Search Documents

By E. G. King

Difficulty has been encountered in making thermodynamic calculations of metallurgical reactions involving interoxidic compounds of the ferroalloy elements because of the serious lack of most thermodynamic data for these substances. This Bureau of Mines report (the first of a planned series dealing with entropies of vanadates, tungstates, and molybdates) presents low-temperature heat-capacity data and entropy values at 298.15° K. for three crystalline sodium vanadates--metavanadate (NaV03), orthovanadate (Na3VO4), and pyro-vanadate (Na4V2O7). The results are combined with data for the constituent oxides and elements to obtain entropies of formation of the vanadates. Previous to this report only one vanadate had been studied Similarly, ammonium metavanadate.4/

Jan 1, 1961

By Rogers F. Davis

This publication has been prepared to supply manufacturers and industrial users a listing of mobile diesel-powered equipment and subassemblies approved and certified by the Bureau of Mines for use in noncoal mines. Testing of diesel-powered equipment is one phase of the Bureau's program of health and safety that concerns approval of electrical and diesel equipment designed to prevent explosions, fires, shocks, or toxic hazards in underground mines, when such equipment is used and maintained properly. Manufacturers submit machinery and component parts to the Bureau for study of their design, safety features, and use. Equipment must pass exacting tests and must meet strict requirements established through research and experience and listed in the Bureau's permissible schedules before the Bureau approves it as permissible for safe use in mines.

Jan 1, 1963

By Don B. Hunter

The Bureau of Mines investigated the extraction of alumina from calcined kaolin by leaching with boiling RCI in a train of three 50-gal continuous, stirred reactors. Slurry discharged from the reactors con-tained an excessive amount of fines, which impeded solid-liquid separation. Autogenous grinding of coarse solids that accumulated in the reactors was the source of the fines. This report describes modifications to the reactors and to the operations that led to decreased fines generation and improved solid-liquid separation. Modifications to the reactors included custom-made impellers, the addition of a baffle system, a subsurface slurry discharge system, and slower rotation of the impellers. Concurrent testing of a continuous horizontal belt filter showed that the form filtration rates were increased from 350 to almost 1,000 Ib/h+ ft-2 when the modified reactors were used.

Jan 1, 1984

By W. W. Weller

Heat capacities of ferrous molybdate (FeMoO4) and ferrous tungstate (FeWO4) were measured over the temperature range 51° to 298.15° K. Ferrous tungstate has a lambda type heat capacity anomaly at 74° K. The 298.15° K entropies are FeMoO4) 30.9 cal/deg mole and FeW04) 31.5 cal/deg mole.

Jan 1, 1966

By H. P. Hermance

The Ore Hill zinc-lead mine in Grafton County, N. H., was investigated by the Bureau of Mines from March to July 1943 and from August to October 1944. Fourteen holes with an aggregate bore of 4,899 feet were diamond-drilled, the old workings were unwatered and sampled to an inclined depth of 250 feet, and the tailings dumps were surveyed and sampled. The deposit at the Ore Hill mine comprises a bedding-plane vein of massive sphalerite and galena with subordinate chalcopyrite and pyrite in a series of interbedded metasedimentary and metavolcanic schists about one-quarter mile east of their contact with the intrusive Baker Pond gneiss. The property was first opened about 1850 and was active at times to 1914. Production records are not available, but the output is believed to have been considerable. In 1944, leasers recovered a marketable mica product from mica schist from the dumps and certain outcrops. This report describes the work performed in the Bureau's investigation and presents the data obtained.

Jan 1, 1948

By Christopher D. Risbrudt

In this comprehensive study of the use of wood products in coal mining, a sample of over 220 mines provided data by questionnaire. Wood use per ton of underground coal was found to vary substantially by mining process and region. In the Eastern Coal region, 1.6 board feet of wood was used per ton of coal, wel above the 0.6 board feet usage per ton in the West. The kind of timber used varied also by Region. Hardwood use is about 40 times greater than softwood in the Eastern Region. There, hardwoods are plentiful, relatively cheap and strong. In the West where softwood forests predominate, softwoods were 2-1/2 times more common in mine wood use than hardwoods. Nearly 80 percent of the wood used in underground coal mines is used in cross bars and props. Nearly 54 million cubic feet of wood products were used in coal mining in the sample year 1979; about twice as much going to underground mines as surface mines. Wood requirements for mining were projected to 2030 for a range of three oil price scenarios. Much greater wood use will be required for greater coal output.

