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By E. J. (Kirk) Conway

The objectives of this project were to: (1) determine the extent to which maintainability design concepts and principles have been applied to the design of underground coal mining equipment, (2) try to assess its impact on productivity and personnel safety, and (3) develop maintainability guidelines to enhance the design of new or rebuilt equipment. An equipment design review was completed at ten operational coal mines. The purpose was to identify design approaches and features that enhanced and degraded the maintenance process. Mine management, safety, and maintenance personnel were also interviewed to identify machine specific design problems. Six original equipment manufacturers were visited and the procedures used to enhance the maintainability of Their equipment discussed. Volume I of the Final Technical Report presents an overview of procedures and protocol used and a summary of the findings. Volume II includes the maintainability design guide for mobile underground mining equipment.

Jan 1, 1988

By Thomas E. Doerfler

Information and data related to the occurrence of fatalities due to major disasters in metal/nonmetal underground mines were analyzed. Standard statistical methods were used to estimate the probability of occurrence of major disasters, and to examine the relationship of disasters to injury statistics published annually.

Jan 1, 1980

By A. L. Foote

This is the final report of work accomplished during 1973-75 under U. S. Bureau of Mines Contract No. H0242015, "System for Handling Underground Mine Supplies and Materials." The purpose of the contract was to develop a mechanical device which could safely perform handling tasks that are normally done manually in underground bituminous coal mines. The report discusses studies leading to construct-ion of a battery-operated, three-wheel vehicle with a six-degree-of-freedom manipulator. Supportive design studies included collection and analysis of production, manual functions, and injury data on the underground bituminous coal mining industry. Transfer tasks in section storage and working places were the prime candidates for mechanical handling. Functional specifications were developed for two handling devices (one to handle existing unit loads and one to handle repackaged unit loads) and for a vehicle to mount the handling device. Design concepts for nine different handling devices were developed and a cost/benefit evaluation made for each. Detail design, capital and operating costs, and method improvement savings data were developed for two battery-operated vehicles and for two different manipulators. The three-wheel vehicle with anthropomorphic manipulator was chosen for development.

Jan 1, 1978

By T. A. Sullivan

Refining in a molten salt electrolyte was investigated as a means of recovering nickel containing less than 1 percent and preferably less than 0.2 percent cobalt from nickel products containing up to 5 percent cobalt. Electrolytic separation of nick and cobalt was accomplished in a molten KCl-LiCl-NiCl2 electrolyte. Nickel containing less than 0.10 percent cobalt was routinely prepared. Factors that influenced the transfer of cobalt to the refined product were the nickel concentration of the electrolyte, the cobalt concentration of the electrolyte, the ratio of nickel to cobalt in the electrolyte, and cathode current densities. A method of recovering the cobalt from the electrolyte was developed. The possibility of preparing high-purity nickel by this process was shown, as well as the preparation of various cobalt-nickel-tungsten alloys.

Jan 1, 1968

By Patrick J. Cain

The fatigue-failure characteristics under high-frequency (10 KHz) cyclic loading were determined for a marble, granite, and quartzite. The rock speci-mens were cyclicly loaded (using a high-power piezoelectric sonic transducer) at a constant strain amplitude generated by forming a longitudinal standing stress (strain) wave in the cylindrical test specimen. The number of load cycles required to fail each rock type at a given strain amplitude was deter-mined. The fatigue fractures were tensile in nature and the fracture load amplitudes were as low as 30 pct of the static tensile strength. Also the internal heating of the rock caused by the material damping (internal friction) was measured. The damping and internal heat generation in the specimens was analyzed to show that nearly all of the power input can be accounted for as a change in enthalpy in the specimen. Using these results the thermal strain in the rock was calculated to evaluate its contribution to fatigue failure. The thermal strain was found to range up to 30 pct of the dynamic strain amplitude depending on the load amplitude and the number of load cycles. The specific energy required for failure was determined and possible applications of the high-frequency fatigue fragmentation process are discussed.

