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By Frank G. Horino

Drill cores from 18 exploratory holes that were drilled into the unleached saline beds were tested for mechanical properties by the Bureau of Mines. Test cores were primarily selected from zones L4B, R4B, L3, and R3A in the Piceance Creek Basin, Rio Blanco County, Colo. Regression analysis techniques were tried in an attempt to relate kerogen yield or apparent specific gravity to the parameters compressive strength, Young's modulus, and Poisson's ratio. Correlation coefficients were very poor, indicating that this type of analysis was not amenable to these data. Analysis of variance techniques were tried using a division of either greater than or less than 10% nahcolite together with the requirement of less than 3% dawsonite. Results showed that a larger percentage of nahcolite tended to lower the compressive strength and to increase Young's modulus. A second analysis was made using a division of less than 3% dawsonite and greater than 3% dawsonite together with the requirement of less than 1% nahcolite. For this analysis, a larger per-centage of dawsonite tended to increase compressive strength, Young's modulus, and Poisson's ratio. Mean compressive strength values were determined for the mining horizons of interest. Average physical properties for design purposes were also determined for the horizons of interest and for a proposed adit based only on logged geologic depths to these horizons. No consideration was given to percentages of nahcolite and dawsonite. Creep data obtained from nahcolite-and dawsonite-rich oil shales provides a best fit to a modified power equation.

Jan 1, 1978

By M. D. Aldridge

The results of a two-year research effort aimed at improving communication systems in coal mines is reported. A review of communication methods presently used in coal mines is presented. Theoretical and-experimental results of a four pronged effort in the areas of (1) through-the-earth propagation, (2) paging system design, (3) improvement of wired telephone systems, and (4) carrier current systems are described. Auxiliary systems not included in the above are considered briefly. Various conclusions are drawn in light of practical constraints and the needs of the mining industry. The study clearly demonstrated the need for nine communications to be designed on system basis. The viability of new technology for providing reliable mine communication for improving mine safety and operating efficiency is shown.

Jan 1, 1973

By Mark Sheppard

This paper is the second of a series recording the results of tests made at various quarries throughout the United States to determine, (1) the relation between the size gradation of feed to, and product from, primary crushers; (2) the particle shape of crushed product; (3) the differences in gradation and particle shape produced by different tries of primary crushers; and ( 4) the differences in gradation and particle shape caused by crushing different kinds of stone. Primary crushing has received comparatively little attention in the technical literature in spite of tine fact that the design of the whole crushing plant should be correlated to the performance of the primary crusher.

Jan 1, 1938

By R. S. Warfield

The Kasna Creek copper deposit near Lake Kontrashibuna in the Lake Clark region, Alaska, was the object of an investigative project by the Bureau of Mines during the fall of 1948. Recessed because of inclement weather, it was completed in 1949. This project was a part of the Bureau of Mines program in Alaska for the development of critical and strategic minerals. The ore bodies are contact-replacement deposits in limestone. Mineralization is mainly specular and micaceous hematite associated with chalcopyrite, calcite, chlorite, quartz, and amphibole. The deposit, on the right limit of Kasna Creek approximately 2 miles from the shore of Lake Kontrashibuna, is composed of two mineralized zones that range in altitude from 2,350 to 2,650 feet. This report contains a brief history of the prospect, description of the physical setting of the property, its geology, and the factual results of the Work performed by the Bureau of Mines.

Jan 1, 1951

By David Schlain

The galvanic corrosion properties of titanium and zirconium were investigated by the Bureau of Mines. The dissimilar metals involved in these experiments included magnesium, magnesium alloy FS1, aluminum alloys, zinc, steel, tin, lead, copper, Monel, nickel, and several stainless steels. Couples were immersed in synthetic ocean water, tap water, 5-percent ammonium sulfate solution, 5-1/2-percent sodium chloride solution, sodium hydroxide solution, 0.1 N hydrochloric acid, and various concentrations of sulfuric acid.

Jan 1, 1956

By Lewis V. Wade

This report provides background information concerning a mine roof simulator currently being considered by the Bureau of Mines. The simulator is a mechanical device with the ability to simulate the forces and displacements associated with mine roof over an area 20 by 20 feet. The topics covered in the report include a conceptual description of the system, definition of system capabilities, discussion of how such capabilities were decided upon, description of available control modes, and a comparison between the mine roof simulator facility and similar facilities existing elsewhere.

