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By M. D. Carver

This publication describes development by the Bureau of Mines of a quality evaluation procedure for certifying the adequacy of production lots of Kroll process zirconium sponge the Bureau had produced for reactor applications. After the procedure was devised, the next step was to apply it in controlling the quality of one-half million pounds of zirconium sponge com-prising 259 production lots, called blends, originating at the Metallurgy Research Center of the Bureau at Albany, Oreg. The Bureau concluded that the evaluation method developed was adequate and that by this method the zirconium blends having impurity levels or other property values outside specification limits were differentiated and thus were diverted from nuclear energy end uses. The research was performed under contract for the Bureau of Ships, Department of the Navy, and for the Atomic Energy Commission (AEC).

Jan 1, 1960

By W. T. Millar

Field reconnaissance and laboratory tests on clay from South Windsor, Hartford County, Conn., indicate that the clay is suitable for lightweight aggregate raw material. Exploration of the deposit supports the conclusion that the reserves of clay are sufficient for economical mining operations to produce lightweight aggregate. Preliminary tests indicated that the clay has a short bloating range. Initial expansion occurred at 2,000° F, and at 2,100° F the clay was slightly overfired and sticky. Rotary kiln tests verified the preliminary data, and these tests showed that the clay would make a good lightweight aggregate if the processing temperature and the kiln feed sizes were closely controlled. Lightweight concrete made from the processed aggregate had properties comparable to those of concrete made from a commercial clay aggregate.

Jan 1, 1964

By Martin H. Stanczyk

Ultrafine grinding of the industrial minerals mica, pyrophyllite, talc, marble, barite, and fluorite was accomplished using the Bureau-developed and patented attrition-grinding process. The materials, representing minerals of diverse physical characteristics, were batch ground in a 10-inch-diameter machine using statistically designed experimental test programs. The tests were made to determine large effects of variables such as feed pulp density, grinding medium size, and quantity of the electrical energy consumed during grinding on product particle size and bulk density. In designing the test programs, it was assumed that there was no interaction between the variables. Relatively coarse commercial flotation concentrates of mica, barite, and fluorspar and mine-run products of pyrophyllite, talc, and marble were readily ground into subsieve size ranges. Considering the great amount of particle size reduction obtained, the electrical energy requirements for grinding were very low. In general, the test results indicated that the best conditions for particle size reduction were approached when grinding with the coarser fraction of sand grinding media, the higher-sand-to-mineral weight ratio, and the higher feed pulp density.

Jan 1, 1972

By Wilbur L. Webb

An electrically powered methane sampling system for application on mining machines was designed, fabricated and laboratory tested. The system will sequentially draw sample air at a controlled rate from up to three machine positions across the mine face and deliver the air to either an approved methane monitor, methanometer or flame safety lamp. The prime considerations in the design were to provide an intrinsically safe, water and dust resistant control box and an explosion-proof power box capable of being operated from the various mining power sources. The power box contains an internal battery that provides operating power prior to mining machine start-up and alter machine shut-down. The internal battery is recharged automatically when mining machine power is available.

Jan 1, 1977

By L. B. Pankratz

Enthalpies above 298° K were investigated for four crystalline sodium borates by copper-block drop calorimetry. Determinations were made to 1,200° K for NaB02, 1,003° K for Na2B407, 1,005° K for NaB305, and 1,046° K for Na2Be013. No phase transitions or other thermal anomalies were found. The enthalpy determinations, when combined with known heats of formation at 298° K and other supplementary data, enabled the calculation of the heats and free energies of formation of the compounds to their melting points. Values of relative enthalpies, entropies, heat capacities, free energy functions, enthalpies of formation, free energies of formation, and equilibrium constants of formation were tabulated at even temperatures.

