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By Kim B. Shedd

The Bureau of Mines measured fiber dimensions on crocidolites (riebeckite-asbestos and magnesioriebeckite-asbestos) from the world's four crocidolite mining regions. The objective of the study was to determine whether there are measurable morphological differences between crocidolite fibers that correlate with the high reported incidence of mesothelioma in miners and mill employees in the Cape Province of South Africa and Western Australia, as compared with little or no reported incidence of this cancer in the Transvaal Province of South Africa or Bolivia. Fiber dimensions measured with the scanning transmission elec-tron microscope showed that crocidolites from Western Australia and the Cape Province have more thin fibers than crocidolites from Bolivia and the Transvaal Province.

Jan 1, 1985

By J. B. Zadra

Much has been published by various investigators on the use of activated carbon for adsorbing precious metals from cyanide solution and pulp. For the benefit of the reader, a list of these earlier publications appears at the end of this report. The present paper deals only with a process for extracting gold from gold-laden carbon and re-use of the de-adsorbed carbon. At the Getchell mine, Redhouse, Nev., experiments have been in progress for several years concerning the use of activated carbon to adsorb gold from their slime circuit pulp. The experimental work has been successful. Their practice has been to ship the gold-laden carbon to a smelter for treatment, which meant the total loss of the carbon in addition to smelter and freight, charges, all of which proved costly and wasteful.

Jan 1, 1950

By John C. Edwards

A fire location computational model was developed by the U.S. Bureau of Mines. The model can determine all the possible paths in a mine that smoke can travel from a fixed fire source to a smoke detector. The associated FORTRAN computer program can be utilized to determine the minimum travel time from a source fire to a smoke detector. The difference in travel time from an isolated fire source to two or more detectors can be used to isolate those airways in which the source fire is located.

Jan 1, 1990

By Louis A. Panek

Determining the change of stress in rock based on measurements of the deformation of a drill hole is a procedure that is increasing in popularity. A closely related procedure involves the applicat10n of this principle to determine the existing stresses in a rock medium, by cutting free (core drilling) an annulus containing the drill hole. In this Bureau of Mines report, expressions are derived from which one can calculate the stress ellipsoid--the three-dimensional change of stress, or the existing three-dimensional stress field, as the case may be. Study of these equations shows that the stress components in three dimensions can be determined by measurements in only two drill holes, and yields general principles that are useful in planning an efficient program of drilling and measurement. Procedures are given for calculating the least squares estimates of the stress components and their standard errors, and for evaluating or comparing calculated values by means of standard statistical inferences.

Jan 1, 1966

By R. S. Dean

Boron compounds have been considered for many years as possible additions to iron and steel. A very recent use of boron-steel rods was for the control of neutron intensity in the graphite-uranium pile at the Clinton plutonium plant(130).4/ Norris(129) reports that slags containing boric oxide reduce the ferrous oxide content of steels and thereby the aluminum required for deoxidation. Boron is not considered an alloying element, but minute amounts produce what is often called a "needled" steel. The study of a series of iron-boron alloys by convenient steps, starting with iron containing no boron, indicated that boron was a hardening agent and made the iron very difficult if not impossible to forge. Then came the discovery that very minute traces of boron are quite different from the smallest amount previously thought worthy of study.

Jan 1, 1946

By F. E. Harris

The United States produces about 30 percent of the world output of salt. Numerous deposits occur in widely separated areas, but the leading producing States are California, Kansas, Louisiana, Michigan, New York, Ohio, Texas, Utah, and West Virginia. Although no great amount of salt is produced at present in Pennsylvania, the potential sources in that State recently aroused a good deal of interest. The United States salt industry is highly organized; it comprises fewer companies than when small crude works with primitive methods and equipment eked out salt for local needs, but concentration of output brought about by modern inventions and methods of production has improved the quality of the produce greatly and accelerated production.

