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By G. W. Grove, O. V. SIMPSON

During the years 1945, 1946 , 1947 , and up to July 1, 1948, only one death was caused by mine fires in bituminous - coal mines of the United States . The one fatality occurred in an Illinois mine in December 1945, and , therefore, there had been a period of 2-1/2 years in which no deaths occurred as the result of mine fires . Moreover, 1946 was the first year since 1930 in which no deaths occurred from mine fires . This record is markedly better than that of 1944 , when 89 fatalities and great property damage were caused by mine fires in bituminous - coal mines and 16 additional men were killed by an explosion that occurred while they were attempting to seal a mine fire .

Apr 1, 1949

By Ann G. Kim

Methane in coal constitutes a serious hazard in coal mining. Draining the methane in advance of mining can mitigate this hazard, conserve energy, and offer economic benefits. This Bureau of Mines report evaluates the Pittsburgh coalbed in Greene County, Pa., to determine if advance drainage is feasible. The gas content of virgin reserves in Greene County is estimated at 100 to 200 ft3/ton, a total of over 370 billion ft3 of gas in an area approximately 310 mi2. Because of the similarity to natural gas, drained coalbed gas could be recovered and added to pipeline supplies of natural gas. The value of conserved gas would offset the cost of drainage and extend energy resources.

Jan 1, 1975

By Andrew B. Cecala, Robert J. Timko, Alexander D. Prokop

Bag loading and stacking processes are the highest dust-exposure job categories in the metal/nonmetal mining industry.1 To cost-effectively decrease respirable dust levels, the Pittsburgh Research Center of the National Institute of Occupational Safety and Health (NIOSH), formerly of the U. S. Bureau of Mines, designed and tested a system called the Bag and Belt Cleaner Device (B&BCD). [ ]

By Charles L. Kimbell

The concept of data availability must be addressed, because there are perceptible changes from year to year, and the availability of accurately reported, precisely defined statistics and nonstatistical information provides the only sound basis for analytical studies required for government policy planning or industry market analysis. As the countries of Eastern Europe and the former U.S.S.R. undergo the transition from centrally planned economies to market economies, there has been a perceptible increase in information availability for rather obvious reasons. Any industrial operation seeking economic assistance from Government and/or private sources outside the country in which the facility is sited must provide some appraisal of its operations at the time it seeks assistance, as well as some information on previous performance to serve as tools in evaluating its potential under the proposed development scheme for which it seeks financial assistance. Additionally, there was growing governmental recognition that concealment of much of the national mineral production, trade, and consumption data for purposes of national military and/or economic security probably never was very successful, never was really necessary for most commodities, and certainly proved unnecessary with the end of the so-called cold war. Indeed, the long-term unwillingness to publish uniform statistical series of reliable,

Jan 1, 1993

By H. V. Makar

Ferrous fractions recovered from urban refuse were tested by the U.S. Bureau of Mines, U.S. Department of the Interior, to assess their character, composition, and response to detinning. This research was conducted as part of the Bureau's efforts to conserve mineral resources through recycling. Results from laboratory and pilot tests established the technical feasibility of detinning scrap recovered from household refuse. Detinned products containing less than 0.03 percent residual tin were produced. Concentrations of other residual elements were determined and compared with those in existing commercial scrap and with proposed specifications. Studies were extended to include evaluations under commercial conditions. Preliminary tests on 5-1/2 short tons of ferrous fractions revealed the need for adequate shredding to assure optimum metal-caustic contact and minimize retention of tin-bearing rinse solution in the final baled product. The washed metal product contained 0.06 percent residual tin. Subsequent melt tests showed a yield of 91.4 percent. Based on these studies, full-scale commercial demonstrations showed that detinned bales equivalent to No. 1 bundle quality could be produced in carload quantities. Up to 5 pounds of tin per gross ton of scrap is con-currently recovered during the detinning process.

Jan 1, 1979

By Charles L. Kimbell

Following the pattern established in the 1989 edition of this study, the concept of data availability must be addressed, because there are perceptible changes from year to year, and the availability of accurately reported, precisely defined statistics and nonstatistical information provides the only sound basis for analytical studies of any type. As the countries of eastern Europe, including the numerous states that formerly comprised the U.S.S.R., undergo the transition from centrally planned economies' to market economies, there has been a perceptible increase in information availability for rather obvious reasons. Any industrial operation seeing economic assistance from government and/or private sources outside the country in which the facility is sited must provide some appraisal of its operations at the time it seeks assistance, as well as some information on previous performance to serve as tools in evaluating its potential under the proposed development scheme for which it seeks financial assistance. This situation, coupled with governmental recognition that concealment of much of the national mineral production, trade, and consumption data for purposes of national security probably never was really necessary and certainly proved unnecessary with the end of the so-called cold war, has led to the publication of increasing amounts of both statistical and nonstatistical information in the countries undergoing economic transition.