Jan 1, 1971

By Maria I. De Rosa

The major fire and fire injury findings for all metal/nonmetal mining categories for 1990-2001 are shown in tables 64-65. Table 66, partly illustrated in figure 22, shows the number of fires, fire injuries, fire fatalities, risk rates, employees' working hours, and lost workdays for all metal/nonmetal mining categories by time period. For all metal/nonmetal operations (including stone and sand and gravel), a total of 518 fires occurred during 1990-2001; 296 of those fires caused 308 injuries and 4 fatalities (Ewhr = 4,012 x 106 hr, In = 0.015, LWD = 36,204). Thirty fires and 26 injuries involved contractors. The greatest number of fires and fire injuries occurred at surface operations; the highest risk rate values were also calculated for surface operations. The number of fires increased during the first four 2-year time periods (1990-1991, 1992-1993, 1994-1995, and 1996-1997), then decreased during the last two periods (1998-1999 and 2000-2001). The number of injuries showed a decrease throughout the periods, accompanied by an increase in employees' working hours. Twenty-five firefighting interventions by mine rescue teams in underground mines and at least 30 interventions at surface operations were required to combat these fires. However, 45 fires destroyed or heavily damaged facilities and equipment (including 19 pieces of mobile equipment) because of failure of firefighting methods, late fire detection, undetected fires, or fire size. Ninety-seven fires were detected late, and 30 fires were undetected. The ignition sources that caused the greatest number of fires were flame cutting/welding spark/slag/flame (169 fires or 33% with 137 injuries), hydraulic fluid/fuel sprayed onto equipment hot surfaces (89 fires or 17% with 46 injuries and 3 fatalities), heat source/explosion and flammable liquids/ gas/refueling fuel on hot surfaces (98 fires or 19% with 73 injuries), electrical short/arcing (51 fires or 10% with 16 injuries), and spontaneous combustion/hot material (46 fires or 9% with 17 injuries). The flame cutting/welding spark/slag/flame source caused fires usually involving welders' clothing or oxyfuel/grease and other materials (including chute and dust collector liners, flammable liquids, belt material, crusher, hopper and shaker deck materials, washer plants, equipment mechanical components, stampler breaker, hydraulic fluid, rubber tires and hoses, gear boxes, bin feeder, dump rope cables, screen liner and screen panel, kiln and shaft material, pipelines, liquor pumps, wood pallets, electrical junction boxes, handrails, grease, refuse, shop and wood). The spontaneous combustion/hot material and electrical fires were usually detected late due to lack of combustion gas/smoke detection systems. At least 55 of the 89 mobile equipment hydraulic fluid/fuel fires became large fires (requiring 12 mine rescue team interventions in underground

Jan 1, 2004

By R. L. Rough, W. K. Overbey

The Bureau of Mines obtained samples of oil - reservoir rock from wells in Ohio , Pennsylvania , and West Virginia as part of an investigation of the susceptibility of petroleum reservoirs to secondary - recovery techniques . Illustrations and tables showing the geographic and stratigraphic sequence of the cored reservoirs and 40 tables of detailed lithologic descriptions of the reservoirs are presented . Information relevant to geologic surroundings , oilfield history , coring and well logging operations , and reservoir core analyses are referenced throughout the report .

Jun 1, 1970

By Seth C. Schaefer

The Bureau of Mines studied thermodynamic properties of Al-Ni alloys con¬taining 0.54 to 30.04 atomic percent nickel with the aid of the high-temperature galvanic cell Al(1) // Al+3 (AlCl3 in NaCI.KC1) // Al-Ni alloy (1 or s). Activities of aluminum and nickel (compared with pure liquid metals as the standard state) show pronounced negative deviation from Raoult's law at 1,273 K. The properties [?G, ?Gxs, ?G ideal, ?GA1, AGxs1, ?Gni , and ?GNixs] have been derived from the experimental data and are summarized in tables and illustrations. At 1,127 K, the thermodynamic stability for the invariant three-phase equilibrium consisting of a saturated liquid, A13Ni, and A13Ni2 has been uniquely defined by an activity for aluminum of 0.751. A free energy of formation at 1,127 K of -7,940 cal/g-atom was derived for the compound A13Ni.

Jan 1, 1975

By R. Lindsay Mundell

In the first half of 1990, lessening of cold war tensions was welcome. But Iraq's invasion of Kuwait in August led to the Persian Gulf War in January and February 1991. The subsequent oil shock contributed to a dampening of the U.S. economy, and the U.S. gross national product rose only 0.9 % to $5,463 billion (U.S. billion = 109). The buildup of military forces in the Persian Gulf area focused greater attention not only on petroleum but also on other strategic materials. The U.S. Department of Defense continued to review stockpile goals and upgrade several mineral materials. In addition, the U.S. Bureau of Mines continued to maintain the standby Emergency Minerals Administration. After the Defense Production Act, which authorizes priorities, allocations, and supply expansion, lapsed on October 20, 1990, the Selective Service Act of 1967 became the authority to ensure that orders of the Armed Forces and defense atomic energy programs were given priority treatment.

