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By Fei-chiu Huang

The principle of time domain reflectometry (TDR) is being used by the U.S. Bureau of Mines to monitor strata displacements induced by mining. The Northwestern University TDR Signature Analysis (NVTSA) Program was developed under contract with the Bureau to allow for visual comparison of three TDR waveforms quickly and easily. This program is interactive, and on-line help is available. The Northwestern University Remote Control TDR Data Acquisition System and Modification of Tektronix SP232 Host Application Program (NUMOD) was then developed to allow acquisition of TDR wave-forms from a remote cable tester via modem. The NUMOD system utilizes commercially available software while the NUTSA program is available from the Bureau. This report begins with a discussion of TDR principles followed by a description of the NUMOD system. An interactive example of signature analysis is then used to demonstrate features of the NUTSA program.

Jan 1, 1993

This section presents highlights of world economic and mineral industry performance in 1982, a year characterized by continued recession, and selected 1983 forecasts of economic indicators of importance to the mineral industry, some of which indicate a modest improvement in the economies of the United States and Western Europe. The U.S. Economy in 1982 In 1982 U.S. gross national product (GNP) in current dollars increased at a rate of 4 percent, but GNP adjusted for inflation (real GNP) declined at a rate of 1.8 percent. Yearend 1982 real GNP was at roughly the same level as in 1980 (table 1). Thus no growth in real terms had taken place in the United States during the 1980-82 period.

Jan 1, 1983

By E. P. Youngman

Before the World War the use of zirconium and its compounds was largely experimental and confined almost wholly to Germany and Austria . Occasionally small lots of zirconium ore had been produced in the United States ( 1,000 pounds in 1869 , 26 tons in 1883 , and 3,000 pounds in 1903 ) and used (with monazite ) in the manufacture of various lighting devices , especially incandescent gas mantles ; but it was not until 1906 that the discovery of the natural zirconium oxide in large quantities near Sao Paulo , Brazil , first gave promise that a zirconium industry eventually might be developed . Edward Rietz , who worked the Brazilian deposits , interested German chemists in extending the use of zirconium , and by 1911 trade journals were listing German firms as manufacturers of compounds or products derived therefrom . For a time zirconia was one of the various oxides used in the Nernst lamp . It was used also for crucibles and hearths as refractory material ; in the manufacture of chemical utensils ; in enamels ; in the place of bismuth subnitrate for defining Röntgenray pictures of the stomach ; as a pigment ; in medicine ; and in a number of other ways . The Germans were credited also with producing a remarkable zirconium steel , which , it was claimed , was much superior to other alloy steels . During the World War the United States Government investigated the possibilities of zirconium , as well as those of other steel -hardening elements , and a large automobile manufacturer actually purchased a substantial quantity of ore with the purpose of employing zirconium in automobile steels . Immediately after the armistice the Government ceased its investigations ; but despite the difficulties experienced by various investigators in reaching concordant results , interest in the use of zirconium as a steel -hardening agent , as well as in other uses of the element and its compounds , continued . In 1918 the Foote Mineral Co. , which had been interested in zirconium for several years , was exploiting the deposit in Brazil formerly worked by the Germans and was supplying zirconia in the form of ore , brick , and cement for refractory and other purposes . About the same time the Electro Metallurgical Co. , which before the entrance of the United States into the war was experimenting with zirconium alloys , supplied in tonnage quantities the demand for these alloys . In 1919 it was reported that American manufacturers , after several years of research, were producing in commercial quantities pure zirconium oxide , which was finding a place in the manufacture of small refractory articles , scorifying dishes , crucibles , tubes , and one- piece furnace linings . In 1920 the lowering of the price of zirconium metal powder ( because of improved metallurgical methods ) promised the production of the metal on a semicommercial scale . In 1924 the Titanium Alloy Manufacturing Co. introduced a new opacifying agent , " Opax , " made from zircon . A year or two later some of the large pottery manufacturers became interested in the use of zirconium oxide as an opacifying agent , the increased production of titanium pigments having resulted in the production of zirconium as a by-product at a price that could compete with tin oxide . In 1928 it was reported that the industrial use of zirconium oxide was increasing steadily in the manufacture of brick , crucibles , and other refractory products , such as high- temperature cements . However , the reluctance of producers to install additional and more suitable

