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By Mulligan John J.

The Bureau of Mines investigated lode tin deposits on Potato Mountain, Seward Peninsula, Alaska. Tin was found to occur as cassiterite associated with quartz, tourmaline, pyrite, arsenopyrite, and earthy clays, but the deposits lack the varied accessory minerals commonly found in tin districts. The tin-bearing deposits are in metasediments along minor breaks and bedding planes but not in the crushed earthy filling of major faults. Cassiterite and sulfides occur with quartz in veins, both with and without earthy clays, and disseminated through tourmalinized wall rocks. The deposits are characterized by irregular segregations containing 1 to 10 percent tin within zones averaging not over 0.25 percent tin. The largest segregation exposed is on the summit of a low hill on the east-central slopes of Little Potato Mountain; most of the outcroppings are in an area trending east to west, roughly 10 to 30 feet wide and 300 feet long. Sample values ranged as high as 12 percent tin, but the average grade may be about 1 percent tin. The extreme irregularity of both grade and composition precludes a more exact determination. Similar concentrations are scattered for over 1,000 feet to the west and north, but these are smaller and lower in grade. Elsewhere on Potato Mountain, generally similar deposits occur as clusters of veinlets at widely separated points in the metasedimentary walls of major faults.

Jan 1, 1965

By B. C. Parks

This paper is a report on the relationships between petrographic composition, chemical composition, physical properties, and thermal behavior of banded bituminous coal. It describes the relationships between petrographic composition, behavior in various laboratory tests, and carbonizing properties of different petrographic types of coal that occur in relatively thick benches in a single bed of high-volatile A bituminous coal - the Hernshaw bed of Boone County, W. Va. Thin-section microscopic analysis and free-swelling index determinations of the thin-section samples were made of a standard column sample. A standard face sample, a representative channel sample, and representative samples of two prominent petrographic benches of bright and dull coal were subjected to chemical analyses and free-swelling-index, plasticity, dilation, agglutinating, low-temperature carbonization, and BM-AGA retort tests. A float-and-sink separation was also made of part of the standard face sample. The fractions from this gravity separation were subjected to petrographic and chemical analysis and free-swelling-index, plasticity, and dilatation tests.

Jan 1, 1959

By F. L. Wideman

Output of ore and waste from metal and nonmetal mines in the United States continued an upward trend and established a new high. The tonnage of ore handled increased 6 percent over that moved in 1964 and the tonnage of waste rose almost 10 percent. Earth moving by these two activities exceeded 3.2 billion tons, an increase of 7 percent over the 1964 total. Crude material from which metal or nonmetal products were derived continued to be about 75 percent of the total material handled. In 1965, surface mining methods were used to produce about 93 percent of the ore, 99 percent of the waste, and 95 percent of the total material handled. These percentages have remained almost constant since the beginning of this decade.

Jan 1, 1966

By C. W. Owings, L. D. Tracy

"IntroductionMany bituminous coal-mining companies have inaugurated extensive safety Programs, but the failure to have approved or permissible equipment or safe practice in only one part of a mine has resulted in disaster. The necessity of using only equipment bearing the U. S. Bureau of Mines approval plate is emphasized by the fact that many accidents are the direct result of carelessness on the part of trusted employees using non-permissible equipment. A concrete example is found in the case of an explosion on October 26, 1926, in a mine in the Pittsburgh district, Pennsylvania.Story of the ExplosionAt about 10 o'clock on the night of the explosion an examination was made in No 2 butt left and parallel off 7o. 14 north, and was found to be clear of dangerous accumulations of gas. (See figure). Several hours later a crew of two men brought a self-propelling rock-dusting machine within 50 feet of the face of Po. 2 butt parallel before they examined for gas. The machine operator found an accumulation of explosive gas about 18 inches from the roof. He began to wave his arms thoroughly mixing the gas and air. Undoubtedly a highly explosive mixture was created, and as the men attempted to run the machine back to fresh air an explosion occurred.The helper dropped to the floor and was burned about the face and wrists. The machine operator ran down the entry and was more severely burned about the face, neck, and arms. He later developed pneumonia and died. Both men reached the door in the chute between No. 14 and No. 15 north. A pumper, who had felt the rush of air, found the men and helped them to walk outside."

