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By R. G. Sandberg

The Bureau of Mines investigated a hydrometallurgical procedure to recover gold, silver, and byproduct lead from a complex lead-zinc sulfide ore. A ferric chloride (FeCI3) preleach, at 40° C in 6 h, extracted about 50 pct of the zinc and formed insoluble silver and lead chlorides. Subsequent acid thiourea leaching, for 1 to 3 h at 40° C, extracted about 85 pct of the gold and silver. Lead chloride was solubilized from the remaining residue with NaCI brine solution at 55° C in 1 h. Lead metal was recovered from the brine solution in an electrolytic cell with an anion perms elective membrane at a current efficiency of 95 pct and current density of 100 A/m2. Spent FeCl3 leach solution was reoxidized in the anode compartment at a current efficiency between 75 and 95 pct.

Jan 1, 1986

By Leo J. Neill, O&apos

Abrasives are essential to the manufacture of munitions - airplanes, gas, shells, tanks, and in fact every product that involves metal forming or finishing. An indication of the importance of abrasives in the national defense and aid-to-Britain programs is the close peace-time correlation between demand for abrasives and automobile production, which in recent years has consumed more than 35 percent of the total output of abrasives. Unprecedented demands on the abrasives industry are forecast by the rapid expansion in airplane output, tie increased mechanization of all armed forces, and the consequent speeding up not only of the factories where finished munitions are made but also of the steel mills and other factories were additional large quantities of abrasives are needed for snagging or rough-grinding semifinished products before they can be used by the fabricators. A recent survey by the artificial abrasives manufacturers indicates that they can readily increase their output 75 percent compared with the previous peak of 1937 without building new plants. By overhauling production schedules, their maximum production possible could be increased to 182 percent of the 1937 output, and the nature of the industry is such that plant capacity could be increased rapidly if need therefor should arise. No figures on the estimated requirements for abrasives in 1941 or 1942 have as yet been compiled, but the industry feels that it can meet demands as they develop.

Jan 1, 1941

By Robert W. Smith

In a certain application2/ it was necessary to compute the beta function B(p, q) for a certain set of values p and q. Since t he set of p and q values was much mo re finely spaced than those in any published tables, the authors decided to make their results available in this report. In connection with this application the functionB(p, q) was needed at various points in the p, q plane at intervals of 0.05, 0.05<p = q< 10.00. Fletcher, Miller, and Rosenhead2/ state that the only tables available in the desired range are those of Rearson.4/ However, the interval used by Pearson was not small enough for the present application. For this reason it was decided to calculate B(p, q) for p = q =0.05 (0.05) 10. 00.2/ This table is published because of the fundamental importance in mathematical analysis of the complete beta function.

Jan 1, 1953

By J. W. Higgs

This paper, describing the operation of the Gifford Hill & Co. plant at Hoot Spur near Texarkana, is one of a series being prepared for and published by the United States Bureau of Mines on methods and costs of mining and preparing gravel and sand throughout the United States. These tapers are designed to disseminate technical information regarding the methods used. The cost tabulations represent local operating expenditures only and not total production costs. Although the publication of total costs might not be advisable in some instances yet a knowledge of operating costs is essential to the technical discussion and study of methods employed. The attention of the reader is specifically called to this differentiation in order that no misunderstanding of the scope of the cost tabulation shall ensue. The plant described combines some features of dredging and some of dry-pit operation, as material is excavated in a dry pit with a drag line, hauled to the plant in standard-gage cars, and then pumped. This operation should be of special interest to operators whose deposits contain a large quantity of clay.

Jan 1, 1936

By L. Mark Irwin, R. A. Marsyla

The objective of this laboratory investigation was to develop a mattesmelting process for the recovery of copper from industrial smelter dusts . Experimentation was conducted on three samples of Cottrell precipitator dust from a northern Michigan smelter with variations in the following conditions : Temperature , charge composition , pelletization , and moisture content . Based on chemical analyses of the furnace slags , poorest recovery of copper was effected in smelting dry charges regardless of composition . Some improvement was noted with uniformly moistened charges and still more with pelletized (but dry) mixes , but best results were obtained from smelting moist , self - fluxing pellets . Under favorable conditions , experiments yielded furnace slags with an average copper content of only 0.15 percent , which is well below that of industrial copper reverberatory slags .

