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The combined production value of natural abrasives, which consist of tripoli, special silica stone, garnet, and emery, decreased in 1985. Shipments of processed tripoli increased slightly in quantity but decreased 6% in value, Production of garnet, an abundant iron-aluminum silicate, increased 24% in quantity and 20% in value. There was an 11% increase in the quantity and a 7% increase in the value of refined garnet shipped when compared with 1984 shipments, a new record high. Production of crude special silica stone decreased 10% in quantity and 14% in value, and shipments of finished special silica stone products decreased 85% in quantity and 68% in value. Both the quantity and value of special silica stone finished products sold or used were the lowest since 1981. Production of emery, an impure aluminum oxide, decreased 56% in quantity and 61 % in value of product mined and shipped. [ ]

Jan 1, 1987

By Ronald B. Hollenbeck

The value of mineral production in Alabama continued to increase and reached a new high of $260 million, 3 percent above the previous high established in 1967. Record high values were reported for bentonite, crushed marble, lime, miscellaneous clay, portland cement, salt, sand and gravel, and scrap mica. The value of coal, total cement, petroleum, and stone accounted for 87 percent of the State's total value of mineral production. Alabama ranked second among the States in the production of bauxite and scrap mica and third in kaolin, masonry cement, and native asphalt.

Jan 1, 1970

By Shouchen Dun, Zong-Ming Li

Manipulation of hand-held objects in 3D space is a complex task. Understanding how individual digits interact with a hand-held object provides helpful information for hand tool designers, researchers, clinicians, and occupational therapists. At the object-digit interface, the contact mechanics can be represented by three force and three torque components. Six-component force/torque transducers can register all the three forces and three torques at the digit-object interface, and therefore are advantageous in the study of manipulation mechanics. The large number of force and torque signals from multiple force/torque transducers are difficult to interpret and therefore making experimental research of manipulation a challenging task. The purpose of this study was to develop a 3D visualization tool for the investigation of the contact mechanics at the object-digit interfaces during manipulation tasks. Methods A 3D stick-figure hand model was created based on digitized 23 anatomical landmarks of the hand. Five miniature 6-component force/torque transducers (4 × Nano17 for the fingers, 1 × Mini40 for the thumb, ATI Industrial Automation, NC) were used to record force and torque data at the tips of individual digits. Thirty channels of force/torque signals from the transducers were collected by a 16-bit analogue-digital converter (PCI-6031, National Instrument, Austin, TX) installed in a computer. The transducers were mounted on a custom-made rectangular aluminum handle for object manipulation. Coordinate frames were established at each transducer, on the handle, and at the base of the MicroScribe digitizer. To visualize the force vectors at the digit-tips, the coordinates of the hand landmarks in the MicroScribe coordinate frame and the force vectors in local transducer coordinate frames were transformed to a common coordinate frame defined on the handle. One healthy right-handed, male subject participated in the experimental study. During the tests, the participant sat in a chair by a testing table. The forearm was strapped to an arm holder in neutral rotation position. The instrumented handle was fixed on the testing table by a C-clamp through an adapting plate. With the hand of the subject gripped on the instrumental handle, the landmarks of the instrumented handle and the transducers, as well as the anatomical landmarks of the hand were digitized using the MicroScribe digitizer for the purpose of coordinate frame establishment and transformation as described above. The subject performed three different maximum isometric voluntary contraction tasks: (1) grasping, (2) rotating in pronation, and (3) lifting. Results The 3D hand model and representative force vector clusters in a single trial of grasping, rotating, and lifting tasks are shown in Figure 1. Each cluster was formed by displaying all the 3D force vectors during the period of “stabilized” maximum effort in a trial. The magnitude and

Jan 6, 2006

By James A. Wasson

This report summarizes the results and conclusions reached by various investigators who have attempted to determine the extent to which hydraulic fracturing will affect the secondary recovery of crude oil by waterflooding. It also discusses the most advantageous use of this well-stimulation method in waterflood projects. A thorough search of the literature was made, and pertinent information was abstracted from appropriate reports. A carefully designed and controlled program of formation fracturing is an effective aid in waterflooding because it increases water-injection and oil- production rates. Generally, fracturing has resulted in little or no reduction in ultimate oil recovery, but under certain circumstances recovery has been substantially increased.

