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By T. A. Sullivan

The use of sulfur combined with either sand or waste copper tailings was investigated by the Bureau of Mines as a substitute for a good graded aggregate in asphalt paving materials. The research was part of a utilization program to develop meaningful uses for a projected oversupply of sulfur. Many sections of the country lack good aggregate for paving but do have available sources of sands and sulfur. The development of paving mixtures of desert sands or tailings with sulfur and asphalt was accomplished in the laboratory and tested by laying small paving test sections. Three types of material were studied for use with the sulfur and asphalt. They were (1) a concrete sand similar in gradation to river or beach sands, (2) desert blow sand, and (3) waste copper tailings. Desert blow sand and waste copper tailings are much finer than concrete sand. Mix designs were established for the three types of materials, sulfur, and asphalt used in the paving materials. The best mix designs were as follows, in weight-percent: 80.5 concrete sand, 13.5 sulfur, and 6 asphalt; and 77 either blow sand or tailings, 17 sulfur, and 6 asphalt. Small-scale testing showed that these mixtures were suitable paving materials but would require specialized equipment for transporting and laying. The chemical modification of sulfur to obtain properties that would allow placement of these materials with normal asphalt paving equipment was studied. Results indicate that reacting sulfur with dicyclopentadiene before adding it to the paving mixture was effective in modifying the sand-sulfur-asphalt paving so it could be placed and rolled with conventional equipment.

Jan 1, 1975

By M. J. Waller

Surface resistivity techniques were used at four field sites to monitor changes in apparent resistivities with variations in soil moisture content in the vadose zone. Apparent resistivity values were correlated with gravimetric moisture contents from soil samples taken at each site. Tensiometer readings were taken at two sites and correlated with the results of gravimetric moisture contents and apparent resistivities. Moisture at two of the sites was added by extensive watering; rainfall events were monitored at the other two sites. A recharge event at a dewatering program was monitored at a fifth site. A Ghosh-Koefed multi-layer computing algorithm was used to derive true resistivities from bulk or apparent resistivities. An automated data acquisition system was developed to measure resistivity changes and to process the data in the field. These studies are the first to evaluate measurement of moisture migration in clay rich soils using surface resistivity techniques. Results indicate that surface resistivity techniques readily measure changes in moisture contents in the vadose zone in clay rich soils. Correlation of apparent and true resistivity values with gravimetric moisture contents is more complex and requires additional research.

Jan 1, 1986

By E. D. Eastman

"The factors that determine the efficiency of reduction of iron oxides by gaseous reducing agents may be considered in two classes; those which effect the equilibrium between the reacting substances end their products, and those which affect the rete of reaction. Both sets are of prectical importance, the former as influencing the maximum possible efficiency and the latter as determining what fraction of the maximum yield may be readily or profitably obtained. In addition, the thermal changes attending the reduction greatly affect the chance of successful industrial application of any such process, and knowledge of them is necessary for the intelligent design of apparatus and control of the reaction. Some aspects of each of these three divisions of the problem are discussed below.I. The Maximum Reducing Power of Fuel Gases on the Oxides of IronsThe gases that heve been considered specifically in this work are coal gas, water gas and producer gas, typical analyses” of which are given in Table 1 Of the various hydrocarbons represented in Table 1, (several being grouped or averaged as C2R4), methane is the only gas assumed to be capable of existence at appreciable pressures under the conditions of interest here. The equilibria in the several systems which may ensue when one of the above gases is allowed to react with the iron oxides, may therefore be represented in the most general case by equations of the type of the following arbitrarily chosen ones:"

Jun 1, 1923

By William H. King

The Mining Division of the Bureau of Mines has been making development and power-requirement studios for the Interior Department Missouri Basin Field. Committee. The studies by the Bureau of Mines have as their purpose, the summarizing of potential future power requirements in the mineral industry within the Missouri Basin, special emphasis being placed on possible expansion of these requirements through construction of new mining enterprises by private capital. In preparing a proposal for the production of phosphoric acid from phosphate rock near Lander, Wyo., it was found that the basic information on the physical and chemical characteristics of the phosphate beds to determine costs of mining and treatment was lacking.

Jan 1, 1949

By David R. Hanson

Transient electrical noise events pose serious problems for data acquisition systems used in monitoring acoustic emissions in laboratory and field environments. The U.S. Bureau of Mines has designed and constructed a trigger discriminator circuit for use in ultrasonic acoustic emission studies. Designed for use with signals in the frequency range of 50 to 400 kHz, the instrument examines .incoming signals for frequency content, amplitude, simultaneity, threshold crossings, and number of channels above threshold. If preselected criteria on these properties are met, a plus 5-V pulse is output that may be used to trigger a data acquisition system, allowing rejection of noise events that do not possess useful information. The system was designed for four input channels, but may be expanded to more channels with minimal design changes.