Jan 1, 1939

By Glen C. Reed

"The Avon mica district of Latah County, Idaho, is situated on a heavily forested spur of the Thatuna Range at an average altitude of 4,000 feet. The nearest rail connection is at Avon, a small farming settlement 7 miles to the south. The main supply point is Moscow, Idaho, which is 35 miles by graveled and graded county roads from Avon.Discovery of mica-bearing pegmatites in 1885 was followed in 1888 by exploitation of several outcrop deposits. Although factual data are unavailable, past production appears to have been well in excess of $100,000. Recent production (September 191 to April 1945) amounted to 65,824.78 pounds of trimmed sheet mica and 33,294.17 pounds of punch mica having a total gross value of $434,298.The several properties of the district are variously owned by estates, individuals, and the State. When active, all wore under lease or sublease to individual operators.The deposits are in an area of pre-Cambrian schists adjacent to a small granitic outlier of the Idaho batholith. The pegmatites are nearly concordant in dip and strike to the foliation of the enclosing schists. The more persistent bodies are usually tabular, lenticular, or pegmatite. Individual dikes range in length from 10 feet or less to 300 feet.The recoverable crude mica content of the pegmatites ranges downward from a maximum of 115 pounds per ton of pegmatite mined. Material discarded in rifting and trimming operations further reduces recovery to a maximum of 5 pounds per ton -of pegmatite mined. The average recoverable sheet content of the 'recently operated .deposit is estimated at 2 pounds per ton of pegmatite -mined. Available data indicate that about 21 percent of the district's recent production of trimmed sheet mica has been ""Group A"" material suitable for exacting condenser requirements. A few of the dikes contain local concentrations of beryl.Reserves of the three known major deposits of the district are estimated at about 600 to 1,000 tons of combined ""indicated"" and ""inferred"" crude block mica. One of these deposits is inferred to contain between 150 and 450 tons of beryl.It is believed that those mica reserves are minable only under a cost-market price ratio similar to that established during 1943 and 1944. A small part of the reserves can be ""high-graded"" under the present price structure. Profitable recovery of the beryl would require a market price four to five times that paid in 1944.Preliminary examination of the Avon mica district was made by the Bureau of Mines in the summer and fall of 1942. A study of the Muscovite mine and a brief reconnaissance of the surrounding district led the Bureau to recommend that the district be explored by angle-dozer trenching."

Jul 1, 1946

By Y. Miron

'This report presents a U.S. Bureau of Mines study to identify the causes of self-heating events beneath the floor of a deep underground coal mine. Mine samples from both heated and unheated areas were examined by various techniques, including visual, microscopic, thermal, chemical, and instrumental tests. The combined results led to the conclusion that pyrite (FeS2) oxidation was the prime cause of the beatings. However, adiabatic oven tests of selected samples did not indicate the effect of the pyrite on the self-heating process, probably because of the experimental conditions. A fast, simple procedure to assess the concentration of pyrite in the mine samples was developed, g the reactivity of the sample with an aqueous solution of hydrogen peroxide (H2O2).

Jan 1, 2010

By G. E. McElroy

"while investigating the presence of heavy strata gases* in certain mines of the East Tintic mining district of Utah, a small, local body of light, very hot gas of high-nitrogen composition was noted in one of the mines. Observations and analyses indicate that this light gas was resulting from very rapid oxidation of finely disseminated pyrite, in lead-silver sulphide ore. The gas was actually mine air which had lost a large proportion of its oxygen content by reaction with the pyrite. This body of gas was hanging in a local high spot about 5 by 5 by 5 feet in size, caused by caving, at the end of a crosscut. Fifty feet from this spot, an air current of 6000 cubic feet per minute was entering the 5 by 7 foot cross-cat from a raise from below.On account of the vapor contained in the gas, the bottom level of the gas could be plainly seen and was practically a horizontal plane, but of slightly wavy appearance, coinciding with the point where an acetylene light was extinguished. This body of gas was visited on three occasions and samples obtained by means of evacaated bulbs and by water displacement. The temperature of the gas was ap¬proximately 175 degrees P. on all three occasions, so that sampling required thick gloves and quick action. Air three feet below the vapor line had a temperature of only 120 degrees F., and a relative humidity of 27 per cent. The stratification of the air and gas mixtures was so sharply defined that the sampler could hold his head a few inches below the vapor level for an appreciable period of time without any noticeable effect other than that due to the high temperature. At one foot below vapor level, it was 135 degrees F., and the relative humidity was 30 per cent. When a candle and an acetylene light were raised into the gas from below, the candle flame was extinguished at a point two inches lower than the acetylene flume, indicating a drop in oxygen content from about 16 per cent to 12 per cent (oxygen content of normal dry air 20.05 per cent) in the distance of two inches."

Sep 1, 1921

By Edward C. Peterson

Recent studies indicate that the United States halt substantial reserves of ilmenite, one of the major titanium minerals. However, the studies showed that sources of rutile, another important source of titanium are limited. This paper summarizes and evaluates results and conclusions reached by the various investigations initiated by the Bureau of Mines and others pertaining to the titanium mineral resources of the Nation. Domestic occurrences of ilmenite that are economically exploitable by present-day beneficiation methods are found in Florida, New Jersey, New York, South Carolina, and Virginia. These deposits are estimated to contain 50.3 million tons of titanium dioxide (TiO2). Occurrences of ilmenite that cannot be processed economically under present technological conditions are found in California, Colorado, Minnesota, Montana, Oklahoma, Oregon, Rhode Island, and Wyoming. These reserves amount to 51.1 million tons of TiO2. Reserves of rutile found in the United States are estimated to be 1.8 to 2.1 million tons of TiO2. Other than occurrences in Florida and South Carolina, rutile is found either in small scattered bodies or in deposits where the mineral cannot be recovered economically by present beneficiation methods.

