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By P. L. Woolf

An investigation was conducted to evaluate the use of a formcoke as the total fuel in the Bureau of Mines experimental blast furnace. The formcoke performed very satisfactorily, and comparisons made with a metallurgical coke showed that the performance with the formcoke was somewhat superior under the experimental conditions used.

Jan 1, 1966

By A. W. Deurbrouck

Four samples of Pittsburgh-bed coal, of various size consist and ash content were dewatered in a pilot-size vacuum-disk filter partially enclosed with a steam jacket. Steam fed at 2.5 to 12.5 pounds per minute reduced the moisture content of the filter cakes from 2.8 to 13.8 percentage points more than normal vacuum dewatering. Approximately 1.5 pounds of steam was required to remove 1 pound of water.

Jan 1, 1966

By R. T. Sorensen

Research and testing in a small scale equivalent of a commercial flota-tion plant was completed on four low-grade, iron-bearing materials from the western Mesabi range. Closed circuit-flotation of calcium-activated silica with fatty acid collector developed data for comparison with the batch process and highlighted problems not evident from previous bench testing. The four ore samples contained from 27 to 39 percent Fe and were equally represented by nonmagnetic taconite and semitaconite type materials. Iron concentrates containing 6.0 percent, or less, SiO2 were made 5, all four samples. Of the two material types, the semitaconite was the ore amenable to treatment, yielding iron recoveries of about 90 percent as cc pared with 70 to 80 percent for the other. Pilot plant tests showed that concentrate grade made in batch tests could be duplicated in the closed circuit and demonstrated that the amount of recoverable middling iron varied considerably between ore samples. The continuous tests also showed that water temperature strongly influenced results in the treatment of one ore but apparently was of indifferent consequence in another. Progress in thickening and filtration of flotation concentrates was made through introduction of tapioca flour to serve the dual role of iron mineral depressant and flocculant.

Jan 1, 1966

By Jr. Jacobson

Thermal reactions of l-methylpyrrole, l-butylpyrrole, and l-isopropyl-pyrrole were investigated by a flow method in the temperature range of 4500 to 5750 C. Those of I-butylpyrrole and l-isopropylpyrrole were also investigated in the 3400 to 4000 C range in a static system. The I-substituted pyrroles isomerize by an irreversible reaction to 2-substituted pyrroles. A reversible isomerization reaction shifted the alkyl group from the 2-to the 3-position on the pyrrole ring. All of the isomerization reactions are homogeneous, unimolecular, nonchain, first-order reactions having similar mechanisms and transition states. There is decomposition and cleavage of the longer alkyl side chain when it is in either the 2-or 3-position giving, as products, pyrrole, 2-and 3-methylpyrrole, 2-and 3-ethylpyrrole, pyridines, and hydrocarbons. The decomposition reactions appear to be by free-radical mechanisms. Pyridine homologs are formed by the expansion of the alkylpyrrole: butylpyrrole produces pyridine, and isopropylpyrrole produces 3-methylpyridine. Approximate Arrhenius equations are given for the formation of the decomposition products.

Jan 1, 1966

By W. H. Oppelt

Two exploratory gasification tests of limited duration were made at Dorsten, Germany, with strongly coking Pittsburgh-bed coal in a fixed-bed pressure gasifier. To reduce the coking potential of the Arkwright coal, ash refuse from the gasification of Dorsten (Leopold) coal was added to pre-pare coal-ash mixtures which contained nominal 20 and 30 percent ash. Major adjustments in principal process variables at the beginning of the tests resulted in wide fluctuations in the rate of gas production, gas offtake temperature, and carbon dioxide concentration in the gas. Because a higher steam-to-oxygen ratio was used in the tests than was customarily employed for routine operation, gas production was lower, and steam and oxygen consumption was higher. After operating conditions had been improved, the results of a 12~-hour-long test with addition of sufficient ash refuse to obtain a nominal 30 percent ash concentration indicated that operation is feasible with this coal mixture using a fixed-bed pressure gasifier equipped with a rotating coal distributor and stirrer.

Jan 1, 1966

By Foster Fraas

A separator for minerals of low magnetic susceptibility and fine particle size in a water suspension is described. A ring-shaped matrix of ferromagnetic fragments rotating so as to pass successively through magnetic-field and field-free regions provides for the separation. Application is illustrated in the separation of hematite and ilmenite from quartz.

Jan 1, 1966

By J. P. Morris

A diphenyl ether calorimeter for measuring high-temperature heat contents of ferrous alloys and iron-and steelmaking slags was constructed and calibrated with specimens of molybdenum, alumina, and platinum that were heated to temperatures ranging from 1,720° to 1,875° K. The standard deviation of the calibration measurements was 0.37 percent. By measurements of the enthalpy of delta and liquid iron, the heat of fusion of iron was found to be 3,298 ±100 cal per mole.

