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By W. F. Marshall

This report describes exhaust-emission data from 10 diesel engines: six 4-cycle, direct-injection, naturally aspirated engines; two 4-cycle, direct-injection, turbocharged engines; one 4-cycle, precombustion-chamber, turbo-charged engine; and one 2-cycle, direct-injection engine. These engines were tested over a 3-year period (1968-70). Lowest emissions were obtained with a precombustion-chamber engine. Emissions from the 2-cycle, direct-injection engine fell within the range of emission rates for the 4-cycle, naturally aspirated, direct-injection engines. Excluding the precombustion-chamber engine and excepting one of the 4-cycle, naturally aspirated engines, carbon monoxide emission rates were about the same for all engines tested. Test data on smoke, odor, and emissions of hydrocarbons, oxides of nitro-gen, carbon monoxide, and aldehydes are given.

Jan 1, 1971

By E. G. Baglin

The Bureau of Mines devised a procedure for selectively extracting platinum-group metals (PGM) and gold from Stillwater Complex flotation concentrate. The Stillwater Complex is the only major U.S. PGM resource. Development of a suitable extraction technique will contribute to its exploitation. The concentrate was roasted at 1,050° C to convert host base-metal sulfides to oxides and the PGM from sulfide minerals to their elemental states. The roasted concentrate was preleached with dilute sulfuric acid to remove easily soluble gangue minerals. After pre-leaching, the concentrate was slurried with 6M HCI and leached at ambient temperature and pressure with a strong-oxidizing agent. Hydrogen peroxide, chlorine, sodium hypochlorite, nitric acid, and a persulfate salt were the oxidants investigated. The two-stage leaching scheme ex-tracted up to 97 pct of the platinum, 92 pct of the palladium, and 99 pct of the gold from the roasted concentrate. The base metals were not solubilized and reported to the residue. No attempt was made to devise a procedure to recover the copper and nickel because they comprise less than 5 pct of the value of the concentrate. Viable techniques for recovering the precious metals from the pregnant solution were sulfide precipitation, cementation with nickel, or adsorption on activated carbon.

Jan 1, 1985

By F. J. Palumbo

An electronic color-sorting machine was tested for recovering colorless glass concentrates from mixed glass products. The tests were made using glass recovered from unincinerated (raw) urban refuse and residues resulting from the incineration of refuse. The results of the study revealed that concentrates analyzing about 86 percent colorless glass could be recovered from mixed unincinerated glass containing 54 percent colorless glass material. Recovery of the colorless glass was about 62 percent. Color sorting the incinerated glass was somewhat more difficult. Multiple-stage processing was required to recover 59 percent of the colorless glass material in a product analyzing 89 percent colorless glass. The feed material analyzed 41 percent colorless glass.

Jan 1, 1971

By M. H. Marvin

This report presents the results of a program to develop backfilling techniques to mitigate undesirable effects of hydraulic borehole uranium mining. Large underground cavities, formed during the borehole mining process, can be backfilled to prevent ground subsidence and to allow mining of adjacent uraniferous sandstone. Three backfilling techniques were tested in the laboratory and in the field: bulk dumping of slurry into the borehole from ground level, slurry injection under water, and slurry injection above the cavity water level. These techniques were tested with sand and with sand and one percent cement (by weight) mixtures. The project was accomplished in four tasks: equipment preparation and transport, mining operation to generate a full-sized cavity, backfilling operation, and assessment through core samples and subsidence checks. The concentrations of cement mixed with sand proved to be inadequate to bond the sand. Bulk dumping resulted in a 30-degree angle-of-repose, much too steep to completely fill the cavity. Both slurry injection techniques filled the cavity satisfactorily. However, underwater injection is the recommended backfilling technique because the borehole water level does not need to be pumped down during backfilling. The borehole itself was filled by bulk dumping of slurry. In conclusion, backfilling of borehole mining cavities is entirely feasible, and the preferred method is slurry injection under water.

Jan 1, 1979

By R. T. Artz

Disposal of sewage is an important part of mine sanitation. Improper... handling and.disposing of sewagerare conducive to the spread of disease and often add foul and nauseating odors to the mine air. The diseases spread by unsafe methods of disposing of waste in mines are typhoid fever, cholera, amebic dysentery, hookworm, and other intestinal diseases due to parasites. Sanitary toilet facilities, with a good sewage-disposal system, each maintained in good order at all times, should help to prevent the spread of diseases transmitted by intestinal body wastos. The metal and nonmetal-mining industries have recognized the impor-dma tance and need for disposing sewage properly; accordingly, facilities of some sort are installed and need today in most large mines. The coal-mining industry has given little thought to the disposal of sewage underground; however, in most mines of the anthracite industry, the inflow of large vol- unes of highly acid mine water and the extensive drainage system required to remove this water provide a natural means for disposing of sewage.