Jan 1, 1995

By Thomas L. McVay

Laboratory batch and pilot plant flotation tests were made to determine the feasibility of recovering commercial grade kyanite from a quartzite- kyanite rock from the Graves Mountain, Ga., deposit. Best results in laboratory and continuous tests were obtained using sodium carbonate for pH control, citric acid for quartz depression, and oleic acid as the kyanite collector. Over 80 percent of the kyanite was recovered in a concentrate analyzing 56.8 percent Al203 and 3.8 percent hydrochloric acid soluble Fe203. Subsequent treatment of the flotation concentrate by magnetic separation reduced the acid soluble Fe2O3 to 0.6 percent and increased the alumina content to 59.2 percent. Acid leaching of the concentrate gave a product analyzing 59.7 percent Al203 and about 0.1 percent Fe203. As a result of the beneficiation research, a commercial kyanite flotation plant was completed in September 1962 by private industry.

Jan 1, 1963

By Terry J. Kreidler

In recent years, west-central Arizona and adjacent California have become the focus of geologic and exploration attention because of its excellent exposure of detachment-fault terrane. Detachment faults, normal faults with nearly horizontal fault planes, are the result of regional extension. Rocks on the lower plate consist of mylonitized intrusive, metasedimentary and crystalline rocks highly altered to chlorite; upper plate rocks comprise sedimentary, volcanic, metasedimentary, and metavolcanic rocks. The movement of the detachment fault causes the rocks on the upper plate to be severely fractured and brecciated thus making them Ideal conduits for mineralizing fluids. Mineralization favored the more reactive sedimentary and volcanic rocks of the upper plate. Three gold deposits, located in upper plate rocks, are currently being mined along the Colorado River corridor: the Picacho Mine near Yuma, Arizona, 70 mi south of the study area; the American Girl Mine In southeastern California, 60 mi southwest; and the Copperstone Mine near the southern end of this study area. Samples from the above three mines were used to create a geochemical model of detachment-related gold deposits. Antimony, arsenic, barium, copper, mercury, molybdenum, manganese, tungsten, and zinc all occur In the mine samples in concentrations at least three times greater than found elsewhere in similar rock types. Samples taken by the Bureau from the wilderness study areas contain similar anomalous concentrations of the same elements as well as elevated concentrations of several other elements Including: lead, fluorine, cerium, uranium, and samarium.

Jan 1, 1992

By F. E. Block, T. T. Campbell, D. Z. Hobbs

Several methods were investigated for the preparation of high- purity elemental boron in an attempt to develop a feasible process for producing boron on a large scale . In the work described in this report , the metal was prepared by metering boron trichloride gas into a crucible containing molten metal reductants . It was necessary to remove reaction byproducts by acid and aqueous leaching . Magnesium and sodium were tested as reductants , but best results were achieved using lithium or zinc as reductants . Contaminants originating from the materials of construction were the chief impurities in boron made by this method . Impurities ranged from 0.5 to 5.0 percent . Impure boron ( 85 to 90 percent ) was also prepared by the magnesium reduction of boron trioxide in a thermite - type reaction . This product contained magnesium as the chief contaminant . Impure boron made in this way could be upgraded by fusing with potassium fluoborate or potassium acid fluoride . After acid leaching the fusion cake , a product containing 95 to 97 percent boron was obtained . Analytical techniques for accurate determination of impurities in elemental boron are a major problem , requiring solution before a valid comparison can be made of the quality of boron prepared by these various methods .

Jan 1, 1964

By R. M. Becker

As part of the Bureau of Mines program for examining the Nation's iron and titanium resources, magnetic, gravity, and geologic surveys were made to permit an estimate of the extent and magnitude of the Iron Mountain, Colorado, titaniferous magnetite deposit. Gabbro is the dominant rock type of the area. Within the gabbro are lenses of titaniferous magnetite, 5 to 25 feet wide and as much as several hundred feet long. These lenses comprise a zone which has scattered occurrences of magnetite for 2,200 feet. To the west, the gabbro grades into a strip of pyroxenite that in turn borders a large monzonite mass. A wedgelike broadening of the pyroxenite with depth accompanied by little or no increase in the titaniferous magnetite is considered a reasonable interpretation of the field data. The iron deposits appear to be limited and discontinuous.