Jan 1, 1993

By B. W. Jong

The U.S. Bureau of Mines investigated anhydrous chlorination and caustic-acid leaching processes to recover Ni, Co, Mo, and W from waste hydroprocessing catalysts. In batch laboratory-scale equipment, the chlorination process extracted 61 to 99 pet of the metals. Final recovery was 65 to 99 pct. The caustic-acid leaching process extracted 81 to 98 pct of the metals. Final recovery was 36 to 99 pct. Chlorination processing included roasting, chlorination, hydrolysis of metal chlorides for recovering Mo or W, water leaching of Ni or Co from the spent charge, purification, and solvent extraction or precipitation of Ni or Co from the purified solutions. Caustic-acid leach processing included NaOH leaching, solvent extraction of Mo or W from the NaOH leach liquor, H2S04 leaching of the NaOH leach residue, purification, and solvent extraction or precipitation of Ni or Co from the purified solution. The estimated fixed capital cost for a commercial-scale plant processing 39,000 Ibid of waste Ni-Mo-AI catalyst was $8 million for the chlorination process and $9.6 million for the caustic-acid leaching process. The estimated operating cost was about $0.20 and $0.40 per pound of the waste catalyst, respectively, for the two processes.

Jan 1, 1989

Design and test a high-production coal mining machine that generates less respirable dust. Background Current coal cutting systems generate excessive amounts of airborne respirable dust and fines during the mining process. Dust control technologies, including dust dilution by ventilation and suppression by water sprays, are not always able to reduce dust levels sufficiently. The U.S. Bureau of Mines (USBM) has designed a cutting system that reduces respirable dust generated by the cutting action of the drum. This cutting system, based on geometric principles developed in the 1500's, makes use of a constant depth, linear cut to remove coal at deeper cut depths and at lower rotary speeds than a conventional rotary drum. A comparison of the linear and rotary cut paths is shown in figure 1. Approach A full-scale prototype of the linear cutting concept was valuated under laboratory conditions to determine its performance relative to standard rotary drums. Results of these evaluations show production of fewer fines, or more uniform product size, a significant reduction in the amount of airborne dust, and reduced torque and power requirements (figure 2). On the basis of these results, a contract effort was undertaken by McCracken and Associates of Bristol, TN, to design a linear cutting head for underground testing.

Jan 1, 1995

This Information Circular from the National Institute for Occupational Safety and Health (NIOSH) documents and supplements the information presented in a series of workshops held during 2002 and 2003. The primary intended audience consists of all who are involved in developing and conducting miners? training. According to the Mine Safety and Health Administration (MSHA), mine operators reported 240,000 full-time equivalent workers and independent contractors reported 42,000 full-time equivalent workers working on mine property during the year 2000. Unfortunately, these workers have a relatively high risk of suffering serious work-related injuries and illnesses. The mining industry has the highest rate of occupational fatalities among all U.S. industries. The fatality rate is 30 deaths per 100,000 workers compared to 4.6 for all private industry(Morbidity and Mortality Week Report, 2001; NIOSH, 2002).Compared to workers in other industries, miners also have a relatively high rate of nonfatal lost-time injuries, and their injuries tend to be more severe (Bureau of Labor Statistics, 1999). Many miners are also exposed to significant health hazards, including coal and silica dust, diesel exhaust, and noise. More than 1000 U.S. miners die of lung disease each year(NIOSH, 1999).

Jan 1, 2002

By J. Douglas Causey

In 1987, at the request of the Bureau of Land Management, the U.S. Bureau of Mines studied 11,069-acres of the 12,290-acre Eldorado Wilderness Study Area (NV-050-423) in order to evaluate its identified mineral resources. The study area is located in Clark County, NV, adjacent to and northeast of the town of Nelson. There are inferred subeconomic resources on the Paul (gold, silver), Bel (gold, silver), Big Horn-Inez (silver, copper, lead, zinc) claims, and Montezuma (gold, silver, copper, lead, zinc) patented claim group in the Eldorado study area. Because of lack of exposures, tonnage and grade on these properties could not be determined. No resources were identified for the other five properties examined in the area. The southern two-thirds of the area is in the Eldorado mining district, a base- and precious-metal district which has been intensely explored for over 100 years. Nine claim groups were examined in the study area. Eight claim groups are within the Eldorado district and include the Montezuma (patented -M.S. 3966), Bel, Eldorado, VAR, SINJUN, Paul, Rusty Bit, and Big Horn-Inez. One property, the Flintstone claim group, is north of the Eldorado mining district at the north end of the study area.