Jan 1, 1975

By P. A. Rey

Water recycle is an important part of the coal preparation process. This study was directed toward: (1) a survey of current practice and an evaluation of both the solid and liquid components of blackwater, (2) an experimental study of blackwater flocculation, and (3) a fundamental analysis of the flocculation process. The solids contained in the blackwater discharge to the fine refuse thickener of a coal preparation plant were found to contain, on average, 56% coal and 44% mineral matter. The mineral matter was largely illitic clay, while the water phase contained relatively large amounts of S04 and Ca++. Detailed studies were made of both natural and synthetic flocculants and the influence of polymer type and pH on the settling rate, turbidity of the supernatent liquid and sludge volume of the settled solids. More tundamental studies were made that clearly indicate the need for controlled mixing of polymer into the suspension to be flocculated, and the need to evaluate, more closely, the structure of the flocs formed during the process. Research recommendations are given.

Jan 1, 1983

By H. John Head, Fred N. Kissell

In This Chapter [Gas reports from around the world Regulations for gassy mines in the United States Differences between metal/nonmetal mines and coal mines Monitoring for methane and taking action Diluting methane with additional ventilation Eliminating ignition sources What experienced mine operators say about methane control and Looking for methane when starting a new mine or expanding an existing mine] This chapter gives guidelines for preventing methane gas explosions during metal and nonmetal mine development and subsequent production operations.3 Emphasis is placed on recognizing the differences between coal mines, where the potential for methane hazards is relatively well understood, and metal/nonmetal mines, where methane may accumulate unexpectedly. Also, interviews with experienced mine operators add much to a complete understanding of what must be done to address methane problems in metal/nonmetal mines. METHANE GAS IN METAL/NONMETAL MINES Gas reports from around the world. The presence of methane gas in metal/nonmetal mines around the world is more common than one might imagine [Edwards and Durucan 1991]. For example: • The former Soviet republics have occurrences of methane and hydrogen in apatite, gold, and diamond ores, where solid or liquid bitumen occurs in the rock. • Scandinavian iron ore deposits include methane and other hydrocarbons in boreholes that intersect pitch and asphalt within the deposits, and methane and nitrogen in boreholes and fissures in arsenic and sulfide ores.

Jan 6, 2006

By S. H. Ash, E. M. Brooks

"Many of the hoisting slopes at the mines in the State of Washington are driven on extra steep dips. To facilitate hoisting they are driven wide enough to provide two tracks. The cars are handled by high-speed, first-motion electric hoists and the trips run in balance.The State mining laws a provide that special man-cars be provided on slopes of 20° or more and that no one be allowed to ride while any loaded car is being hoisted in any slope in a mine. Obviously, in addition to the fact that it is more or less hazardous to ride while an empty trip is being hoisted, considerable hoisting time is lost during the day if some one has to ride the trips in the slope.Owing to the locations of pumps and various types of equipment, more or less travel is required up and down the slope. Not only to provide a proper safety factor but also to comply with the law, some other means of transportation in an¬other passageway is desirable. This is sometimes recognized in large mines by pro viding separate hoisting shafts, or slopes, and necessary equipment, which are use for transporting men and material. The handling of material in itself would justify the system in most large mines.The following description of an automatic electric man-hoist was prepared from data furnished through the courtesy of Mr. Thomas Murphy, superintendent of the Northwestern Improvement Company's mines in the Roslyn-Cle Elum coal field.The special features of this hoist are that no hoistman is required and its operation is always under the control of the person or persons riding the trip.The hoist was installed at mine No. 5, Roslyn, Washington, to provide a means of entering and leaving the mine on idle days or at night when no hoistman was on duty and to make it unnecessary to use the main hoist for a man trip during working hours. It has been in operation for about two years and has given very satisfactory service.The hoist, with all accessories, is housed in a concrete building 200 feet back from and in direct line with one of the main airways. One car with a capacity of six men operates over a distance of 1,200 feet on a 38° pitch.The wiring details of the electric circuits which control the operation of the hoist are shown in Figure 1-a.The hoist is driven through a worm gear by a 500-volt shunt-wound direct-current motor at a car speed of 120 feet per' minute. A gravity friction brake with magnetic release is mounted on the- motor shaft and is wired in multiple with the motor field coils. The hoist drum is also equipped with emergency friction brakes, which operate by gravity and are released, in case of overspeed, by the governor geared direct to the drum shaft. When these brakes set the control circuit is opened at contact 2E-2C and the motor stops.If the descending car meets some obstruction and is stopped, the hoist continues to run and unwind the rope. To guard against this occurrence, a weighted sheave wheel rides the rope 4 feet from the drum, and if the rope becomes slack the rider drops downward and opens the contact 2C-2E which stops the hoist.Limit switches, S1 and S2, are located on the hoist indicator, which is connected to the drum shaft through sprockets and chain. The pointer P indicates the position of the hoist at all times."