Jan 1, 1982

By K. K. Kelley, W. W. Weller

This report contains experimentally determined heat capacity data for four crystalline sulfides -- AsS , GeS , NiS , and Ni3 S₂ -- over the temperature range from 50 ° to 298.15 ° K. The heat capacity data were used to evaluate the entropies of the sulfides at 298.15 ° K. Entropies of formation from the metals and rhombic sulfur and from the metals and diatomic sulfur gas are also included .

Jan 1, 1964

By J. H. Field

Results of studies by the Federal Bureau of Mines on a pilot-plant scale for removing hydrogen sulfide and carbonyl sulfide from gas mixtures by the hot carbonate system are given in this publication. Gases containing up to 10 pet. hydrogen sulfide and 48 grains carbonyl sulfide per 100 cu.ft. were treated. In most tests carbon dioxide also was present and was removed simultaneously with the sulfur compounds. Because the rate of absorption of hydrogen sulfide is much more rapid than that of carbon dioxide over a wide temperature range, selective removal of hydrogen sulfide occurred in the bottom section of the absorber near the point of gas entry. Hydrogen sulfide was removed to pipeline specifications with carbonate solutions by using split-stream flows in the absorber and regenerator.

Jan 1, 1960

By Clarence O. Babcock

This Bureau of Mines publication presents guidelines for mining near surface and underground bodies of water. The guidelines were based on information developed under contract in three phases of study, as follows: (1) Collection and documentation of data from worldwide sources; (2) application of existing guidelines, foreign, Federal, and State, to case histories of previous inundations; and (3) development of recommended guidelines for underground coal mining near bodies of water aimed at maximum efficient utilization of underground coal resources consistent with minimizing inundation hazards. While the contract guidelines were for the mining of coal seams, they may also be used for mining any tabular sedimentary mineral deposit. Tables are given for the determination of the size of coal pillars needed; for other bedded deposits, similar tables could be determined based on their strength properties.

Jan 1, 1977

By F. D. DeVaney

[In the course of the investigation by the U. S. Bureau of Mines and the Missouri School of Mines and Metallurgy at the Mississippi Valley experiment Station at Rolla, Mo., on the beneficiation of the low-grade manganese ores of the country, some samples from the Cuyuna District, Minn., have been examined. The work was done under the direction of W. H. Coghill, supervising engineer of the Mississippi Valley Experiment Station. Josoph and Kinney5 in venting about the relative importance of Minnesota deposits of low-grade ore compared to the total reserves say:]

Jan 1, 1930

By Robert H. Bedford

The New Almaden mine was discovered in 1824, and since that date production of quicksilver has exceeded 1,000,000 flasks. Because of this high production record, the New Almaden area was, upon passage. by Congress of the Strategic Minerals Act of 1939, immediately considered by the Bureau of Mines as a promising location for exploration. In 1941, the Federal Geological Survey undertook a survey of the entire district. R. R. Trengove, an engineer of the Bureau of Mines, made a preliminary study for a project in 1942, and in August 1943 the Bureau, in close cooperation with the U. S. Geological Survey, began the development project described herein. The Bureau of Mines drilled 36 holes, totaling 6,807 feet of diamond drilling, along the contact between the serpentine and Franciscan, sandstones and other sedimentary formations. The ore bodies are found along this contact and occur in the carbonate-silica rock. This report briefly describes the location, history, and ore deposits of the property. The recent operations are outlined, and the work performed by the Bureau is explained in detail.

