Search Documents

By L. F. Willmott

The Bureau of Mines at Morgantown, W. Va., has been investigating, on a pilot plant scale, various methods of gasifying bituminous coal with oxygen and superheated steam to produce synthesis gas, as part of the broader program of finding new uses for coal. Differences in the pressure gasification methods used have depended on differences in the manner in which the pulverized coal is fed to the gasifier. One of the methods of feeding the coal that was investigated was the continuous, integrated coal-water slurry system. Goal and water were first mixed to produce a slurry; then the slurry was pumped through a heated coil. to evaporate the water fraction; the resulting steam was superheated, and some of it was separated so as to adjust the ratio of the residual steam to the coal fraction and make the resulting mixture suitable for partial combustion with oxygen in a pressure gasifier. Both before and during this reported3 developmental work it was necessary to make an extensive literature search into the technology of aqueous slurries in order to establish design criteria for the pilot plant and to correlate results of various phases of the work with that of other investigators, The pilot work coincided with the commercial development of a long-distance pipeline for the transportation of coal as a coal-water slurry, and this fact tended to broaden the scope of the pilot plant work and the extent of the literature search. This bibliography is the compilation of the material that was collected.

Jan 1, 1963

This report describes the new Bureau of Mines Core Repository System (CORES) and presents the methods for selecting, processing, and storing physical samples and descriptive data for future reference by earth scientists. The system preserves splits of chip samples and longitudinally sliced segments of core. A records retrieval system provides for storage of data on microfilm and magnetic tapes and uses the keysort parameters of location and commodity for the identification of data.

Jan 1, 1978

By W. H. Eddy

The Bureau of Mines used several laboratory batch flotation schemes combined with magnetic separation to investigate the feasibility of recovering potash feldspar and glass sands from molybdenite tailings. Four molybdenite tailings or prospective tailings were used as test samples. Feldspar concentrates containing from 10.7 pct to 12.0 pct K2O were recovered from three of the four samples. The alkali content of the fourth sample met the grade for a mixed feldspar. All the feldspar concentrates contained iron in excess of the 0.10-pct-Fe203 specification for most uses. Electron-beam microprobe examination of the feldspar concentrates showed the presence of an iron-bearing potash feldspar in quantities that were excessive with respect to most iron specifications. However, a high-quality glass sand was produced from all of the samples.

Jan 1, 1980

By Noel N. Moebs

This report summarizes a Bureau of Mines study on the use of geotechnology to identify and reduce ground control hazards at slate quarry operations in eastern Pennsylvania. The major ground control hazard is falling rock, attributed to weathered bedding plane faults, which weaken quarry highwalls. It was demonstrated that these faults can be detected outside of the quarry perimeter using surface resistivity measurements. Falls of ice from quarry highwalls constitute a second major hazard, which requires water diversion as a basic control method. In situ stresses seemingly cause only minor problems in slate extraction although they could interact with developed stresses and lead to failure of barriers between quarries. Pull tests showed that rockbolts anchor firmly in slate and should prove effective in securing loose rock.

Jan 1, 1986

By T. M. Romslo

"The Keystone and St. George properties are in the so-called Johnson Camp area and adjoin a property that in recent years has become a steady producer of low-to medium-grade copper-zinc ores. The Keystone Copper Co. was active intermittently from 1908 to 1938 and during 1926 to 1937 produced a recorded 1,100 tons of 5 percent copper ore. There is no evidence that ore has been produced from the St. George property.In the Johnson Camp area both igneous and sedimentary rocks ranging in age from pre-Cambrian to Quaternary are exposed. The ore bodies are in the Paleozoic rocks and occur principally in the Abrigo formation, which is composed mainly of limestones and shales. The rocks of the productive zones are metamorphosed and are cut by systems of fractures and faults. Chalcopyrite and sphalerite, the principal ore minerals, replace altered limestones to form deposits locally called mantos and chimneys.Investigation of the Keystone and St. George deposits by the Bureau of Mines included topographical and geological mapping of the surface and the underground workings and diamond drilling from the surface. A total of 10,067.8 feet was drilled in 22 holes. The drilling started November 13, 1947, and was completed August 19, 1948.This report records factual information obtained during the course of the investigation."

Jul 1, 1949

By J. R. Koehler

The U.S. Bureau of Mines (USBM) ground control research program includes several projects focused on developing design criteria for yielding-pillar-based longwall gate road systems. As part of this program, mining practices at the Sunnyside Mines, Sunnyside Reclamation and Salvage Co., Sunnyside, UT, are being documented to preserve the long history of yield pillar system evolution on the property. Published information describing the specific in-mine performance of the numerous gate road configurations utilized at the Sunnyside Mines is very limited. To overcome this deficit, USBM personnel interviewed 30 longtime mine employees representing nearly 700 years of mining experience at the Sunnyside operations. Mining conditions in 12 specific areas in the Nos. 1, 2, and 3 Mines were discussed in the interviews. Also, broad topics such as general mining practices, safety, and geology were often addressed during the discussions. Comprising the body of this report is an extensive record of the events and conditions experienced while mining the identified areas. In addition, eight significant conclusions were developed that accurately summarize the general opinions of the interviewed personnel regarding mining conditions and practices at Sunnyside.