Jan 1, 1988

Remotely monitor overburden response to longwall mining using time domain reflectometry (TDR) and a combination of hardware and software, as part of the U.S. Bureau of Mines (USBM) program to characterize subsidence. Background TDR was developed in the 1960's as a method to locate, discontinuities in coaxial transmission cables. In this method, voltage pulses sent along a cable are reflected by cable defects. The pulse reflections are used to determine the type and magnitude of the defects. The TDR concept was extended to material property measurement by embedding cables into particular materials and evaluating the cable's dielectric behavior as material properties were modified. This technique was adapted by the USBM in 1978 for use in monitoring rock movement during underground mining. The same concept is utilized today. A coaxial cable is grouted into a rock mass that is expected to deform. Progressive rock movement causes the cable to deform, as shown in figure 1, and changes to occur in the cable's electrical properties, which then produce changes in TDR reflection signatures. The technology has advanced to the point where it is now possible to distinguish shear deformation from tensile deformation and to quantify rock mass displacements by analyzing the TDR signatures.

Jan 1, 1995

Minimize the risk of conveyor belt fires in underground coal mines by improving the accuracy of and means by which flammability data are acquired. Approach Develop a large, laboratory-scale flammability test for mine conveyor belting that realistically assesses its fire resistance. Background A conveyor belt fire in an underground coal mine is a serious threat to life and property. To minimize the risk of belt fires, the U.S. Code of Federal Regulations (CFR) for underground coal mines requires approved fire-resistant belting. Despite this precaution, about 25% of the reportable underground coal mine fires from 1983 through 1988 involved conveyor belting. In several instances, hundreds of feet of belting were destroyed. The current flammability test for fire-resistant belting is specified in 30 CFR, Part 18.65 and is conducted by (be Mine Safety and Health Administration (MSHA). The small-scale test is performed in a 21-in-cubical chamber with 6-in-long by 1/2-in-wide belt samples. To evaluate the flammability of conveyor belting under more realistic conditions, the U.S. Bureau of Mines conducted large-scale fire tests of belting. The large-scale data were then utilized in the development of an improved laboratory-scale flame test for fire-resistant belting.

Jan 1, 1991

By Stuart Bjorklund

This paper is one of many reporting various aspects of the Bureau of Mines program initiated in August 1939 by passage of the Strategic Minerals Act J the scope of which was greatly expanded by subsequent legislation. In its program of investigation of mineral deposits, the Bureau of Mines has as its primary objective the more effective utilization of our mineral resources to the end that they make the greatest possible contribution to national security and economy. The occurrence of chromite in the Knik Valley near Palmer, Alaska, was brought to the attention of the Bureau of Mines in September 1941 by George Johnson, of Anchorage. At that time a preliminary investigation was made by Robert S. Sanford, an engineer of the Bureau of Mines. The area was investigated on June 4 and 5, 1943, by Henry R. Joesting and Leo H. Saarela, engineers of the Territorial Department of Mines. In August 1942, a second chromite occurrence, the Highway deposit, in the Knik Valley, was reported to the Territorial Department of Mines by John E. Ryan of Anchorage.

Jan 1, 1948

By Bruce I. Thomas

The occurrence of tin-bearing gravels along Tozimoran Creek in central Alaska has been known for a number of years. In September 1944 the Bureau of Mines investigated an area approximately 1,000 feet long and 200 feet wide along Tozimoran Creek to deter-mine the cassiterite content of the stream gravels, which are about 4 feet deep and covered by 3 feet of overburden. Nine trenches and two shafts were excavated, from which samples of the underlying gravels were taken. This report contains a discussion of sampling methods and tables giving the results of analyses.

Jan 1, 1948

By Marilyn Biviano

This analysis was conducted in response to concerns raised by the Chairman of the Energy and Commerce Committee of the House of Representatives regarding the potential impacts on automobile production, GNP and employment resulting from embargoing south African supplies of the platinum-group metals, platinum and rhodium. This analysis should be considered an addendum to the recently released study in which the direct economic costs I of a U.S. embargo on selected South African strategic and critical materials are estimated. The estimated GNP and employment impacts result when a mineral shortage reduces domestic industrial production and are in addition to the direct costs estimated in the earlier study. The direct cost to this nation resulting from a decision to embargo six south African strategic and critical minerals was estimated at $1.85 billion per year during the 1988-1992 time frame of the study. The estimated direct costs include the costs to U.S. consumers resulting from higher strategic mineral prices, lower mineral consumption, and the cost of developing higher cost domestic mineral resources. A large proportion of the costs result from the shortage of the two metals: platinum and rhodium. The average direct annual cost of embargoing is estimated at about $1.4 billion for platinum and $384 million for rhodium.2