Jun 1, 1931

By Howard J. Pincus

The purpose of the study is to investigate the effects of fracture filling and associated alteration on the mechanical behavior of rocks. Results are presented for specimens from the Climax and Henderson mines in Colorado and the San Manuel mine in Arizona. The rock types studied from each location are from 1) Climax, medium-grained - granite, fine-grained granite, granite porphyry, schist, and gneiss; 2. Henderson, rhyolite porphyry; 3. San Manuel, quartz monzonite and quartz monzonite porphyry. A description of the rocks was made including: color, texture, mineral composition, composition and fabric of fracture fillings, density and porosity. Unconfined and triaxial compression tests were run on the Climax and San Manuel specimens. Sonic relocities were measured during the compression tests; Shore sceleroscope hardness was measured before the compression tests. Tentative conclusions are that some relation appears to exist between compressive strength and the following properties and features for all the specimens: dynamic Young's modulus, sonic velocity, density, rock composition, and composition and fabric of fracture fillings - veinlets. There appears to be some relation between compressive strength and Shore scleroscope hardness and porosity for quartz monzonite (San Manuel). A relation appears to exist between compressive strength and texture for schist and between com¬pressive strength and extent of failure on fracture fillings for fine-grained granite, schist, and gneiss (Climax). We plan to perform additional analyses of data collected so far and data yet to be collected in the next few months, with emphasis placed on devising a practical index of alter¬ation that can be used in the field. Limitations on interpretations arise from such factors as heterogeneity of the rocks studied, the small range of confining pressures used, and other factors presented in the text.

Jan 1, 1973

By James Westfield

This publication covers the work of the Division of Coal Mine Inspection, Bureau of Mines, as performed under provisions of the Federal Coal Mine Safety Act. It presents background information and data since 1952 when the Act became effective and includes up-to-date statistics for the calendar year 1962. During that year, approximately 9,704 coal mines were active in the United States, and the Bureau made 12,810 regular inspections. BACKGROUND The Federal coal-mine inspection program was established to carry out the provisions in Public Law 49, 77th Congress, (H. R. 2082) approved May 7, 1941. This act has since been amended as Title I, Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also included Title II, Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal Mine Safety Act.

Jan 1, 1963

By H. C. Carpenter

This literature study of methods for desulfurizing residual fuel oil was conducted by the Bureau of Mines at the request of the Department of Health, Education, and Welfare. The sulfur compounds in residual fuels are believed to consist chiefly of condensed thiophenes and other polycyclic sulfur compounds. Hydrodesulfurization appears to be the most promising method for desulfurizing these oils and is the only method applicable to all types of sulfur compounds. There are indications in the literature that hydrodesulfurization without hydrocracking of residual oils may require higher pressures than used in present desulfurization processes, but no cost data and little experimental data are available on the higher pressure operation. Literature proposals for hydrogenating residual oils and heavy crude oils are exclusively for hydrocracking the oils to lower boiling products with accompanying partial desulfurization of the residual fuel fraction. Costs of the hydrocracking operations appear the closest available to probable costs of hydrodesulfurizing the oils, and have been reported (in 1955 to 1957) as $500 to $840 investment cost per daily barrel of capacity, with total operating costs of 70 cents to $1.10 per barrel.

Jan 1, 1963

By Lewis A. Smith

This circular presents a summary of the domestic chromium industry, and discusses the salient features of the world situation , reflecting the literature of the subject . The United States Bureau of Mines has in its files additional detailed information on many subjects briefly discussed in this paper and desires to assist the industries and the public by giving further data in response to individual inquiries . It will welcome comment and criticism and any contributions that would assist in making future editions of this circular more accurate . Unlike most common metals , chromium is rarely marketed as a pure metal . The chromium industry deals mainly with chromite , the principal ore of chromium , and with ferrochromium , the basic alloy in which chromium enters the metallurgical industry.

Apr 1, 1932

By D. G. Willard

The U.S. Department of Interior, Bureau of Mines has evaluated the potential resource and annual availability of cobalt from 27 deposits or districts in 11 market-economy countries. More than 95 pct of primary cobalt production from market-economy countries, mainly byproduct output from copper and nickel operations, was analyzed. Approximately 1,200,000 mt of cobalt is potentially recoverable at the demonstrated resource level. Very large additional resources exist, especially in laterite deposits, but are at the inferred level. The producing operations evaluated in this study are expected to produce about 19,000 mt of cobalt in 1989, significantly less than the available capacity of about 31,000 mt. More than 14,000 mt per year of cobalt is produced from copper-cobalt deposits in Zaire and Zambia, of which 11,000 mt can be produced at a copper price of $O.60jlb or less with a O-pct discounted cash-flow rate of return (DCFROR). Approximately 4,400 mt of cobalt is produced annually from nickel-cobalt deposits in six countries, of which about 1,800 mt (in Canada and Brazil) could be produced at a nickel price of $1.50jlb or less at a D-pct DCFROR. Approximately 200 mt per year of cobalt is produced from a cobalt mine in Morocco. Most of the evaluated nonproducing operations and prospects that could potentially produce cobalt as a principal product or byproduct would require a total cost (including a 15 pct-DCFROR) significantly exceeding January, 1989 market prices of the principal commodities. Principal-commodity dependence, transportation routes, cobalt toxicity, and other issues that could affect the availability of cobalt are addressed herein.

