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By R. Lusignea

This report describes the development of a device for the nondestructive testing of resin grouted roof bolts by means of mechanical frequency response. Various alternative methods were evaluated and the mechanical frequency response method was selected. An interactive program of design, testing, and development culminating in the current prototype instrument demonstrated the capabilities of the method and suggested potential applications of the instrument. The resin bolt testing device utilizes a swept frequency dynamic compliance measurement in the 1 to 2 kHz range which is interpreted by an electronic signal processor to give a "GO" or "NO GO? readout. Field tests have shown that the device can reliably determine the bond quality of the front half of the bolt (nearest the roof surface). Tests were carried out on both experimentally installed bolts and typical mine bolts installed by a conventional bolting machine. The development program has led to recommendations for improvement of the prototype and future development work.

Jan 1, 1979

By Fei-chiu Huang

The principle of time domain reflectometry (TDR) is being used by the U.S. Bureau of Mines to monitor strata displacements induced by mining. The Northwestern University TDR Signature Analysis (NVTSA) Program was developed under contract with the Bureau to allow for visual comparison of three TDR waveforms quickly and easily. This program is interactive, and on-line help is available. The Northwestern University Remote Control TDR Data Acquisition System and Modification of Tektronix SP232 Host Application Program (NUMOD) was then developed to allow acquisition of TDR wave-forms from a remote cable tester via modem. The NUMOD system utilizes commercially available software while the NUTSA program is available from the Bureau. This report begins with a discussion of TDR principles followed by a description of the NUMOD system. An interactive example of signature analysis is then used to demonstrate features of the NUTSA program.

Jan 1, 1993

By Milford L. Skow

This report summarizes the principal activities and results of 15 years of research by the Bureau of Mines, U.S. Department of the Interior, on methane control in coal mines. This research has investigated fundamental factors regarding the occurrence and movement of methane in coal beds, removal of methane prior to mining, and control of methane during mining. The report includes a bibliography listing the more than 150 publications resulting from the Bureau's methane control program as well as numerous other references, a section on methane recovery and use, a look at the upcoming Bureau of Mines research program, and a brief review of methane drainage practices in other coal-producing countries.

Jan 1, 1980

By Robert H. Ridgway

This circular outlines salient facts regarding the manganese-ore industry in the United States and the world. It is founded chiefly upon published information available in the literature of the subject. The Bureau of Mines has in its files additional, more detailed data upon many of the topics presented very briefly here, and will endeavor to assist the mineral industries and public by giving further information in response to individual inquiries. The Bureau will welcome comments, criticisms, and contributions of data that may assist in making later additions of this circular more accurate, or in developing more fully its mineral files pertaining to manganese. In reporting the production of manganese-bearing ores in the United States the following classification has been adopted by the Bureau of Mines: (1) Metallurgical-grade ores, under which have been classified manganese ores containing 35 percent or more of manganese used in the manufacture of iron and steel, ferruginous manganese ore containing 10 to 35 percent of manganese, manganiferous iron ore containing 5 to 10 percent of manganese, and manganiferous zinc residuum; (2) battery ore; (3) fluxing ores, under which are classified ores that may contain a few ounces of silver and are rich enough in manganese to make them valuable chiefly for fluxing purposes in nonferrous smelters; and (4) miscellaneous ores, under which are classified the ores shipped to brick manufacturers, glass makers, and manufacturers of manganese chemicals.

Jan 1, 1933

By J. R. Thoenen

"The curtailment of imports of foreign potash during the World War directed attention to the necessity of establishing a domestic source of potash for fertilizer, and considerable study has been given to the subject by Government bureaus, research organizations, and private individuals. These studies have covered all known sources of potash, and among them the extensive greensand deposits of New Jersey in which the potash content is found in the mineral glauconite have been investigated.Several hundred patents have been obtained covering processes for the extraction of potash from siliceous minerals, but up to the present time none have proved successful on a large commercial scale.When the investigation of the potash deposits of Texas was started by the Federal Government, the laboratory study of the drill cores was assigned to the Nonmetallic Minerals Experiment Station at New Brunswick, New Jersey, with the object of ascertaining a possible commercial method of utilization.The purpose of this preliminary study was to investigate existing literature and previous investigations to ascertain the extent and availability of the deposits, the extent of commercial success so far attained in potash extraction, the most promising known methods and by-products obtained from them, probable markets, and possibility of competition with foreign potash, and by a study of these data to determine whether further chemical engineering analysis and laboratory investigation were warranted.As the study advanced it became evident that adequate reserves of green-sand were available for many years supply. and that whereas many processes had been patented few had been tried commercially. In collaboration with former private and Government investigators these patents were first divided into two"

