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By P. C. Good

High-purity chromium was prepared in massive form by the electrolysis of chromium trioxide solution at high temperatures. The metal thus obtained, containing 50 to 150 p.p.m. of oxygen, 20 p.p.m. of nitrogen, and traces of metallic impurities, could be hot-worked to rod and sheet and drawn to wire ductile at room temperatures. Optimum concentrations and operating conditions were established for the deposition of chromium from chromic acid baths containing sulfate, fluoride, and silicofluoride ions. Current efficiencies of 13 percent were attained with baths containing sulfate ion, and efficiencies of 40 to 44 percent with baths containing fluoride and silicofluoride ions. Cation exchange resins were used for removing metallic impurities from chromic acid solutions containing sulfate ion; solutions containing fluoride and silicofluoride ions were purified by recrystallization.

Jan 1, 1960

By John Dixon

This paper is one of a series on milling methods and costs being published by the Bureau of Mines. Acknowledgment is made to J. B. Tyrrell, managing director, and Wm. Sixt, manager of the Kirkland Lake Gold Mines, for permission to publish this article. The Kirkland Lake Geld Mining Co.'s mill is located on Government Road at the west end of the productive part of the Kirkland Lake mining area, 1 mile west of the village of Kirkland Lake. The crushing plant is connected to the shaft house of No. 2 shaft, which is now the only operating shaft.

Jan 1, 1931

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 L. A. Grant

This paper describing the concentrator practice of the Montana Mines Corporation at Helena. Mont., is one of a series of articles on milling methods and costs being prepared by the United States Bureau of Mines. The Spring Hill mine and mill are located 4 miles south and west of Helena, Mont., near the head of Grizzly Gulch. The mine portal is on the east slope of the gulch, and the mill is directly opposite on the west slope. Grizzly Gulch is one of the tyro gulches which unite at the south end of Helena to form Last Chance Gulch, on which the main street of Helena is built.

Jan 1, 1931

By B. M. Bird

For several years the U.S. Bureau of Mines and the University of Washington have been cooperating, in a study of coal tabling. The first pert of the work consisted of experiments using, one of the commercial-sized coal washing tables in the laboratories of the College of Mine. As an outgrowth of this work, hindered-settling classification has been successfully applied in the tabling of coal4, and several important improvements, mainly in the riffling, have been made in the table itself. Both of these developments have resulted in increasing the rapacity and efficiency of the coal-washing table. In order to facilitate further progress in this work an investigation has been undertaken to throw more light on the mechanism of table separation. The final separation of a table is obviously the resultant of several operations; namely, stratification, removal of the top strata or parts of them as washed coal by the cross-flowing water, and removal of the bottom strata or parts of

Jan 1, 1929

By R. E. Heithecker, Van A. Mills

"Crude oils are capable of dissolving quantities of gas under pressure. This fact has been known for some time, but questions have arisen as to the effects of gas in solution upon the characteristics of the oil. Previous investigations4 show that gas in solution in an oil affects the viscosity and surface tension of the oil, but the effects on the volume and A. P. I. gravity of the oil have not been known. The results given in this report show that there is a decided change both in volume and in the A. P. I. gravity of the oil due to the solution of the gas in the oil under pressure. As gas is dissolved, the volume of the oil and the A. P. I. gravity increase. The converse of this phenomenon is also true: if the gas is released from a saturated oil, there is a shrinkage in volume and a decrease in A.P.I. gravity due to the release of gas from solution. However, various oils show marked tendencies to retain a portion of the dissolved gas upon releasing the pressure to that of the atmosphere. This retained gas has an appreciable effect on the volume and A. P. I. gravity of the oil because the oil does not resume its initial volume or gravity while it retains dissolved gas. In a sense the oil has been ""freshened"" and will not return to its original or weathered volume until it loses some of the lighter fractions. Wiggins5 has shown that a fresh oil decreases both in volume and in gravity because of the weathering of the lighter fractions while the oil is standing in storage tanks.This paper includes data attained during the determination of volume and gravity correction factors to be applied in the oil recovery investigations of the Bureau of Mines. Three oils having a wide range in gravity were used in determining the correction factors. These oils were from the Bartlesville-Dewey field, Oklahoma, the Seminole field, Oklahoma, and the Inglewood field, California. The same gas that was used in the oil recovery experiments was used throughout this investigation. Determinations were made of the volume and A.P.I. gravity increases resulting from the gas going into solution at 200, 400, 600, 800, and 1,000 pounds pressure; also the increases in the volume and gravity of the oil due to retained gas were determined after the dissolved gas was liberated from solution by releasing the pressure to that of the atmosphere.Samples of residual and liberated gas were taken throughout the investigation in order to study the selective absorption and selective retention by the oil of the various constituents of the gas. The analyses of these gas samples showed that there was selective absorption and selective retention of the constituents of the gas. The tests on Inglewood crude gave the most pronounced example of selective absorption and selective retention of the gas.All of the tests were conducted at a constant temperature of 709F."