Jan 1, 1963

By Stephen P. Signer, John L. Lewis

This paper presents the results of a case study conducted in a two-entry gateroad in a coal mine where excessive roof deformation and bolt loading resulted in failure of many roof supports. The instruments consisted of 16 fully grouted, strain-gaged resin bolts, load cells on both full and partially grouted cable bolts, and vertical deflection multipoint extensometers. These instruments were installed on-cycle to measure loading on bolts in an existing support pattern and to determine if cable bolts could be used to improve roof stability. Results showed significant amounts of movement within the bolted zone. In some cases, these movements were enough to load the supports past their ultimate strength. Geology appeared to be a significant factor in localized roof degradation; that is, a very weak rock layer in the immediate roof overlain by a very strong rock layer contributed to the development of shear planes. Only one instrumented bolt had a maximum strain of less than 2,000 microstrain, which was the yield point of the steel. The average maximum strain on all bolts was 20,000 microstrain. However, electrical continuity to many gages was lost and a pattern was noted that would indicate possible bolt failure. Wire mesh and concrete cans installed as secondary support performed very effectively.

By E. J. Gleim

An important phase in the Bureau of Mines investigation of electrical machines designed for operation in gassy coal mines is testing enclosures of electrical components for explosion-proof qualities. In brief, this testing consists of filling and surrounding the enclosure with an explosive atmosphere of methane and air and then igniting the atmosphere within the enclosure to determine (1) Whether the resulting explosion is confined without discharge of flame; (2) whether the enclosure walls are permanently distorted; and (3) whether excessive pressures are developed within the enclosure. Ordinarily, the pressures encountered in routine testing do not exceed 100 pounds per square inch gage. Hence, the designer of the machine does not have too much difficulty in taking corrective measures to prevent flame discharge and distortion of the enclosure. Occasionally, however, the explosion pressures greatly exceed 100 pounds. Then the goblet of the designer may not be solved so readily, From experience over the year 0, the testing personnel often can predict that certain construction will result in high. Pressures, but, only in a very general way, has it been possible to advise designers what modifications might be made to reduce the explosion pressures to normal values. For example, if high pressures were developed in a motor starter having a partition with an opening through it, some enlargement of the opening may appear to be the logical procedure, but it has not been- possible to give information concerning the exact amount the opening should be enlarged to prevent development of high pressures .

Jan 1, 1952

By Forrest T. Moyer

INJURY experience in the metal and nonmetal mineral industries during 1964 was better in rates of occurrence but worse in severity rates than in 1963. The frequency rate of injuries per million man-hours was improved at metal mills, nonmetal mines, and sand and gravel operations, and was virtually unchanged at metal mines; however" the rate of occurrence of work injuries at nonmetal mills, stone operations, nonferrous reduction and refining plants, and slag plants was higher than in 1963. The severity rate of injuries during 1964, data for which are presented for the first time in this chapter, was better at metal mills, nonmetal mines, stone operations, and slag plants. However, the severity rate was worse at metal mines, nonmetal mills, sand and gravel plants, and nonferrous smelters.

Jan 1, 1965

This study was conducted to determine the effects of a machine-mounted scrubber and water sprays on face methane levels. Testing was conducted in the NIOSH ventilation test gallery which was designed to simulate a full-scale mine entry. In the test entry, a model mining machine, equipped with water sprays and a simulated dust scrubber, was located at the face of a 20-ft box cut. Blowing ventilation was provided using a curtain with a 40-ft setback distance. Methane released from a pipe manifold located inby the mining machine was monitored at six locations that were 1 ft outby the pipe manifold. Tests were first conducted to evaluate the effects of using sprays and scrubber separately on face methane levels. Additional tests were conducted to determine how a scrubber used with various water spray systems would affect face methane levels. The use of either sprays or scrubber reduced face methane levels significantly. The combined use of sprays with the scrubber further reduced face methane levels a small amount. Primarily the sprays affected methane levels by changing airflow distribution close to the face.