Feb 1, 1929

By Robert H. Merrill, James V. Williamson, David M. Ropchan, George H. Kruse

In- situ rock stresses were determined by flatjack and borehole - deformation methods . Estimates of the stress distribution around a flatjack were obtained by a combination of flatjack and borehole - gage techniques . The investigations were part of a study , conducted jointly by the State of California and the Federal Bureau of Mines , to determine the stress in rock at the site of an underground powerplant for the Oroville Dam near Oroville , California . The stress distribution around each of three flatjacks was nonsymmetric ; however , stresses obtained from 9 flatjack and 157 borehole measurements are considered reasonably accurate for engineering purposes . The stress near the edge of the openings is between 800 and 1,600 psi ; the stress in the undisturbed rock is approximately 500 psi , nearly hydrostatic .

Jan 1, 1964

By R. V. Ramani

This volume is the fourth of a four-volume final report on research carried out under a contract from the U.S. Bureau of Mines on the development of a computer simulation model for surface mine reclamation planning. The other volumes are titled as follows: Volume I: Ore Reserve Estimation, Volume II: Dragline Model, and Volume III: Mine Coordinate Generator System. The Open Pit Materials Handling Simulator (OPMHS) was first developed" in 1971 and modified and updated in 1975. The present work is an update of the 1975 version and provides a direct link between the geology and reserves system and the various activities of the mining equipment in a mining system. Also, the modeling techniques in OPMHS/2 have incorporated a flexible method for describing various equipment (shovels, trucks, belts, trains, etc.), locations, their sequence of operations, place changes, and their interactions. These features allow for studying mining equipment selection, mining method analysis and reclamation planning. This report describes the Open Pit Materials Handling Simulator Version 2 (OPMHS/2). The report details the program features, operation, and application. Through an extensive set of appendices, the data input sequence, input variable definitions, sample data listing and program output are presented in detail.

Jan 1, 1985

By E. J. Harris

Data obtained from mine ventilation pressure and quantity surveys are required to accurately diagnose ventilation problems, project future air quantity needs, and to locate conditions adversely affecting the efficiency of a mine ventilation system. A method for making mine ventilation pressure surveys with aneroid altimeters was presented in Bureau of Mines Information Circular 7809, and a description of field calculation technique is presented. This report supplements Information Circular 7809 by developing the information obtained during a mine ventilation pressure survey into a single equation suitable, with appropriate modification, for use with desk-top calculators and digital computers. The equation can be used to calculate the ventilation pres sure from the base station to any underground station, or between any two underground stations, and can be programed for semiautomatic sequential calculation using a desk-top calculator. An example of application to a programed desk-top calculator is provided in the appendix.

Jan 1, 1973

By Matthew J. Sheridan

The Bureau of Mines study described in this report was conducted in the Denver, Colo., area (1) to summarize existing conservation practices as related to the most beneficial utilization of deposits of sand and gravel; (2) to identify the conflicting positions of the aggregate producer, the mineral owner, nearby residents, and local government officials responsible for determining land status and for issuing operating permits; and (3) to show the need for planning in Denver and in other expanding communities toward obtaining the benefits of conservation of our rapidly dwindling mineral resources. In order to determine the effects of urbanization on the Denver aggregate industry, interviews were held with owners of sand and gravel operations, with producers of concrete and bituminous pavement, with city and county planning and zoning personnel, and with representatives of various interested organizations. The conservation and ultimate utilization of deposits of construction raw materials near expanding urban areas can best be accomplished by long-range land-use projection and the requesite cooperation of technically advised planning and zoning administrators, government officials, mineral producers, and land developers.

Jan 1, 1967

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 G. W. Birge, D. E. Wolfson, J. G. Walters

An investigation was conducted to determine the relationship between ASTM and Micum tumbler data and to develop equations that would enable the conversion of data from one test method for comparison with those determined by the other , and thereby facilitate the international exchange of data . Relative strengths of 18 commercially produced cokes were determined by ASTM and Micum tumblers and ASTM shatter test . Two of the samples were coke produced for foundry use , and two were produced in beehive ovens . The remaining 14 samples were produced for blast furnace consumption and had ASTM tumbler stabilities of 36 to 58. Statistical procedures were used to relate the three test methods and also to evaluate the effect of charge weights , top sizes of coke , and types of screens specified by the two standard tumbler procedures , square - hole wire mesh for the ASTM tumbler and punched round - hole for the Micum . A significant result was that the data obtained with like screens have a higher degree of correlation with a smaller standard deviation than data from the screens specified for each tumbler .