Jan 1, 1966

By Jr. Taylor

The following heats of solution have been measured in 1.160 molal H2SO4 at 25° C: AH298, kcal./mole Be(c) + 77.44(H2SO4?47.849 H2O) H2(g) + BeSO4 (soln) -92.83 ± 0.11 BeSO4 ?(c) + 77.44 (H2SO4?47.849 H2O) BeSO4(soln) -16.45 ± 0.02 BeSO4?2H2O(c) + 77.44(H2SO4?47.849 H2O) BeSO4?2H2O(soln) -5.395 ± 0.019 BeSO4?4H2O(c) + 77.44 (H2SO4?47.849 H2O) BeSO4?4H2O(soln) 1.513 ± 0.010 Combining these data with other experimental results and data taken from National Bureau of Standards information yielded the following heats of formation at 298° K:

Jan 1, 1966

By R. W. Dalzell

The performance characteristics, efficiency, and operating pressure of jute line-brattice systems were studied under varying underground conditions; various fabric grades and installation methods were used. The test results indicate that line-brattice system efficiency is dependent upon the method of ventilation the method of installation, porosity of fabric, and size of tight rib area.

Jan 1, 1966

By Raymond L. Lowrie

Coal deposits in the Boulder-Weld County coalfield in Colorado are analyzed in relation to economic factors governing the growth, stability, and competitive potential of the coal industry. Recoverable reserves, estimated to be 571 million tons, are discussed in detail, particularly those in the Erie and Frederick Quadrangles. Geology of the coal measures, quantity and quality of water resources, and chemical and physical properties of the coal are described. Coal production factors, including mining techniques and equipment, labor requirements, transportation facilities and rates, and markets, are considered for coal's position in competition with alternate fuels. Growth of the fuels market, through increasing thermal-electric power generation in the Denver Metropolitan Area, will stimulate coal production in Colorado. Reserves of the contiguous Boulder-Weld coalfield, if mined in a sustained, year-round, high-tonnage operation, could be used to supply much of that fuel demand.

Jan 1, 1966

By Alla D. Mah

Compilation of data on materials of metallurgical interest is one of the important activities of the Berkeley Thermodynamics Laboratory of the Bureau of Mines. Recent renewed interest in metallurgy of vanadium renders the present compilation a timely guide for experimentation to improve present methods or to develop better methods of extractive metallurgy. Thermodynamic data for vanadium and its inorganic compounds have been critically surveyed, selected, and compiled into one convenient reference from which information can be readily obtained for evaluating heat balances, determining trends, and establishing limits of metallurgical processes. By indicating the direction of experimentation, this report enables the saving of time, effort, and expense which would otherwise be necessary for trial and error experimentation. Much of the data has been obtained experimentally at the Berkeley laboratory. Other data were collected through an extensive survey of worldwide literature through April 1965. Estimates were made when no data were avail-able. Data on the vanadium halides was sparse, and the results derived from existing data were at times divergent. Some of the selected values for the halides may need modification as more or better experimental data become available.

Jan 1, 1966

By E. G. Davis

The Bureau of Mines made laboratory-scale experiments to examine the technical possibilities of reclaiming manganese from slags produced by oxygen lancing of high-manganese pig iron. Ferromanganese was added to molten pig iron to yield a 4-to 5-percent manganese hot metal, which simulated a product obtainable from the blast furnace. This was injected with oxygen to reduce the metal to 1 percent or less manganese and form a slag containing about 40 percent manganese. The molten slag was water-quenched, treated with H2SO4) roasted at 660° C, and water-leached to give soluble manganese and iron sulfates. The sulfates were precipitated as hydroxides, converted to the oxide form, and smelted to produce a standard ferromanganese containing 74.6 percent Mn and 0.01 percent P. As an alternate method of manganese recovery, a manganese cell feed was prepared from the leach solutions and electrolytic manganese was produced. Direct smelting of the high-manganese slag resulted in 74.2 ferromanganese meeting ASTM specifications except for phosphorus content. The high phosphorus content of the metal and high slag-to-metal ratio obtained made this approach unattractive.

Jan 1, 1966

By James S. Browning

Research by the Bureau of Mines demonstrated that organic heavy liquid adhering to or adsorbed on fine mineral particles can be effectively removed by a novel method embracing pulping or displacement washing with hot water alone or in combination with a detergent. Displacement washing with steam alone or in combination with a detergent also was effective for removing the heavy liquid. In tests of sized minus 48-plus 200-mesh mineral charges, both the hot water washing with detergents and detergent steaming effectively reduced the heavy liquid losses on the particles to about 0.2 pound per ton of mineral or less. Centrifuging of the wash solutions permitted an almost complete recovery of heavy liquid from the solution as a pure heavy liquid product.