By Sabri Ergun

Cost estimates and technical feasibility are compared for six chemical coal cleaning technologies. The comparison is based on conceptual application of the chemical cleaning methods for removal of pyritic and organic sulfur from a utility grade bituminous coal. The process layout includes receipt of 8,000 tpd ROM coal, fine coal pulverizing, desulfurization, and preparation of a compacted clean coal suitable for storage and shipment. The methods are: the Magnex iron pentacarbonyl process, the KVB dry oxidation process, the Battelle hydrothermal caustic leaching precess, the TRW Meyers ferric ion leaching process, the Ledgemont oxygen/water leaching process, and the Bureau of Mines/Energy Research and Development Administration air/water leaching process. Capital costs estimated for the desulfurization operation alone, scaled to 8,000 tpd, range between $14 MM and $122 MM, while estimated operating costs for desulfurization alone on the same scale of operation range between $7 and $17 per ton clean coal produced. Relatively little is known about the chemical cleaning of coal, and present cost estimates indicate that the method might not be competitive at its present state of development when used alone to clean utility grade coals for sulfur removal. The principal attractiveness of chemical coal cleaning lies in its potential for combination with physical cleaning to produce cost competitive compliance coals in a combined process with high-Btu yields.

Jan 1, 1977

By Louis R. Iverson

Patterns of species colonization, biochemical interaction among species, and competitive phenomena were studied in four reclaimed areas in western North Dakota ranging in age from one to four years after mining, along with a site from a native mixed grass prairie for comparison. Early successional changes in floristic composition and soil chemistry were quantified. The mined sites had been contoured, topsoiled, fertilized and seeded. Despite seeding of agronomic species, initial colonization was by fugitive species; analysis of the seed bank in topsoil showed that the most dominant colonizers immigrate after topsoiling. Of the 95 species encountered, Kuchia scoparia was the most dominant in the first two years following mining. Kochlo had relatively low densities in the first year (50-80 plants m-2), but was robust and attained heights of 88 cm with a biomass of about 400 g m-2 In the second year, the plant densities increased to over 10,000 plants m"2 but the height and biomass were reduced to 15 cm and 90 g m-2. However, during the third and fourth years Kochia density declined and was practically non-existent by the fourth year, while the planted Agropyron grasses had concomitantly increased. Other pioneers like Amaran thus retroflexus, Chenopodlum album, Helianthus annuus, Salsola spp. And Setaria spp. showed a less abrupt but similar decline. Chemical analysis of the soils over the same time period showed decreases in electrical conductivity (E.C.), and in the concentrations of P, Ca, Mg, Na, Li, Sr, and SO4 (due to leaching), while N increased. Field studies were conducted on the competitive relations between the dominant species - Kochia scoparia and Agropyron spp. - during early succession. It was found the Kochia acted as a "nurse" crop for several months during the first year of Agropyron spp. establishment, but then began to shade heavily by late July, thus reducing grass tillering. Field and growth chamber experiments on the intraspecific competition relations of Kochia demonstrated that its density and dry matter production, per plant and per unit area, conformed to several laws of plant population biology. Autotoxicity or the depression in growth of a species by its own degradation compounds, in Kochia, appears to be the main factor causing the decline in its growth. Results from a field experiment indicated that thinning dense second year Kochia stands to the density of first year stands did not alter the growth of Kochia, providing strong evidence for autotoxicity. Similarly, several growth chamber experiments demonstrated that small amounts of decaying Kochia leaves and especially roots were toxic to Kochia growth, but not Melilotus officinalis or Agropyron canlnum, Chemical analysis of the soils and plant tissues indicated nutritional im¬balances as shown by P/Mn and P/Zn ratios may be responsible for autotoxicity. In addition to Kochia, a bioassay experiment showed allelochemics to be important in several other colonizing species. Although our results indicate that later stage species generally have greater toxicities than first year colonizers, autotoxicity in the very initial stages seems to be accentuated by harsh habitat conditions. Several practices (mowing. fire, etc.) are used to manage grasslands. Mowing of the first year erect, annual, colonizing vegetation was shown to be beneficial in the growth and establishment of wheatgrasses after mining in western North Dakota. Plots containing Kochio predominantly were mowed in mid-and late-July, and in mid-August, during the first year of growth after recontouring, replacing topsoil. seeding and fertilizing. It was found the Kochia densities were reduced to two percent of the control and its biomass reduced to less than one-third when the area was mowed in mid-August. On the other hand, wheatgrasses showed increases of 23% in stem density and 860% in biomass production over the controls when mowed in mid-August. The mowing of Kochia just before seed-set apparently reduces interspecific competition between Kochia and Agropyron spp. during the following growing season. The method is highly recommended for use in hastening the establishment of planted grasses.