Jan 1, 1964

By H. C. Carpenter

This literature study of methods for desulfurizing residual fuel oil was conducted by the Bureau of Mines at the request of the Department of Health, Education, and Welfare. The sulfur compounds in residual fuels are believed to consist chiefly of condensed thiophenes and other polycyclic sulfur compounds. Hydrodesulfurization appears to be the most promising method for desulfurizing these oils and is the only method applicable to all types of sulfur compounds. There are indications in the literature that hydrodesulfurization without hydrocracking of residual oils may require higher pressures than used in present desulfurization processes, but no cost data and little experimental data are available on the higher pressure operation. Literature proposals for hydrogenating residual oils and heavy crude oils are exclusively for hydrocracking the oils to lower boiling products with accompanying partial desulfurization of the residual fuel fraction. Costs of the hydrocracking operations appear the closest available to probable costs of hydrodesulfurizing the oils, and have been reported (in 1955 to 1957) as $500 to $840 investment cost per daily barrel of capacity, with total operating costs of 70 cents to $1.10 per barrel.

Jan 1, 1963

By H. C. Carpenter

This literature study of methods for desulfurizing residual fuel oil was conducted by the Bureau of Mines at the request of the Department of Health, Education, and Welfare. The sulfur compounds in residual fuels are believed to consist chiefly of condensed thiophenes and other polycyclic sulfur compounds. Hydrodesulfurization appears to be the most promising method for desulfurizing these oils and is the only method applicable to all types of sulfur compounds. There are indications in the literature that hydrodesulfurization without hydrocracking of residual oils may require higher pressures than used in present desulfurization processes, but no cost data and little experimental data are available on the higher pressure operation. Literature proposals for hydrogenating residual oils and heavy crude oils are exclusively for hydrocracking the oils to lower boiling products with accompanying partial desulfurization of the residual fuel fraction. Costs of the hydrocracking operations appear the closest available to probable costs of hydrodesulfurizing the oils, and have been reported (in 1955 to 1957) as $500 to $840 investment cost per daily barrel of capacity, with total operating costs of 70 cents to $1.10 per barrel.

Jan 1, 1963

By Ellsworth Y. Dougherty, Edwards F. Fitzhugh

"INTRODUCTION During the summer of 1945 the Bureau of Mines made approximately 200 miles of reconnaissance magnetic surveys in north-central Mirnesota. The survey started near the western end of the Mesabi Iron Range and extended into the area to the southwest, west, and northwest and also southward to the-northern limits of the Cuyuna Iron Range. The purpose of the survey was to data to assist exploration for iron ore in the region through:1. Supplying a relatively unit form network of traverses, by which and future surveys of localities in the urea ray be correlated. Suggesting localities in which more detailed magnetic surveys may be justified, and, Disclosing localities in which there is lass hope of obtaining significant results from further magnetic surveys.The instrument used was a Hotchkiss Superdip, and traverses for calibration and comparison were run with a Schmidt-type magnetometer. Field observations and work directly related thereto were carried out under contract by E. J. Lang-year Co., Minneapolis. Engineers of the Bureau of Mines planned, directed, and reviewed the survey."

Aug 1, 1946

By D. E. Shanks

This U.S. Bureau of Mines (USBM) research simplified an earlier hydrogen chloride (HCI) leach-sparge process developed by the USBM to recover reduction-grade alumina from domestic kaolin clay. Improvements were made by decreasing the initial leaching acid concentration from 25 to 20 pet, decreasing the leaching time from 1 to 2 h to 15 to 30 min, eliminating the solvent extraction step for Fe removal, and eliminating the step to recover the AI content of the bleedstream circuit. A 10-cycle bench-scale experiment of the simplified process showed that the ferric chloride (FeC13) concentration built up to 9.3 g/L in the recycle stream. This did not interfere with any of the unit operations or final alumina product purity because Fe forms stable soluble chloride complexes when sparged with HCI and is easily washed from the large aluminum chloride hexahydrate (ACH) crystals. The reduced leaching time and acid concentration did not decrease Al extraction.

Jan 1, 2010

By R. J. Gunderman

Redesigns of the operator compartments on a continuous miner and on a face haulage vehicle are described. The objective was to optimize the compartments within limitations of existing equipment and functional configurations. Both safety and production should be improved through more comfort for the operator and more natural placement of controls. Design guidelines supplied by the Bureau from a previous contract were used along with human factors analyses to determine requirements. Mock-ups were fabricated from layouts and used to refine design details. The new compartments were implemented and the machines evaluated underground. Comments and reactions to both machines were favorable.