Oct 1, 1928

By Andrew J. Fergus

The purpose of this study was to provide basic information to aid further research on beryllium mineral flotation. Contact-angle and microflotation (Hallimond tube) methods were used to study collector action and flotation response of beryllium minerals and associated gangue minerals with representative commercial surfactants. Chrysoberyl received prime attention. Results indicated that selective flotation of beryl and chrysoberyl from fluorite and quartz is possible with sodium isooctyl phosphate below pH 2, and fluorite and topaz are readily collected by both anionic and cationic surfactants. Several modifying reagents were studied at one pH and one level of collector concentration. Aluminum sulfate, starch, and sodium silicate proved to be depressants in chrysoberyl flotation.

Jan 1, 1968

By J. F. Barkley

During the present war emergency, under the urge of the Federal Government to store coal, the following; questions are arising n the minds of coal users: (a) Will the coal lose any of its heating value in storage? (b) Will it slack and give a smaller-size coal? (c) Will its burning characteristics change in any way? (d) Will it catch fire from spontaneous combustion? (e) What precautions should be taken when storing coal? In regard to the loss of heating value of coal in storage, tests made by the Bureau of Mines show that the loss commonly has been overestimated. Various types of storage tests were made on New River, Pocahontas, Pittsburgh Gas, and Sheridan Wyoming coals. The following is quoted from Bureau of Mines Bulletin 136, Deterioration in the Heating; Value of Coal During Storage, by H. C. Porter and F. K. Ovitz:

Jan 1, 1942

By D. J. Judy, D. J. Rabovsky, W. H. Pailes, V. Castranova, K. Van Dyke, J. Rabovsky, N. A. Sapola, M. McPeek