May 1, 1927

By G. C. Lammers

The object of this study was to determine the economic feasibility of hydraulically transporting Sandow (Tex.) lignite 100 miles and dewatering and thermally drying the transported lignite to a surface-dry condition. The most important factors involved in the feasibility of hydraulic transport, are the degradation incurred during transit, the length of the line, and the cost of alternative methods of shipment. In pipeline tests in which roughly 75 miles of hydraulic transport was simulated the percentage of minus-325-mesh solids increased from about 1 to 41 percent for both lignite and bituminous coal; in the micron sizes the coal fared considerably better than the lignite. Such degradation, even though it enhances flow through the pipe-line, severely aggravates the dewatering problem on lignite. Cost studies indicated that continuous vacuum filters offer the most economical means of dewatering minus-1/8-inch material. Surface moisture, if high, must be removed by relatively expensive thermal drying.

Jan 1, 1958

By G. S. Rice, R. V. Wheeler

"FOREWORDThe cooperative mine safety research program was carried on successfully in the year 1930 in a manner similar to that described in the report for 1929It is believed that the results of such fundamental work as is being done are unquestionably of great benefit in their application in coal-mining operations, in the saving of life and health of minera. The research result compared and checked by investigations in the two organizations, and further by large-scale tests, as in the Experimental Mine, give confidence to mine operators, miners and State mining officials in the findings of the various researches.The annual report of the contact officers of the United. States Bureau of Mines and the British Safety in Mines Research Board to the Director of the Bureau and the Chairman of the Board respectively, follows:Annual Reports for 1930 To: The Director, Bureau of Mines.The Chairman, Safety in Mines Research Board."

Sep 1, 1931

By George S. Rice

In response to numerous requests for information as to the status of internal-combustion mine locomotives of the Diesel type that use heavy or nonvolatile oil for fuel, with special reference to their safe use in coal mines, the United States Bureau of Mines is issuing this t port. Data were obtained on application of such locomotives to coal mining only in Belgium, France, Germany, and Great Britain. The locomotives are used in coal mining in other countries, as well as in potash, iron, and other kinds of mining, but their chief development has been in coal mining in Germany, France, and Belgium. Recently popular interest in the Diesel type of engine for motive purposes was aroused in this country by the successful application of Diesel engines to railroad locomotives hauling fast transcontinental trains, and, according to published statements, at a low cost of fuel per mile of run.

Jan 1, 1936

By Peter F. Steidl

As part of the Bureau of Mines methane control program, the Upper Free-port coalbed was studied in Fayette County, Pa., where this coalbed lies about 650 feet below the Pittsburgh coalbed and contains the largest remaining reserves of any coalbed in the county. Coal and overburden isopachs, structure and joint pattern maps, and a fence diagram were prepared using data from gas and oil exploration logs and coal outcrops. These maps will aid in deter-mining the need and/or feasibility of degasifying the Upper Freeport coalbed in the study area. Much of the coalbed in this area is under 600 to 1,400 feet of overburden. By correlation with data from the Pittsburgh coalbed, the gas content at depths of this order is estimated to be between 140 to 300 cf/ ton of coal, for a total of 190 to 400 billion cubic feet of methane in this coalbed in Fayette County.

Jan 1, 1977

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace- time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200- foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By Merwin H. Howes

Gnome shaft, situated about 24 miles southeast of Carlsbad, N. Mex., was designed and sunk by the U.S. Atomic Energy Commission for conducting a peace-time experimental nuclear explosion in the thick salt beds of the Permian Salado formation. Excavation was started July 1, 1960, and completed July 26, 1961. The 10-foot diameter shaft, lined with concrete through the rock section, was sunk 1,216 feet. A drift was driven approximately 1,140 feet on the 1,200-foot level terminating in a shot chamber. On completion of 100 feet of shaft, by means of a truck-mounted crane, facilities were installed for conventional sinking. About 709 feet of rock and 506 feet of salt were encountered in the shaft. Salt beds at this place are reported to be over 1,200 feet thick. The overlying rock section varies greatly in composition and thickness of beds and contains a 28-foot bed of water-bearing dolomite. The aquifer was sealed to facilitate shaft sinking and to prevent water-seepage damage in the salt section of the shaft. Sealing was accomplished by grout injection through holes drilled into the aquifer and by grouting behind the concrete liner.

Jan 1, 1963

By James J. Snodgrass

The Bureau of Mines has investigated vibration levels produced by blasting at four underground sites to establish how such factors as type of explosive, delay blasting, charge weight, and geology affect amplitudes of ground motion. A summary of the work is presented and the results of further analysis of the data are discussed. Square root scaling was found applicable to two of the underground sites and could be applied with minor error to all the sites. Comparison of empirical propagation equations in the different rock types indicates that although the site effect is apparent, the combined data may be used as a basis for engineering estimates of vibration amplitudes from subsurface blasting in many different rock types. Recommendations for predicting and minimizing vibration amplitudes from underground blasts are given.