Jan 1, 1966

By Frank A. Peters

The Bayer process treating Jamaican bauxite was evaluated from an economic standpoint, using standard estimating methods and published data, to present a reference point for cost estimates for nonbauxite alumina processes. The estimated operating cost for a plant producing 1,000 tons of alumina a day is $47.96 per ton of alumina when charging $8 per ton for bauxite and $2.30 per hour for direct labor. The estimated fixed capital cost is $46 million.

Jan 1, 1966

By F. W. Hoertel

The effects of certain process variables on the grain size, grain type, and microhardness of vapor-deposited tungsten were established, and the near-optimum parameters and the efficacy for the vapor deposition process were determined. No significant change in the grain size or microstructure resulted from ultrasonic vibration of the substrate during deposition, from variations in the hydrogen (H2) to tungsten hexafluoride (WF6) ratio, or from small increases in reaction-chamber pressure. Near-optimum conditions were continuous deposition at atmospheric pressure, a deposition rate of 2-mils thickness/square inch of substrate area/hour, a temperature of 5500 C, and a hydrogen to WF6 ratio of 4:1. The addition, individually, of about 2 volume-percent of butane, 24 volume-percent of carbon dioxide, or 4 volume-percent of propane to the hydrogen and WF6 mixture produced deposits with the finest grain size for each gas. A corresponding increase in microhardness accompanied the decrease in grain size. The addition of gases did not alter the columnar microstructure found in vapor-deposited tungsten.

Jan 1, 1966

By Louis A. Panek

Determining the change of stress in rock based on measurements of the deformation of a drill hole is a procedure that is increasing in popularity. A closely related procedure involves the applicat10n of this principle to determine the existing stresses in a rock medium, by cutting free (core drilling) an annulus containing the drill hole. In this Bureau of Mines report, expressions are derived from which one can calculate the stress ellipsoid--the three-dimensional change of stress, or the existing three-dimensional stress field, as the case may be. Study of these equations shows that the stress components in three dimensions can be determined by measurements in only two drill holes, and yields general principles that are useful in planning an efficient program of drilling and measurement. Procedures are given for calculating the least squares estimates of the stress components and their standard errors, and for evaluating or comparing calculated values by means of standard statistical inferences.

Jan 1, 1966

By Thomas M. Garland

A field study was made by the Bureau of Mines in cooperation with oil companies to determine the feasibility of changing the injection profile of water-input wells after water breakthrough at producing oil wells. A secondary objective was to study the particle size and quantity of plugging material required to change the input profile and the methods of applying these materials. Fifty-three injection wells were treated with various amounts and types of plugging materials and the injection profile was definitely changed in most of the wells treated. Increased efficiency of water injection after treatment was indicated by tracer surveys and injection-well performance. There were some indications that the rate of water production was reduced and the rate of oil production was increased as a result of selective-plugging treatments, but ,s found that an immediate change in the rate of oil and water production did not normally occur. In many cases, beneficial results from a treatment may never be observed in the rate of oil or water production due to the many factors that affect the performance of producing and injection wells.

Jan 1, 1966

By Willard L. Hunter

The smelting of tin slags was undertaken at the Bureau of Mines Albany Metallurgy Research Center (AMRC) to produce crude columbium-tantalum ferro-alloy as a unit operation in the production of pure columbium and tantalum oxides or chlorides. Columbium and tantalum-rich alloy was prepared during short unrelated campaigns over a total period of 12 years. Tin slags from Malaya and the Congo (Geomines) were smelted. These slags were reduced by carbon in a small, single-phase, steel-making furnace} a larger three-phase, steelmaking furnace, and a three-phase, submerged-arc furnace, In all cases depleted slags were fluid and easily tapped from the furnace. However, unless diluted by iron additions, the metal product was a viscous, high-melting, heterogeneous mixture that could be removed from the furnace only by hand rabbling.

Jan 1, 1966

By D. C. Crowell

This publication presents the results of a laboratory investigation of displacement of gas by injection or imbibition of water into sandstone models under essentially isobaric conditions. A brief discussion of scaling requirements is included. The influence on residual gas saturation of independently varying the parameters of dimensional ratios of the porous media, rates and methods of flooding, surface tension, initial water saturation, and permeability is shown. Of these variables, increased initial water saturation and decreased surface tension reduced residual gas saturation significantly, whereas variations in flooding rate and dimensional ratios had no apparent effect. No correlation was evident between absolute permeability and residual gas saturation.

Jan 1, 1966

By Bernard Porter

The rate of the heterogeneous reaction between high-purity uranium metal and uranium tetrafluoride in molten lithium fluoride was measured. The apparent heat of activation for the reaction is 16.91 kilocalories per mole of UF4. A surface-controlled mechanism is suggested in which UF4 is adsorbed on the uranium metal surface. Additional UF4 reacts with the adsorbed species and the metal site to form an activated complex that decomposes to the product UF3. The reaction is an important source of metal loss in the electrowinning of uranium metal.

Jan 1, 1966