Jan 1, 1988

By J. B. Littlefield

[Ata. meeting of the Subcommi ttce on Chemical _ et.lOds of Air Ant:..1ysis of-the American Public Health Ascociation in October 1937, the llse of the impinger for collectinG lcs.d fu.l1e wa:., discussed. The Bureau of Mnes de-cided to obtain infornw.tion on the efficiency of the lerge and midget im-pingers for this purpose y using the electric recipitator as a reference method. 'I'ests ~ ere made aJ,so to aScer ain the effici ency of the recently developed midget i;npi gerS..! for collac ing lead dust. For comparative pur-poses, samples collected by tte large impinger wore included.]

Jan 1, 1938

By J. E. Miller

This paper reports experimental determinations by the Bureau of Mines of compressibility factors to 4,000 pounds per square inch absolute (p.s.i.a.) for helium at temperatures from -10° to 130° F. and for 16 helium-nitrogen mixtures at 70° F. This information is needed for computing accurate discharge volumes and is necessary for determining an average-density value for use in orifice-meter formulas. In thermodynamic calculations, several functions of the compressibility factor with pressure and temperature are required. The data in the original publications (6, 8)5 of this study have been reexamined and have been given a more comprehensive treatment. The recalculated compressibility factors are higher by approximately 0.2 percent because in the earlier work a linear relationship between the compressibility factor of helium and pressure was assumed.

Jan 1, 1961

By William J. Wuest

The technical analysis of parameters that can influence roof and rib reinforcement is important to the operation of safe and profitable underground mines. One such parameter, studied in this U.S. Bureau of Mines investigation, is the effect of time on untensioned, resin-grouted bolt anchorage characteristics. A group of seventy-three 4-ft-long bolts with three different grout column lengths were I installed in a stable coal mine roof. The bolts were then subjected to standardized pull tests at various intervals throughout a 37-month period. For each test, load-deformation data were reduced to determine axial stiffness and yield point. The magnitudes of these two anchorage characteristics at the time of installation were compared with results from subsequent pull tests to determine if anchorage capacity deteriorated. Bolts with 18-in grout columns were studied over 9 months, and no measurable loss occurred. Bolts with 48-and 24-in grout columns were studied over 37 months and also exhibited no measurable loss.

Jan 1, 2010

By S. J. Page, J. A. Organiscak

Dust surveys were conducted around small truck-mounted rock drills operating at surface coal mines to assess their airborne respirable dust generation and in-service dust control methods. Of four out of seven drills sampled, respirable dust concentrations measured around the drill deck ranged from 8.68 to 95.15 mg/m with3concentrations ranging from 1.37 to 2.69 mg/m at distances 12.2 to 30.5 m downwind of these drills. The other3drills had noticeably lower respirable dust concentrations measured around the drill deck at or below 1.30 mg/m.3Rotoclone-type dry dust collectors were commonly used with dust being emitted from around the drill deck shroud, collector exhaust, and collector fines dumping. Wind speed and direction was also a factor in the dust concentrations measured on the bench. Dust control modifications were made to three rock drills to reduce their airborne dust emissions. Dust controls tested included water injection into the Rotoclone exhaust, Rotoclone exhaust extension, improved sealing of drilling deck shroud, shrouding the Rotoclone hopper dump process, and wet drilling. These control techniques showed noticeable improvement in dust concentrations measured around the drills. Finally, repositioning the drill operator showed that operator dust exposure can be improved by avoiding the dust cloud around the drill.

Jan 1, 1995

By Perry G. Cotter

The borides of the transition metals in Groups IV and VI exhibit, in addition to a certain degree of hardness, considerable resistance to heat and oxidation. They have high melting points (1,850°-3,060° C.) and low coefftcients of thermal expansion and can be bonded with other materials and hot-pressed to desired shape (cermets). Suggested uses for the borides include use in rockets and jet engines, as thermocouple protection tubes, as containers for molten metals in die casting, as flame-plated coatings on less refractory compositions to prevent erosion by hot gases, and as control rods and neutron shielding material in nuclear engineering, The Federal Bureau of Mines investigation of zirconium diboride started in 1950 at the Boulder City Nev,, Metallurgy Research Laboratory, Its purpose was to reduce the cost of raw materials for the production of zirconium diboride.

Jan 1, 1961