Jan 1, 1961

By A. D. Garman

This digest of Brazilian mining law is based upon Decree 4265 of January 15 , 1921 , and its regulation , Decree 15,211 of December 28 , 1921. Unless otherwise stated , the references are to the latter exclusively , since it includes practically everything contained in the law itself . It should be borne in mind that these regulations do not necessarily apply to mines other than those on private and national land . Each State of the Union is free , in respect to State land , to regulate or interpret the national mining law , which is very general in its terms , as it sees fit . Whether such local regulations are anywhere in force with respect to the law of 1921 the bureau has not been informed . Article 64 of the Constitution indicates that only such portions of territory as are required for the defense of the frontiers , for fortifications , military constructions , and federal railways belong to the Union . Lessees of such lands , unless in debt to the Treasury , have preferential prospecting rights for one year ( art . 28 ) . This carries with it the right to work any mines discovered (Law , art . 12 ) .

Jul 1, 1930

By Frank Ruskey

This report describes a computer program devised by the Bureau of Mines to model coal-mining situations where one or more panels encounter oil or gas wells. The program seeks in several hundred trials to evade the wells if possible or to minimize their influence by shifting or skewing the mine plan and/or adjusting the centerline dimensions of the entryways. Upon completion of computations, the program sorts the hundreds of models which have been tested, and lists the 10 best with their associated parameters. It also draws a mine plan of the best configuration, showing the entryways and crosscuts along with the "lost" coal remaining in the barrier pillars surrounding the various wells.

Jan 1, 1972

By W. A. Stickney, J. W. Town

Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .Batch and continuous - circuit flotation , leaching , precipitation , and electrodeposition studies were made by the Bureau of Mines to determine optimum conditions for treatment of complex mercury - antimony sulfide and mercury- arsenic sulfide ores and concentrates . On the Red Devil ore sample over 95 percent of both the mercury and antimony sulfides were recovered in a flotation concentrate containing 35.6 percent mercury and 21.0 percent antimony . By selective flotation a mercury concentrate containing 71.0 percent mercury and 2.9 percent antimony was obtained with a mercury recovery of 90.4 percent . Leaching results show that , with 150 grams per liter of sodium sulfide and 50 grams per liter of sodium hydroxide , 95 to 99 percent of the mercury , antimony , and arsenic sulfides could be extracted from the concentrates treated . Sodium hydroxide reagent consumption was based on the sulfides generated in the dissolution of the sulfide minerals and on the method of metal recovery used . Selective leaching of the antimony and arsenic sulfides with potassium sulfide dissolved more than 95 percent of either of these two sulfides and 0.5 to 5 percent of the mercury sulfide present . Methods for recovering mercury and antimony from solution were electrodeposition of mercury followed by electrodeposition of antimony , aluminum precipitation of both mercury and antimony , or antimony precipitation of mercury followed by antimony electrodeposition . The method used in recovering the mercury depended on the mercury- antimony content of the solution being treated .

Jan 1, 1964

By Mark W. Ryan

The U.S. Bureau of Mines conducted a study to determine if commercially available automatic sprinklers could withstand the high static pressures in deep underground coal mines without leaking and if exposure to the mine environment affected their leak pressures. New sprinklers and sprinklers exposed to the mine environment were subjected to increasing pressures until leakage occurred. The average leak pressures of the new sprinklers ranged from 640 to 2,300 psig and were significantly different for sprinklers from different manufacturers and for different types of sprinklers. Generally, standard-response sprinklers withstood higher pressures than fast-response sprinklers. The results indicated that most commercially available sprinklers would withstand the high static pressures in deep underground coal mines; however, they would not provide the same reliability and safety factor as sprinklers used aboveground at or below their rated pressure of 175 psig. The average leak pressures of the sprinklers exposed to the mine environment ranged from 740 to 1,180 psig. The mine environment affected the ability of 66% of the sprinklers to withstand high static pressures. New sprinklers were also evaluated at pressures of at least 500 psig for 30 days to determine their ability to withstand long-term exposure to high static pressures; no leakage was observed.

Jan 1, 2010

By V. B. Dale

This is one of a series of reports covering the mineral resources of the Nation. It describes briefly most of the known tungsten deposits in Yuma, Maricopa, Pinal, and Graham Counties, Ariz. Most of those described were examined by the author. An effort was made to determine the position of the various deposits by section, township, and range and to give accurate road direction to each property from a prominent landmark. All available maps have been used in making these determinations, but in unsurveyed areas it was necessary to make approximate projections of subdivisions. The township and range numbers refer to the Gila and Salt River base and meridian.

