of Bureau of Mines (Bureau) investigations in the JMD during the period 1984-1988. Volume 2 consists of a detailed description of Bureau investigations of mineral de-posits, prospects, and occurrences. Volume 3 is a report on industrial minerals within the district. This study has identified and examined more than 300 mines, prospects, and occurrences containing gold, silver, copper, zinc, lead, nickel, cobalt, tungsten, molybdenum, chromium, and PGM. More than 20 of these were discovered during this study. An additional 20 prospects not mentioned in the literature were rediscovered during the JMD study.

Jan 1, 2012

By H. D. Kline

This publication describes mining and milling methods and costs at the Madison mine of National Lead Co., St. Louis Smelting & Refining Division, in the Fredericktown district of southeast Missouri and is one of a series prepared by the Federal Bureau of Mines on methods, practices, and costs of mining and milling throughout the United States. The are bodies of the Madison mine are known for the complexity and diversity of their are minerals. Sulfides of copper, nickel, and cobalt occur in commercial quantities with lead sulfide, which is the most valuable metallic mineral in are bodies of the Bonne Terre formation in southeast Missouri. Several attempts were made by various operators to mine the complex ores and separate the sulfide minerals before 1927 when National Lead Co. became interested in the Fredericktown district. Operating then as the St. Louis Smelting & Refining Co., the company began mining and milling ores from the Madison mine in 1944 and has operated continuously since then. A recently built refinery produces copper, nickel, and cobalt metal from a concentrate containing iron sulphides and small quantities of copper, nickel, and cobalt sulphides.

Jan 1, 1961

By J. W. Thompson

RAILROAD GRANT-MDIERALS. Diatomaceous or infusorial earth when found in such quantity and quality as to render lands containing deposits valuable therefor are mineral lands within the meaning of the mining laws and must be excepted from grants to the Central Pacific Railway Company. Central Pacific Ry. Co., In re, 45 Land Decisions, 223, p. 226. RAILROAD GRANT-CLASSIFICATION, If any evidence of minerals is found upon lands within a railroad grant and the showing is sufficient in the opinion of prudent and qualified persons to warrant further exploration and expenditure, with reasonable prospects of success, then the land can not be classified as nonmineral and is not subject to the grant to a railroad company. But where there is no present indication of minerals nor any geological evidence upon which to base a mineral finding, land should not be classified as mineral, or held for further classification and reserved from the railroad's grant, upon the surmise that future prospects might disclose evidences of minerals. Southern PacUl.c Ry. Co., In re, 45 Land Decisions, 326, p. 329. INDEMNITY SELECTION BY RAILWAY COMPANY, Under section 3 of the act of July 2, 1864 (13 Stat., 365), and the joint resolution of May 31, 1870 (16 Stat., 378), the Northern Pacific Railway Company could take coal and iron land within its primary or grant limits. It could not base an indemnity selection upon the claim that certain land was coal or iron in ;;haracter, as such land was not lost to it as part of the grant. But the company was authorized to select other lands in lieu of those lost because of their mineral character, but the word "mineral" did not include iron or coal, and, accordingly, the railroad company was entitled to take coal lands under its indemnity selection.

Jan 1, 1917

By Donald B. Lindsay

This report presents the findings of an investigation into the characteristics of a number of techniques for cleaning ambient air with special emphasis on their applicability to the removal of the short-lived radioactive decay products of 222-radon, the so-called " radon daughters" that have been identified with the induction of lung cancer in underground uranium miners. The purpose of the study was to review the requirements for control of radon daughter concentrations in mine air, and to examine all techniques whose feasibility has been demonstrated in principle and which in our judgment would be capable of meeting those requirements. The study has included a review of all pertinent literature, both technical and proprietary, on the subject of the control of miner exposure to the radon daughters and in the area of potentially applicable air cleaning technology. Information about the nature of the problem and about the experience of the uranium mining industry in applying air cleaning methods to its solution was obtained by visiting mines where such methods are in use, and by written correspondence and telephone conversations with other industry sources. Information on performance characteristics and costs of applicable air cleaning methods and equipment was obtained from the experience of our own engineering staff and by visits, interviews, and correspondence with manufacturers of industrial air cleaning equipment.

Jan 1, 1978

By John E. Rourke, O&apos

This report documents the process of site selection, instrument installation, data acquisition, and preliminary data analysis followed to characterize the physical response of overlying strata to longwall mining. A system of surface, subsurface and mine level instrumentation was installed at the Allen Mine in Weston, Colorado where the overburden varied in thickness from 600 to 900 feet. Survey monuments, automatic-recording strain-meters, multi-point rod extensometers, inclinometer-extensometers, stressmeters and tape extensometer convergence stations were installed to monitor displacements and stress changes. A preliminary analysis of the data acquired up until project termination has shown the system to be operative and strata response to be similar to that reported for other subsidence monitoring case histories. Recommendations for continued monitoring of the instrumentation systems are presented.