Jan 1, 1993

By M. J. Kovalik

Illinois No.6, a high-volatile B coal of low fluidity, was blended with fluidized-bed char and coke breeze to improve the strength of the coke obtained from carbonizing this coal. Twenty-one tests, selected from those made in the small-scale Hanson carbonizer, were carbonized in the BM-AGA 13-inch-diameter, cylindrical retort, with a coal charge of about 90 pounds; the strength of the cokes was determined by the standard ASTM tumbler test. Using the same procedure, 10 tests were made with High Splint, a high-volatile A coal from Harlan County, Ky. Carbonization of the blends produced larger and stronger cokes than did the Illinois No.6 coal singly. The optimum blend contained 6 percent each of char and coke breeze. Further improvement in coke strength was realized by either preheating this blend prior to carbonization or by adding a small pro-portion of a premium blending coal. The former method could possibly eliminate the use of premium coking coals in blends with Illinois No. 6 coal to make an acceptable metallurgical coke. Except for no improvement in coke strength by preheating, results for High Splint coal showed behavior similar to that of the Illinois No.6 coal.

Jan 1, 1973

Provide a machine for economically drilling probe holes in coal mines (required where there's a possibility of unmapped, abandoned workings) to check for possible water flood or gas hazards ahead of the face. Approach A lightweight air-powered drill, that mounts on a light-weight frame anchored to the face with an expandable packer, is used to drill one or more probe holes. The anchor installs quickly and will lock the drill in any desired position. How It Works The drill is portable and can be broken down to small components for ease of transportation. One man can carry these sections through restricted access routes to the working place. Components that are separable are the anchor assembly, drill frame assembly, and drill motor assembly. The drilling sequence is as follows: A 2-inch-diameter anchor hole is drilled 2 feet deep. The fixed anchor tube is rubber packer is expanded. A second anchor hole is drilled through a bushing in the anchor frame. The removable anchor tube is inserted and its rubber packer expanded. (This anchoring system withstood pulls of up to 14,000 pounds.) Next, the frame is attached to the anchor with two screw knobs, and the motor is attached to inserted in the hole and the rubber packer is expanded. A second anchor hole is drilled through a bushing in the anchor frame. The removable anchor tube is inserted and its rubber packer expanded. (This anchoring system withstood pulls of up to 14,000 pounds.) Next, the frame is attached to the anchor with two screw knobs, and the motor is attached to the frame with a single locking pin. Installing the anchor and drill takes less than 12 minutes.

Jan 1, 1981

By H. J. Van der Veer, F. E. Griffith

"Reflector button signs similar to those used to attract the attention of motorists on the public highways at night are now being used to good advantage by a few mining companies in underground workings for danger, warning, direction, and safety signs and signals. Most safety signs and signals used in underground mining are of the electric light painted-board, or enameled or porcelain metal-plate,type, all of which have good features as well as some disadvantages; among the disadvantages are: The filament of electric incandescent lamps is prone to ""burn out"" occasionally anti usually the lamps are not replaced promptly; painted-board and enameled or porcelain metal-plate signs can be seen only a short distance and often are ""passed up"" unintentionally by employees, consequently these signs do not always serve the purposes intended and may be the cause of injury or death through failure to warn the men of danger.The advantage of using reflector button signs in mines or underground workings is that the cap lamps or headlights with which employees and locomotives generally are equipped, if directed at these buttons will reflect the light back to its source, and if they are arranged to spell words of warning or direction, or if suitable symbols are used, they are discernible and can be read at a distance of several hundred feet. The distance the light is reflected depends largely on the color of the buttons used. The reflector buttons also in many instances can be used to good advantage in conjunction with other methods previously mentioned.Several types of reflector buttons are available, among them the flat-lens type with mirrored metallic foil or plate back, the facet-cut-lens type with a mirrored metallic foil or plate back, and a type with a hemispherical smooth lens with a parabolic mirrored metal back. Lenses for the different types are available in several colors. Crystal, amber, red, and green are the colors of the buttons used to the greatest extent in underground signs up to the present time. These buttons may be had in different sizes, also.It has been observed that crystal-colored buttons reflect light the greatest distance (about 1,000 feet) and red-colored buttons the least (about 500 feet); reflection from green and amber colors ranges somewhere between the red and crystal colors in distance.Reflector buttons for underground use should be designed to reflect light a maximum distance; they should be made of materials that resist oxidation and corrosion, especially of the mirrored backs, and should be relatively free of protruding parts or projections that will collect dust.Reflector buttons approximately 3/14 inch in diameter seem best suited for underground use in general because fewer reflector units are required for a signal of given size."

