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By J. R. Boyle

The Bureau of Mines developed cost estimates fur the disposal of phosphate rock washer slimes by pond settling, from a study of the method used at the International Minerals a Chemical Corp., Moralyn Phosphate Operations, Polk County, Fla. Data were obtained by basing phosphate production and slime generation statistics on plant capacity rather than on actual company records. Cost estimates, which were prepared as a guide in evaluating alternative disposal methods and in identifying needed areas of research, could be applicable to any Florida plant using the same disposal method. To conserve mineral resources and to improve environmental conditions, the Bureau recommends further research directed toward developing alternative methods of disposal, including the recovery of water and P205 values from the slimes.

Jan 1, 1969

By E. D. Calvert

The Bureau of Mines, in its effort to promote greater utilization of domestically abundant materials, conducted reasearch on an alternate mold material that has commercial potential for titanium investment casting. Using variations of the conventional lost wax molding process, investment shell molds were formed entirely of fused, calcia-stabilized Zr02 and a Zr02-forming binder. Optimization of binder/slurry properties', stucco grain size and dis¬tribution, and curing practices resulted in a structurally sound investment shell that was distortion free and thermally stable. Small titanium castings, weighing up to 10 pounds, were prepared in unheated molds by both static and centrifugal casting techniques. Microstruc¬tural examination of the castings revealed that mold fill and surface quality were enhanced by centrifugal casting, although good results also were obtained from the statically poured molds. Microstructural and electron microprobe examinations showed that excessive, brittle case formation could be avoided by curing the dried shell molds in air for at least 2 hours at 1,400° C. Increasing curing temperature and time above these levels yielded added bene¬fits. Molds fired in vacuum at 1,500° C for 4 hours yielded castings essen¬tially free of case formation. The tensile properties of as-cast test specimens (no surface conditioning performed) id the chemical composition of representative metal samples showed that castings produced were comparable to Grades C-1 and C-2 unalloyed titanium This indicated that no sifnificant degradation of metal properties resulted from mold/metal interaction.

Jan 1, 1981

By David R. Jessey

This volume contains the detailed mine site reports written by the WAPORA, Inc. and KETRON, Inc. staffs. It is a companion Appendix Volume to Control of Water Pollution from Surface Mining Operations. Copies of this report are maintained on Open File at the U.S. Bureau of Mines Research Center, Spokane, Washington.

Jan 1, 1981

By F. V. Meriwether

The Bureau of Mines, in cooperation with the Federal, State, and local health services, and the mining companies, and miners? organizations, has for several years been carrying on sanitary surveys of mining districts in various states, with the purpose of collecting information on good and poor practices in mine sanitation, construction of approved wash-houses and change houses, the measures being taken to combat preventable diseases, the essential features of good houses for mining towns, and other conditions affecting the health and efficiency of miners and their families. The knowledge thus gained is disseminated for the common benefit of the mining industry. The sanitary conditions in the coal-mining districts of Alabama, as found by a recent survey made by the writer, are presented in this report. In addition to the towns on which this report is chiefly based, at least twice as many were visited where no details :were taken, but their general conditions are taken into consideration in summing conditions in the coal districts.

Jan 1, 1926

By J. J. Forbes

Since 1910 the Bureau of Mines has given training in the care and use of oxygen breathing apparatus under conditions that may exist during mine fires and after mine explosions. In 1929 the Bureau supplemented this instruction by initiating a course in advanced mine rescue training to prepare mine officials and others to organize men for mine rescue and recovery operations. The course of instruction has been developed and expanded since its inception to keep abreast with new ideas, methods, and equipment. Four miners' circulars were issued to be used in the training course. The first of this series (Miners' Circular 33) deals with mine gases and the various methods of detecting them; the second (Miners' Circular 34) gives instructions for sampling and analyzing mine atmospheres; the third (this circular) describes methods and equipment for protection against mine gases; and the fourth (Miners' Circular 36) explains procedures in sealing and unsealing mine fires and in conducting recovery operations, These circulars have been revised from time to time to keep them up to date.

