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By K. K. Kelley, L. B. Pankratz

The heat contents of four silicate minerals -- akermanite , cordierite , gehlenite , and merwinite --were measured from 298 ° to around 1,700 ° K by the dropping method . The results were compiled into tabular and equation forms suitable for thermodynamic calculations . The heat contents of these compounds are nearly additive with respect to their constituent oxides .

Jan 1, 1964

By A. L. Johns, M. V. Healey

This paper presents one of a series of digests of foreign mining legis- lation and court decisions which is being prepared in advance of a general report relative to the right of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of tie laws of Ecuador has been prepared from the best available information in Washington, but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers to whom it is being referred through the courtesy of the Department of State..

May 1, 1930

By Terry J. Close

The highly-mineralized 43,700-ha Rapid River study area, on the southeast side of Hells Canyon Wilderness and west of the village of Cuprum, in Adams County, western-Idaho, was investigated in 1992 by the USBM (U.S. Bureau of Mines) in conjunction with its Idaho Land Assessment Program. The 1992 study updated data gathered during the USBM's 1974-76 Wilderness investigation. The studies consisted of the evaluation of 61 mineralized sites and the estimations of tonnages, grades, and minability of these sites. Most of the sites studied are in two mineralized locales--Windy Ridge and Jackley Mountain. A few isolated sites, peripheral to the two locales, were also examined. The 61 sites contained more than 340 mine and prospect workings, including about 10,300 meters (34,000 feet) of underground workings, plus 134 drill holes.

Jan 1, 1993

By G. L. Finfinger, J. Cervik, L. J. Prosser

The Bureau of Mines has completed an underground degasification project in which an underground piping system was used to transport methane from the coalbed to the surface. In a 10-month period four horizontal holes were drilled to an average depth of 1,450 feet. All four holes were surveyed vertically and azimuthally. In 991 days of degasification, 255 MMcf of gas was drained from the coalbed. The underground piping system proved to be a safe and effective means of transporting methane from the coalbed to the surface.

Jan 1, 1981

By Michael T. Nigbor

The Bureau of Mines assisted the Rocky Mountain Energy Co. in a pilot-scale in situ leaching experiment at Casper, Wyo., to determine if sulfuric acid can be used as a cost-effective alternative lixiviant (leachant) for uranium in situ leaching. This experiment, which lasted more than 2 years, is the first fully documented pilot-scale operation in which the leaching-restoration cycle was completed using sulfuric acid instead of the more common carbonate-bicarbonate leachant This report describes activities at the experimental site, presents extensive geochemical data from startup to site restoration, compares laboratory and field experiments, and discusses the environmental aspects of acid leaching. The data showed that sulfuric acid is apparently an effective leaching solution. Three to five grams of acid per liter of ground water resulted in a production solution grade of 80 to 100 ppm uranium. Restoration was successful, but required extended flushing. The pH was the last chemical parameterto return to baseline, requiring about 350 days. This was longer than was predicted in laboratory simulations. The data also showed that mobilization of toxic elements such as selenium, arsenic, radium, thorium, and molybdenum stayed within reasonable limits and quickly fell back to preleach concentrations during restoration.

Jan 1, 1982

By Thomas J. Peters

In 1987, at the request of the U.S. Bureau of Land Management, the Bureau of Mines studied the 350-acre Henry?s Lake Wilderness Study Area (ID-035-077) in order to evaluate its identified mineral resources. The Wilderness Study Area is located in northern Fremont County, ID, approximately 140 air miles north-northeast of Pocatello and 3 miles south of the Montana border. The Wilderness Study Area is near the north shore of Henry's Lake at the foot of the southwest-facing slope of Black Mountain. Archean hornblende gneiss, the main rock type present, crops out northeast of the Madison Range Fault, which trends northwest across the southwest corner of the Wilderness Study Area.

Jan 1, 1988

This report summarizes the work performed by the Bureau of Mines on the development of analytical procedures for determining metallic and interstitial impurities in high-purity tungsten. Fourteen published methods and seven unpublished methods are briefly described. Carbon, hydrogen, nitrogen, and oxygen, in microgram to higher quantity levels, can be determined by several methods. Trace levels of 29 metallic impurity elements can be determined by optical spectrography, X-ray spectrography, and other instrumental methods.

