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By Gene F. ] [Faufaul

This contract was concerned with the design, development, fabrication and testing of an improved tamper-proof filter cassette assembly for use in the, collection and evaluation of dust particulates, primarily in mining areas. This report presents the design effort, fabrication and tenting of five- prototypre unit$ as well as the design and production of 1000 filter cassettes with sampling heads. This new improved filter cassette has been tested and approved by NIOSH as meeting the requirements specified in the contract.

Jan 1, 1978

By C. W. Morris

This Final Report describes the major technical activities that were accomplished to produce a comprehensive continuous miner training system (CMTS) for coal industry utilization. The primary product of this program was a continuous miner part-task trainer. It is composed of an interactive computer graphics system combined with the operating controls of a continuous mining machine mounted in a simulated cab. The cab contains an audio system for reproducing continuous miner operational sounds. The trainer is supplemented with a complete set of cognitive materials that provide instruction in the operation, safety and health of continuous miner operations. A complete summary of the field test and evaluation of the CMTS is provided along with a set of recommendations for further training program refinements, expansions, and utilization.

Jan 1, 1982

By B. J. CROSS., Henry Kreisinger, John Blizard, C. E. Augustine

This bulletin presents the results of 36 tests made on a 468-horsepower Edge Moor boiler fired with pulverized coal at the Oneida Street Station of the Milwaukee Electric Railway & Light Co., Milwaukee, Wis. The tests were made by the fuel section of the United States Bureau of Mines in cooperation with the research department of the Combustion Engineering Corporation. Illinois coal was used as fuel; the furnace, burners, and feeders were designed by the Locomotive Pulverized Fuel Co. The object of the tests was to determine what over-all boiler efficiency could he obtained with pulverized coal under various conditions of furnace operation and with coal of different fineness and moisture content. The investigation was thorough. The pulverized coal, as it was supplied to the furnace, was weighed in specially designed tanks placed on platform scales. Twenty-nine of the tests were of 24 hours duration, three of 16 to 18 hours, and four of 12 hours. All tests are reported excepting two-8 and 20-which had to be stopped abruptly, No.8 because a motor actuating the coal-feed screw burned out and No. 20 because of trouble with the feed pump. Tests 1 to 27, inclusive, were made with round burners and tests 28 to 3Rwith spreading burners. In the first nine tests a large excess of air was supplied in an effort to prevent the ash fusing at the bottom of the furnace. In tests 10 to 16 the supply of excess air was reduced in order to get a high efficiency, regardless of the slagging of ash at the furnace bottom. Tests 17 to 27 were made with a water screen about 10 inches above the bottom of the furnace, to make possible the burning of coal with a small supply of excess air without the ash fusing at the bottom of the furnace. Tests 28,29, and 30 were made without the water screen and with a small supply of excess air, and tests 31 to 38 with a water screen around the walls near the bottom of the furnace. Tests 32, 33, 34, and 35 were run with coarser coal than that used ordinarily at the plant. Tests 36,37, and 38 were made with undried coal.

Jan 1, 1923

As part of the Bureau of Mines program to reduce U.S. reliance on foreign suppliers of strategic and critical metals, research was conducted to improve technology for the recovery of critical metals from hardface alloy grinding waste, a form of superalloy scrap. This report describes a hydrometallurgical process that demonstrated on a laboratory scale that 79 pct of the chromium, 97 pct of the cobalt, 99 pct of the manganese, 99 pct of the nickel, and 90 pct of the tungsten could be recovered in chemical form from hardface alloy grinding waste. The process involved deoiling the grinding waste, followed by chloride-based dissolution of the deoiled material. A high-grade calcium tungstate (CaW04) product was recovered from the resultant leach residue by caustic leaching and precipitation. Iron, cobalt, man-ganese, and nickel chlorides were sequentially recovered from the leach liquor by solvent extraction. Amine extractants were used to extract the iron, cobalt, and manganese; decanal oxime was used to extract the nickel. Market-grade cobalt chloride (CoCI2), manganese chloride (MnC12), and nickel chloride (NiCl2) products could be produced directly from the resultant strip liquors. The final raffrnate was a relatively pure chromic chloride (CrCI3) solution that compared favorably with commercial solutions.