Jul 1, 1930

By Rudolf E. Grauer

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Jan 1, 1981

By R. L. Blake

The crystal structure of hematite, a-Fe203, has been refined as part of a continuing study of the behavior of phases in the Fe-O system during reduction and oxidation. Three-dimensional diffraction intensities were collected on two spherical single crystals of hematite with a semiautomated Buerger single-crystal diffractometer. The first crystal refined was a natural Elba hematite with minor impurities. The other, a synthetic crystal, was refined at the request of Mossbauer spectroscopy investigators concerned with impurities in the natural crystal. The structure has been refined with a least-squares program and the final structure for the natural crystal irradiated with CuKa-radiation gave a discrepancy factor (R) of 3.65 percent using 49 unrejected reflections of the 51 measured. For the synthetic crystal, using MoKa-radiation, the discrepancy factor converged to 2.8 percent using 95 unrejected reflections and was 3.3 percent for all 109 reflections. The structure model of Pauling and Hendricks has been confirmed with essentially no change in the iron coordinates and approximately a 5-percent change in the oxygen coordinates. Selected interatomic distances and angles were calculated as were anisotropic temperature factors.

Jan 1, 1970

By Charles L. Kimbell

Virtually every available measure of total world mineral industry activity demonstrated that 1982 was little, if any, better for the industry than 1981 had been. Levels of production, trade, and consumption for virtually every major commodity declined; unit prices for most commodities fell, particularly in terms of constant dollars, and as a result of cutbacks in output and lower prices, capital available for investment within the industry was reduced. These conditions, coupled with the existence of considerable idle capacity, tended to retard investment, although there was an upturn in U.S. oil industry investment overseas. Despite the overall depressed situation of the world's mineral industry, there were indications of possible improvements in market economy countries near yearend, as output of some materials increased marginally and as prices for some mineral commodities reversed their downward trends. The downturns in total world mineral industry activity were not universal from the viewpoint of individual countries. Indeed, output of a number of commodities increased in centrally planned economy countries, and these gains were insufficient to offset declines in market economy countries, thereby sharply altering the proportion of total world output accounted for by each of these two groups of countries. There was a similar shift in consumption on a percentage basis.

Jan 1, 1984

By C. A. Komar

The Bureau of Mines conducted oil-displacement tests in the laboratory with three water-in-oil and five oil-in-water emulsions that were created with ultrasonic energy at a frequency of 20 kHz and an acoustic intensity of approximately 100 watts per cm2. Emulsions of either crude oil or kerosine, brine, and 112 to 2 percent emulsifier were formed during 30 seconds of acoustic irradiation. Results indicate that ultrasonic energy induces greater and more uniform dispersion of one liquid in another in the presence of small amounts of chemi¬cal emulsifiers. When the emulsions were injected as a buffer slug before waterflooding, recovery of the oil-in-place was 8 to 22 percent greater than with conventional waterflooding in the test specimens, regardless of the con¬tinuous phase (oil or brine). The emulsions do not appear to be applicable to the Appalachian area; however, because the oilfields are too "tight," the clays in the formation remove the emulsifier from the displacing fluid, and not enough additional oil is produced, compared with recovery using conventional waterflooding, to warrant the increased operating costs.

Jan 1, 1969

By J. L. Schwendeman

This is the final report of work done under contract H0210060 for the U. S. Department of the Interior, Bureau of Mines. This program was to show the feasibility of using plastic liners containing sand and other fillers as a means of roof support in coal and other mines. This laboratory study was conducted in two phases, namely: Phase I, directed toward determining which state-of-the-art resin systems might have utility as a means of roof support in a coal mine, consisted of a canvass of resin manufacturers to learn which resins were available commercially that might have utility for this application. The resins submitted by the manufacturers were evaluated in a number of simple tests to define which of them would be most suitable for roof support use.

Jan 1, 1972

By K. P. V. Lei

The Bureau of Mines investigated molten-salt electrorefining as a practical method for reclaiming vanadium from vanadium scrap. An electrolytic process utilizing a KC1-LiC1-VC12 electrolyte at 615° C was developed for producing ductile vanadium with a purity over 99.9 percent. The recovery of the vanadium in the cell feed ranged from 88 to 93 percent with a current efficiency from 83 to 95 percent.