Jan 1, 1950

On December 16, the General Services Administration (GSA) suspended weekly sales of surplus silver from the national defense stockpile because Congress approved the Defense Appropriation Act, which contained an amendment to halt silver sales. The amendment, introduced by Senator James A. McClure (R., Idaho), prohibits sales for 6 months while the impact of the sales and alternative methods of disposal are evaluated. The GSA sold 2 million troy ounces since sales started October 14. 46.5 million troy ounces were authorized to be sold during this fiscal year and an additional 58.6 million troy ounces were authorized to be sold over the following two fiscal years. The stockpile held 139.5 million troy ounces of silver when sales began in October. Brush Wellman, Inc., a vertically integrated producer of beryllium products announced plans to modify its Delta, Utah beryllium concentrate processing facility to utilize beryllium concentrates containing as little as 7% beryllium oxide. The company plans to invest $2.5 million for this modification with completion expected in mid-1983. Implementation of this plan to consume lower grade beryllium minerals will significantly increase world reserves of beryllium concentrates.

Jan 1, 1981

By K. K. Kelley, W. W. Weller

Heat capacity measurements of akermanite ( Ca,MgSiO ) , cordierite (Mg2A14 Sig018 ) , gehlenite ( Ca₂Al₂ SiO ) , and merwinite ( Ca ,MgSiO ) were conducted over the temperature range from 50 ° to 298.15 ° K. The entropies at 298.15 K ( expressed in cal / deg mole ) were evaluated as follows : Akermanite , 50.0 ± 0.5 ; cordierite , 97.3 ± 0.9 ; gehlenite , 47.4 ± 0.4 ; and merwinite , 60.5 ± 0.5 . All four compounds have positive entropies of formation from their constituent oxides at 298.15 ° K ; the values range from 4.6 cal /deg mole for akermanite to 10.1 cal / deg mole for cordierite .

Jan 1, 1963

By J. H. Jacobs

The first authorization, in November 1940, was for a plant of only several hundred pounds capacity at Boulder City, Nev. Improvements in the process and subsequent additions to some sections have enabled the plant to produce more than 2,000 pounds of manganese per day for substantial periods. By the time pilot-plant operations were suspended in June 1945, over 1,500,000 pounds of metal had been produced. The future of electrolytic manganese production obviously depends not only on satisfactory development of methods but on availability of raw material and demonstration of valuable uses. Investigations of manganese-ore deposits in this country, made since 1938 by the Bureau of Mines, have revealed large amounts of ore suitable for making electrolytic manganese. At first the pilot plant was operated on ore from the Three Kids mine near Las Vegas, Nev. After practical features of the process had been worked out, other ores from throughout the United States were tested in the pilot plant. The purpose of this paper is to compare the results obtained on the following ores: Three Kids; Ladd mine, Tracy, Calif.; Chamberlain, S. Dak., nodules; and ore from Metals Reserve stockpiles at Deming, N. Mex.; Cushman, Ark.; and Philipsburg, Mont.

Dec 1, 1947

By W. H. Oppelt

A lignite from west-central North Dakota (Mercer County) was dried by the Bureau of Mines by the Fleissner process at saturated steam pressures to 1,500 pounds per square inch absolute (p.s.i.a.). Normally, the process is operated at pressures of 200 to 370 p.s.i.a. At the highest pressure the temperature of the saturated stearn is 596° F. The purpose of the investigation was to evaluate the influence of very high stearn pressure and temperature on moisture removal, steam consumption, and physical and chemical characteristics of the dried lignite. Two drying cycles were used: A normal cycle, corresponding to previously established standard time requirements, and an accelerated cycle, wherein time requirements were determined by boiler capacity and handling speed. Blank tests to determine stearn requirements for heating the empty autoclave were performed for each cycle and each test condition. Moisture removal, final moisture content, net steam consumption, and size stability of the dried lignite were determined.