Dec 1, 1937

By L. B. Pankratz

The Bureau of Mines measured heat capacities of alpha and beta spodumene (LiAlSi2O5) and of beta eucryptite (LiAlSiO4) over the temperature range 51° to 298° K. The entropies at 298° K were found to be 30.9 ± 0.2 cal/deg mole for alpha spodumene, 36.9 ± 0.3 cal/deg mole for beta spodumene, and 24.8±0.2 cal/deg mole for beta eucryptite. High-temperature heat content measurements above 298° K were conducted for the same compounds. Measurements were made to 1,150° K for alpha spodumene, 1,600° K for beta spodumene, and 1,470° K for beta eucryptite. Tables of heats and free energies of formation are given from the elements and from the constituent oxides.

Jan 1, 1967

By D. W. Frommer

Laboratory mineral-dressing investigations were conducted on talc-bearing samples from Arkansas and Texas under the Bureau of Mines program of examinations and surveys, which is concerned, in part, with the improvement of conservation and utilization of domestic mineral resources. Two of the soapstones in question were successfully upgraded by flotation, utilizing stage additions of a frother and an amine to promote their talc content. The process could enable the producers to meet more rigid specifications of higher priced talc commodities. INTRODUCTION Talc is an industrial mineral with distinctive properties, such as softness, smoothness, large surface area in relation to mass, chemical inertness, and good retention as a filler, that make it particularly valuable to a number of industries. Sales to 6 industries -ceramics, paint, insecticide, rubber, roofing, and paper -consumed 84 percent of the domestic production of talc, pyrophyllite, and ground soapstone in 1952. Mine production in that year totaled 600,908 tons. Sales of crude and ground material were 593,147 tons valued at $11,347,317.2/

Jan 1, 1956

Case 1: A driller raised a drill rig mast into a 7200-volt overhead power line. Both he and his helper were killed. Case 2: A driller-helper was pulling a winch cable toward a stack of drill steel when the cable contacted a 12,000-volt power line. The helper was killed, and the driller at the rig controls was severely injured. [ ]

Jan 1, 2006

By Merle L. Bowser

The Bureau of Mines has constructed a miniature oxygen deficiency alarm system using an electrochemical cell as the sensor. Distinct audible signals are produced at either of two preselectable oxygen levels which can be varied from approximately 10 to 20.9 percent oxygen. The high or cautionary range produces a 500-cycle-per-second tone pulsed at about a 1-cycle-per-second rate, whereas the lower or more dangerous oxygen level produces a continuous 500-cycle-per-second tone.

Jan 1, 1968

By R. G. Knickerbocker, David Schlain, F. K. Shelton, J. H. Jacobs

"Many manganese ores contain from 0.1 to several percent cobalt. If such ores arc used for the production of ferromanganese, the cobalt is lost; on the other hand, if they are used for the production of electrolytic manganese, the cobalt can be recovered during the purification of the electrolyte.The production of cobalt in the United States is insignificant compared to the amount consumed, most of which is imported from the Belgian Congo. Cobalt-bearing manganese ores may therefore constitute an important reserve of cobalt in times of emergency. Moreover, the combined value of manganese and cobalt in some ores may be sufficient to warrant the recovery of both metals by the electrolytic manganese process, whereas the recovery of either manganese or cobalt alone might not be economically feasible.In view of the potential importance of manganese ores as a source of cobalt, a survey has boon made of the cobalt content of manganese ores. Most of the data have been obtained from analyses made in the Bureau of Mines, but valuable data have also been obtained from publications of the Geological Survey, various State publications, and other sources. Unfortunately, most published analyses of manganese ores do not include cobalt determinations; when such analyses were fairly detailed, but did not include cobalt, it was presumed that cobalt was not present in significant quantity.Information on the cobalt content of domestic manganese ores is given in table 1. Ores containing 0.1 percent or more cobalt are listed in table 2, and the districts in which such ores occur are shown in figure 1. Most of the known cobalt-bearing manganese ores occur in the southeastern part of the United States. A group of deposits in central Arizona and a few scattered deposits in other States also' contain cobalt."