Jan 1, 1982

By Irvin G. Burough

Andros Analyzers Incorporated has designed and built two prototype continuous methane monitors capable of being mounted on a mining machine'. These instruments were designed for in-mine safety use. The monitors incorporated an NDIR optical/electronic analyzer design in which the response to the sample gas (methane in air) was achieved by synchronous detection and measurement of the amplitude oscillations of the trasmitted energy from an infrared source caused by the pressure modulation of the sample gas within the optical cell. Zero and span stability were to be achieved by the amplitude modulating of the infra-red source and using detected signal to correct for optical/electronic system variation. This design effort was to simplify and reduce the cost of the major components while eliminating the need for daily calibration. This report is the final report on this effort.

Jan 1, 1981

By W. A. Calhoun

"INTRODUCTION A letter from S. D. Strauss, vice president of Metals Reserve Company, Washington, D.C., dated May 22, 1945, to the chief of the Metallurgical Branch, Bureau of Mines, in Washington; includes the following: Because of the present critical shortage that exists in the supply of corundum required by certain industries in war production, the Reconstruction Finance Corporation, Mr. W. C. Keeley, Vice Chairman for Metals and Minerals, War Production Board, has recommended that the Reconstruction Finance Corporation though Metals Reserve Company, proceed with preliminary mill testing of the corundum ore in Gallatin County, Montana, and that the results of that testing be transmitted to the War Production Board. If the results of the testing work are considered satisfactory, Metals Reserve Company will then provide for the actual mining and milling of the ore for the production of corundum concentrates.Pursuant to the above stated recommendation by the War Production Board, Metals Reserve Company desires to make -use of the facilities of the Bureau of Mines testing plant at Rolla, Missouri, for conducting sink and float and other concentration tests on representative samples of the Montana corundum ore. Two, and possibly three samples of ore are to be tested which will have an aggregate weight of approximately 50 tons."

Dec 1, 1947

By Richard S. Gaps

The Derby and Alexander Claim, located within the Tunnel Ridge Wilderness Study Area (WSA), has placer gold resources. No lode deposits are known within the area, but lode gold deposits are found within 1 1/2 mi of the WSA. In additon, rock units which contain lode gold deposits north of the WSA are found within the northern portion of the study area. INTRODUCTION The Tunnel Ridge Wilderness Study Area (WSA), CA-030-402, encompasses 4,623 acres of BLM administered public land in Trinity County, California, about 35 mi west-northwest of Redding (fig. 1). Major access to the Tunnel Ridge vicinity is by U.S. Highway 299. Ac-cess to the WSA boundary is by a secondary paved road from Junction City and several light duty dirt and gravel roads (fig. 2). The WSA is on the southwest slope of Weaver Bally Mountain. The topography is rugged with moderate to steep slopes; elevations range from about 1,600 ft to 5,900 ft.

Jan 1, 1983

By J. R. Thoenen

Up to 1914 almost all of the world's supply of potash came from Germany and Alsace. With the cessation of shipments from Germany during the World War the importance of a domestic supply was evident, During the past 15 years the United States has been working toward the establishment of a domestic potash industry which would end foreign dominance in this commodity. The Federal government has taken an active part in this program. As its share in the work, the Bureau of Mines has ascertained the potash resources in certain districts through core drilling and has engaged in a comprehensive program of research on the extraction of potash from its various minerals. Until the passage of the Winter bill (H. R. 496) by Congress in 1928 the Bureau of Mines had not been able to give any consideration to the western ores, wyomingite (leucite) and alunite. With the Passage of this bill, however, the ray was opened for the extension of the potash studies to cover these materials.