Jan 1, 1963

By R. Barany

Thermodynamic calculations pertaining to the minerals gibbsite, kaolinite, halloysite, and dickite have been hampered by the lack of adequate heat and free energy of formation data. Previous data for gibbsite were highly uncertain, and there were no data for the other three substances. By use of hydrofluoric acid solution calorimetry, the Bureau of Mines derived heat of formation values from the elements and from the oxides for the four substances, and the data were combined with known entropy values to obtain the corresponding free energies of formation. The results show that gibbsite and halloysite are thermodynamically unstable with respect to the oxides (a- alumina, a- quartz, and liquid water) at 298.15° K,, while kaolinite and dickite are only moderately stable (to about the same degree), The instability of halloysite, in comparison with kaolinite and dickite, results in a 60°-lower equilibrium decomposition temperature.

Jan 1, 1961

Objective: To enable mine operators and mine inspectors to make quick and accurate measurements of the explosible nature of coal and rock dust mixtures.

Jul 1, 2008

By Perry G. Cotter

The objective of this investigation was to synthesize and investigate the properties of a high-temperature refractory material based on a combination of boron, silica, and magnesium. A magnesium-thermic reaction was used for the synthesis. X-ray examination of the product indicates that the crystalline portion of the composition is a combination of magnesium borides, magnesium silicate, and magnesium orthoborate. Chemical analysis of a representative sample shows, in weight-percent, boron 17.6, silicon 23.9, magnesium 17.8, and chromium 0.5. The balance is largely oxygen. The composition is resistant to high temperatures under oxidizing conditions and is stable in water, hydrochloric acid, and hydrogen. It has a low density (less than 3 grams per cubic centimeter) and a hardness value in the range of quartz. It has a melting point above 1,700° C. and can be hot-pressed to shape in the temperature range between 1,200° and 1,350° C. The properties described in this paper indicate that the material may have some uses as a high-temperature refractory, and because of its boron content it may have some value as a thermal-neutron-absorption material.

Jan 1, 1961

By C. A. Herbert

Timber decay is due largely if not wholly to a fungus growth on the timber from which it derives&apos; food; a warm, moist atmosphere is necessary for rapid growth. The decay is spread from infected timber to sound timber by countless microscopic spores or seeds given off by the fungus growth and carried by air currents or by long, cottonlike threads, which spread from timber to timber. Haulage roads in most mines in the central coal fields are also return aircourses; hence moisture and temperature conditions are ideal for the rapid decay of mine ties and mine timber. Possibly the return air, which contains a higher percentage of carbon dioxide than normal outside air, also stimulates the growth of fungi. Those familiar with coal mining have observed the more pronounced growth of fungi and decay of timber in poorly ventilated worked-out sections of mines where the air is moist and where usually the percentage of carbon dioxide in the air is considerably above normal.

Jan 1, 1934

By Bill M. Stewart

To decrease the potential for fine coal waste slurry impoundment failures, the Bureau of Mines investigated a new disposal technique. The fine coal waste slurry is rapidly thickened (i.e., dewatered) and deposited on a slightly sloping surface. To accomplish rapid dewatering, a chemical flocculation system using polymers was developed to treat the fine coal waste slurry stream. The fine solids formed flocs, settled from suspension, and rapidly released excess water. During the last 5 days of the field test, slurry flowing at rates from 498 to 675 gal/min with a specific gravity range of 1.15 to 1.33 was successfully treated and dewatered. During this period, untreated slurry had an average moisture content of 227.4 pct (30.7 wt pct solids). The effectiveness of the dewatering system was determined by monitoring the moisture content of the deposited waste with respect to time. Sixty-five hours after ending the field test the average moisture content was 54.9 pct (64.5 wt pct solids); 68 days after the field test the average moisture content was 28.8 pct (78.0 wt pct solids).