Jan 1, 1988

By William F. Hahn

This report describes an illumination system suitable for use in a slope under construction, Simulator work was performed using actual lighting hardware to verify adequate light levels to meet MSHA proposed regulation (as published in the Federal Register, January 13, 1977). The sequence of operating activities for two different slope driving sites are discussed and lighting requirements are defined for each,

Jan 1, 1981

By Lucia Kuizon

The Miranda Pine Roadless Area Review and Evaluation (RARE II) study area (No. 5114) comprises 12,600 acres (5,100 ha) in Los Padres National Forest in Santa Barbara County, California, about 15 mi (24 km) east of Santa Maria (fig. 1). Mineral investigations are made by personnel from the U.S. Bureau of Mines on National Forest lands identified as Further Planning Areas in the RARE II program. The Bureau of Mines reviewed literature, mining claim records, and production files; examined the study area; and sampled mineral properties where appropriate.

Jan 1, 1983

By F. D. DeVaney

Metallurgists and coal-washing engineers have used heavy liquids for years in studying the characteristics of ores and coal. By such means true separations can be made between the various specific-gravity increments in the materials examined. To use of heavy liquids has permitted determination of the possible grades of tailings and concentrates by specific-gravity methods on any particular size, and therefore the size to which the ore must be crushed to free the valuable material. The simplicity of float-and-sink separation and the high degree of efficiency attained in the laboratory are factors that commend the method for commercial concentrations.

Jan 1, 1940

By D. E. Traut

A fluidized countercurrent ion-exchange system was developed, operated, and evaluated by the U.S. Department of the Interior, Bureau of Mines. The system consisted of integrated multiple-compartment absorption and elution columns in which the solution flows were continuous except for short periods when resin increments were withdrawn. The exchange of uranyl carbonate between a simulated in situ uranium leach liquor and a strong-base ion-exchange resin together with the subsequent elution with an ammonium chloride solution was studied. The effects of the number of sections, section height, amount of resin withdrawal, solution flow rate, and column diameter were investigated. The kinetic and equilibrium relationships for the absorption and elution steps were also examined. The experimental data indicate a strong interdependence between variables. Solution retention time appears to be a major limiting variable in the absorption process, while resin residence time is the determining factor in the elution process. The column was efficient over a range of conditions, but close control was needed for optimum operation.

Jan 1, 1978

By F. D. DeVaney

Metallurgists and coal-washing engineers have used heavy liquids for years in studying the characteristics of ores and coal. By such means true separations can be made between the various specific-gravity increments in the materials examined. To use of heavy liquids has permitted determination of the possible grades of tailings and concentrates by specific-gravity methods on any particular size, and therefore the size to which the ore must be crushed to free the valuable material. The simplicity of float-and-sink separation and the high degree of efficiency attained in the laboratory are factors that commend the method for commercial concentrations.

Jan 1, 1940

By Aldo L. Furno

Sufficient quantities of combustible vapors are released by some sulfurs to produce flammable atmospheres under prolonged storage. Hydrogen sulfide and carbon disulfide appear to be the principal flammable constituents in the vapor space above molten sulfur. If sufficient carbon disulfide is present, ignition of the vapor-air mixtures can occur spontaneously on contact with the heated surfaces found within storage tanks.

Jan 1, 1963

The Bureau of Mines, in an effort to improve resource conservation, mine planning and development, is currently investigating the loading behavior of pillars in multiple-seam developments. The simultaneous mining of two or more coalbeds may cause instability between room-and-pillar operations resulting in an interaction known as pillar load transfer. Although pillars may be adequately designed for single-seam mining, the development of a second seam may complicate loading conditions in both operations. If pillars are not adequately designed to contend with this load transfer, failure of the mine structure may result. To improve multiple-seam development and pillar design, the Bureau studied the loading characteristics of pillars in three separate multiple-seam operations. In all three cases, instrumented pillars recorded increasing pressure after development of the second seam. Increases in the average pillar pressure ranged from 7 to 110 pct over predicted overburden loads. An analysis of pillar loading before and after second-seam mining indicates that the ratio of overburden to innerburden thickness is a critical factor influencing load transfer. Based on this relationship, safety factors for case study pillars are calculated and alternative design considerations are discussed.