Jan 1, 1978

By W. R. Hardwick

This Information Circular describes the development of block-caving methods and practices by the Miami Copper Co. at the Miami mine in Gila County, Arizona. It is one of a series published by the Bureau of Mines on mining methods, practices, and costs in various mining districts of the United States. This report gives a history of the district and outlines early prospecting and exploration including methods of sampling and estimation of ore tonnage and value at the Miami mine. Early mining methods are described, particularly those that influenced developments in the caving method. Mine exploration, development, and operating methods for block caving are described with particular attention to those factors, physical, economic, engineering, and managerial that have improved efficiency in the mining operations over a long productive period. Extraction, ventilation, wage system, safety, water supply, power plant, and shop facilities are discussed. The last section gives a brief sumary of such costs as are available for publication.

Dec 1, 1964

By E. R. Palowitch

This report is the result of a series of coal-cleaning tests using a dense-medium cone-type washer. Detailed results are given for 2 tests using a magnetite medium and 4 tests using a pulverized-refuse medium. Approximately 120 float-and-sink tests and over 500 separate chemical analyses were made in conjunction with these tests. In these tests higher recovery efficiencies and sharper separations were obtained when using a magnetite medium, especially on coal sizes below one-half inch. When sizes above 1 inch at low specific gravities of separation are cleaned, the pulverized refuse medium compared favorably with the magnetite medium.

Jan 1, 1956

By A. E. Petersen

To reduce U.S. dependence on imports of titanium, the U.S. Bureau of Mines has investigated the recovery of titanium from perovskite (CaTi03). Domestic perovskite deposits represent a significant, but untapped, titanium resource. An acid sulfation method was developed that will extract about 97 pct of the titanium and the columbium and 70 to 90 pct of the rare-earth byproducts from perovskite concentrates. A flow-sheet for recovering titanium as pigment-grade titanium dioxide (Ti02) is discussed. Test work performed in developing each unit operation is described. The first three unit operations have been demonstrated using laboratory-scale continuous methods of operation: acid sulfation of perovskite concentrates, leaching sulfation residue to dissolve metal values, and precipitation of titanium oxysulfate monohydrate (TiOS04?HP) from the resulting leach flltrate. Batch testing of other unit operations was performed: TiOS04?H20 redissolution and iron reduction, precipitation of Ti02 by hydrolysis, and regenerating recoverable acid with rare-earth byproduct recovery. Cost evaluation results are provided, indicating that processing perovskite concentrates by acid sulfation may be an economically viable means of producing Ti02.

Jan 1, 2010

By Fred C. Turin, Jasinder S. Jaspal, Alan G. Mayton, William J. Wiehagen

This report describes serious injuries occurring to bulldozer operators working at U.S. coal, metal, and nonmetal mines. The period covered is 1988-97. The data were collected by the Mine Safety and Health Administration (MSHA). A total of 873 injury records are examined. These injuries resulted in 18 fatalities and 31,866 lost workdays. All of these injuries occurred to dozer operators while they were doing common production tasks. An injury classification system was developed to code the narrative information that describes the circumstances surrounding the injuries. Injury records are categorized by activity (task being done), incident result (what apparently happened to the dozer), and operator impact (how the operator was injured). Where information is available, contributing factors are identified. This classification system supplemented the standard injury/illness data classification system compiled by MSHA. The results of the study indicate that, from 1993 to 1997, the number of serious injuries to dozer operators declined by 30%. The reduction in serious injuries was accompanied by a decrease in days lost due to injury. Although the number of reported injuries has decreased, dozer operators being jolted and jarred accounts for the largest percentage (70% of the incidents) and severity (75% of the workdays lost) of serious injuries while operating the equipment. Vertical jars (while backing up the dozer) resulting in injury to the operator accounted for a sizable percentage of jolting and jarring injuries. Working near an edge carries significant risk for fatal injuries. Of 116 incidents where the dozer fell over an edge, rolled over, or fell into a hidden void, 14 (12%) resulted in fatal injuries. In cases where the dozer operator either jumped or was thrown out of the cab in a fall over or rollover, 7 out of 26 were killed. Overall, 80% of the fatalities occurred while working near an edge or hidden void or on a steep slope. Further reductions in injury risk will require more widespread use of seatbelts, field and laboratory research interventions to better assess the effect of alternative engineering (e.g., seat and seat suspension) designs to dampen or isolate the effects of shock and vibration, and continued focus on hazard awareness, recognition, and response.

Jan 4, 2001