Jan 1, 1959

By Francis X. Cannaday

The Bureau of Mines developed equipment to measure the sonic velocity of pulses transmitted through rock samples varying in size from laboratory specimens to mine pillars in place. Pulses are produced by electronically excited piezoelectric ceramic transducers. Special equipment components were developed by Bureau facilities; other components are commercially available. The technique permits a nondestructive, repetitive, stable, shaped pulse to be used in place of explosive caps or hammer blows. Longitudinal wave travel time measurements were taken on an oscilloscope screen; transverse wave measurements were taken under special field conditions. Results were consistently repeatable within the accuracy of the oscilloscopes utilized.

Jan 1, 1966

By C. E. Julihn

In the fall of 1933 a new discovery of gold was made in the old Mojave mining district of California about 70 miles north of Los Angeles. It led to mining operations that have surpassed in their results all reasonable expectations and are of exceptional promise for the future. In less than 3 years, exploration has opened up a number of veins, from some of which a substantial amount of high-grade ore has been shipped, while a large tonnage of milling ore has been disclosed. Two mills, operating on ore averaging better than $12 a ton, will probably produce more than a million dollars worth of gold in 1936, and a considerable increase of their output in the following year is anticipated. While continuance of these operations for a number of years is already assured by ample reserves of ore, future discoveries of still other veins are reasonably possible, as occurrence of gold throughout the volcanic rocks of the district is widespread and the veins now being mined showed little to attract attention at the surface.

Jan 1, 1937

By John W. Frey

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of cw Zealand, as prepared by Dr. Frey the best available information in Washington, has been slightly amplified in accordance with suggestions transmitted through the courtesy of the Department of State by W. L. Lowrie, Consul General at Wellington.

Oct 1, 1929

By G. L. Neumann

The Guymard mine in Orange County, N. Y., is reported to have been discovered in 1862 and mined until 1876, producing 10,000 tons of lead and zinc ore. The property was examined by an engineer of the Bureau of Mines in 1948. Development work was done by the Bureau in April and May 1949 and March 1950. During these two periods four drill holes totaling 2,090 feet were completed. The mineralized sections of the core were sampled and assayed.

Jan 1, 1952

By John F. Papp

International and U.S. chromium material flow, losses, and environmental releases and transfers from mining through industrial processing, end use, and recycling are identified and quantified. Average (1983-92) U.S. consumption has been: metallurgical industry, 87 pct; chemical industry, 10 pet; and refractory industry, 3 pct. Average chromium content of aluminum, cobalt, copper, nickel, and titanium alloys and alloy, carbon, and stainless steel alloys was estimated. Anthropogenic chromium consumption was estimated for the cement and copper industries. N on-commodity cycle anthropogenic chromium mobilization resulting from U.S. fuel and fertilizer use was estimated. Commodity cycle anthropogenic world chromium loss from mining and primary consumer industry was estimated to be equivalent to about 56 pct of chromium contained in chromite ore production and represented a loss rate of 181 kt-Cr/Mt-CrOre. Chromium released to the atmosphere from natural and from anthropogenic sources were comparable in magnitude. Chromium released to soil was mostly from anthropogenic sources, and aquatic releases were all anthropogenic. Domestic product chromium losses exceed process losses by more than a factor of 10 showing the importance and potential environmental impact of post-consumer recycling. The location of historical and current domestic chromium industry processing sites in 23 States were reported. Chromium releases and transfers to the environment were estimated from 1973 through 2002 by primary consumer industry. A decrease in chromium releases and transfers to the environment was anticipated.

Jan 1, 1995

By Bruce I. Thomas

The Fairbanks mining district forms an arc 40 miles long and 8 miles wide on the north side of the Tanana Valley in central Alaska. This is a region of broad valleys and rounded hills that range in elevation from 600 to 2,600 feet Lode-gold production started in 1910 and has continued sporadically to the present, but the largest single mine produced only 40 tons per 24-hour day. Total recorded lode-gold production of the district is 241,000 fine troy ounces of gold from ore that averaged 1.32 fine ounces per ton. The ore was mined chiefly from narrow veins and veinlets alined along anticlinal folds at Ester Dome and the Pedro Dome-Cleary area. The only proven reserves are reported to be at the Ryan Lode at Ester Dome and at the Keystone Mines, Inc., holdings in the Pedro Dome-Cleary area. An inferred lode-gold resource for the district of approximately 4,000,000 ounces is considered to indicate only the order of magnitude of the lode-gold potential because of the absence of detailed data needed to evaluate the numerous deposits.

Jan 1, 1973