"Platelet activating factor (PAF) can be released from pneumocytes following exposure to occupational dust (Am. Rev. Respir. Dis. 135:83, 1987). In addition, PAF has been shown to induce pulmonary inflammation, edema, and bronchoconstriction (Hosp. Prac. 19, 67, 1983). This investigation reports the effects of PAF on the properties of three types of cells found in the lung. PAF (1-100, K1/2 = 2.5 pH) caused depolarization of neutrophils as well as generation of chemiluminescence and secretion of hydrogen peroxide. These responses were dependent on the presence of extracellular sodium. However, PAF did not alter oxygen consumption of neutrophils. Although PAF (10 uM) caused depolarization of alveolar macrophages, no stimulation of chemiluminestence, superoxide secretion, or oxygen consumption was observed. However, PAF (10 uM). did potentiate chemiluminescence and superoxide secretion in response to zymosan (2 mg/ml) by 55% and 36%, respectively. In addition, PAF (10-90 uM) caused aggregation of alveolar macrophages. PAF (2-10 uM) also caused depolarization of type II cells, but did not affect membrane integrity or oxygen consumption. However, PAF (10-18 PM) enhanced the activities of two distinct forms of cytochrome P-450 in type II cells and caused aggregation of type II cells at PAF doses above 18 uM. These data indicate that PAF can affect the secretory activity of pulmonary phagocytes and the ability• of type II cells to detoxify foreign compounds (Bureau of Mines Grant - G1175142).INTRODUCTIONPlatelet activating factor (PAF) is a glycerophospholipid (1-0-alkyl-2-acetylsn-glycerol-3-phosphoryl choline) which has been shown to Mediate a broad range of biological activities (1-3). Its pulmonary actions include contraction of pulmonary tissue (4), secretion of leukotrienes from leukocytes (5), airway constriction (6), pulmonary edema (7), and enhanced migration of neutrophils into the airspaces of the lungs (8,9).PAF can be released from several different cell types, such as, basophils, neutrophils and alveolar macrophages, in response to a variety of particulates or membrane stimulants which include zymosan, calcium ionophore, phorbol esters, chemotactic agents, and endotoxin (10-13). Therefore, PAP may play an important role in the development of pneumoconioses by mediating pulmonary responses of lung cells to a variety of occupational dusts. To investigate this possibility, we determined the effects of PAF on several physiological parameters of neutrophils, alveolar macrophages, and alveolar type II epithelial cells."

Jan 1, 1988

By David E. Fogelson

The breakage of rock by explosives depends largely on the ability of an explosive to transfer its stored potential energy to the rock as strain energy. Therefore, the relative rock-breaking abilities of explosives can be determined indirectly by determining the relative amounts of strain energy transferred to the rock at the time of detonation. This report presents experimental data on the strain energy contained in explosion-generated strain pulses in a granite gneiss. Six explosives were tested. The scaled total radial strain energy Es/W flowing outward through a spherical shell of scaled radius R/W1/3 surrounding the point of detonation was found to follow an exponential decay propagation law of the form [ ]

Jan 1, 1959

By Jack C. White

This U.S. Bureau of Mines report assesses the resource potential of trace metals present in commercial Ti mineral concentrates. Metals of greatest interest: are those defined as "strategic and critical" by the U.S. Congress in 1981. Metals of interest in Ti mineral concentrates are Cb, Cr, Ta, Th, U, V, and Zr. Commercially available Ti mineral concentrates were studied. Characterization and analysis of major and minor constituents were performed by X-ray diffraction, neutron activation, inductively coupled plasma emission, atomic absorption, and classical wet chemical techniques. Of the metals investigated, the Cb, Ta, and V content of some concentrates may be a significant potential resource, depending on their amenability to recovery.

Jan 1, 2010

By Ludwig Schmidt

The policy of buying crude oil on a gravity basis , recently instituted by the major crude oil purchasing agencies in the Mid- Continent field , has caused a new and vital interest to be taken in the work of the U. S. Bureau of Mines for preventing evaporation of crude . From the early years of the industry oil men have recognized that the gravity of crude oil is usually an index of the gasoline content , but it has not been so generally known that the gravity of the crude oil decreases if evaporation is permitted . In 1919 the Bureau of Mines began a survey to determine the evaporation losses of crude petroleum in its various stages of handling from the well to the refinery , The results of this study are presented in Bulletin 200 ( Wiggins , J.H. , Evaporation losses of petroleum in the Mid- Continent Field , Bulletin 200 , U. s . Bureau of Mines , 1922. ) and Bulletin 225 ( Wiggins , J.H. , Methods of decreasing evaporation losses of petroleum , Bulletin 225 , U. S. Bureau of Mines , ( In press ) The findings of this survey were so startling that soon after the preliminary report had been published , several tank companies began manufacturing vapor- tight tanks for the purpose of reducing these important losses . Since that time the development of this type of apparatus has been so rapid that today , every oil trade journal carries numerous advertisements of vapor- tight tanks and equipment as well as technical articles dealing with various problems in connection with the elimination of evaporation losses , whereas three or four years ago the subject was scarcely even thought of. The present report has been prepared in response to numerous requests for information on the apparatus actually being used to prevent evaporation losses . At this time oil operators are also extremely interested in holding the lighter fractions in the crude oil in order to prevent a lowering in gravity . The practice of removing the vapors from crude- oil tanks by means of a slight vacuum and extracting the gasoline from them is not discussed here .

