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By Synthia N. McIntosh

The U.S. Bureau of Mines investigated the feasibility of using ammonium carbamate (NH2CO2NH4) leaching to recover manganese from steel plant slag. This investigation showed that treatment of the slag in hydrogen prior to leaching enhanced manganese extraction. Up to 80 pct of the manganese and 50 pct of the iron could be extracted from a silicon steel slag that had been pretreated in hydrogen at 700° C. Two 4-h leaching stages conducted at ambient temperature with a solution containing ammonia and carbon dioxide dissolved manganese and iron as their carbamate complexes. Heating the pregnant solution to 65° to 85° C decomposed the complexes and precipitated the metals as insoluble carbonate salts. Ammonium carbamate leaching of other slags from several steelmaking plants produced lower manganese extractions, which suggests that the method cannot be applied satisfactorily to all steelmaking slags

Jan 1, 2010

By E. D. Eastman

"The factors that determine the efficiency of reduction of iron oxides by gaseous reducing agents may be considered in two classes; those which effect the equilibrium between the reacting substances end their products, and those which affect the rete of reaction. Both sets are of prectical importance, the former as influencing the maximum possible efficiency and the latter as determining what fraction of the maximum yield may be readily or profitably obtained. In addition, the thermal changes attending the reduction greatly affect the chance of successful industrial application of any such process, and knowledge of them is necessary for the intelligent design of apparatus and control of the reaction. Some aspects of each of these three divisions of the problem are discussed below.I. The Maximum Reducing Power of Fuel Gases on the Oxides of IronsThe gases that heve been considered specifically in this work are coal gas, water gas and producer gas, typical analyses” of which are given in Table 1 Of the various hydrocarbons represented in Table 1, (several being grouped or averaged as C2R4), methane is the only gas assumed to be capable of existence at appreciable pressures under the conditions of interest here. The equilibria in the several systems which may ensue when one of the above gases is allowed to react with the iron oxides, may therefore be represented in the most general case by equations of the type of the following arbitrarily chosen ones:"

Jun 1, 1923

By G. W. Elger

This report describes pilot-plant studies and an economic evaluation of a process developed by the Federal Bureau of Mines, Albany Metallurgy Research Center, to produce synthetic rutile from a rock-type ilmenite concentrate. In this process, ilmenite blended with coke and lime is smelted in an electric arc furnace to separate most of the iron as salable pig iron and to form a titania-enriched slag of low iron content, which is treated with oxygen and titanium pyrophosphate. The titanium oxides are converted to crystalline rutile; the phosphate glass contains most of the associated impurities. The treated slag is ground and leached with sulfuric acid to liberate rutile crystals, which are concentrated by physical methods. In pilot testing conducted to obtain data for a cost estimation, a synthesized product containing about 88 wt-pct TiO2 and less than 2 pct FeO was extracted from a rock-type ilmenite concentrate containing about 45 wt-pct TiO2. The estimated fixed capital cost (on a mid-1975 basis) of a plant producing 500 tpd of synthetic rutile is $28,290,100. Based on 330 operating days per year, the estimated operating cost for this process is $351 per ton of synthetic rutile. The estimated selling price of synthetic rutile made from rock-type ilmenite is $344 per ton, based on a credit of $160 per ton of pig iron and a 20 pct interest rate of return on investment after taxes.

Jan 1, 1976

By Robert M. Doerr

The oxidation kinetics of Ni-Y alloys in the range 0.04 to 8 weight-percent Y, and of high-purity Ni, were compared by the use of a sensitive volumetric apparatus. The reactions followed approximately the parabolic rate law; for oxidations in 02 at 0.5 atm and 1,200° C, the parabolic rate constant was about 0.37 + (0.064) (Y-2.11) mg cm-2 min-1/2, where Y represents the weight-percent Y in the alloy. Internal oxidation of Y occurred in the alloy specimens and the resultant Y203 particles, which were in patterns related to the eutectic structure of the alloys, served as markers showing that the subsequent oxidation of the surrounding Ni was by inward diffusion of O. The scale consisted in each case of NiO, but the inner parts of the scale on the alloy specimens included the patterned Y203 particles. The thicknesses of the inner parts of the scale depended directly on the Y concentration, and the thicknesses of the Y2O3-free outer parts of the scale were inversely related to the Y content of the alloys. There is thus a relationship between the thickness of the outer part of the scale and the protectivity of the scale. Outward diffusion of Ni and inward movement of 0, from the inner boundary of the Y2O3-free part of the scale, is proposed as a mechanism for these results.