Jan 1, 1974

By J. C. Barrett

Bureau of Mines research on the arc welding characteristics of titanium was initiated in 1948. Little was known about the art except that the easily contaminated metal required more protection from the atmosphere during welding than most other metals. Chambers were designed and built within which titanium could be welded with adequate inert gas protection. Welds were made and their properties studied, and prototype items were made successfully. This report, presenting a resume of the titanium arc-welding experiments undertaken by the Bureau of Mines, demonstrates that the process is successful if conducted under proper conditions and describes the welding of prototypes. INTRODUCTION The Bureau of Mines' first report on methods of joining titanium covered the subject of spot welding,4/ outlining the conditions necessary for producing spot welds in ductile titanium consolidated by powder metallurgy methods and describing the characteristics of such welds. This report embraces the field of fusion weld-ing of titanium and traces the development of suitable methods and equipment for producing such welds.

Jan 1, 1956

By Thomas M. Barczak

This US. Bureau of Mines report examines the roof and floor contact pressure provided by the interaction of a shield with the surrounding strata. Controlled forces were applied to an 800-ton two-leg shield in the Bureau's mine roof simulator; the distribution of forces acting on the canopy and base of the shield were measured with 24 hydraulic pressure cells. Several influential factors that affect the load distribution were investigated: (1) the magnitude of loading (leg pressure); (2) the profile of the canopy, principally the upward-sloping tip; (3) the base-lifting device; (4) horizontal load acting on the shield; and (5) compliancy of the immediate roof and floor. It was concluded that the shield does not develop full canopy or base contact without deformation of the strata. Maximum contact pressures are developed at the rear of the canopy and on the toes of the base. Less than 10 pct of the available shield capacity is developed at the canopy tip despite the design intention to ensure tip contact. Horizontal loading reduced the toe pressure acting on the base by as much as 75 pct. The base-lifting device exaggerated the inherently high toe loading, increasing the contact pressure by more than 200 pct.

Jan 1, 2010

By S. S. Gross

A program was conducted to determine whether sufficient quantities of the flame retardant, ammonium phosphate, could be incorporated in a water-based foam solution to prevent or delay reignition (burnback) without. significant degradation of foam properties. Up to 20% of mono and diammonium phosphate was added .to d high expansion foam solution. This mixture was applied as a high expansion foam to burning wood and coal samples. The effect of this mixture on burnback was laboratory tested by placing the wood or coal sample in front of a radiant panel. It was found that diammonium phosphate levels of 20% by weight prevented reignition without degrading foam properties. A field test was then conducted using a 20%, diammonium phosphate mixture and a control with no phosphate on a wood crib fire. The experimental foam did extinguish the crib fire faster than the control as evidenced by the smoke from the crib. However neither crib reignited.

Jan 1, 1982

By H. W. Kilau

The Bureau of Mines used a high-temperature rotational viscometer to test basic oxygen furnace slags to determine fluorspar requirements and to evaluate colemanite and fused boric acid as substitute fluidizers. A continuous technique of viscosity measurement was adapted to better determine the viscosity-temperature profiles of volatile fluorspar slags. Criteria used for estimating slag fluidizer effectiveness were (1) the apparent solidification temperature, and (2) the temperature range of slag crystallization. Colemanite and fused boric acid in high-basicity slag were superior fluidizers to fluorspar when compared on the basis of boron versus fluorine concentration. Fused boric acid was nearly equivalent to ceramic-grade fluorspar when compared on a simple weight basis, while colemanite was inferior to fluorspar. Fluorspar slags volatilized fluorine during viscosity testing. Colemanite and fused boric acid slags were stable, no boron losses being detected. A fluidizing limit was found for fluorspar at 2.9 percent fluorine concentration; higher concentrations impaired viscosity and caused foaming and crusting of slag. Concentrations of boron up to 4.4 percent resulted in very fluid slags with no fluidizing limit.