Dec 1, 1946

By Robert Alfred

This paper is one of a aeries being published by the Federal Bureau of Mines on methods and practices used in mining and preparing crushed stone for market. Performance, in terms of units of work or tons produced per machine and per operator man-hour, is given whenever that information can be obtained. Direct operating costs are useful for comparing different methods and are included if available. In addition to descriptions of equipment and methods used the Bureau considered it desirable to discuss the engineering reasons for the choices that have been made, This paper is particularly concerned with the operation of the Liberty quarry and plant of the Campbell Limestone Co, The plant is in Pickens County, adjacent to the main line of the Southern Railway, and is about 18 miles west of Greenville, S, C. Access also is available by United States Highway No, 123, The company's main offices are at Knoxville, Tenn.

Jan 1, 1958

By H. W. Sheffer

Technical and economic aspects of community refuse disposal systems and their effects on the environment are identified and described. Seven landfills and two incineration systems, located throughout the United States, are reviewed.

Jan 1, 1971

By Davis E. Traut

TiC14, AIC13, and VC14 were coreduced simultaneously via a Kroll-type magnesium reduction to form an alloy sponge as part of a research effort by the Bureau of Mines to produce titanium alloy powder. Reduction tem-peratures of 750°, 850°, and 950° C, a range of chloride feed rates from 34 to 152 Ib/(ft2·h), and crucible diameters of 7-3/4 and 10-1/4 in were tested. Microprobe analyses using a 40-um-diam spot showed no effect on alloy microhomogeneity (distribution of Al and V in the Ti, considered critical as a powder property), due to changes in process variables within these ranges. Statistical analysis of these data for alloy sponge indicated greater variation in the chemical composition (AI and V) than that found in commercial Ti-6Al-4V plate or Plasma Rotating Electrode Process (PREP) powder. Therefore, a one-step approach to pow-der, such as grinding the Ti alloy sponge, would not produce a powder product of acceptable chemical homogeneity. An approach that homoge-nized the sponge, such as with a melting step, would produce an accept-able powder product with respect to chemical homogeneity.

Jan 1, 1987

By E. G. King

Thermodynamic calculations involving the oxides of tungsten and molybdenum have been hampered by lack of accurate entropies and high temperature heat contents. This paper presents work by the Federal Bureau of Mines on new low-temperature heat-capacity data leading to the evaluation of the 298.15° K. entropies of tungsten dioxide and tungsten trioxide, as well as high-temperature heat contents (above 298.15° K.) of molybdenum dioxide, molybdenum tri-oxide, tungsten dioxide, and tungsten trioxide. Included are heats of fusion of the two trioxides. The heats of formation at 298.15° K. of these four oxides are tabulated as measured by Mah4 5/ of this laboratory. Included also are the 298.15° K. entropy of Mo02 measured by Kin 6/ of this laboratory, and that for Mo03 according to Kelley and King.7/ These basic data provide a consistent compilation from which to perform accurate thermodynamic calculations involving these compounds. No previous low-temperature- heat-capacity measurements have been reported for tungsten dioxide. Seltz, Dunkerley, and DeWitt8/ measured the low-temperature heat capacity of tungsten trioxide. The only previously-reported high-temperature heat-content measurements for any of the oxides were conducted by Cosgrove and Snyder,9/ who measured molybdenum trioxide to 1,300° K.

Jan 1, 1960

By D. A. Rice

As part of a cooperative effort between the Bureau of Mines and the Florida Institute of Phosphate Research (FIPR), with input from the phosphate industry, the conversion of phosphogypsum to sulfur is being investigated. The proposed process incorporates the thermal reduction of phosphogypsum to calcium sulfide (CaS) and a hydrometallurgical treatment to convert calcium sulfide to sulfur (S°). The research described herein is focused on the latter half of the process. It was demonstrated that calcium sulfide could be converted to ammonium bisulfide (NH4SH), and that ammonium bisulfide could be oxidized by air in the presence of a catalyst, to elemental sulfur, which was adsorbed on the catalyst. Two methods for recovering sulfur from the catalyst were developed: (1) thermal treatment to volatilize sulfur, and (2) leaching the sulfur from the catalyst with liquid anhydrous ammonia. Over 90 pct of the sulfur adsorbed on activated carbon (the catalyst) was recovered by both methods. Based upon the encouraging laboratory investigations, a hydrometallurgical scheme was proposed for the overall conversion of calcium sulfide to elemental sulfur.