Jan 1, 1966

By R. R. Wells

An important activity of the Bureau of Mines is the continual search for new sources of minerals. As a part of the investigation of strategic mineral deposits in the United States, samples of mercury ores were submitted to the Ore Dressing sections of the Salt Lake City and Albany stations for metallurgical testing. This paper gives data summarizing the results obtained from laboratory beneficiation studies of mercury ore samples submitted during the period 1941 to 1947. Ores tested included three from Jackson County, Oreg., one from Valley County, Idaho, one from Storey County, Nev., and one from Sonoma County, Calif. In general, the ores from Oregon were not amenable to concentration by flotation because of intimate association of cinnabar with other minerals or because of extremely low grade. One Oregon ore was amenable to direct distillation provided lime was added to reduce corrosion of the retort.

Jan 1, 1950

By F. W. Lee

The paramount importance of water to life of all forms on the earth is too well known to require elaboration in this brief paper. It has repeatedly been termed the most valuable of all our mineral resources. Its importance is justifiably recognized in the extensive areas covering the earth which receive sufficient rainfall to sustain a relatively luxuriant vegetation; but in those areas where rainfall is insufficient to support anything but a relatively meager plant growth, the location of a water supply and its development become of even more vital interest to those attempting to obtain a living from the soil. Geological investigations concerning the water supply of the United States have been most extensive, important work having been accomplished by Federal, State, and local governments and by private enterprise. A casual examination of the titles of the 739 Water-Supply Papers published by the United States Geological Survey3/ alone testifies 'to the vital nature of our water resources and the extensive work that has been done on them.

Jan 1, 1936

By John B. Gayle

The suitability of fluid petroleum coke as a blending agent for producing metallurgical coke has been investigated using the Tuscaloosa and sole-heated experimental ovens. From the results of tests with three representative blends, it has been fond that additions of fluid petroleum coke effect the following changes: (1) Increase in size, resistance to shatter, and apparent specific gravity of cokes produced; (2) little or no change in coke hardness and stability or in the amount of breeze formed; (3) increased charge density; (4) modification of expansion characteristics of blends charged; and (5) decreased ash and increased sulfur contents of blends charged and cokes produced. Substitution of a calcined sample of fluid coke of greatly reduced sulfur content resulted in a coke of inferior physical properties. This effect indicates that additions of the calcined product should probably be limited and that other methods for producing a low sulfur fluid coke should be considered.

Jan 1, 1956

By Nicholls Harry R.

The Bureau of Mines studied the effect of varying the, diameter of explosive charges on the generation and propagation of strain waves. The parameters compared were strain amplitude, impulse, energy, and pulse shape. Three different explosives were detonated in three different charge diameters. Charges of cast 50/50 pentolite-detonated at the same velocity in 5-, 2.5-, and 1.5-inch diameters. Charges of ammonium nitrate-fuel oil prills and 45-percent semigelatin dynamite showed a strong detonation rate-diameter dependency. Detonation of these two explosives was considered nonideal. Differences in the diameter of the charge caused less difference in the strain-generating abilities of pentolite than in those of the other two explosives. This was also true for impulse and energy. Rise and fall times of the strain pulses for all three explosives were proportional to detonation time and cavity volume, respectively.

Jan 1, 1966

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Dec 1, 1964

By P. C. Good

This Bureau of Mines report describes the preparation of phosphoric acid directly from phosphate ore, without prior beneficiation, in a small-scale, continuous process research unit, as part of an effort to improve minerals and metals recovery from domestic resources while minimizing environmental effects. Three phosphate-matrix samples, ranging in grade from 18.2 pct P20S5to 11.9 pct P205, were dry-fed at a rate of 1.82 kg/hr (4 lb/hr) to a continuous-circuit, 12-liter, single-tank digester to yield phosphoric acid and byproduct gypsum filter cake. Comparison with earlier data shows that a significantly improved filtration rate was attained in a single-tank reactor compared with that attained in a five-tank reactor train processing the same ore. Iron and aluminum impurities in the product phosphoric acid averaged about 60 pct higher than amounts reported in commercially prepared, concentrate-derived acid. All gypsum filter cakes prepared had a firm, sandy texture, rendering them physically suitable for stacking or landfill use. Introduction of dry attritioning and air classification approximately doubled the attainable filtration rate when the dry-beneficiated product was digested. In air classification, there was a 12-to 14-pct P205 loss. Depending on the technique used and the matrix grade, overall P205 recovery ranged from about 72 to 89 pct.