Jan 1, 1988

By C. B. Manula

This report is volume 5 of an eleven-volume final report for a Grant completed by The Pennsylvania State University for the Bureau of Mines to develop a dynamic general purpose computer simulation model for underground coal mining. The simulator developed under the Grant has a wide range of possible applications in the design and evaluation of underground coal mining systems from the standpoints of health and safety, productivity, and mine environment. The Master Design Simulator consists of nine free-standing function-oriented subsystem models linked together into an integrated, comprehensive model of an entire mining system. The subsystems comprising the Master Design Simulator include geology and reserves, methane generation, roof support, subsidence, production, rail haulage, cost, water generation, and ventilation. This volume of the final report describes the Subsidence subsystem of the Master Design Simulator. This subsystem uses the finite element method to simulate ground movement caused by an advancing mining face in an underground coal mine. The model is structured around the concept that the ground mass is a layered media of different thicknesses and material properties. Gob areas are considered to be unfilled with broken rock at the beginning of mining. After mining starts, the gob areas are filled with broken material which provides resistance to the lowering of the overlying strata. The model is tied to the Geology and Reserves subsystem, but it can also operate as a free standing routine. A case study is presented illustrating the application of the model. A detailed user's manual, including a program listing, is included in the appendices.

Jan 1, 1974

By G. B. Clark

One portion of this project was to test a blast shield and to design some features for a novel tunneling method termed the Automated Drill and Blast System (ADBS). The ADBS tunneling concept was developed for the design of an excavation system of greater efficiency than conventional drill, blast, and muck (DBM) systems by minimizing the down time and approaching the non-cyclic efficiency of continuous tunneling by means of small charge blasting. Small charge blasting uses simultaneously detonated, small light charges (less than 200 grams per hole) in four to eight shallow (24 to 36 in. deep) holes usually in a line. Limitation of the total explosive per blast reduced air blast overpressure, fly rock velocity, vibration, and noise. Thus, shielded equipment can remain at the face and a tunnel shield permits support personnel to work outby the shield at all times. The ADBS equipment will be composed of five components: (1) a chassis, upon which is mounted automated mucking equipment, and a frame which carries (2) the hydraulic drill(s), (3) load/blast system(s), and (4) control cab(s). The blast shield may have its own mounting. Ventilation, horizontal, and vertical alignment controls are incorporated in the system. The blast sheild, which protects personnel outby the advance equipment from air blast overpressure, fly rock, and gases, was tested with full scale small charge blasting. A blast shield was designed, fabricated, and tested under conditions anticipated for a working model. The shield was designed to expand to fit the tunnel shape, to seal itself to the tunnel periphery, and to contain air blast, fly rock, and gaseous explosion products. In addition, the shield, which was lined on the inby side with rubber belting, reduced the blast noise level outby the shield to 113 dBA or less, which is very near permissible levels. The test results show conclusively that the shield concept is viable. Based partially on the shield tests, a blast resistant control cab was designed to be located on the equipment chassis inby the blast shield to protect operators during blasting, and to contain all the controls necessary for system operation and safety. The economics of tunnel driving using the ADBS were compared with those of DBM. Four rock types, which determine advance rate, and four cost categories were examined. The results of this analysis are as follows: 1. ADBS advance rate is faster because equipment remains at the face and operation procedes semi-continuously. 2. ADBS bit and explosive cost (which accounts for 4%o of the total advance cost) is higher than for DBM. 3. ADBS equipment cost, on a per foot basis, is lower than for DBM. 4. Due to a reduced labor force, ADBS labor cost is lower than for DBM. 5. Because of the overbreak reduction due to controlled blasting, ADBS tunnel support cost is lower than for DBM. 6. On a per foot basis, total ADBS advance cost is from 17% to 20% lower than for DBM, depending on tunnel diameter and rock type. The small charge method greatly reduces ground vibration, increases personnel safety by limiting excessive fracture, and decreases tunnel support requirements by reducing overbreak. The overall analysis, tests, and results to date show that the Automated Drill and Blast System may be developed into a viable tunnel excavation method. The method also may be adapted to use in the mining of ore. For some types of mining operations, the cyclic nature of conventional drill and blast methods may not be a disadvantage, either where the drilling and mucking may proceed simultaneously or where the operations are carried out in adjacent working faces. The proposed method would find application where continuous methods of excavation are desirable.