Jan 1, 1974

By C. C. Merrill

Columbium, tantalum, titanium, and zirconium are present in solid waste products generated by the chlorination of rutile used for production of titanium tetrachloride (TiC14). The columbium and tantalum were separated from titanium and zirconium by liquid-liquid extraction techniques using a secondary amine. Salts of these elements are in a leach liquor produced by water leaching of mineral waste from the chlorination of rutile. This waste, produced at the rate of approximately 50,000 tons per year, is about 40 wt pct water soluble. Leach liquors, separated by filtration, were further separated into a solid fraction and a liquid fraction by pressure hydrolysis, The solid fraction containing Cb, Ta, Ti, and Zr was dissolved in HC1-HF and used as a feed solution. Columbium and tantalum were removed from the organic extractant with 1 [N] HC1. A miniature 10-stage reactor showed that the columbium and tantalum present in solution could be separated with a continuous flow.

Jan 1, 1972

By C. W. Smith

The Bureau of Mines conducted physical and chemical beneficiation studies on three samples of waste investment casting molds to devise a method to liberate and recover zircon. Rod mill grinding, autogenous attrition grinding, and caustic leaching were liberation methods inves-tigated. Flotation, gravity separation, and caustic leaching and sizing were recovery methods investigated. Flotation techniques produced con-centrates containing up to 74.2 pct zircon with a zircon recovery of 53.4 pct. Gravity concentration produced concentrates containing up to 98.6 pct zircon; however, recovery of the zircon was only 57 pct. Caustic leaching and sizing produced concentrates containing up to 98 pct zircon with attendant recoveries of 81 pct.

Jan 1, 1985

By Gerald W. Elger

The Federal Bureau of Mines developed a modification in the conventional Kroll process for preparing high - purity hafnium metal . This modification involved the partial replacement of magnesium by sodium in the batch reduction of purified hafnium tetrachloride to sponge metal . The raw tetrachloride was purified either by thermal degassing of the volatile contaminants to the atmosphere or by fused- salt treatment . In the fused- salt treatment , the tetrachloride was contacted with molten alkali chlorides to remove the impurities . The reaction byproducts were removed from the metal by heat treatment in an evacuated furnace . The metal sponge was consolidated by melting into buttons or ingots , which were analyzed for impurities . The purity of the metal prepared by the modified process is superior to that of the metal produced by the conventional method . The hafnium metal was comparable to crystal - bar hafnium except for the oxygen content , despite the abnormally high impurity concentrations in the raw tetrachloride . Several ingots were successfully cold - rolled to sheet .

Jul 1, 1960

By Lester G. Morrel

THE RICH and varied occurrences of metallic ores in Australia, extensive nickel deposits on New Caledonia and phosphate rock on several widely scattered small islands were important aspects of the economy of the South Pacific area. Relatively small quantities of gold and nonmetallic minerals produced in New Zealand, Fiji, and the Territory of Papua-New Guinea remained important to the domestic economies of these islands, but had little importance to overall world mineral supplies. The value of mineral commodities produced in this area in 1964 was estimated at $658 million,3 compared with $585 million in 1963. The year's greatest commodity gains were in bauxite and aluminum, beryl concentrate, manganese ore, nickel smelter products, tin, and coal. Annual increases were recorded in virtually all countries and possessions in the area except Papua-New Guinea, where the drop in output of alluvial gold accounted for a decline of about $160,000. Mineral industry activities in Australia overshadowed those in all other parts of the South Pacific in 1964. Outstanding developments were the sales contract negotiations and physical preparation for exploiting the rich iron ore discoveries in Western Australia, the initiation of domestic crude oil production, the commissioning of two new steal mills and an alumina refinery and a start on the new alumina-aluminum project based on Cape fork bauxite deposits. The principal mineral development in 1864 in New Zealand was the progress on plans of the Newzealand Steel Co. to use indigenous iron sans as the resource base for a local steel industry. In New Caledonia, additions and expansion of the nickel mining and smelting facilities continued throughout the year. Plans for extensive geophysical studies were announced by the Government Geological Departments of British Solomon Islands and Fiji.