Jan 1, 1994

By Jeffrey P. Schubert

The study site in northeastern Illinois underwent surface mining for coal in 1943 and was reclaimed by the state of Illinois in 1972-1973. Additional soil amendments and seed were applied to the spoil surface in 1975-1980. Previous studies in 1975-1978 had shown that the surface spoil materials and five final-cut lakes at the site were quite acidic and the lakes contained high concentrations of sulfate and dissolved metals. Surface runoff water from monitoring plots in 1976 were only moderately acidic and the mean concentrations of most dissolved metals and sulfate in the runoff waters were less than 25% of the concentrations found in Lake B. By 1980, vegetation had become well established over most of the mined area. However, the five final-cut lakes (Lakes A-E) remained acidic. The purpose of the study reported here was to determine the physical and geochemical subsurface conditions of the spoil materials, the hydrologic flow system within the spoils, and the magnitude of acidic spoil leachate migration into the lakes and into the wetland prairie north of the mine site. Lakes A, B, C, and E were still very acidic in 1980-1981 (pH range: 2.9-3.4; aridity range: 110-860 mg/L as CaCO3). Lake B had the worst water quality, with mean concentrations of dissolved aluminum, iron, manganese, and sulfate of 75, 25, 37, and 3340 mg/L, respectively. Shallow groundwaters in spoil materials around Lake B had a lower pH and about two to four times greater concentrations of aridity, aluminum, manganese, zinc, and other metals and nearly 20 times greater dissolved iron than the water in Lake B. The shallow groundwaters in undisturbed soils and bedrock 10-30 m north of the mine site spoils generally were alkaline, but did contain occasional moderately high sulfate and metal concentrations. Pumping tests and recovery tests conducted in piezometers showed hydraulic conductivities of spoil materials ranging from less than 10- to 10-5 m/s; hydraulic conductivities of natural soils and bedrock were measured between 10-10 to 10-7 m/s. Water levels in spoil materials increased rapidly in response to rainstorm events and the recession curves were relatively quick to decline, lasting only two or three days. Quick infiltration of rainfall into the spoil surface and percolation down to the water table caused a rise in groundwater levels and movement of spoil groundwater into the lakes. This groundwater component in the lake water budgets could account for most of the water quality problems occurring in the acid lakes.

Jan 1, 1984

By F. R. Cattoir, R. E. Cumings

Columbium metal was electrorefined in a fused - salt electrolyte . Excellent results were obtained in lowering the impurity content in a 94 - percent columbium anode feed material to produce a 99.8- percent - pure metal . The reductions of the major impurities follow : Oxygen from 19,800 to 500 ppm , carbon from 9,700 to 25 ppm , iron from 9,200 to 630 ppm , nitrogen from 2,100 to 90 ppm , and silicon from 750 ppm to not detected . Columbium with a purity of 99.9 percent was produced from 99.5- and 99.8 - percent grades of columbium. The investigation was devoted to the evaluation of a fused - fluoride - salt electrolyte ( KF - NaF- K₂ CbF, ) for electrorefining columbium. The effects of the columbium concentration and the voltage upon the product's purity were investigated . The effect on the cathode current efficiency of ampere - hours of deposition and the formation of a dual valence state of the columbium was also investigated .

Jan 1, 1964

By Terry S. Cory

This report describes a complete system design methodology for medium frequency (MF) wireless radio systems for use in coal mines. The emphasis Is on AC mines where no trolley wire exists and, for which, conventional trolley phone communications can not be used. The report constitutes an MF system design handbook and includes a compendium of all previous MF technology elements as well as a reference Index with abstracts of all pertinent literature. A particular strawman system design analysis is Included for the Helvetia Coal Co. Lucerne #8 mine In the Upper Freeport seam.

Jan 1, 1979

By J. E. Miller

Primary standard gas mixtures were developed for more accurate calibration of analytical instruments at the Bureau of Mines Helium Research Center and for calibration of analytical instruments used in the helium conservation program. A 10-kg-capacity balance is used to weigh a 4-kg metal cylinder filled to high pressure (1,800 psi maximum) with the component gases of the desired mixture. At 1,800 psi, a cylinder contains about 60 g of helium, or 420 g of nitrogen. An accuracy of ±0.05 mole-percent or better is claimed for each component in the mixtures.