Jan 1, 1978

By Laird Crocker

This report describes a study of beryllium recovery from sulfate leach liquor by di-2-ethylhexyl phosphate (EHPA) solvent extraction in conjunction with caustic stripping. The work was one phase of Bureau of Mines research on process development for Spor Mountain, Utah, ores. Solution for the solvent extraction studies was prepared by sulfuric acid leaching of ore containing 0.6 pet BeO, Before solvent extraction of beryllium, the leach liquor was treated to prevent coextraetion of iron by either (1) removal of ferric iron by amine solvent extraction or (2) reduction of ferric iron to nonextractable ferrous iron by treatment with sulfur dioxide. Beryllim was extracted from the aqueous leach liquor by countercurrent multistage contacting with a kerosine solution of EHPA. The loaded organic solution was stripped with sodim hydroxide solution. Subsequently, beryllium hydroxide was precipitated by boiling the sodium beryllate strip solution and converted to beryllium oxide of 98 pct BeO-grade by calcining. Material of this grade can be directly processed into beryllium-copper alloy or be used as starting material for further refining to produce high-purity, nuclear-grade beryllium. Over 90 pct of the beryllium contained in the leach liquor was recovered as beryllia.

Jan 1, 1963

The latest Active List of Permissible Explosives and Blasting Devices was published in July, 1929, as Bureau of Mines Report of Investigations 2947, 2 under the title or "Active List of Permissible Explosives and Blasting Devices Approved Prior to June 30, 1929.' Subsequent Reports of Investigations 2253, 2958, 2962, 2972, 2988, 2992 and 3000, were issued to record the official actions taken during July, August, September, October, 1929, and January, February, and March, 1930. No changes were made during November and December, 1929, and April, 1930. The following additional changes in the list recording the actions taken during May, 1930, are now authorized. [ ]

Jan 1, 1930

By Charles B. Carpenter

In general terminology, the West Texas Permian Basin comprises the area south of the Texas Panhandle and west of the Bend Arch or Central Basin region. It is outlined mere definitely by geologists, however, as that area underlain by the south half of the Permian Salt Basin4/ and includes Scurry, Mitchell, Sterling, Howard, Glasscock, Reagan, Crockett, Upton, Midland, Martin, Gaines, Andrews, Ector, Crane, Pecos, Ward, Winkler, and Loving Counties in Texas, and Lea and Eddy Counties in New Mexico. The oil fields of the area, of which more than 70 have been discovered, are shown in fire 1. Approximately 4,200 producing oil wells have been drilled in these fields. Oil has been produced from limestones and dolomites of Permian age in most of the fields in the West Texas Permian Basin. Some of the fields produced oil from sandstone beds above the limestone, and in two fields production has been found below the limestone in formations of Ordovician age.

Jan 1, 1936

By Gerald L. Finfinger

The Bureau of Mines conducted an experimental degasification project in Island Creek Coal Co.'s Virginia Pocahontas No. S mine. Methane from the overlying Pocahontas No. 4 coalbed was entering mine workings in the Pocahontas No. 3 coalbed through fractures in the roof rock. Small-diameter (l-S/B-inch) holes were drilled into the overlying coalbed to reduce the gas pressure and intercept methane flows, which were piped to the surface through an underground 6-inch-diam steel pipeline. The total methane flow rate from the vertical holes averaged 150,000 ft3/day for the first month. Methane flows into the mine were reduced by 47 pet, thereby demonstrating the effectiveness of this form of degasification in reducing ventilation requirements and providing a safer working environment.

Jan 1, 1979

By Corale L. Brierley

Beneficiation of phosphate in the southeastern United States generates a slurry of finely divided clay. These clay-wastes are impounded to allow the particulates to settle. The aggregation of phosphatic clay-slime wastes and slimes produced from potash beneficiation by microbial processes was studied using several bacterial species known to produce polymeric substances. Experiments included flocculation capacity of clay-slimes by whole cells, the determination of respiratory activity of whole culls in the presence of phosphatic clays, observation of clay flocculation rates by polymers derived from these organisms, and clarity of polymer-flocculated clay suspensions. The polymer-producing organisms exhibited little capacity for flocculating phosphate and potash clay-slimes. Fungal spores of Cladosporium cladosporioides (isolated from a phosphate clay-waste impoundment), when agitated with clay-slime for several days, caused the clay to form pellets. Separation of the clay/fungal pellets (density 1.1 g ml-1) from the process water might he possible using a screening technique. Studies with C. cladosporioides included the determination of suitable energy substrates and supplements for growth, absorption studies of a pigment produced by the organism, determination of the time required for bioflocculant production by the organism, and an elucidation of the conditions required for the pelletization of clay-slimes by the fungus.

Jan 1, 1982