Jan 1, 1954

By Douglas W. Fuerstenau

This report presents the results of an investigation of comminution in tumbling mills. Five different topics involved with ball mill and rod mill grinding kinetics were studied and the results analyzed in terms of phenomenological size reduction and transport models. Continuous rod mill grinding was found to be characterized by high Peclet numbers which permit simulation to be carried out by several methods. The dry batch ball mill grinding of mineral mixtures showed that the breakage rates of the components were composition-dependent but time-independent and were normalizable with specific energy. Locked-cycle tests on mineral mixtures showed that a grinding circuit may take a long time to attain steady-state, during which time the composition of the mill holdings, and hence the breakage rates of the components, continuously changed. This study revealed that under plant conditions, grinding circuits can be in transience perpetually. The transport of mineral mixtures through drums was found to exhibit complex size and/or density-dependent segregation. However, the grinding media in a ball mill can eliminate such segregation, thereby simplifying the modeling of the continuous grinding of complex feeds. Wet batch rod mill grinding on single minerals divulged that the normalizability of breakage kinetics is valid for slurries of constant pulp density at different hold-ups but cannot be extended to slurries varying in pulp density.

Jan 1, 1983

By Arden D. Fugate

This work was conducted to determine a feasible process for converting siliceous fluoride offgases to a commercially usable product. The offgases were generated by pyrohydrolytic defluorination of low-grade fluorspar in a gas-fired rotary kiln, and fluorine was collected as a hydrofluoric-fluosilicic acid. A silicon-free fluoride solution for further processing was then produced by neutralizing the acidic scrubber solution with anhydrous ammonia, silicon being separated as orthosilicic acid. Ninety to ninety-nine percent of the fluorine originally present remained in solution as ammonium fluoride. Silicon was also separated from synthetic fluosilicic acids, having F-to-Si weight ratios ranging from 3.50 to 14.3. The solutions below a ratio of 4.06, the F-to-Si ratio of H2SiF6, containing dissolved silicon were desiliconized as completely as those containing less than the stoichiometric quantity of silicon. An electrolytic-grade cryolite was recovered from the ammonium fluoride solution by reacting with either sodium aluminate or alumina trihydrate and sodium hydroxide. A product containing 97 to 100 percent of the fluorine, represented by Na3A1F6, was recovered, and 94 to 99 percent of the theoretical yield was realized.

Jan 1, 1963

By Lorenz E. Sieffert, Lawrence B. Berger, H. H. Sehrenk, Ralph W. Stewar, James A. Gale

"INTRODUCTION The purpose of the investigation discussed in this article was to evaluate the toxic hazard from gases produced when thermosetting plastic materials used for electrical insulating purposes are burned or thermally decomposed in enclosed spaces. For brevity the term ""toxicity"" is used throughout the article to refer to the nature of gases produced under these conditions. A need for immediate study of the problem was created as a re¬sult of the battle damage reports received from various United States Fleet units. These indicated that the fumes emitted when these materials were burned or thermally decomposed had, in several instances, resulted in toxic atmospheres. In attempting to develop a suitable test method for evaluating toxicity, it was recognized that no single test procedure could be expected to duplicate the variety of conditions that might exist in an actual fire aboard ship. In view of the immediate need, however, it was felt that considerable information could be obtained, at least to classify comparatively the several types of materials as to the toxic effect caused by burning or thermal decomposition, through the development of a sound empirical method which could be applied to all of the materials. On this basis, it was decided to modify the Navy flame resistance test for thermosetting plastics to render it applicable to the determination of the toxic, gases evolved when this test was employed. A wide variety of materials was tested, both molded and laminated, to cover the types commonly used by the Navy in electrical applications. Toxicity determinations were conducted at the Bureau of Mines Central Experiment Station, Pittsburgh, Pa. Parallel tests, to determine the flame resistance of the materials, were conducted at the Material Laboratory, U. S. Navy Yard, New York, N. Y."

Oct 1, 1947

By P. M. Daling

This report, sponsored by the U.S. Bureau of Mines, presents the results of an examination of available safety assessment methods and their applicability to the mining industry. Standard safety analysis procedures were evaluated for relevance to the mining industry and mine operators' needs. The major safety concerns and needs of mine operators were identified through telephone contacts and a visit to a mine site. Safety assessment methods recommended for use by the mining Industry were also Investigated for potential adaptability to a user-interactive computer system. Several methods were determined to be immediately transferrable to the mining industry; these techniques are described in a user's handbook produced as part of this project. The handbook gives detailed instructions on appropriate application and utilization of these methods. Other techniques will require further development before they can be effectively transferred to the mining industry. These methods, their advantages, disadvantages and resource requirements are described in the final project report. Recommended system safety analysis techniques facilitate an evaluation of total mine system safety and a determination of safety-related interactions among systems within a mine. The application of these methods to the mining industry could result in reductions in both the frequency and the consequences of mine accidents.