Apr 1, 1946

By Ren G. Dong, Richard McCormick, Dan E. Welcome

Vibration exposure at workplaces is generally multi-axial. The health effects of vibration exposure also likely depend on the vibration direction. Therefore, there is a wide interest in the simulation of multi-axial vibration in laboratory experiments. Advances in technology have led to the development of a new 3-D test system for studying hand-transmitted vibration exposure and health effects. The purposes of this paper are to introduce the system and to present the results of its preliminary evaluations. Test System As shown in Figure 1, the system is basically composed of three vibration generators, a multi-axis vibration control system, instrumented handle, handle fixture, and shaker-fixture linkages (stingers). [ ] Figure 2 shows the array of three vibration generators (MB Dynamics, Energizer BLACK-500 lbs) and their associated support bases and foundation developed by MB Dynamics (Cleveland, USA), which create the 3-axis simultaneous motion. These electrodynamic exciters are powered by power amplifiers which provide current proportional to the analog drive signal from a controller. The controller (JAGUAR Multi-Input/Multi-Output closed-loop vibration controller) was provided by Spectral Dynamics, San Jose, California, USA). NIOSH-designed instrumented handle was equipped on the system.

Jan 6, 2006

By Steven J. Page, William A. Heitbrink, Andrew B. Cecala, Edward D. Thimons, John A. Organiscak

Miners at noncoal surface mining operations are often exposed to high levels of respirable dust. In an effort to lower the respirable dust exposure of these surface miners, the National Institute for Occupational Safety and Health (NIOSH) has been conducting research to address this problem in a practical and economically viable manner. One successful effort deals with lowering the dust exposure of equipment operators in enclosed cabs. Many types of surface mining equipment utilize enclosed cabs to protect equipment operators from dust exposure. Normally when the equipment is new, the cabs are fairly airtight. These tightly sealed cabs, combined with good filtration systems, generally provide the operator with good dust protection. However, most mining equipment is older, and as aging occurs, many components of the enclosure deteriorate. The structural integrity of the cab diminishes and the effectiveness of the air filtration system fails. NIOSH has been successfully researching costs-effective methods to improve both filtration effectiveness and cab integrity of these older cabs in order to provide a healthier work environment for equipment operators. Dust sampling records indicate that drill operators and helpers have the highest dust exposure of all workers at surface mining operations. Since much of the overburden contains a high percentage of silica, the health hazard associated with this dust can be even more serious. NIOSH research is addressing techniques to lower respirable dust levels at surface drilling operations. INTRODUCTION NIOSH's mission is to assure a safe and healthy work environment for the working men and women of this nation. The primary emphasis of NIOSH's Pittsburgh Research Laboratory (PRL) is mining health and safety research. This report focuses on two areas of research

By Frank A. Peters

This evaluation of the sulfurous acid process for the production of metallurgical-grade alumina is the first of a series concerning various known methods of extracting alumina from low-grade aluminous materials and was undertaken to permit comparison with other processes. In the process with which this Bureau of Mines report is concerned, calcined clay is leached under pressure with 20 percent sulfurous acid and then filtered to remove a siliceous residue. The aluminum sulfite remaining in the filtrate is precipitated as a monobasic sulfite which, together with iron sulfite, is then decomposed under pressure to form a crude alumina hydrate and iron oxide. This intermediate product is purified in a modified Bayer process to yield alumina suitable for electrolytic reduction to aluminum. A study estimate (16)3 is used for these evaluations. The capital cost, not including land, is estimated at $95,701,600 on a Marshall and Stevens index basis of 240.0 for a plant producing 1,000 tons a day of alumina or 350,000 tons a year. The annual operating cost for this size plant is estimated at $22,831,100 or $65.23 per ton of alumina using clay at $1 per ton. Depreciation and local taxes are included in the estimate, but profit and Federal taxes are not considered.

Jan 1, 1962