Jan 1, 1986

By T. E. Gray, A. W. Deurbrouck

This report describes the preparation characteristics of significant coalbeds in Kanawha County , W. Va . It is one in a series of Federal Bureau of Mines reports planned to determine coals suitable for producing metallurgical coke , either as mined or after beneficiation . Almost 9.4 million tons of coal was produced in Kanawha County , W. Va . , in 1959 , of which about 67 percent was cleaned mechanically in 10 cleaning plants . It has been estimated that more than 5,505 million tons remain in the county . Samples were collected from Pittsburgh , Stockton - Lewiston , Winifrede , Cedar Grove , Peerless , Upper Kittanning , Coalburg , Powellton , Eagle A , No. 2 Gas , and the Lower Kittanning beds . These beds were selected by the Bureau based on current production rates and estimated minable reserves . Float - and - sink tests of the samples collected from Eagle A , Peerless , Cedar Grove , Winifrede , and No. 2 Gas beds show that these coals at one location each are suitable for metallurgical use without washing . Lower Kittanning bed at four locations ; Pittsburgh , Stockton - Lewiston , and No. 2 Gas beds at two locations each ; and Coalburg , Powellton , Winifrede , Peerless , Upper Kittanning , and Cedar Grove beds at one location each can be upgraded to metallurgical quality by mechanical cleaning . Crushing the samples to 3/ 8- inch top size increased yields substantially at 1.30 specific gravity of Pittsburgh ( 17.5 percentage points ) and Upper Kittanning ( 13.0 percentage points ) beds and increased yield for the other beds sampled to a lesser amount . At this specific gravity , finer crushing caused In the 1.58 specific gravity float a general decrease in ash and sulfur . fractions of the other samples tested , most of the yields , and ash and sulfur contents , were lowered slightly by finer crushing .

Jan 1, 1963

By M. Howard Berliner

The Harding pegmatite dike is well known for the production of spodumene and lepidolite in the period 1920 to 1930. It attained greater prominence during the last war by being the largest producer of domestic tantalum ore from the rare mineral microlite. The deposit is believed to be the only proved reserve of tantalum ore in the United States today. In 1943 the main portion of a large tantalum-bearing zone in the Harding dike was developed by the Bureau of Mines with the assistance of the Federal Geological Survey. Analysis of this zone from 39 diamond drill holes and quarry exposures showed a large deposit containing 2 pounds of microlite per ton and 21 percent spodumene, In September 1948, the Bureau of Mines resumed development of the deposit with a view to extending the tantalum-bearing zone farther to the southwest or delimiting the ore body. Seven diamond-drill holes failed to penetrate the ore zone in its southwestward projection, Much of the following general information is summarized from the report on the first exploratory work of the Bureau of Mines by John H. Soule.2/

Jan 1, 1949

By W. R. Moorehead

This paper, describing the mining methods and colt at the New Indria quicksilver mine, is one of a series of similar papers being prepared by the Bureau of Mines on various mines in the United States. The New Idria mine lies at an elevation of 3,500 to 4,200 feet in the Coast Range of San Benito County, Calif. The property is accessible by automobile stages from Gilroy or Hollister via Tres Pinos. Tres Pinos, 65 miles northwest of the mine, is the nearest railroad point.

Jan 1, 1931

By Robert W. Geehan

"INTRODUCTION The Bureau of Mines has been investigating deposits of critical and essential minerals in the United States since 1939. Many of the mines were developed.A preliminary examination of the Sultan mine was made in January 1945 by the author, who recommended investigation by drifting and crosscutting. The Bureau conducted a project at the mine from April to June 1946. Claims investigated are in sec. 20, T. 25 S., R. 58E., Mount Diablo base and meridian, in southern Clark County, Nev., about 7 miles southwest of Good-springs.The Sultan mine has been an intermittent producer of zinc-lead-silver ore since 1910. During World War II, ore was shipped to the Government stock pile at Jean, Nev., and to the International Smelting& Refining Co.'s smelter near Salt Lake City, Utah. Throughout the past year, ore has been milled and the concentrates have been shipped to the smelter."