Jan 1, 1983

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldwell Counties in western Kentucky. According to the latest available statistics, this district supplied 1/5,960 short tons of fluorspar in 1937, compared with the total domestic production of 181,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By J. B. Clemmer

Fluorspar is one of the most important nonmetallic minerals and is used extensively in the metallurgical, ceramic, cement, and chemical industries. The steel industry consumes most of it, but as the Mineral is the chief source of fluorine, it is becoming increasingly valuable to the chemical industry in the production of fluorine compounds. The development of nontoxic organic fluorides for use as refrigerants in mechanical refrigeration and air-conditioning units illustrates the increasing use of fluorspar in the chemical industry. Most domestic flurospar comes from deposits in the Illinois-Kentucky district, which centers around Rosiclare, Ill. About a dozen companies operate in the district, which comprises parts of Pope and Hardin Counties in southern Illinois and Crittenden, Livingston, and Caldrell Counties in western Kentucky. According to the latest available statistics, this district supplied 165,960 short tons of fluorspar in 1937, compared with the total domestic production of 151,230 tons. Imports totaled 37,063 tons.

Jan 1, 1939

By Steven R. Davis

Voyageurs National Park in northern Minnesota, and a 30-mile radius area of influence on the United States side of the International Border, was examined for hardrock (nonferrous metallic minerals and diamonds) mineral potential and environmental sensitivity by the U.S. Bureau of Mines. The investigation also included an analysis of current Metallic Minerals Leasing Rules of the State of Minnesota, and the probable effects of changes proposed to the current rules by the State of Minnesota in order to "encourage mineral exploration and development." The study has determined that the proposed changes to the Minnesota State Leasing rules will have minimal, if any, impact on the likely, foreseeable levels of mineral-related activities in the State as a whole, and particularly, in the area of influence to the Park. Voyageurs National Park management was advised on the extent and character of the proposed rules changes, and on those items of concern meriting a specific and timely response by the National Park Service.

Jan 1, 1994

By Paul M. Tyler

According to Lindgren , the economic importance of pegmatites stems from the fact that they represent the principal natural storehouse of two classes of mineral products : (1 ) common minerals in exceptional size and purity and ( 2 ) several of the rarest minerals , which are not commercially available from other types of deposits . Most pegmatites can be described simply as coarse- to very coarsegrained granites . Pegmatite includes coarse -textured igneous rocks of any composition , such as syenitic , alkali syenitic , dioritic , or gabbroitic ; but basic pegmatites are far less common than those that are associated with acid rocks and correspond approximately to the mineral composition of ordinary granite . Moreover , only a very few basic pegmatites can be considered as economic sources of useful minerals . Whereas , in ordinary granitic rocks the individual minerals usually measure 1/8 to 1/4 inch across , in pegmatites they are characteristically over 1 inch and often more than 12 inches in diameter . Although some of the constituents of the pegmatite may be only a fraction of an inch in length , single crystals more than 10 feet long are by no means unusual , and some crystals are enormous . A whole quarry was operated in the Urals within a single crystal of feldspar . Huge quartz crystals are quite common although usually imperfect . Muscovite plates 10 feet in diameter have been mined in India , and the Purdy mica mine in Canada contained a mica crystal measuring 6.5 by 9.5 feet and weighing nearly 7 tons , which supplied more than $20,000 worth of trimmed mica sheet . A loglike crystal of spodumene in the Etta mine in the Black Hills of South Dakota was 42 feet long . Giant crystals of beryl weighing several tons apiece have been mined from several properties . Because so many rare minerals are found in substantial concentration only in pegmatites , it is a common fallacy to suppose that pegmatites are always enriched in rare elements . Traces of most of these elements , of course , are found in almost all igneous rocks , and they reappear in the sediments derived from igneous rocks . It does not follow , however , that all or even most pegmatites contain higher percentages of rare elements than other granitic rocks . Geological evidence points to the probability that notable concentrations of rarer minerals or elements in pegmatites are more or less fortuituous , such additions often being ascribed to events subsequent to the original emplacement of the main body of the pegmatite . Most pegmatites consist principally of potash , feldspar , and quartz . Even mica , although commonly present , is not an essential constituent . Probably

Feb 1, 1950

By R. H. Sprute

The Federal Bureau of Mines conducted full-scale field tests in electro-kinetic dewatering and consolidation of slimes in cooperation with the Hecla Mining Co. at two of the firm's underground mines in north Idaho. To test the technique on new deposits, 4,000 ft3 of slimes from a collection sump, pumped into a watertight stope equipped with electrodes, were treated in two steps. Immediately after placement, direct current was applied using a floating electrode to hasten settlement of suspended fine particles. After removal of clarified water, the residue was further dewatered and hardened with electrokinetic treatment. In 25 hours, the material had become firm and dense with a surface capable of supporting workmen. In testing old deposits, 10,000 ft3 of slimes, placed in an unused tail drift 10 to 12 months previously, were treated. This material was sufficiently consolidated by electrokinetics to allow its removal from the mine with standard ore-handling equipment. In both tests, electrokinetic treatment densified slimes in a relatively short time with moderate power consumption.