Jan 1, 1991

1. A total of 14,413 mining operations reported employment to the Mine Safety and Health Administration (MSHA). Nearly half (48.9%) were sand and gravel operations, followed by stone (28.5%), coal (14.7%), nonmetal (5.7%), and metal mines (2.1%). 2. Mine operators reported 240,000 full-time equivalent workers1 (down 3.9% from 1999). Independent contractors reported 42,000 full-time equivalent workers working on mine property (up 8.6% from 1999). Coal operators accounted for 26.8% of reported employee hours, followed by stone operators (25.9%) and sand and gravel operators (12.1%). 3. Eighty-four (84) work-related mine fatalities occurred in 2000 compared to 90 the year before. •The mine fatality rate was 29.8 per 100,000 full-time equivalent workers compared to a fatality rate of4.6 per 100,000 employees for all private industry. •Thirty-one percent (31%) of the fatalities occurred in underground work areas, which account for only17% of total employment. •Although the largest number of fatalities (28) occurred among miners who work for coal operators, coal contractor employees had the highest fatality rate (61.1 per 100,000 full-time equivalent workers). 4.There were 10,839 nonfatal lost-time injuries reported to MSHA, occurring at a rate of 3.8 injuries per 100full-time equivalent workers, and resulting in a total of 417,918 lost workdays.2 •Among all employees,3 the highest injury rate occurred among coal operator employees (5.6 nonfatal injuries per 100 full-time equivalent workers). •The highest percentage (34.7%) of nonfatal lost-time injuries were due to handling materials (e.g., over-exertion in lifting, pulling, or pushing objects), which also accounted for the greatest percentage of lost workdays (29.3%). •Among the most frequently occurring injuries, the most severe (as measured by the median number of days lost) were associated with accidents involving falls of ground, the use of powered haulage, and slips or falls. •The most frequently reported part of the body injured was the back (22.9% of all injuries). Back injuries accounted for the highest percentage of lost workdays (21.6%). 5.Seven hundred sixty-seven (767) cases of occupational illness were reported to MSHA. •The most frequently reported illness was repetitive trauma, resulting in joint, tendon, or muscle inflammation or irritation (37.3%). •There were 155 (20.2%) illnesses reported as hearing loss. The majority (68.4%) of hearing loss cases occurred among surface workers. •Coal workers' pneumoconiosis accounted for 14.5% of reported illnesses.

May 15, 2002

By Paul Hatmaker

Lime was a highly useful commodity thousands of years before the simple chemistry of its manufacturing process was known. The employment of lime for agriculture, building, and even certain essentially chemical purposes is so old that its origin is among the unrecorded details of man's first ventures into the manufacture and use of prepared substances. Lime is a most versatile material and consequently has come to be widely utilized in modern civilization. Immediately before the depression of the early 1930's the annual production of lime in the United States was more than 4 million tons, valued at 33 to 42 million dollars. This output was sold to many industries, so many that mere enumeration becomes tedious. In addition to agricultural and building lime the sales statistics compiled annually by the Bureau of Mines include lime sold to the steel and other metallurgical industries as refractory and fluxing material, as well as that used by paper mills, glass works, tanneries, and water-treatment plants. These major uses normally consume about 86 percent of the domestic sales. The remaining 14 percent includes lime sold for use in the manufacture of alcohol, alkalies, bleaches, calcium acetate, calcium carbide, coke gas and byproducts, glue, insecticides, oils and fats, paints, and rubber, in the refining of salt, in the manufacture of sand-lime and slag brick, in the disposal of sewage and garbage, in the manufacture of silica brick, in the refining of sugar, in the textile industries, and in wood distillation. Many other uses are also known for which complete sales data are not available.