Jan 1, 1966

By S. J. Page, P. Bolsaitls, W. E. Wallace, C. A. Hill, M. J. Keane

"Boiling respirable quartz dust in water for 10 to 40 minutes decreases the cytotoxicity for both erythrocyte hemolytic potential and pulmonary macrophage release of lactate dehydrogenase in vitro. The potential is reduced to near zero in the boiling concentration range of 1 to 10 mg quartz per ml water in boiling times of 20 to 40 minutes. Below this range the detoxification occurs over a longer boiling time. Above this range the hemolytic potential remaining after 40 minutes of boiling approaches native quartz potential with increasing concentration up to 30 mg quartz per ml water. Replacing the media with fresh at the midpoint of boiling results in full detoxification through 20 mg per ml. Pre—boiling the medium with quartz or silica gel reduces the effect of subsequently boiling test samples. Detoxification persists after mild drying at 110 C for 8 hours, and persists after three days of resuspension in water at room temperature. Additional data on persistence of the effect, on the use of acidic and basic media treatment, and on surface analyses are presented, with a discussion of a working hypothesis and research needs.IntroductionResearch underway to determine interactions of quarts and other mineral dust surfaces with pulmonary fluids and alveolar macrophages in culture led to the observation that when dusts were autoclaved in aqueous suspension, their cytotoxic effects on macrophages wore suppressed, in some cases fully and even after several days incubation with the cells. This finding was in direct contradiction to earlier results from both short term macrophage lysosaal enzyme release assays, as well as longer term cytotoxicity assays from macrophages in culture; in those studies, dusts were steam autoclaved at 121 121 ºC with no liquid water but with steam present. (1,2) However detoxification under boiling conditions has been reported in other research.(3). It was decided to use the hemolysis assay to further investigate these findings, because of its sensitivity, simplicity and cost."

Jan 1, 1988

The Bureau of Mines equipped a longwall shearer with a water-jet-assisted cutting system and measured dust levels during the cutting of a simulated coal block. The block was cut dry, at a conventional water spray pressure of 190 psi, and with water-jet-assisted cutting pressures ranging from 1,000 to 6,000 psi. At water pressures of 3,000 psi and higher, dust concentrations were reduced by as much as 85 pct via water-jet-assisted cutting in comparison with conventional water sprays. This reduction was achieved without any increase in the water flow rate.

Jan 1, 1986

By W. C. McBee

Over the past several years the Bureau of Mines has developed a sulfur concrete (SC) technology in which chemically modified sulfur is mixed with suitable mineral aggregates to produce construction materials that are resistant to corrosion by acids and salts. Modified SC materials have been tested in actual operating conditions in 50 corrosive process environments at 40 commercial plants. SC components ranging from small test coupons to 4-ton acid sump tanks were fabricated and installed at plant locations where chemical corrosion was destroying conventional concrete materials. Through cooperative agreements with several companies, floors, retaining walls, and foundations were cast in place us-ing SC materials, then monitored for resistance to corrosion and retention of strength properties.

Jan 1, 1983

By L. D. Gent

This report reviews the current state of the art of remote control techniques for underground continuous miners. A delineation of aspects requiring additional data is presented. Also a summary and delineation are presented in overview form for the related section functions: roof control, haulage, ventilation, power supply and rock dusting. The automated remotely controlled continuous miner project is a long-range research effort. However, the program has been divided into intermediate steps resulting in incremental production increases throughout the program. Data are developed relating the impact of our proposed research and development accomplishments to potential productivity impact.

Jan 1, 1975

Ecuador a gross domestic product (GDP) grew 8% despite a slowdown in production and sales of petroleum, the dominant economic sector. Crude petroleum exports, which amounted to about 35% of total exports in 1977, were valued et $484 million,2 a decrease of 14% from 1976 values. Petroleum export sales were depressed because foreign buyers were somewhat uncertain that State-owned Corporación Estatal Petrólera Ecuatoriana (CEPE) held legal title to the oil until final settlement with Ecuadorian Gulf Oil Corp. In addition to the legal complication, Ecuador maintained a relatively high export price for oil until late in the year. There was also a shrinkage of traditional U.S, markets owing to the Alaskan pipeline becoming operational and an increased availability of Mexican supplies. The export market was also affected by increased domestic production in Peru and Chile, which lessened their import needs, and the pressure of greater competition from the Middle East in supplying crude oil to Caribbean refineries. About 20.4 million barrels or 40% of Ecuador's total crude exports went to the United States. Only 27 wells were drilled in Ecuador during L977; of these, 16 produced oil, 3 were dry holes, and 8 were suspended. About 31 wells were planned for 1978. Three new oilfields were discovered during 1977; two by CEPE in northeastern Ecuador and one by the Argentine State oil company Yacimientos Petraliferos Fiscales (YPF), operating in Ecuador under a service contract. CEPE's two discoveries tested at 5,000 and 1.450 barrels per day, respectively. The YPF discovery tested at about 1,000 barrels per day. Ecuador altered its position regarding