Jan 1, 1966

By Beatrice Lukens, David Schlain, John D. Prater

"The electrolytic manganese process4/ developed by the Bureau of Mines involves the electrolysis of a solution of manganese sulfate and ammonium sulfate in a diaphragm-type cell. Metallic manganese is deposited on the cathodes, and sulfuric acid is produced at the anodes. The spent electrolyte contains, in addition to the sulfuric acid, approximately 40 percent of the manganese sulfate and most of the ammonium sulfate originally present in the feed solution. This spent solution is used to leach fresh ore that has previously been subjected to a reducing roast. The resulting leach liquor is purified and returned to the cell.Manganese of very high purity is produced by the electrolytic process. The properties of this metal are so different from those of the best grade of manganese that can be made by any other commercially feasible process that it is virtually a new material. Electrolytic manganese has been used in the preparation of new high-manganese alloys with valuable properties.3/ and further developments are to be expected. The electrolytic manganese process not only results in a product of superior qualities, but is applicable to large tonnages of domestic ores that are unsuitable for direct use in producing ferromanganese.The future industrial use of electrolytic manganese is of course, related to its cost. Decreases in the cost of production will lead to wider use of the metal; conversely, increases in the volume of production made possible by greater demand will bring further .decreases in cost."

May 1, 1946

By Russell J. Foster

Public awareness of, and involvement in, recycling has increased significantly in recent years. Nevertheless, recycling is generally perceived as a new development, and is familiar only in the context of municipal solid waste management. The actual magnitude and scope of metals recycling in the United States have gone virtually unnoticed. Over time, both the quantitative and qualitative aspects of secondary metals recovery and reuse have changed substantially, while the attendant regulations have become increasingly stringent. This U.S. Bureau of Mines report examines trends and developments in major metal demand and recycling, and analyzes the possible impacts of regulations with regard to recycling activities.

Jan 1, 1994

By Kevin Malone

Mercury, or quicksilver as it is often called, has many applications in modern technology. Used principally in electrical apparatus, industrial contol instruments, insecticides and fungicides, electrolytic preparation of chlorine and caustic soda, chemical processes, pharmaceuticals, and dental preparations, the liquid metal has unusual properties that make it a preferred material for many industrial uses. United States consumption of mercury during the past 40 years shows a rising trend. In all except 4 years, U.S. production has been less than the domestic requirement, and imports, principally from Spain, Italy, and Mexico, have supplied most of the deficit. After World War II, domestic output decreased rapidly until 1950, when it was the lowest in the 100 years covered by production records. Higher mercury prices since 1950 have reversed the decline in domestic output and reduced the gap between U.S. production and consumption. Domestic output in 1958 was the highest in peacetime since 1883; however, the nation still imported 28 percent of its mercury requirements from 1950 to 1960 the price of mercury was high as a result of industrial applications of the mercury cell, the impact of the cold war and the Korean war, and the Government stockpiling program. The stockpiling program, in effect, put a floor under mercury prices even though only 9,428 flasks of domestic mercury went into the stockpile under the original program which ran from July 1954 to December 31, 1957. Under an extension of the program, an additional 17,463 flasks was purchased.

Jan 1, 1962

By W. Hermanson

This report, which covers the period from January 16 to October 21, 1974, describes the work performed in compliance with the requirements of contract no. H0242028 and modifications 1 and 2 thereto. The purpose of the contract was to further reline and modify three of the canopies (shuttle car, loader, and roof drill) which were developed under contract no. H0220031, and to conduct further testing and demonstration of the relined designs. Modifications I and 2 involved conducting further in-mine evaluations of the face. drill and cutter canopies, also developed under contract no. H0220031. In addition to the canopy modifications, the contract involved an evaluation of an operator's seat concept for a shuttle car which was developed for the USBM by another contractor.

Jan 1, 1974

By T. E. Gray

This report describes the preparation characteristics of the more significant coalbeds in Monongalia County, W. Va. It is one of a Bureau of Mines series planned to determine coals suitable for producing metallurgical coke, either as mined or after beneficiation. Over 9.5 million tons of coal was produced in Monongalia County in 1957, of which more than 7 million tons was cleaned mechanically in 8 cleaning plants. On January I, 1954 the Bureau of Mines estimated that 1,576 million tons of recoverable coal remained in the county in beds 28 inches or more thick.