Jan 1, 1965

By C. M. Harrer

This paper describes the location, features, qualities, extent, and potential of iron occurrences and some associative resources - limestone and dolomite, coal, petroleum and natural gas, power, and water - in New Mexico. Reconnaissance investigations were made of 118 iron occurrences to determine their extent, attitude, and potential; character samples were analyzed to determine their quality and impurities; and pioneer metallurgical investigations were made on character samples to present their metallurgical problems. Some factors influencing past and potential iron markets are discussed. The most abundant iron minerals are magnetite and hematite, The higher grade deposits are extensive contact-metamorphic and pyrometasomatic replacements in calcareous Paleozoic rocks associated with intrusives. Low-grade deposits of considerable potential are the extensive Cambrian oolitic hematites of sedimentary origin and the Precambrian magnetite-hematite taconite iron formation. Iron occurs also as extensive colluvial and alluvial concentrations. A wide variety of accessory elements are indicated and these pose metallurgical and economic problems.

Jan 1, 1963

By C. M. Harrer

This paper describes the location, features, qualities, extent, and potential of iron occurrences and some associative resources -limestone and dolomite, coal, petroleum and natural gas, power, and water - in New Mexico. Reconnaissance investigations were made of 118 iron occurrences to deter-mine their extent, attitude, and potential; character samples were analyzed to determine their quality and impurities; and pioneer metallurgical investigations were made on character samples to present their metallurgical problems. Some factors influencing past and potential iron markets are discussed. The most abundant iron minerals are magnetite and hematite. The higher grade deposits are extensive contact-metamorphic and pyrometasomatic replacements in calcareous Paleozoic rocks associated with intrusives. Low-grade deposits of considerable potential are the extensive Cambrian oolitic hematites of sedimentary origin and the Precambrian magnetite-hematite taconite iron formation. Iron occurs also as extensive colluvial and alluvial concentrations. A wide variety of accessory elements are indicated and these pose metallurgical and economic problems.

Jan 1, 1963

This report describes the activities and publications of the Bureau of Mines Health and Safety Research and Testing Center, Pittsburgh, Pa., for the fiscal years 1960-65. It includes a discussion or work being conducted on roof control, dust explosions, ventilation, health, coal mine fire control, and electrical-mechanical testing, and an abstract of each paper published during the report period.

Jan 1, 1966

By R. Havens

During the course of the investigation of possible domestic sources of manganese, engineers of the Bureau of Mines examined and sampled two manganese mineral deposits in northeastern Utah. The Daggett Chief claims are situated in the northern part of Daggett County,5 miles southwest of Manila, Utah, and approximately 57 miles from Green-River, Wyo. Owners of the property are J.E. Harris Of Salt Lake City, Utah, Nels Palleson of Manila, Utah, and J. P. Larson. The manganese occurs in a vein 6 to 8 feet wide in a shale and sandstone formation. Two distinct occurrences Of manganese are present Within the vein, and samples of each were subjected to testing. Lot A, representing .probably the major portion of the Manganese; was composed of nodules and veinlets of manganese oxides in a semicompact; gray, shaly formation. Lot B represented a 15-inch vein of dense iron-manganese ore. .Most of the laboratory work at Salt Lake City, Utah, was done on these two samples; but preliminary testing also was carried out on a small sample, physically similar to lot A, submitted by the owners.

Jan 1, 1949

By Susan E. Brink

The first step in determining whether Mn can be recovered by in situ leaching is to develop and test a selective lixiviant. Two column leach tests and one core leach test Were conducted by the U.S. Bureau of Mines on Mn oxide ore using aqueous sulfur dioxide (SO2) as the lixiviant. The column tests showed that aqueous S02 could selectively dissolve available Mn oxides from calcite-rich ore in a heap leach system. However, the core test showed that calcite gangue side reactions can have pronounced negative effects on the likelihood of successful in situ leaching of a calcite-rich ore with aqueous S02. Petrographic and geochemical analyses showed that both Mn (IV, III) oxides and calcite were dissolved. The abundance of dissolved Ca caused precipitation of gypsum. Acid consumption by calcite dissolution caused a rise in pH that caused the SO/S species to shift to S032-(sulfIte), which hindered reductive dissolution of Mn oxide. Gypsum precipitation did not affect complete leaching of the rock fragments in the column tests; however, it plugged the natural permeability in the core. Manganese recoveries were high for the column tests and low for the core test.

Jan 1, 2010

By V. L. Burdick

A literature review of current uses of Mn02 in ceramic applications with suggestions for future research. Historical background, oceanographic distribution, geology, exploitation, law and politics. Uses of Mn02 in ferrites, semiconductors, catalytic processes, thermo-luminescence and photochromic materials. Select bibliography of 33 items, plus 129 references.