Jan 1, 1959

By Raymond L. Lowrie

For many years it has been considered that an average of 50 percent of the coal in the deposits exploited has been recovered. Owing to many changes in mining methods during the past two decades, this study was initiated to obtain an up-to-date measurement of recovery percentage and thus establish part of the basis from which presently recoverable reserves may be estimated. Recovery percentages were determined within mined areas of 200 underground coal mines. These comprised a statistical sample selected to be representative of operating mines in relation to their significance to depletion of reserves. The results ranged from 29 to 91 percent and averaged 57.0 ± 1.7 percent (95-percent confidence limit). Six factors were identified mathematically as significantly affecting recovery percentages: (1) Pillaring system, (2) top rock and conditions, (3) bottom rock and conditions, (4) marketability, (5) coalbed thickness, and (6) productivity. Skill and attitude of mine operators toward recovery, although not measured, were probable factors. Five other variables that were tested did not show any significant relationship with recovery percentages. Also, five mining equipment features were identified, through discussions with mine officials, as affecting adversely recovery percentage at some mines.

Jan 1, 1968

By E. L. Garton

The United States Bureau of Mines has recently collected samples of crude petroleum from wells in the newly developed Joiner. Kilgore, and Longview fields of Rusk and Gregg Counties in the East Texas district, and from the Van field of the East Central district of Texas.

Jan 1, 1931

By E. L. Garton

The United Status Bureau of Mines has recently collected samples of crude petroleum from well] in the newly developed Joiner, Kilgore, and Longview fields of Rusk and Gregg Counties in the East Texas district, and from the Van field of the East Central district of Texas. East Texas Cruder The four samples of crude oil from the East Texas fields are all typical "intermediate base" crudes according to the classification given by Smith and Lane. 3 Sample 31,063 is from the discovery well in the Joiner field. This well came in on October 3, 1930, with an initial production of 400 barrels per day. Sample 31,062 was obtained from a well that was completed on February 1, 1931, with an initial production of 3,500 barrels per day. The 32 East Texas crudes are produced at an average depth of approximately 3,600 feet. which is the deepest Woodgine-sand production so far encountered in any of the Texas or Louisiana fields.

Jan 1, 1931

By Floyd D. Everett

The J. B. fluorite deposit is in the Washington mining district, southwestern Beaver County, Utah (fig. 1). Fluorite outcrops were found during 1942, and three lode claims wore located. Little work was done on the property until October 1943, at which time the Bureau of Mines started development to determine the subsurface extent of the fluorite mineralization exposed at the surface. The most prominent rocks in the J. B. mine area are porphyries, which vary considerably in composition. Dacite porphyry appears to be the most common host rock for the fluorite-quartz-calcite lenticular masses. The dacite porphyry in the area is highly brecciated over a strike length of more than 1 mile. Fluorite deposits in the brecciated zone cover a strike length of approximately 400 foot. The fluorite lenses range in length from 40 to 200 feet and in width from 4 to 10 feet (fig. 2). The Bureau of Mines work on the J. B. property was started in October 1943 and completed in October a year later. The work consisted of surface trenching by bulldozer and hand methods, shaft sinking, drifting, and crosscutting. Eleven trenches totaling 1,800 linear feet were excavated. An inclined shaft was sunk to a depth of 105 feet, and from thin shaft 577 feet of drifts and crosscuts were driven to outline the extent of the mineral deposit (fig. 3). Two hundred ninety-seven samples were taken in the surface trenches and underground workings. The locations of the samples and analyses arc shown in accompanying figures and tables. Results of metallurgical tests comprise the concluding section of this report.

Jan 1, 1950

By W. T. Benson

The nickel-bearing laterite deposits in the Pine Flat and Diamond Flat areas, Del Norte County, Calif., were investigated by the Bureau of Mines to determine the extent and nickel content of the two deposits and the amenability of the ores to metallurgical treatment. The work was based on drill-hole sampling and metallurgical tests in which attrition scrubbing and sizing, reduction roasting, and magnetic separation were used. Results of the sampling indicated that the deposits are comparatively small and are marginal or submarginal in grade. Metallurgical tests showed that no separation of cobalt from nickel and iron was made by sizing; however, a large portion of the chromium was separated. Reduction roasting and magnetic separation did result in upgrading the iron, nickel, and cobalt, and the simultaneous rejection of chromium.

Jan 1, 1963