Jan 1, 1934

By Robert H. Peters

Groundfall accidents have been the leading cause of fatalities in the underground coal mining industry for many years. Statistics from the Mine Safety and Health Administration (MSHA) indicate that approximately half of the victims of these fatal accidents were in an area where no devices had been installed to support the mine roof. This report was prepared by the U.S. Bureau of Mines to provide guidance to operators of underground mines concerning the use of techniques that may help to keep miners from going under unsupported mine roof. The report is divided into two major sections. The first section reviews the findings from several areas of empirical research pertaining to strategies for convincing employees to avoid unsafe acts and/or adopt self-protective behaviors. The strategies are (1) incentives and feedback, (2) disciplinary actions, (3) training (primarily fear communications and behavioral modeling), and (4) nondirective techniques. This literature review has a broad focus and should be helpful in making decisions about how to encourage a wide variety of types of self-protective behaviors. The second major section of the report presents an analysis of each strategy's potential for keeping miners away from unsupported roof.

Jan 1, 1991

Recommendations from 44 mining industry workshops are summarized and reviewed in the context of Bureau of Mines research and development programs on-going during the period 1974-1977. Approximately 1,000 specific recommendations for research and development are summarized in a systematic and comprehensive format appropriate for review by mining research and development program managers. Relevant Bureau of Mines research programs are briefly described and some opportunities for future research and development are identified.

Jan 1, 1979

By John C. Machisak

The thirty-fifth consecutive National Safety Competition sponsored and conducted annually by the Federal Bureau of Mines, Department of the Interior, closed with several noteworthy accomplishments to its credit. Some of them are: 1. A record low injury-frequency rate of 18.293 disabling work injuries per million man-hours equal to that established in 1957. 2. The third lowest injury-severity rate (4,335). 3. The second highest number of mines and quarries participating (672) 4. A record number of participants finishing the competitive year without a disabling work injury. 5. All recipients of Sentinels of Safety trophies free of disabling work injuries for the first time since 1952.

Jan 1, 1961

By H. C. Carpenter

This literature study of methods for desulfurizing residual fuel oil was conducted by the Bureau of Mines at the request of the Department of Health, Education, and Welfare. The sulfur compounds in residual fuels are believed to consist chiefly of condensed thiophenes and other polycyclic sulfur compounds. Hydrodesulfurization appears to be the most promising method for desulfurizing these oils and is the only method applicable to all types of sulfur compounds. There are indications in the literature that hydrodesulfurization without hydrocracking of residual oils may require higher pressures than used in present desulfurization processes, but no cost data and little experimental data are available on the higher pressure operation. Literature proposals for hydrogenating residual oils and heavy crude oils are exclusively for hydrocracking the oils to lower boiling products with accompanying partial desulfurization of the residual fuel fraction. Costs of the hydrocracking operations appear the closest available to probable costs of hydrodesulfurizing the oils, and have been reported (in 1955 to 1957) as $500 to $840 investment cost per daily barrel of capacity, with total operating costs of 70 cents to $1.10 per barrel.

Jan 1, 1963

By D. W. Bridges, Donald R. Peterson, Masami Hayashi

Techniques are described for recovering about 80 pct of the cobalt and nickel contained in superalloy scrap by anodic dissolution of the scrap and simultaneous electrodeposition of a pure cobalt - nickel alloy at the cathodes in an electrolytic cell partitioned by permeable diaphragms into separate anode and cathode compartments . Superalloy scrap was alternatively prepared for subsequent anodic dissolution either by melting and casting massive scrap into suitably sized anodes , by packing moderate - sized discard scrap in inert metal baskets that subsequently served as anodes , or after concentrating the superalloy portion of grinding debris , by magnetic separation to reject corundum or other abrasives , slagging any remaining abrasives from molten grindings , and finally casting the superalloy metal into anodes . In the processing , purified electrolyte -- 1 N in NiSO4 and in NiCl₂ , and 0.1 N in CoSO4 and in CoCl2 --was charged to the cathode compartments and discharged from the anode compartments at a rate sufficient to overcome the backward migration of ionic impurities from the anodes to the cathodes . Discharged electrolyte was purified by reacting it first with SO2 and next with limestone , and then recirculated to the cathode compartments , in which a 50 pct cobalt - 50 pct nickel alloy was deposited on either blanks of stainless steel or starting sheets of cobalt - nickel alloy . The process was made self - sustaining by either adding H2SO4 to the catholyte feed to throttle the rate of cobalt - nickel deposition , thereby compensating for the slower rate of cobalt - nickel dissolution from the anode and losses occurring in electrolyte purification , or alternatively , adding H₂SO4 to