Jan 1, 1967

By W. M. Myers

Jet is a substance of organic origin and has been defined by the U. S. Geological Survey as a "dense black lignite, taking a good polish, and sometimes used for jewelry". Jet is characterized by the lustrous, intense black surface it displays when polished. It is due to this property that the expression "jet black" is so commonly used to imply intense blackness.

Jan 1, 1923

By R. L. Balmer

This information circular, which describes the methods and costs of sinking a small underground shaft with steel supports at the Keystone mine of American Smelting and Refining Co., near Crested Butte, Colo., is one of a series being prepared by the Bureau of Mines on current shaft-sinking practices in various mining districts of the United States. Preparations for sinking a combined exploration, development, and production shaft from the lowest level of the Keystone mine began early in 1957. This vertical, three-compartment, 6-1/4-by 16-foot rectangular shaft was to be sunk in separate stages or lifts so as to correspond with the progress of an associated lateral exploration and development program. The first section of the shaft was collared and sunk to a depth of 209 feet between September 1957 and April 1958. Because of the depressed base-metal market, the mine was shut down as soon as the initial phase of the exploration and development program had been completed and before any deeper sinking could be attempted.

Jan 1, 1962

By R. W. Van Dolah

A premature detonation of an explosive charge occurred on January 30, 1961, at a face being prepared for blasting in the underground Jefferson Island Salt Mine, Diamond Crystal Salt Co., Jefferson Island, Iberia Parish, La. The accidental blast injured the powderman fatally; his helper was injured also, but recovered. The accident represents the first fatality reported to the Bureau of Mines in connection with the use of ammonium nitrate-fuel oil (AN-FO) blasting agents in underground mining in the United States. Representatives of the Bureau of Mines Explosives Research Laboratory, Pittsburgh, Pa., and field representatives of the Bureau's Health and Safety Activity conducted the investigation, upon request of the manufacturer of the ammonium nitrate being used and with concurrence by the mine management.

Jan 1, 1962

By Mark P. Meyer

A mineral investigation of the Chugach National Forest, Alaska was conducted jointly by the U.S. Geological Survey and the U.S. Bureau of Mines from 1979 to 1983 as part of the RARE II program. The U. S. Geological Survey remapped the geology and distribution of mineral resources. The Bureau investigated mines, prospects, and mineral occurrences. Previously unreported mineralization in three areas, Long Bay, Wells Bay, and Miners River were discovered in the western portion of the SOUND study area. Copper, lead, zinc, gold, silver, nickel, cobalt, fluorite, and arsenic were found in north-northeast to north-northwest trending shear zones, veins, felsic dikes, and granitic intrusives in Tertiary Orca Group metasedimentary rocks.

Jan 1, 2011

By L. J. E. Hofer, J. L. Snyder, J. N. Barn, J. E. Chilton, W. E. Thomas

Various silicone materials have been proposed for use in mining environments. The catalytic methane sensors now employed are poisoned by silicone vapors. Activated charcoal and carbon cloth adsorbents will increase the sensor lifetimes in an environment containing significant silicone vapor concentrations. The results of a study of catalytic methane sensor operation with adsorbent materials in hexamethyldisiloxane-air mixtures are reported. Sampling techniques developed for measuring silicone vapor content of mine atmospheres are described.

By M. Clair Smith

This report is one of a series being prepared by the Bureau of Mines on exploration, development, mining methods, and costs at various open-pit mines in the United States. These reports have been prepared in cooperation with various mining companies. A similar program, conducted from 1928 to 1939, was generally conceded to have contributed to improving the efficiency of mining operations. The purpose of these reports is to promote development and conservation of our mineral resources by disseminating technological information on mining methods and practices. This report describes exploration, development, equipment, and mining by open-pit methods of the remainder of an ore body that had been previously worked by underground methods. The Tripp pit of the Consolidated Coppermines Corp. is located at Kimberly, Nev., a small mining company town having an elevation of 7,250 feet, 9 miles by road west of Ely, Nev. (fig. 1). The pit extends over the area formerly mined by underground methods from the Morris and Brooks shafts.

Jan 1, 1962