Jan 1, 1979

By Andrew F. Conn

This report summarizes the results from the first year of an anticipated multiphase program to develop improved coal mining equipment which utilize the CAVIJET? cavitating water jet method. This laboratory parametric study demonstrated the advantages of cavitating jets over non­cavitating jets in cutting coal, by producing comparable slot depths at one-fifth of the operating pressure, at better than one-half of the spe­cific energy. These results suggest that CAVIJET-augmented mining devices can be developed with compact, low-pressure pumps. Thus, CAVIJET should be capable of operating with safer, lighter support equipment, while providing all of the advantages (reduction of dust and sparks, reduced damage to cutters) of conventional hydraulic mining methods.

Jan 1, 1976

By Carl Belser

This paper, covering Chaffee, Fremont, Gunnison, Lake, Larimer, Park, and Summit Counties, Colo., is the second of a series reporting on the tungsten potential of the Colorado region. The assembled information was obtained by examination of some properties, personal contacts with owners, and access to unpublished reports by other engineers. The tungsten-bearing areas of the 7 counties cover approximately 400 square miles and are in 10 distinct areas, which vary in size (fig. 1) from 1 square mile up to 290 square miles. The tungsten mineral wolframite was discovered by a man named Hackay near Dale on the Florence & Cripple Creek Railroad in the early 1900's, and wolframite and hubnerite were noted at Climax and the adjacent areas in Lake and Summit Counties at an early date, but no records of shipment from any of the areas are available before World War II. It is not known when scheelite was first discovered, but it was recognized in the Stockton mine during World War I. In the counties listed 64 properties are known to contain tungsten; of these, 18 have had some commercial output, although only 3 of them produced in 1953. The total production through 1953 is estimated at 115,000 short-ton units of tungsten trioxide. In 1953 by far the major portion came from the Climax mine.

Jan 1, 1956

By Gary E. Sherman

To aid the U.S. Army Corps of Engineers in their Resource Development Navigation Study, the U.S. Bureau of Mines (Bureau) examined the potential for mineral development near ten Alaska port sites. This report presents the results for the following four sites: Balboa Bay, Beluga, Lost River, and Point MacKenzie. There are 579 known deposits within the area considered for these ports. The majority of the deposits are located within a highway/railroad corridor examined for the Point MacKenzie port site. Based on the current level of knowledge, coal deposits near the Beluga and Point MacKenzie port sites are most likely to be developed in the near future. This conclusion is based on the fact that coal projects in these areas are actively being pursued for development. The mineral wealth surrounding the four port sites is substantial. Mine models were used to examine the potential for mining tin, gold, silver, copper, and molybdenum. The models were based on published reserve and grade data and therefore do not include proprietary company data which, if available, would likely change the analysis results. Of the models examined, the tin placer mine model developed for the Lost River port site proved to be closest to being economic.

Jan 1, 2011

By Joseph Grumer

The range of composition of gases synthesized from solid fuels which are exchangeable with natural gas on current gas appliances was evaluated by theoretical principles. These principles consider primarily the flashback, blowoff, and yellow-tipping characteristics of air-entraining burner flames. It was found that complete identity between the synthetic and natural product is not necessary. Gases such as may be obtained by hydrogasification of coal and other solid fuels without the removal of unreacted hydrogen offer advantages in flame characteristics. Between 25 to 37 percent hydrogen can be tolerated in the sendout gas.