Jan 1, 1982

By E. G. Baglin

As part of an effort to decrease U.S. dependence on imports of critical and strategic metals, the Bureau of Mines investigated three leaching methods for extracting the base metals and recovering platinum-group metals (PGM) from matte prepared from Stillwater Complex flotation concentrates. Because of a limited supply of natural material, synthetic matte of composition similar to matte prepared from natural concentrates was used to devise the extraction sequences. The validity of the sequences was verified with matte prepared from Stillwater concentrates. In two-stage matte leaching, first-stage H2S04 leaching extracted 99 pct of the nickel and iron from the matte but negligible amounts of copper and PGM. Second-stage oxidative leaching with Fe2(S04)3 or FeC13 solubilized more than 98 pct of the copper and no precious metals. Sequential leaching, in which acid and oxidizing lixiviants were added sequentially to the matte without an intervening filtration step, extracted 99 pct of the Fe, Ni, and Cu. A roasting-leaching technique, in which the residue from first-stage leaching was roasted between 360° and 500° C before a second leaching with H2S04, solubilized 98 pct of the copper. The three leaching methods yielded high-grade PGM residues containing more than 98 pct of the PGM in the matte.

Jan 1, 1982

The Bureau of Mines, through its Minerals Availability Program (MAP), investigates the mineral supply potential of the United States and market economy countries (MEC&apos;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 Allan F. Smith

The influence of hydraulic fluids on spontaneous heating in bituminous coals is determined by measurement of the temperature increases produced in coal-fluid mixtures heated to a temperature sufficient for the initiation of self-heating. Similar tests on as-received coal samples and water-coal mixtures are compared with the results obtained for the various hydraulic fluids. Three of the four coals were sampled from coalbeds known to have a history of spontaneous heating. The data provide a basis for predicting the possible effects in gob or carbonaceous refuse of coal mines.

Jan 1, 1963

By W. L. Barry

A review of the practices of analyzing for precious metals at the Reno Research Center, U.S. Bureau of mines, is presented. A general description of fire assaying, the physical layout of a fire assay laboratory, and the use of fire assaying in combination with atomic absorption, induction coupled plasma, and emission spectroscopy is reviewed. The combination of techniques significantly decreases the detection limits for precious metal analyses and simplifies the analysis of the platinum-group metals. Methods of protecting personnel from ingestion of lead are also discussed.

Jan 1, 1982

Real gross national product increased at a larger-than- expected annual rate of 8.3 percent in the first quarter of 1984, with both consumption and investment spending increasing significantly in real terms (table 1). Residential and nonresidential fixed investment increased at annual rates of 25.7 and 14.6 percent during the first quarter of 1984, and investment in nonresidential structures, which declined in 1983, also increased during the first quarter of 1984, nearly attaining its 1982 level. The annual level of personal savings increased $27.7 billion, while the personal savings rate (the ratio of personal savings to disposable income) increased to 5.8 percent during the first quarter. The increase in the personal savings rate comes as welcome news to analysts concerned over the flow of loanable funds to the private sector and the impact on interest rates in 1984 of increased private and Government demands. U.S. Minerals Industry Performance A major upswing in the performance of the metal mining sector occurred during the first quarter of 1984, with production increasing almost 11.2 percent from January to March, The recovery of the metal sector is also reflected in the performance of primary metal industry profits, which were positive during fourth quarter 1983 following seven consecutive quarterly losses (table 1). Two thousand nine hundred more metal mining production workers were employed in February 1984 than in February 1983.

Jan 1, 1984

By R. N. Johnson

This report is a summary of the work performed for the Bureau of Mines to evaluate the feasibility and desirability of a movable in-pit crusher combined with conveyors to substantially reduce or eliminate truck or train haulage in large open-pit non-fuel mineral mines. The report includes an introduction and summary of previous work, an analysis of movable crusher system components, a description of the selected system, a review of possible movable crusher system applications, and finally requirements for future work to bring about the general availability of such systems. It was clear from the program that there is a real need for movable in-pit crushers.

Jan 1, 1982

By D. Harrington

We Americans fondly believe that ours is the greatest , most progressive and most civilized country in the world , but the cold statistical facts reveal that we apparently have little appreciation for the lives of those whose efforts of various kinds give us whatever greatness we have . The latest available statistics indicate that the annual death rate per 100,000 persons , from accidents is nearly 80 , or far higher than that of any other country in the world ; it is more than double the rate in Denmark , Belgium, Netherlands , France , Sweden , Italy , Ireland , Germany , Norway, and Austria; it is practically double the rate in England and Wales and in Japan , and is from 25 to 60 per cent higher than the corresponding rate in Scotland , New Zealand , Australia, Switzerland , and Canada . And added to this is the fact that of the main industries of the United States mining has by far the worst accident record , viewed from either the frequency or the severity basis . The National Safety Council's latest figures for 27 of the country's main industries give mining the highest or worst accident frequency rate, 74.43 in 1929 ; meat packing comes next with 55.94 , and construction third with 50.41 . In accident severity in 1929 mining also was the worst offender , with a rate of 9.99 ; quarrying is second with 6.11 , and construction third with 4.62 . Metal mining's frequency rate in 1929 was 52.16 , as against 69.25 for bituminous coal mining ,99.68 for anthracite mining, and 74.43 for the entire mining industry ; accident severity for metal mining in 1929 was 5.99 , as against 11.69 for bituminous coal mining , 10.87 for anthracite mining , and 9.99 for the mining industry as a whole . Although this figure indicated that metal mining is on a much safer plane than either bituminous or anthracite coal mining, the frequency rate of 52.16 for metal mining was higher in 1929 than the frequency rate of all but one of the other 26 industries about which data are available ; the metal mining severity rate of 5.99 , while much better

Mar 1, 1932