Jan 1, 1968

By W. D. Mcmillan

Soapstone is the term applied to an impure, massive, soft rock with a greasy feel. It is of variable composition, consisting chiefly, however, of talc, tremolite, and chlorite. Although limited quantities of soapstone are used as building material, in fireplaces, and in the manufacture of laundry tubs, sinks, laboratory-table tops, and-oven and furnace blocks, the principal part of the production is ground for use in roofing paper, insecticides, and as a filler in asphaltic paints.

Jan 1, 1949

Preventive maintenance practices are listed in the manufacturers' instruction books. In general, equipment that requires frequent and extensive preventive maintenance is generally the most costly. The manpower spent on these frequent trips to remote areas is such that it is usually better to invest in a more costly system which requires little preventive maintenance. The best preventive maintenance for the system is a good installation. 7.2 Preventive Maintenance and Inspections With any system, periodic inspection is required because of the corrosive atmosphere and adverse conditions that exist in underground mines. These inspections can spot potential trouble in the system. Repair or replacement at that time averts the possibility of losing effectiveness of all or part of the system. 7.2.1 Cables Approximately once per month all cables in the communications system should be inspected for kinking, chafing, cracking, wear, stretching, or other signs of physical abuse. Particular attention should be paid to cable glands at the entry or exit points to the various units in the system, where the cable goes around sharp corners, in the vicinity of holding cleats which may be clamping the cable too tightly causing potential damage, and across the areas where the cable is exposed to physical damage from outside sources, such as equipment or falling objects. If a cable is damaged, it should be replaced as soon as possible. It is mandatory that the ground leads and connections to carrier current phones be thoroughly inspected and maintained in good condition, since considerable hazard may exist to the operator or equipment if a ground connection is broken. 7.2.2 Pager Phones The most readily available test set to determine if a pager telephone is operating correctly is the pager phone itself. The following physical check of the system can be performed at any phone station. 7.2.2a Listen Circuit Remove the handset from its cradle and listen to determine if the circuit is functional, as indicated by the presence of noise or conversation on the line. If no noise or voice signals are present at the handset receiver, take the following corrective action: 1. Operate the handset press-to-talk switch several times. Any corrosion on the contacts of this switch may cause a receiver to be temporarily inoperative. Repeated operation may clear the condition. 2. Open the cabinet and see if the battery cables are properly connected and are making firm contact. Check the handset cable and its connections in the cabinet of the pager phone, and see if there is any evidence of a break in the cable, corroded contacts, or poor connections. 3. Remove the handset receiver earpiece by unscrewing it counterclockwise (to the left), and remove the receiver from the socket. Examine the handset cavity; in some units, a patch of cotton batting or floss is used as a barrier to reduce acoustic feedback in the handset. If the cotton patch has absorbed moisture, remove it and replace with a crumpled ball of soft rubber, stuffed just far enough into the handset so it will not touch the receiver or switch terminals. 7.2.2b Page Circuit and Talk Circuit Push the page switch, squeeze the handset press-to-talk switch, and call any other phone. Release the page switch

Jan 1, 1984

By Richard E. Ray, George N. Aul, Fred Garcia, William P. Diamond

Increasing longwall panel dimensions, particularly face width in gassy coalbeds, may result in unexpected increases in methane emissions. To investigate this problem, continuous longwall face emission monitoring studies were conducted at two adjacent mines operating in the Pocahontas No. 3 Coalbed, where longwall faces were to be extended from 229 to 305 m (750 to 1,000 ft). It was predicted by regression analysis of methane emissions data from 229 m (750 ft) wide longwall faces that extending faces to 305 m (1,000 ft) would increase methane emission rates by only 7 percent (0.6 m3/min (20 cfm)), to 8.6 m3/min (304 cfm) at the VP-1 Mine. In contrast, it was predicted that extending faces at the VP-3 Mine could increase methane emissions by as much as 13 percent (1.8 m3/min (65 cfm)) to 16.1 m3/min (567 cfm). The geologic and mine design factors influencing the variation in face emissions between the two mines will be discussed.

By Richard J. Mainiero

The U.S. Bureau of Mines in cooperation with Jim Walter Resources, Inc. (JWR), Brookwood, AL, evaluated the use of sheathed explosive charges in breaking up large stones that can jam the feeder¬breaker or pan conveyor on longwalls and halt operations. Use of the sheathed charge reduced the downtime of the longwall panel to 15 to 30 min as compared with the 1 to 2 h required to drill and shoot the stone. Firing the sheathed charge at the face caused no significant damage to Iongwall equipment. Use of the sheathed charge also represented an improvement in safety by eliminating the exposure of miners to the inherent hazards of the face for extended periods of time. Another benefit, which is difficult to quantify, is the elimination of the temptation to shoot mudcaps or adobes, which is illegal in U.S. underground coal mines.