Jan 1, 1965

By H. A. Doerner

"The pure mineral chromite, FeO.Cr203, consists of ferrous and chromic oxides, chemically united in equal molecular proportions. Unfortunately, pure chromite as defined above appears to be a rare exception. In most chrome ores the mineral may be considered a combination of spinel, MgO.Al203, and chromite, with the latter predominating. The ratios between the four common constituents Fe0, Mg0, Cr203 and A203 vary greatly, and other minor constituents such as TiO2 and. Fe203 may also be present.In the mechanical concentration of chromite ores the maximum grade of concentrates that can be produced is thus limited by the composition of the chrome minerals present. Pure chromite contains 68 per cent Cr203, but the Cr203 content of the chrome minerals in commercial ores varies between 45 and 60 per cent and the average is not far from 55 per cent.Chromite is usually associated with serpentine. Other silicates, quartz, dolomite, magnetite, ilmenite and other iron Minerals are frequently present.The amenability of a chrome ore to concentration, depends upon the kind and amount of the various gangue minerals present and the amount .of crushing necessary to separate the chromite from them.A relatively small amount of chrome ore is concentrated by milling. In most cases the mine product is simply hand-sorted. Such chrome deposits as are known in the United. States can not be worked in this way on account of one or both of the following conditions: High cost of labor and finely disseminated impurities. There are, however, several deposits in the United States, Canada, and Alaska which may be able to compete with imported or by efficiently utilizing modern ore-dressing and milling methods."

Nov 1, 1930

The panic bars (and associated linkages and electrical circuitry) that are defined in this document are a machine operator-actuated control for the emergency deenergization of the tram motors on self-propelled, electric and diesel face equipment; including haulage equipment such as shuttle cars. There are nine basic types of panic bars (and several variations) that are recommended in this document, but all of the panic bars are characteristically of the "fire door" type that is frequently encountered on outside exit doors of many public and some commercial buildings. It is also the intent of the following panic bar designs that, when emergency brakes are added to the face equipment machinery for which they are required, that they be designed and hooked up so that actuation of the panic bar will result in automatic application of the emergency brakes (immediately following the deenergization of the tram motors). The following panic bar design requirements are a restatement of the proposed requirements defined in the Federal Register, requirements cited in 'Guidelines for the Design and Installation of Devices for Deenergization of Self-Propelled Electric Face Equipment/ Automatic Emergency Brakes" by C. E. Lester and J. D. Greenhalgh of MESA, and Bendix recommendations that were formulated as a result of discussions with personnel at the various machine manufacturers and underground coal mines that we surveyed, discussions with G. L. Judy (our consultant), etc:

Jan 1, 1974

By G. A. Morrison

Iron ores associated with the Oriskany formation extend from the West Virginia border to the southwestern corner of Virginia. The deposits have been mined at many places, and the district is credited with the production of approximately 13,000,000 tons of ore to 1925, when mining operations ceased (fig. 1). The Oriskany iron-ore deposits occur in the Alleghany Mountains throughout their extent in the State. The name Oriskany was originally given to the limonite ore that was supposed to occur in the Oriskany sand-stone. At present, the name applies to all iron-ore deposits occurring in the lower part of the Devonian shale, Oriskany sandstone, and Helderberg limestone. The principal ore-bearing minerals are goethite and limonite. This report deals principally with the occurrences in Allegheny, Bath, Botetourt, and Craig Counties, Va. The Bureau of Mines, as part of the strategic-minerals program, began a project to develop the reserves of the area in November 1943; and continued until December 1944. Work started near Oriskany and extended northeast for nearly three-fourths of the area of the more important deposits. During the program 163 holes were drilled, totaling 11,651 feet; 256 feet of prospect tunnels were driven; 1,346 samples were collected; beneficiation tests were performed; and bulldozer trails and trenches wore excavated. The work served to delimit and appreciably extend the reserves of several areas. Analyses of channel samples are -given in appendix A, and diamond-drill and churn-drill hole logs and sample analyses are given in appendixes B and C, respectively.

Jan 1, 1950