Sep 1, 1947

By J. W. Griflith, P. A. Mack, C. M. Lang, S. Riling

"N-acetyl-beta(B)-D-glucosaminidase is a N-acetyl-beta((B)-D-glucosaminidase enzyme se¬creted by alveolar macrophages in response to phagocytosis of particulate material. Alveolar macrophages participate in the degradation and fibrosis of pulmonary tissue that results in pneumoconiosis. Known quantities of four characterized respirable dusts were bronchoscopically placed into the right caudal lung lobe of macaque monkeys. Bronchoalveolar lavage (BAL) samples were collected from dust-exposed right lung and unexposed left lung of the same individuals at 2-week intervals for 12 weeks after dust instillation. The samples were tested for N-acetyl-B-D-glucosaminidase activity to determine if the enzyme levels could serve as an indicator of pulmonary injury induced by generic coal dusts when compared to known fibrogenic and nuisance dusts. Installation of generic quartz, anthracite, or TiO2 dusts produced significant elevations of enzyme activity and increased numbers of macrophages in the dust-exposed lobes. Elevations in enzymatic activity and macrophage numbers were greatest in response to generic quartz dust. These results suggest that quantitative levels of N-acetyl-B-D-glucosaminidase activity may be a useful indicator of acute and chronic lung injury following exposure to fibrogenic and nonfibrogenic dusts.IntroductionCoal workers pneumoconiosis (CWP) is an occupational pulmonary disease associated with the inhalation of coal mine dust. An important external factor in the development of CWP is the composition of the respirable coal mine dust. A cause-and-effect relationship exists between coal mine dust and CWP, but it has not been shown that exposure to generic coal dusts will cause CWP [12]. Numerous immunological, biochemical, and cellular changes occur in CWP; however, in this study, only N-acetyl-beta(B)-D-glucosaminidase (NAGase), protein, and alveolar macrophages (AM) will be examined [7, 32, 33]."

Dec 1, 1996

By Jr. Herty

Manufacturers and consumers of steel have come to realize during the past few years that cleanliness is of great importance in steels which must meet rigid specifications for various physical properties. Of equal importance is the consistent production of steel which is uniform in these properties. For maximum utility, steels should be uniform not only from heat to heat, but also from ingot to ingot and within each ingot. In the manufacture of killed steels such as the higher carbon forging grades, uniformity as indicated by the usual chemical analysis is easy to obtain, provided that a normal top discard is taken, as is always the case in steels poured with hot-top practice. No such uniformity, however, holds true for the nonmetallic matter, which consists for the most part of the products of deoxidation of the steel. For a large tonnage of steels which go into articles manufactured by deep-drawing processes, killed steel has never been successfully applied because with the present deoxidation practice, low-carbon killed steel is almost invariably extremely dirty. To obtain the desired qualities for deep drawing, the steel is rimmed, - that is to say, deoxidized with manganese and perhaps a small amount of aluminum, - the resultant product being of high purity in the skin of the ingot, but very badly segregated at the center of the ingot, particularly in the upper-central section. This segregation necessitates a very heavy top discard, and one of the major segregates is carbon which renders the steel too hard to draw properly. If clean, low-carbon killed steel could be made successfully, much better ingot yields would be obtained than by the present rimming steel practice. Furthermore, banded structures and outside and inside seams, which are undoubtedly due in a large measure to blowholes in the ingot, are defects which are very difficult to control in rimmed steel.