Jan 1, 1980

By G. E. McElroy

Tae purpose of this paper is to present types of charts adapted to aid in the graphic solution of fan-performance problems of selection and operation, and to urge the adoption of similar charts by the National Association of Fan Manufacturers as standard forms for presenting fan-performance data. As matters now stand, it is difficult for the average engineer to solve such problems because a laree number of variables are involved, and performance data are not presented in a manner that permits their direct application to many problems encountered in practice. The performance of any centrifugal machine is determined not only by the machine itself but also by the fluid-flow system on which it operates. Actual performance of centrifugal fans is therefore e matter of the type, size, and speed of fan, on the one hand, and of the relation of pressure to quantity of flow, as determined by the physical condition of the airway system, on the other.

Jan 1, 1936

By G. E. McElroy

[The purpose of this paper is to present type: of charts adapted to aid in the graphic solution of fan-performance problems of selection and operation, and to urge the adoption of similar charts by the National Association of Fan Manufactures as standard forms for presenting fan-performance data. As matters now stand, it is difficult for the average engineer to solve such problems because a large number of variables are involved, and performance data are not presented in a manner that permits their direct application to many problems encountered in practice. The performance of any centrifugal machine is determined not only by the machine itself but also by the fluid-flow system on which it operates. Actual performance of centrifugal fans is therefore a matter of the type, size, and speed of fan, on the one hand, anti of the relation of pressure to quantity of flow, as determined by the physical condition of the airway s: stem, on the other.]

Jan 1, 1936

By Michael Horn

This report presents a structural analysis of the economies of Spokane County, Washington and 21 surrounding counties. An economic trading region made up of 22 eastern Washington, northern Idaho, and western Montana counties, with Spokane, Washington as the central place, was defined for this study. The Micro IMPLAN modeling system with the 1990 county database was used to create an Input/Output based model of the regional economy. The leading industries, with respect to employee compensation, employment, value of exports, and total industry output are shown for each county and the region. The value of total industry output from natural resource based industries is also shown (or each county and the region. The total industry output from the Spokane Economic Trade Area (S ETA) region is valued at $22.3 billion. The SETA region provides $7.1 billion in employee compensation to a work force of 374,000. Spokane County, Washington accounts for about 50 percent of the regional total output, employee compensation, and employment. Both Spokane County and the region as a whole produce about 80 percent of total industry output for final demand with the remaining 20 percent going to intermediate inputs for further production. About $7.4 billion of the $22.3 billion SETA output is exported from the region. Spokane County exports about $4.7 billion, or 41 percent of the $11.5 billion Spokane County output. Exports account for more than 50 percent of the total output in 12 of the 22 counties within the region. Based on the output of the top 25 industries in each county and the SETA region about 9 percent of the industry output from Spokane County and 18 percent of the regional industry output come from natural resource based industries. For counties other than Spokane County, total industry' output from natural resource based industries represents from 12 percent to 81 percent of county output from the top 25 industries. Natural resource industries account for more than 50 percent of total county output in 8 counties within the region

Jan 1, 1994

By J. A. Woolf, E. S. Leaver, N. K. Karchmer

"In the cyanidation of silver ore, the need of oxygen is well recognized. Various methods have been introduced for supplying the oxygen. In usual practice, air is the source of oxygen and the methods of application are mechanical.This article gives the results of touts made to show the rate of dissolution of silver from each of the common silver minerals in cyanide solution, under conditions similar to those used in the practical recovery of silver from its ores. The effect of oxygen in aiding the dissolution of the silver from each mineral is also shown by a comparison of the methods of supplying the oxygen. Oxidation by preliminary roasting (500°C.) of each mineral sample gives the maximum extraction of the silver by treatment with cyanide.Each silver mineral5 used in these experiments was as pure as could be obtained from the mineral dealer. In their natural occurrence, silver minerals are not usually free from mineral impurities. They are usually closely associated with other minerals often forming, a complex mixture. The form of crystallization, the proportions, and properties of the diluent that incases or has been dispersed with the silver mineral may decidedly affect the dissolution rate of the silver from each mineral. While the following results should aid in the cyanidation of silver ores, each ore should be studied from the basis of the form and condition of the silver that is to be recovered.All the tests reported in this article were made on synthetic samples, prepared by mixing the particular silver mineral with clean sea sand. Each mineral was ground in an agate mortar to pass 100-mesh before mixing with the sand which had previously been ground in a porcelain pebble mill to 100-mesh. Such proportions of each mineral and the sand were used as to give a head assay of approximately 20 ounces of silver per ton to the synthetic sample.Agitation was carried on in stoppered bottles approximately one-third full of pulp, method apparently supplied all the atmospheric oxygen that would be taken up by the solution under usual conditions, because tests conducted in open bottles did not show increased recovery,"

Jan 1, 1931