Jan 1, 1979

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Jan 1, 1965

By Ralph H. Whaite

The Bureau of Mines program for microfilming maps of abandoned mines in the Pennsylvania anthracite region is described. A catalog of the maps that have been microfilmed in the Eastern Middle anthracite field--the first area to be covered in the program--is presented. Additional catalogs will be published as significant mining areas are completed.

Jan 1, 1965

By R. R. Brown

The solubility and the activity of aluminum chloride hexahydrate, A1C13?6H2O, in aqueous solutions were determined as a part of the Bureau of Mines, U.S. Department of the Interior, research to improve mineral processing technology for recovering alumina from low-grade domestic resources. The solubility of A1C13 in pure water was found to be 31.09 and 31.77 wt-pct at 25° and 85° C, respectively, and decreased drastically to 10 and 0.1 wt-pct when the respective amounts of 20.3 and 37 wt-pct hydrochloric acid (HCI) were added in solution. The equilibrium constant for the solubility of hexahydrate, activities, and activity coefficients of A1C13 and H2O were calculated and compared with the results from the available methods of estimation. The results were shown to be useful in leaching nonbauxitic ores for extraction of alumina by changing the solubilities of component salts upon addition of HC1. Simultaneous solubilities of A1C13, FeC13, KC1, and NaC1 in solutions of HC1-H2O were also determined and their effects on the purity of A1C13?6H20 crystallized from mixed salt solutions are briefly discussed.

Jan 1, 1979

By F. E. Block, T. T. Campbell, D. Z. Hobbs

Several methods were investigated for the preparation of high- purity elemental boron in an attempt to develop a feasible process for producing boron on a large scale . In the work described in this report , the metal was prepared by metering boron trichloride gas into a crucible containing molten metal reductants . It was necessary to remove reaction byproducts by acid and aqueous leaching . Magnesium and sodium were tested as reductants , but best results were achieved using lithium or zinc as reductants . Contaminants originating from the materials of construction were the chief impurities in boron made by this method . Impurities ranged from 0.5 to 5.0 percent . Impure boron ( 85 to 90 percent ) was also prepared by the magnesium reduction of boron trioxide in a thermite - type reaction . This product contained magnesium as the chief contaminant . Impure boron made in this way could be upgraded by fusing with potassium fluoborate or potassium acid fluoride . After acid leaching the fusion cake , a product containing 95 to 97 percent boron was obtained . Analytical techniques for accurate determination of impurities in elemental boron are a major problem , requiring solution before a valid comparison can be made of the quality of boron prepared by these various methods .

Jan 1, 1964

By M. E. Adam

This report describes the construction and testing of large (30 ft high by 55 ft wide) stopping and overcast structures in an oil shale mine. The work was undertaken to develop construction techniques and cost data, and to measure leakage rates on full scale structures in an oil shale mine. A design data base was developed by reviewing industry practice, oil shale industry plans, and technical literature. Alternate layouts for room and pillar mining were examined to find ways to reduce the size and number of ventilation control structures. Six full size stoppings and one overcast were built in the Colony Pilot Mine. Leakage rates were measured using both SF6 tracer gas techniques and the ?brattice window? method. The leakage was measured both before and after a full scale face blast. Blast air pressures were measured across two of the stoppings. Cost and leakage data were used to evaluate the projected overall performance of various combinations of the stoppings in a two-panel oil shale mine.

Jan 1, 1986

By G. M. Potter

During the investigation of the occurrence of manganese deposits in the western United States, examining engineers of the Bureau of Mines collected samples from four properties in Siskiyou and Mendocino Counties northern California. As the ores were too low-grade to be acceptable to manufacturers of ferromanganese, beneficiation studies were made between 1941 and 1945 to determine the amenability of the ores to concentration. The Johnson and Reynolds properties are near Fort Jones Siskiyou County. The ore occurs in a number of small lenses in that area. Samples were taken for testing for amenability to treatment in a small custom-gravity plant, tentatively planned. by the Waiter Johnson interests of San Francisco. A 2-ton representative sample was obtained from numerous exposed portions of an outcrop on the property of the Mayland Mining Co. The Mayland mine is about 8 miles from Sawyers Bar in Siskiyou County. The ore body consists of stringers and irregular masses of oxide, and. silicate ore scattered through quartz, which these minerals have replaced.