Jan 1, 1990

By Alan R. Buehler

A mineral survey of the 20,792-acre Sand Butte WSA (Wilderness study Area), ID-57-8, was conducted by U.S. Bureau of Mines personnel in 1985, at the request of the Bureau of Land Management. The WSA is in Lincoln County, south-central Idaho, about 15 miles south-southeast of Carey. There are no mines, prospects, or claims within the WSA. Basaltic lava is the only rock type exposed within the WSA. The only mineral resource is a few tons of a platy variety of lava (slab pahoehoe) which is suitable for use as decorative stone. Similar slab pahoehoe, produced from other lava fields in southern Idaho, retails for approximately $125/ton. The deposit in the WSA is too small to be mined commercially but may have value to consumers who gather their own decorative stone. INTRODUCTION A mineral survey of the Sand Butte WSA (Wilderness Study Area) 1/ was conducted in June 1985 by the USBM (U.S. Bureau of Mines) and the USGS (U.S. Geological Survey) at the request of the BLM (U.S. Bureau of Land Management). The USBM examines individual mines, prospects, claims, and mineralized zones, and evaluates identified mineral and energy resources. The USGS evaluates potential for undiscovered resources based on areal geological, geochemical, and geophysical surveys. Results of the investigations will he used to help determine the suitability of the WSA for inclusion into the National Wilderness Preservation System. The immediate goal of this and other USBM mineral surveys is to provide data to the President, Congress, government agencies, and the public for land-use decisions. The long-term objective is to ensure the Nation has an adequate and dependable supply of minerals at a reasonable cost.

Jan 1, 1986

By J. S. Browning

The physical properties and specific gravity ranges of various liquids and salt solutions used for laboratory sink-float separations of rocks or minerals are presented. The test equipment and techniques employed by the Bureau of Mines in making sink-and-float separations of particles as coarse as 3 inches to as fine as 400 mesh are described. Also discussed are methods of recovering and reclaiming the liquids or salts from the minerals and wash solutions, as well as the hazards encountered and precautions to be followed while working with the materials. The laboratory use of various liquids for separating minerals of different specific gravities has been recognized for many years. During this time, laboratory sink-float procedures have proven their utility as a rapid and moderately accurate means for determining the mineral content of ores, test products, and plant products in certain nonmetallic concentrating operations, such as those producing mica, spodumene, kyanite, and so forth. These procedures also have been used as analytical tools for determining the mineral content and associations of other metallic and nonmetallic ores.

Jan 1, 1961

By J. Douglas Causey

In 1984, at the request of the Bureau of Land Management, the Bureau of Mines studied 29,020 acres of the 43,165-acre Terry Badlands Wilderness Study Area (MT-024-684) in order to evaluate its mineral resources. Within this report, these 29,020 acres are referred to as the study area. Located in Custer and Prairie Counties, MT, the study area is about 2 miles northwest of Terry. The study area is underlain by essentially flat-lying units of the Fort Union Formation of Paleocene age with some Quaternary alluvial deposits in stream valleys. No mines or prospects were found in the study area. Bentonitic clays and lignite coal units were examined and sampled; however, no clay resources or coal reserves were identified. Estimates of coal resources will be reported by the U.S. Geological Survey in a joint U.S. Geological Survey-U.S. Bureau of Mines publication. Gravel along the Yellowstone River, a source of agate for private collectors, could also be used as sand and gravel aggregate although material on the south bank of the river is closer to population centers and road systems. Clinker found in the study area could be a source of road metal, but is not well situated in relationship to areas of use. No geothermal resources have been identified although water suitable for direct heat applications may underlie the study area. All the area is leased for oil and gas exploration.

Jan 1, 1985

By Warren D. Longwill

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Jan 1, 1981

By R. D. Leitch

The pollution of streams by acid mine drainage has become of great importance in the past few years in certain regions of the United States. Large quantities of acids are used in a discharged from other industries than mining, notably in tube, sheet, tin-plate and era hell inn works. These are usually less important then coal mines as a source of acid drainage, because of their more limited distribution throughout the States most affected by acid waters and their relatively smaller numbers. Streams are naturally alkaline and are, therefore, able to take care of rather large quantities of acid wastes, but when such enormous quantities as are often found in mining districts enter the streams, the natural alkalinity is quickly overcome. When a neutral or almost neutral condition has been reached, the further addition of a relatively slight quantity of acids will cause a great difference in the quality of the water.