Jan 1, 1976

By S. H. Ash

The paramount responsibility of Government is to protect the general welfare. One of the chief functions of the Bureau of Mines is to investigate and publicize methods of increasing safety and efficiency in mining operations. In an industrial civilization, energy resources constitute the foundation of a sound economic structure (14).4/ Coal is only one source of energy, but it provides more than half the energy consumed in the United States.

Jan 1, 1946

By Stephan Stecura

One of the principal objectives of the Bureau of Mines program for development of superrefractory ceramic materials is to obtain fundamental data on the physical properties of refractory oxides. Elements of particular interest to research workers in the Bureau include groups III and IV of the Periodic Table and the rare-earth group. This report contains thermal expansion and phase inversion measurements on oxides of scandium, yttrium, lanthanum and 12 lanthanide series elements (promethium and terbium omitted) up to 1,350°C, made by high-temperature X-ray diffractometer techniques. Thermal expansion values were calculated from unit cell dimensions measured at selected temperatures; with anisotropic oxides expansion was determined parallel to each major crystallographic axis. The combined random and systematic errors in the thermal expansion values are considered to be less than 3 percent of the total expansion at 500° C, and approximately 2 percent at 1,000° C, No difference in expansion coefficients was observed between heating and cooling cycles for oxides that did not undergo phase inversion. Tabular data of linear expansion, in percent, linear expansion coefficients, and graphical presentation of linear expansion as a function of temperature are presented.

Jan 1, 1961

By Leslie D. Marrus

This project and final report represent an effort to collect, analyze, and verify reliability and performance data on currently available medium -to-high seam models of continuous miners being used in underground coal mining. The analysis determined availability, mean time and tons between failures, amounts of down time associated with various failures, labor and part costs required to correct failures, and various indices of maintainability. Machine performance and reliability are discussed relative to cumulative tons (machine age) produced and production rates (machine loading). It was determined that performance can be significantly improved given preventive maintenance programs that will increase machine availability.

Jan 1, 1976

By John C. Machisak

THIS INFORMATION CIRCULAR covers the calendar year 1055 and contains statistical data on employment and injuries pertinent to metal and nonmetal mining and to their mills and processing plants that are voluntarily reported annually to the Federal Bureau of Mmes. This report, unlike previous publications, lists not only production and development workers but also office employees associated with mining and milling or processing. The last publication m the series, Information Circular 7798, Injury Experience in the Metal and Nonmetal Industries, 1954, also contains unpublished injury and employment statistics for 1943 through 1953. The Bureau is authorized to request data on injuries and employment from operators in the metal- and nonmetal-mining industries. The information voluntarily submitted by these operators contributes immeasurably to the promotion of safety in the mineral mining industries as it discloses the hazards to which metal and nonmetal workers are continually exposed during mineral extractive operations.

Jan 1, 1959

By H. E. Dresch

This report summarizes the work accomplished under Bureau of Mines contract H0188068. The contract required design and construction of a high voltage (7.5 KV) explosion proof cable connector for use on underground coal mine drag cables. A connector was constructed with elastomeric phase insulators that provide insulation shielding throughout the connector length. Connector housing was made of flame resist-ant cast poly urethane with no exposed metal components. Electrical and mechanical testing of the completed coupler resulted in satisfactorily meeting most of the design testing requirements.

Jan 1, 1981

By BUREAU OF MINES

This report is submitted in accordance with provisions of the Synthetic Liquid Fuels Act of April 5, 1944 (30 U. S. C. 321-325, as amended), which require that: "The Secretary of the Interior shall render to Congress on or before the first day of January of each year a report on all operations under this Act." Owing to the broad scope of the content and the diversity of interests represented, the Annual Report for 1954 has been divided into two separate publications. Each is being published by the Bureau of Mines as a Report of Investigations, and the respective titles follow: R. I. 5118, Part I - R. I. 5119, Part II - 011 From Coal. 011 From 011 Shale. The introduction, identical in both reports, summarizes research progress in 1954 under the entire Synthetic Liquid Fuels program. A free copy of either publication may be obtained by writing to the Bureau of Mines, Publications Distribution Sec- tion, 4800 Forbes Street, Pittsburgh 13, Pa. The R. I. number and title of the publication desired should be indicated.

Mar 1, 1955