Jan 1, 1952

By G. L. Hundley

An anhydrous chlorination process has been developed by the Bureau of Mines for the production of copper, ferric oxide, and sulfur from chalcopyrite. The first part of the process is a chlorination step in which elemental sulfur and a mixture of iron-copper chlorides are produced. This paper describes the second step of the process in which the copper and iron chlorides are reacted with oxygen to selectively convert the iron chloride to ferric oxide and chlorine leaving the copper in the chloride form. The chlorides are pulverized and dropped countercurrent to a flow of oxygen in a vertical 20-cm-diam. reactor at 800° C. By leaching with brine, the copper chloride may be separated from the insoluble iron oxide and reduced to copper powder by electrowinning. It has been demonstrated that 70 to 80 pct of the iron can be converted to oxide in a single-stage operation with a chlorine content in the offgas of 80 pct. After removal of the oxygen, this chlorine could be recycled to the chlorination step. A two-stage operation will convert 98 to 99 pct of the iron in the mixture to insoluble oxides. The offgas from the second stage contains 70 pct chlorine.

Jan 1, 1974

By N. S. Dalal, A. H. Hoffman, X. Shi, D. E. Banks, J. K. H. Ma, Y. Rojanasakul

Excessive production of reactive oxygen radicals by alveolar macrophages is proposed to play an important role in oxidative lung injury. A major product of oxygen radical formation is the highly reactive hydroxyl radical (•OH) generated via a biologic Fenton reaction. In addition to its known ability to induce lipid peroxidation, recent studies have suggested that the •OH may exert its cytotoxic effect through the alteration of [Ca2+], homeostasis. To test this potential mechanism as well as to investigate the relationship between •OH and Ca" overloading in cytotoxic injury, isolated rat alveolar macrophages were exposed to externally generated radical system, H2O2 (0.01 to 1 mM) and Fe (1 mM) and their [Ca2+] levels and cell injury were monitored using quantitative fluorescence microscopy with the aid of the specific Ca" indicator, Fura-2, and membrane integrity indicator, propidium iodide. Electron spin resonance measurements using the spin trap 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) confirmed the production of the .OH radical by this system. Upon the addition of the radicals, the macrophages displayed a rapid initial rise in [Ca2+] which was followed by a slower but more pronounced [Ca2+], elevation that reached a level 3 to 5 times higher than the basal level. This process preceded cell death as evident by nuclear propidium iodide fluorescence. Depletion of extracellular Ca" inhibited both the [Ca2+], response and cell injury. Preincubation of the cells with the Ca" channel blocker verapamil or .0H radical scavenger mannitol similarly inhibited the [Ca2+], rise and loss of viability. Firefly luciferase assay of cellular ATP content demonstrated that the alterations in [Ca2+], following .0H treatment preceded the depletion of ATP. Changes in membrane potential caused by Na* substitution with K* had no significant effect on either the unstimulated or stimulated [Ca"], levels. Taken together, these measurements indicate that .OH-induced injury in alveolar macrophages is associated with the alteration in [Ca2+], homeostasis. The mechanism of •OH-induced [Ca2+] loading is not due to nonspecific membrane damage or energy depletion, but mainly due to an increase in Ca2+ influx through Ca2+ selective channels. This Ca2+ over-load state as well as energy depletion caused by the oxidant may activate certain cellular degradative processes leading to cell injury and death.

Nov 1, 1995

By Erich K. Bender

This report summarizes work performed under Phase I of USBM Contract No. H0366024, Noise Reduction of Jumbo Mounted Percussive Drills. Four drills -Gardner-Denver D93LAR and DH123 and Ingersoll-Rand 0475 and VL120 models were measured at the two manufacturers? test sites; data are given in terms of characteristic noise and vibration levels. A survey of percussive rock drill users is reported. The rationale for the choice of a demonstration drill, the Gardner-Denver DH123, is given and a desired noise reduction goal is established.

Jan 1, 1976

By A. D. Garman

This digest of Brazilian mining law is based upon Decree 4265 of January 15 , 1921 , and its regulation , Decree 15,211 of December 28 , 1921. Unless otherwise stated , the references are to the latter exclusively , since it includes practically everything contained in the law itself . It should be borne in mind that these regulations do not necessarily apply to mines other than those on private and national land . Each State of the Union is free , in respect to State land , to regulate or interpret the national mining law , which is very general in its terms , as it sees fit . Whether such local regulations are anywhere in force with respect to the law of 1921 the bureau has not been informed . Article 64 of the Constitution indicates that only such portions of territory as are required for the defense of the frontiers , for fortifications , military constructions , and federal railways belong to the Union . Lessees of such lands , unless in debt to the Treasury , have preferential prospecting rights for one year ( art . 28 ) . This carries with it the right to work any mines discovered (Law , art . 12 ) .

Jul 1, 1930