Jan 1, 1926

By James D. Noll, Jon A. Hummer, Aleksandar D. Bugarski, George H. Jr. Schnakenberg, Steven E. Mischler, Larry D. Patts

The National Institute for Occupational Safety and Health conducted a study to determine the effects of selected, state-of-the-art emission control technologies on the ambient concentrations of particulate matter and gases emitted by underground diesel-powered mining equipment. Tests were conducted in an isolated zone of an underground mine to evaluate the effectiveness of alternative fuel formulations, namely, water-fuel emulsions, blended biodiesel fuels, ultralow sulfur diesel fuel, and #1 diesel; and selected exhaust after treatment devices, namely, diesel oxidation catalysts (DOCs), diesel particulate filter (DPF) systems, and filtration systems designed around high-temperature disposable filter elements. The results showed that using a cold-weather and warm-weather water-fuel emulsion formulation reduced mass concentrations of elemental carbon (EC) by about 70% and 85%, respectively. The 20% and 50% soy biodiesel blends reduced EC by 49% and 66%, respectively. The reductions were slightly less pronounced for the 20% and 50% yellow grease biodiesel blends—33% and 56%, respectively. EC concentrations were unaffected by using ultralow sulfur diesel in place of #1 diesel. Use of the reformulated fuels did not substantially alter the concentrations of nitric oxide and carbon monoxide. However, a measurable increase in the nitrogen dioxide (NO2) peak concentration was observed during the biodiesel tests. The ArvinMeritor (AM) fuel-burner DPF system with a palladium-catalyzed DOC reduced EC concentrations by 92%. The diesel filter elements from Donaldson Co., Inc., and Filter Service & Testing Corp. reduced the EC concentration of the mine air by 92% and 70%, respectively. When the palladium-based DOC was used with the AM DPF, it raised the average and peak downstream NO2 concentrations by a factor of three. Tests of the AM DPF system with a platinum-catalyzed DOC and CAP/ETG catalytic particulate oxidizer system had to be terminated because the elevated NO2 concentrations threatened to overexpose the operator. The tests with only a selected DOC also resulted in increased NO2 concentrations in mine air.

Jan 8, 2006

By D. J. Bauer

Solvent extraction techniques were used to determine the extraction sequence of yttrium and the rare-earth elements in an amine solvent extraction system. Single-stage extraction with Primene 81-R resulted in separation factors of 3.8 between yttrium and dysprosium and 25 between yttrium and cerium. Yttrium was concentrated in the aqueous phase. EDTA and DTPA, as aqueous phase counterextractants, enhance separation factors in mine-rare-earth sulfate systems. Yttrium separation from heavy rare-earth elements exhibits marked sensitivity to the position of yttrium in the selectivity scale of the rare-earth elements with the sequestrants. Yttrium-ytterbium separation is more effective with EDTA, whereas yttrium-dysprosium separation is more effectively increased with DTPA.

Jan 1, 1963

By Joseph C. Zelanko, Anthony T. Iannacchione

One of the most difficult, longstanding engineering problems associated with coal mining is the catastrophic failure of cog mine structures known as bumps. For more than 70 years, researchers and practitioners have assembled a wealth of technical information on coal bumps in an attempt to understand and control them. However, many technical issues raised long ago are still being debated today. This paper examines past experiences and recognizes achievements in the realm of coal bumps. U.S. Bureau of Mines (USBM) researchers collected and analyzed 172 coal bump incident reports and compiled the pertinent statistics into a database. Actual field studied are also discussed. Examination of past experience has shown that there is no one set of defining characteristics that is responsible for coal bumps. In all cases, bumps occur when complex arrangements of geology, stress, and mining conditions interact to interfere with the orderly dissipation of stress. However, it is evident from the database that a tremendous reservoir of knowledge has been established from past experience that has unquestionably limited the severity of coal mine bumps in the United States.

By H. E. Powell

The magnetic susceptibilities of 57 minerals containing titanium, zirconium, vanadium, columbium, tantalum, chromium, molybdenum, and tungsten were determined. The source and petrographic analysis of each sample are given. Included are values for isomorphous series of minerals showing wide ranges of composition and for a few high-purity synthetic minerals.

Jan 1, 1968