Jan 1, 1964

By Eugene H. Skinner

The U.S. Bureau of Mines conducted experiments on the use of lightweight concrete in the density range of 100 Ib/ft3 for liners in underground mines. Three test sections were completed: a monolithic, portal-type structure with integral walls and arch constructed aboveground; an underground test section constructed in a mine drift using plywood forms; and a second section constructed in a drift using an air-supported formwork. The lightweight concrete in the two underground test sections was placed using piston pumps and a slickline. Fiber reinforcement was added to the concrete in the mine sections without any apparent problems with either pumping or placement of the concrete. In another experiment, the Bureau and Hecla Mining Co., Mullan, rD, used lightweight concrete in the density range of 25 Iblfe to replace timber blocking in a raise preparation structure. Other experiments are described in which low-density, lightweight concrete blocks were produced for mine ventilation doors, stoppings, and barricades. Other mine uses reviewed include pillars and collapsing beams. An advantage of low-density concrete is that it will display up to 50% deformation at a constant yield stress. These hlllovative concepts in deformable concrete lining systems will aid mine operators by decreasing capital and maintenance costs, increasing the available space in underground haulageways, and providing productivity gains and improved resource recovery in the soft, caving, squeezing, or bursting grollnu conditions often found in deep mines.

Jan 1, 1989

By James Westfield

This publication covers the work of the Division of Coal Mine Inspection, Bureau of Mines, as performed under provisions of the Federal Coal Mine Safety Act. It presents background information and data since 1952 when the Act became effective and includes up-to-date statistics for the calendar year 1962. During that year, approximately 9,704 coal mines were active in the United States, and the Bureau made 12,810 regular inspections. BACKGROUND The Federal coal-mine inspection program was established to carry out the provisions in Public Law 49, 77th Congress, (H. R. 2082) approved May 7, 1941. This act has since been amended as Title I, Advisory Powers Relating to Health and Safety Conditions in Mines, under Public Law 552, 82d Congress, approved July 16, 1952, which also included Title 11, Prevention of Major Disasters in Mines. Public Law 552 is known as the Federal Coal Mine Safety Act.

Jan 1, 1963

By Ronald S. Conti

The Bureau of Mines conducted a comprehensive laboratory study of the thermal ignitability of various carbonaceous dust clouds with particular emphasis on various ranks of coal dust. The tests were conducted using a new 1.2-L furnace. Autoignition temperatures of dust clouds were obtained as a function of coal volatility and particle size. Dust particles and gas samples were collected by a rapid-sampling system in order to study the reactions involved in preignition and postignition processes. The autoignition temperatures measured in the new 1.2-L furnace were significantly lower and therefore more conservative than those measured previously in the Godbert-Greenwald furnace. The combined effects of thermal and electrical ignition of dust clouds were also studied in the 1.2-L furnace using electrical discharges of varying energies at ambient and elevated temperatures. The minimum spark energy necessary to ignite a dust cloud decreased significantly as the temperature of the dust cloud increased.

Jan 1, 1983

By Charles E. McCarthy

Part 1 of this report is concerned with the electric-furnace production of calcium aluminate and iron alloy from a variety of siliceous ferruginous ores of aluminum. The furnacing research was directed, first, to determine the extent of the field in the CaO-Al2O3-SiO2 system, in which calcium aluminates with the optimum leaching characteristics are obtained; second, to produce suitable quantities of these aluminate mixtures for pilot-plant leaching tests; third, to investigate the physical chemistry of the reduction reactions during furnacing; and, fourth, to study the economics of the process. The third and fourth steps were not completed. Part 2 comprises another phase of the work and will appear as a second Report of Investigations. It deals with the extraction of metallurgical-grade alumina from the calcium aluminate slag produced in the electric furnace and includes the following steps: leaching, desilicating, precipitating, dewatering, filtering, and washing of the aluminum hydrate. No claim is made that the data are complete, nor has the chronological order of obtaining data been followed. Rather, it is emphasized that additional work is necessary if the full possibilities of the process are to be evaluated. and made available.

Jan 1, 1949

By Robert E. Wood

The compressibility factors, Z, of helium, nitrogen, and helium-nitrogen mixtures in the three-dimensional space of temperature, pressure, and gas composition have been related to the Leiden form of the virial equation of state. The dependency of virial coefficients through the fifth on temperature and gas composition has been established for the temperature range 133.15° to 748.15° K. Compressibility factors, Z, have been computed from the equation of state and tabulated as functions of gas composition, pressure, and temperature. Tabular values of Z are presented for 30.00 through 100.00 percent helium for temperatures from 240° through 700° R for pressures from 14.696 through 3,050 psia and for temperatures from 720° through 1,300° R for pressures from 14.696 through 1,500 psia. Tabular values of Z are presented at increments of 5.00 percent helium and 20° R, and, for pressures greater than 50 psia, at increments of 50 psi.

Jan 1, 1967