Jan 1, 1932

By Mirza A. Beg

The Piedmont physiographic province of east-central Alabama lies in a humid subtropical climatic zone. Such an area with mature land forms underlain by rocks rich in feldspars provides conditions condusive to development of gibbsite, a major source of alumina; a raw material for which the United States relies on foreign suppliers for 85 percent of its needs. Gibbsite occurs in the northern and inner sections of the Piedmont Province of Alabama in Coosa, Clay, Randolph, Chambers, Elmore, Tallapoosa and Lee Counties in soils and saprolite derived from amphibolites, granites, feldspathic hornblende gneiss and other gneissic rocks. The major occurrences of gibbsite are in areas underlain by hornblende gneiss in Chambers and Randolph Counties. This region provides the proper physiographic and mineralogical setting for large areas containing up to 25 percent of saprolitic gibbsite. These areas provide potential sources of alumina that could be used to meet the United States future needs. Narrow zones and pockets rich in gibbsite also occur in soil and saprolite derived from areally restricted feldspar rich zones of narrow linear amphibolites in the inner Piedmont and feldspathic zones in various granites distributed throughout the Piedmont.

Jan 1, 1982

By Merle L. Bowser

An alinement (steering) sensor for continuous mining machines has been developed under a Bureau of Mines contract. A laser source in the entry projects a beam parallel to the centerline of the entry. The beam is optically shaped to a narrow, vertical fan and illuminates an array of optical sensors bunted on the mini machine. These sensors interpret the location of the beam into meter readings of heading (angle) error and lateral displacement errors. The system, which was tested for 5 months in an operating mine, appears to be fundamentally sound, and with some modification, should be applicable to remote or automatic guidance of continuous miners and other machines.

Jan 1, 1976

Many USBM research and information products are available through the systems or formats listed below: Mines FaxBack: Return fax service. 1. Use the touch-tone handset attached to your fax machine's telephone jack. (ISDN [digital] telephones cannot be used with fax machines.) 2. Dial 202/219-3644 3. Listen to the menu options and punch in the number of your selection, using the touch-tone telephone 4. After completing your selection, press the start button on your fax machine. Mines Data: Computer bulletin board. Log on via modem through 202/501-0373, or call 202/501-0406 for technical assistance. CD-ROM: This USBM disk is updated quarterly and sold by GPO's Superintendent of Documents. For information on the latest product, please contact Rodger Wedgeworth, 202/501-9557. Internet/World Wide Web: Text and graphics. Access via PC-based browsing software such as Netscape or Mosaic. Universal Resource Locator (URL) is: http:/www.usbm.gav Internet/Gopher Server: Text and tables only. Using Gopher client software, access via port 70 as follows: gopher.usbm.gav Internet System Administrator: webmaster®usbm.gov (or contact your local System Administrator).

Jan 1, 1995

By Francis E. Federspiel

A mineral purvey of the Granite Chief RARE II area (A5-261), covering about 23,400 acres (9,470 ha) of Tahoe National Forest and the Like Tahoe Management Unit, was conducted by the U.S. Bureau of Mines and the U.S. Geological Survey in 1979 and 1980 (fig. 1). The investigation by the Bureau of Mines indicates that the area has a low potential for mineral resources. Samples taken from prospect pits and favorable outcrops indicate no minable quantities of precious or base metals. Placer deposits are too small and low grade to be considered a resource.

Jan 1, 1981

By E. D. Wilson

A study of factors related to subsidence was specified in a project proposal entitled "Structural Analysis of Block-Caving Operation, San Manuel Copper Mine, Pinal County, Ariz.," approved by the Bureau of Mines early in 1953. This proposal was designed by Charles H. Johnson, then chief of the Base Metals Branch of the Minerals Division, Washington, D. C., assisted by Dr. Leonard Obert, chief of the Applied Physics Branch, Region VIII (now Region V), College Park, Md., and E. D. Gardner, chief mining engineer, Bureau of Mines, Washington, D. C. It read as follows: This project is a study of the mechanics of undercut block caving in a deep ore deposit. The San Manuel is a low-grade disseminated copper deposit containing nearly a half billion tons of ore lying at depths of 500 to 2,000 feet. Development is just starting. Production is to begin in 3 to 4 years (in 1956) at a rate of 30,000 tons of ore a day, or 60,000 tons of copper a year. A Government loan of $90,000,000 /subsequently increased to $94,000,000/ and a long-term Government purchase contract support the capital investment, which will total about $110,000,000.

Jan 1, 1957

By William O. Vanderburg

This paper gives the results of a reconnaissance of the mining districts in Pershing County, Nev., made from March 9 to April 1, 1936. During the field work nearly all of the mining districts in the county were visited, and considerable data were obtained on active and inactive properties. The report covers the location of the various mining districts, nature of the deposits, information on past

Jan 1, 1936