Jan 1, 1960

By D. C. Dahlin

To identify and characterize potential domestic chromium resources, the Bureau of Mines investigated podifom chromite deposits along the Border Ranges Fault in southern Alaska. Part 1 of this two-part report describes an extensive field investigation and preliminary resource evaluation studies by the Bureau's Alaska Field Operations Center. This paper, part 2, describes the mineralogy of 38 samples that were collected from low-grade deposits in the Chugach Mountains, on the Kenai Peninsula, and on Kodiak Island, and presents the results of laboratory batch beneficiation tests designed to concentrate the chromite. The samples are peridotites and chromites that consist primarily of variable amounts of chromite, olivine, and serpentine. They were beneficiated by a sequence of grinding, sizing, and gravity concentration operations. Twenty-four high-chromium or marginal high-chromium chromite concentrates, six high-iron or marginal high-iron chromite concentrates, and five submarginal concentrates were produced with chromium recoveries that ranged from 37 to 95 pct. Three very low-grade samples were not beneficiated. These results indicate that several of the de- posits may be significant chromium resources, Potential precious metals association with the chromite was also investigated. Analysis of these samples indicates that the chromite deposits are not good platinum sources.

Jan 1, 1985

By A. L. Toenges, F. A. Jones, J. N. Sxudder, E. R. Maize

"INTRODUCTION This report is the second of a series of studies of analysis of energy requirements and characteristics of various machines used in the production of coal in underground mines and the losses in distribution of energy to these machines. The test equipment used in these studies is described in Report of Investigations 3615. 7/ The preliminary study data and results of tests made on various types of mechanical-leading cutting, and transporting equipment at two mines. This report is analysis of the energy requirements of the energy requirements of the underground equipment of a third mine. An analysis of the use of energy and its distribution usually requires in a saving in energy consumption and the reduction of hazards. The distribution system should be designed to supply energy effectively and study for the efficient operation of all machines."

Feb 1, 1943

By Edward L. McHugh

The study area, which comprises 28,443 acres within the Jacumba Wilderness Study Area, is in the California Desert Conservation Area, and along the U.S.-Mexico border 25 miles west of Fl Centro, CA. The U.S. Bureau of Mines evaluation of mineral resources is based on examination of mining claims, known mineral occurrences, and mineralized zones during the fall of 1983. Limestone resources were identified inside the study area; tungsten resources may he present. Metasedimentary rocks intruded by Cretaceous Quartz diorite predominate in the study area. Tungsten and some gold have been found in skarn zones along intrusive contacts; limestone deposits are in the pre-Cretaceous rocks. Tertiary and Quaternary volcanic flows, pyroclastic rocks, clay beds, and diatomite in lake deposits nave been investigated for possible non-metallic resources. Evidence of mining or prospecting was found at 26 sites in or just outside the study area. In 1983, 106 claims were held in 13 claim groups. One claimant was sporadically prospecting for gold on claims in the north part of the study area in 1983, and gravel was being mined from alluvium 1/4 mile to the east.

Jan 1, 1985

By David R. Peterson

This report presents a deep ocean mining operational simulation which is capable of describing the response of the bottom collection unit to specified mining ship maneuvers and the corresponding operation of the mining ship maneuvering system. Bathymetry, obstacles, collector and pipe dynamics and ship maneuvering capabilities are included in the simulation. The simulation is capable of evaluating the technical requirements and operating costs for specified mine plans, Results are useful in assessing mine size requirements and provide operating 'cost 'estimates useful as inputs to deep ocean mining economic feasibility assessments, The simulation is used to determine the consequences of obstacles to mining system operations in terms of impact on mine size requirements and reduced production arising from obstacle avoidance maneuvers of a towed (unsteered) collector.

Jan 1, 1979

By David M. Gullikson

As part of its program of petroleum production research the Federal Bureau of Mines has long been engaged in the study and development of systems of analysis of oilfield waters (8, 12, 20, 21, 22, 27, 30).21 However, many of the early chemical procedures developed by the Bureau and widely adopted by the petroleum industry are time consuming, and some are unreliable for determining certain constituents found in California oilfield waters. Because of the need for more rapid and more accurate methods having greater sensitivity with low concentrations of some constituents, a study has been made by the Bureau's Petroleum Research Laboratory at San Francisco, in developing new techniques and modifying previously published techniques for analyzing oilfield waters by flame spectrophotometric, potentiometric, and colorimetric methods. Test solutions were synthesized for testing the suitability and accuracy of the procedures, and the effect of interfering ions. These solutions contained known quantities of characteristic constituents of oilfield waters including sodium, magnesium, potassium, calcium, lithium, strontium, barium, sulfate, chloride, bromide, iodide, carbonate, bicarbonate and borates in a wide range of concentrations. The compositions of these synthetic brines are listed in table 22. Many California oilfield waters contain salts of petroleum-derived organic acids and several synthetic oilfield waters also were prepared to which large quantities of naphthenates or salts of petroleum acids were added.

Jan 1, 1961