Jan 1, 1981

By Donald F. Reed

During the first 6 months of 1948 the Bureau of Mines investigated the titania, deposit on the Wynn 0. Christy property in northern Hot Spring County, Ark. The property is situated in Magnet Cove, about half a mile north of the Magnet Store and U. S. Highway 270 (fig. 1). The purpose of the investigation was to determine the extent and grade of the ore body and to obtain a representative sample of the ore in as nearly natural condition as possible for use in metallurgical testing. All of the titania that has been marketed from Arkansas mines has been in the form of rutile from a deposit about 2 miles west of the Christy property. The titania in the Christy property occurs principally as brookite, which, with fragments of novaculite, quartz, and limonite, is imbedded in red clay. It is difficult to recover a core of the material. Three types of drills - a diamond drill, a bucket drill, and a Baker cable-coring tool operated on a churn rig - were employed in an effort to procure proper samples in their natural state. The Baker tool was found to be the most efficient and to be capable of drilling to a depth of 150 feet, making 80 to 100 percent core recovery (fig. 8). Total footage drilled was 1,536.9 in 21 holes, of which 7 were diamond-drill holes, 13 were bucket drill holes, and one was drilled with the Baker tool. The ore body was found to be 900 feet long, 500 feet wide, and more than 141 feet deep and contained 5.8 percent TiO2 and 0.52 percent 1720. Most of the deeper drill holes bottomed in ore, and there is a possibility that the ore may persist to a depth of several hundred feet. The Metallurgical Division of the Bureau of Mines is conducting experimental work at the Mississippi Valley Experiment Station at Rolla, Mo., for the purpose of developing methods of concntrating and utilizing the ore.

Jan 1, 1949

By T. C. Wesson

The need for elemental-analysis information on coal mine dust for use in health and safety research prompted this study by the Bureau of Mines. Neutron-activation and X-ray fluorescent techniques were used to obtain five-element analysis (silicon, aluminum, iron, calcium, and magnesium) on 444 samples from 68 coal mines in 10 States. From these analyses, the average composition of the dust in coal mines was determined. The contribution of the primary dusting material (limestone dust) to the makeup of coal mines was shown. Regional differences in mine-dust composition were indicated.

Jan 1, 1974

By M. E. Volin

The Smuggler is one of the mines in the Aspen district, located the central part of Pitkin County, Colo. It was first examined in July 1943 by C. R. Wilfloy, former mining engineer of the Bureau of Mines at Salt Lake City, Utah, in, company with the lessees, R. D. Rohlfing of Aspen and J. W. Vanderwilt of Denver. The purpose of this examination was to sample a mineralized breccia zone that appeared continuous along the contact between the Leadville and Weber formations. These preliminary samples showed that the zone contains low but significant amounts of lead and zinc and that the minerals are partly oxidized and thus not easily concentrated. The mine was examined again in May 1946 by the senior author and William Herron, one of the present lessees of the property. This examination reviewed the previous sampling and recommended investigations by the Bureau of Mines. Sampling and drilling investigations were conducted by the Bureau from October 1946 to February 1947 and again from August 1947 to April 1948. Aspen is the center of a famous mining district that produced over $102,000,000 in silver and lead ores from 1880 to 1918, when a dispute closed down the mines (fig. 1). All of the workings below the Cowenhoven tunnel in Smuggler Mountain and the lower Durant tunnel in Aspen Mountain have been flooded since that time. The Cowenhoven portal now is caved, and Smuggler Nos. 1 and 2 tunnels are the only accessible workings in Smuggler Mountain. The only operating mine is the Midnight, situated 4 miles south of town at an altitude of 9,700 feet.

Jan 1, 1950

By John R. Benham

The Bureau of Mines examined the Bear Canyon RARE II area in 1982. The area has no identified mineral deposits. The few claims that were located in the study area are devoid of any workings. No concentrations of economic minerals were found in the samples taken. There are no mineral, geothermal, or oil and gas leases in the area; the nearest oil well is 10 mi (16 km) east. The nearest mining operation was the Ruby Gold Placer worked in 1914, 7 mi (11 km) southeast (Hart, 1966, p. 45); the Pliocene Paso Robles Formation which contained the gold does not extend into the area. SETTING The Bear Canyon RARE II area covers 19.7 sq mi (51 sq km) or 12,600 acres (1500 ha) in west-central California. It lies in the Santa Lucia Range 10 mi (16 km) southwest of King City and adjoins the southeast side of the Ventana Wilderness. It is 10 mi (16 km) from the Pacific Ocean. Primary access is by the San Antonio River road on the Hunter Liggett Military Reservation, which parallels the area's southern border. Further access to the area's interior is by jeep and foot trails.

Jan 1, 1983

By L. E. Schultze

[The Bureau of Mines conducted bench-scale studies to develop techniques for stripping tetravalent cerium from tri-n-butyl phosphate solutions. Experiments were conducted in a constant-temperature bath using beakers and mechanical stirring. Ninety-five pct of the cerium was stripped from a 50-pct tri-n-butyl phosphate 50-pct kerosene solution containing 0.18 M cerium in 15 minutes at 50° C using 0.11 M aqueous formaldehyde.]

Jan 1, 1974