Jan 1, 1990

By John A. Ruppert

1. It has been proposed that the addition of enough limestone to an open -hearth s lag to give a CaO-3P2O5 ratio of approximately 2-followed by SiO2 firing in an oxidizing atmosphere under the proper conditions of time and temperature will result in a clinker having a magnetic phase containing a preponderance of Mn, Fe, Al, and Mg as oxides and a nonmagnetic phase consisting for the most part of a phosphorus-containing dicalcium silicate. It has been postulated further that the metal oxide phase can be recovered by fine grinding and magnetic separation. These broad principles have been substantiated by numerous clinkering operations made in an electrically fired studio-type kiln, a batch rotary kiln, and a continuous rotary kiln and by magnetic separations made in a Davis -tube separator and a laboratory-size Jeffrey-Steffensen three -roll continuous separator. 2. Quenching the clinker after firing seems to improve its grindability. Microscopic examination of the ground clinker indicates .that the oxide phase grinds down at a somewhat faster rate than the silicate phase. 3. Very fine grinding is necessary to approach liberation, of the oxide phase from the silicate phase. Grinding to ininus-325-mesh, followed by magnetic separation, gave only a rougher concentrate, which had to be reground before final separation. 4. Although the manganese content of the final concentrate was higher, there was some evidence that manganese recovery was lower from a clinker made from a flush s lag than one made from a mixture of tap and flush slags. A possible explanation is that a clinker made from a mixture of slags has a higher iron content and hence is more magnetic and more easily separated.

Jan 1, 1952

By George A. Savanick

The U.S. Bureau of Mines has patented and transferred to industry an abrasive-enhanced water-jet rock drill. This drill incorporates three novel components: a collimator, jet deflectors for cutting clearance, and an unpressurized swivel, which rotates at 1,000 rpm while passing 20 gpm of an abrasive slurry flowing at 1,000 ft/s. Drilling occurs through the action of a 10,000-psi, 2O-gpm water jet into which is entrained 72 lb/min of abrasives. The pumps, hoses, and fittings are those commonly used in the water-jet-cleaning industry. Only inexpensive, common sandblasting abrasives are used. This drill can cut through hard rocks with moderate-pressure jets; e.g., rocks with a compressive strength of 73,000 psi can be drilled with a 1O,OOO-psi abrasive jet. In addition to drilling holes, the drill can cut deep, narrow kerfs; collar a hole at any angle; drill through rubble; and chamber holes. The development of the abrasive jet drill is a significant advance in the state of the art of hard-rock drilling. The Government of the United States has licensed the abrasive jet drill patent to Weatherford Water Jetting Systems.

Jan 1, 1989

By W. H. Oppelt

Converting small-particle lignite to a stable, storable fuel of relatively high heating value was investigated. The fuel was prepared by thermal pretreatment of the lignite in an 8-inch i. d. rotary-drum retort, then the pretreated material was pelletized in an experimental 15-inch-i. d. rotary-drum pelletizer. Pelletizing tests were made with both starch and bituminous binders. During the first phase of the project, the quantity, composition, and heating value of products from the thermal processing of Kincaid lignite from Burke County, N. Dak., in an B-inch i. d. rotary-drum retort were investigated at a series of temperatures from 250° to 950° F. to establish optimum conditions for preparing feed material for pelletizing. To determine the response to thermal treatment of different lignites, 5 other lignites from Divide, McLean, Mercer, and Stark Counties, N. Dak., and 1 lignite from Saskatchewan, Canada, were processed at 700° F.

Jan 1, 1958

By Wm. F. Netzeband

The purpose of this paper is to present to the operators, in other districts a detailed description of the ruining method used and the results obtained to exploiting one of the zinc-lead deposits of the Kansas-Oklahoma-Missouri district. No. 1. mine is located in the heart of the town of Picher in the extreme northeast corner of Oklahoma. HISTORY The first prospect drilling was done at No. 1 mine late in-1914, and shaft sinking was started early in 1915. Sufficient ore was developed to start construction of the mill in April, 1016, Production begin in August, 1916, and the mine s been producing, except for short periods, to the present time. The property was originally a 40-acre tract, but additional properties have been consolidated with the original one until the mine now covers 200 acres.

Jan 1, 1929

By Richard P. Walters

This Bureau of Mines report reviews and assesses the technology for preparing electrodeposited coatings of the platinum-group metals from molten alkali metal cyanide baths. Methods are described for the preparation and purification of the cyanide electrolyte. Vacuum drying, fusion, and purity of the cyanide salts are discussed. Use of a sodium borosilicate test tube as a sodium-ion-conducting membrane for the addition of the desired platinum-group metal is described. The optimum plating parameters of potential and current density for Pt, Pd, Rh, Ru, and Ir coatings that result in the best deposits are given. A method for producing platinum-rhodium alloy coatings of predetermined composition is also described. The importance of careful substrate surface preparation is illustrated. While problems still remain with respect to coating porosity, careful application of the methods described permits the preparation of adherent, coherent electrodeposited coatings of the platinum-group metals.