Jan 1, 1931

By John E. Pahlman

The Bureau of Mines conducted column-leaching tests on 25 domestic Mn ores to determine the feasibility of extracting Mn by in situ or heap leaching with dissolved sulfur dioxide (S02) solutions. The ores tested were obtained from deposits in Arizona, Arkansas, California, Colorado. Maine, Minnesota, Nevada, and South Dakota. Dissolved S02 was found to be effective for leaching Mn; extractions greater than 90 pct were obtained with solution application rates of 1 mL/min from uncalcined, minus 2.5-plus 1.3-cm ore pieces. Leaching these ores with solutions containing only 5-wt-pct S02 and no added H2S04 resulted in Mn being selectively extracted over Fe except when Fe was present as goethite or siderite. Ca solubilization was inhibited by controlling the solution application rate (1 mL/min). The rate of leaching was found to be principally dependent upon the rate at which the leaching solution can penetrate the ore, since the solubilization of Mn upon contact with S02 was observed to be rapid. Despite low water permeabilities of the ores (as low as 10-2 to 10-4 darcy). greater than 90 pct of the Mn was extracted from even the largest ore pieces tested (approximately 10 cm in diameter). It appears, therefore. that leaching Mn opens up the pores, allowing penetration of the leach solution into the ore pieces.

Jan 1, 1988

By C. H. Herty

Manufacturers and consumers of steel have come to realize during the past few years that cleanliness is of great importance in steels which must meet rigid specifications for various physical properties. Of equal importance is the consistent production of steel which is uniform in these properties. For maximum utility, steels should be uniform not only from heat to heat, but also from ingot to ingot and within each ingot. In the manufacture of killed steels such as the higher carbon forging grades, uniformity as indicated by the usual chemical analysis is easy to obtain, provided that a normal top discard is taken, as is al¬ways the case in steels poured with hot-top practice. No such uniformity, however, holds true for the nonmetallic matter, which consists for the most part of the products of deoxidation of the steel. For a large tonnage of steels which go into articles manufactured by deep-drawing processes, killed steel has never been successfully applied because with the present deoxida¬tion practice, low-carbon killed steel is almost invariably extremely dirty. To obtain the desired qualities for deep drawing, the steel is rimmed, - that is to say, deoxidized with manganese and perhaps a small amount of aluminum, - the resultant product being of high purity in the skin of the ingot, but very badly segregated at the center of the ingot, particularly in the upper-central section. This segregation necessitates a very heavy top discard, and one of the major segregates is carbon which renders the steel too hard to draw properly. If clean, low-carbon killed steel could be made successfully, much better ingot yields would be obtained than by the present rimming steel practice. Furthermore, banded structures and outside and inside seams, which are undoubtedly due in a large measure to blowholes in the ingot, are defects which are very difficult to control in rimmed steel. These defects would be minimized by clean killed steel.

Jan 1, 1931

By John W. Frey

Although there are certain general uniform provisions in the laws ... of the several Provinces of Canada the differences are so great that it is considered advisable to present digests of separate mining laws rather than a digest of Canadian mining law as an entity . This analysis , accordingly , has been divided as follows : Nova Scotia , New Brunswick , Quebec , Ontario , British Columbia , and a group of Provinces under Dominion Law .

Sep 1, 1930

By Gerald W. Elger

This report describes development of the fusion-leach crystallization precipitation process for producing a hafnium content feed material for hafnium-zirconium separation plants. Mixtures of zircon, potassium silicofluoride, and potassium carbonate (or potassium chloride) were fused to prepare soluble potassium zirconium hexafluoride-potassium hafnium hexafluoride salts. High extraction of these salts was obtained by countercurrent leaching the fused material in dilute hydrofluoric acid. About one-half of the hafnium was recovered in hafnium-enriched mother liquor by cooling clarified lead: liquor to crystallize most of the zirconium salt. Additional hafnium was recovered from the primary crystals in a multiple dissolution-recrystallization step. Hafnium-enriched oxides having a hafnium-zirconium ratio of more than three times that of zircon were precipitated from the combined mother liquors. The hafnium and zirconium recoveries in the precipitate were 83 and 24 percent, respectively. About 71 percent of the zirconium and the remainder of the hafnium were recovered in potassium zirconium hexafluoride crystals of low-hafnium content.

Jan 1, 1966