Jan 1, 1984

By R. R. Lowery

The Bureau of Mines developed hypereutectic aluminum-silicon alloys which 11.7.d better mechanical properties than the unmodified hypereutectic alloy. A commercial aluminum-20 weight-percent silicon LIr alloy was selected as a ary base for improvement. The primary silicon. grains were reduced from ASTM 4-5 to ASTM 8.5 by the use of phosphorus and phosphorus compounds. The remaining eutectic matrix was refined by sodium metal additions of 0.2 weight-percent. Solid solution strengthening of the alpha aluminum was obtained by adding 2 percent copper and 0.5 percent magnesium. Also, 1 percent nickel was added to harden the alloy. Optimum thermal treatment consisted of a solution treatment for 10 hour:, at 480° C with hot water quench, followed by aging for 6 hours at 175° C. The final alloy exhibited a Rockwell B hardness of 75 ±2 in the heat-treated condition. The ultimate tensile strength was 39,5O0 psi with no recordable elongation. The coefficient of linear thermal expansion was 20.4 x 10-6 per °C in the temperature range 20° to 300° C. No wear resistance data were collected.

Jan 1, 1966

By H. A. Dierks, H. B. Link

The purpose of this investigation was to develop a practical feeder apparatus to introduce comparatively large pieces of coal and similar material into a pipeline under pressure in connection with the vertical hydraulic transportation of solids , termed " hydraulic hoisting . " This method of hoisting the precrushed run - of - mine product of an underground mine has been given unusually wide attention abroad and could be of considerable significance to the U.S. mining industry in its search for operating improvements and cost reduction . A lock-hopper assembly was developed after a series of sinking velocity tests were made by dropping anthracite in a column of water . The system functioned reliably as an automatically operated feeder apparatus .

Jan 1, 1964

By Robert W. Ageton

The Bureau of Mines is currently conducting a comprehensive study to evaluate all aspects of recovering gold from large, low-grade deposits in the Golden Sunlight area, Whitehall mining district, Jefferson County, Mont. Prior to World War II this area produced significant quantities of gold. The study includes geologic mapping, diamond drilling, assaying, computer analysis of assay data, metallurgical research and ore testing, mine and mill planning, and an economic evaluation of all factors bearing on the establishment of a producing gold mine. Preliminary evaluation of the deposit indicates about 31 million tons of submarginal gold resources. American Exploration and Mining Co. (AMEX) has assisted the Bureau in this project by providing drill site preparation, control assays, and geological aid for the Bureau's exploration work and by furnishing comprehensive assay information of the property and copies of base and geologic maps. This report presents the geology and mining history of the area, together with a summary of Bureau work in progress.

Jan 1, 1969

By S. J. Gasior

Pilot plant studies showed the technical feasibility of fluidized-bed operation for producing hydrogen and synthesis gas by the steam-iron process. A mixture of iron and iron oxide from 20-to 100-mesh was partially reduced with a simulated producer gas and then oxidized with steam and/or carbon dioxide. Results of tests show the effects of pressure, temperature, bed height, gas-to-solids ratio, type of iron oxide, and composition of gas on the gas and solids conversions during reduction and oxidation. A baffled free-fall solids system was also found operable. The short residence time of about 5 seconds limited conversion of the solids.

Jan 1, 1961

By Kevin Malone

Mercury, or quicksilver as it is often called, has many applications in modern technology. Used principally in electrical apparatus, industrial contol instruments, insecticides and fungicides, electrolytic preparation of chlorine and caustic soda, chemical processes, pharmaceuticals, and dental preparations, the liquid metal has unusual properties that make it a preferred material for many industrial uses. United States consumption of mercury during the past 40 years shows a rising trend. In all except 4 years, U.S. production has been less than the domestic requirement, and imports, principally from Spain, Italy, and Mexico, have supplied most of the deficit. After World War II, domestic output decreased rapidly until 1950, when it was the lowest in the 100 years covered by production records. Higher mercury prices since 1950 have reversed the decline in domestic output and reduced the gap between U.S. production and consumption. Domestic output in 1958 was the highest in peacetime since 1883; however, the nation still imported 28 percent of its mercury requirements from 1950 to 1960 the price of mercury was high as a result of industrial applications of the mercury cell, the impact of the cold war and the Korean war, and the Government stockpiling program. The stockpiling program, in effect, put a floor under mercury prices even though only 9,428 flasks of domestic mercury went into the stockpile under the original program which ran from July 1954 to December 31, 1957. Under an extension of the program, an additional 17,463 flasks was purchased.

Jan 1, 1962