Feb 1, 1923

By Fred N. Kissell

Air recirculation caused by dust scrubbers at coal mine working faces was examined by the Federal Bureau of Mines with regard to the potential hazards caused by a possible buildup of methane gas. A theoretical analysis indicated that there was no apriori way to predict the effect of scrubber recirculation on methane concentration levels. Experiments conducted in a full-scale model of a working face area indicated that methane levels were dependent to a great extent on the location of the scrubber exhaust, but that the scrubber recirculation did not substantially increase the methane concentration above those levels that would have prevailed were the scrubber not in operation. An analysis of two underground scrubber trials showed that the scrubbers had no significant effect on methane levels, and a review of explosions attributed to recirculation showed that these were characterized by a lack of fresh air as well as recirculation. It was concluded that high methane levels are due more to a lack of fresh air than to recirculation.

Jan 1, 1975

By H. R. Babitzke

The purpose of this Bureau of Mine- investigation was to develop columbium and tantalum alloys suitable or u at elevated temperatures. Columbium and tantalum were combined with tungsten, hafnium, zirconium, molybdenum, vanadium, and titanium, and the resulting alloys were evaluated with respect to workability, hardness, electrical resistivity, strength at elevated temperatures, oxidation resistance, and weldability. Cb-33Hf-10W-10Ti, Cb-20111-5Mo, and Cb-30Hf-5Mo exhibited superior high temperature properties. Cb-33Hf-10W-10Ti had tensile strength values of 44,300 psi at 1,200° C and 16,500 psi at 1,400° C, Cb-20Hf-5Mo had values of 35,700 and 20,700 psi, respectively. The corresponding values for Cb-30Hf-5Mo were 38,900 and 17,800 psi. These alloys are fabricable by conventional methods with excellent strength at temperatures up to and including 1,400° C. An oxidation rate of 7 to 21 mg/cm2/hr was observed up to 1,000° C.

Jan 1, 1967

By Carl N. Anderson

This paper, which is one of a group presented by the United States Bureau of Mines covering mining practice in different districts, deals in particular with the methods employed in mining the horizontal type of zinc-lead orebodies of the West Baxter area of the Tri-State zinc and lead district. These orebodies, locally termed "sheet-ground" bodies, with their relatively low working faces and low tenor of zinc and lead, require changes in the mining practice which is used in the balance of the district. In addition to the general mining methods, this paper also describes the system of hand sorting employed prior to the direct milling of the ore. The Hartley mine is situated mile west of Baxter Springs, Kans., as indicated in Figure 1. Its general outline and the location of the shafts with respect to the milling plant are shown in Figure 2.

Jan 1, 1932

By Edward M. Kawenski

Tests were made in the Bureau of Mines Experimental Coal Mine on stop-pings similar to those used in operating coal mines to obtain information on air leakage through the face and the rupture strength of a stopping subjected to a pressure differential. Block stoppings were made from cinder, slag, and gravel aggregates with and without mortared joints and coatings. Sheet stop-pings were uncoated brattice cloth and nylon or brattice cloth and expanded metal-lath coated with asphalt, latex, mortar, or rigid urethane foam. Limited data were obtained on air through stoppings subjected to simulated roof convergence and to shock forces created by the firing of an adjacent charge of explosive. The pressure differential required to rupture stoppings was determined. shows that coating the face of a stopping effectively reduces ail: leakage. Block stoppings, particularly those with mortared joints, are most resistant to pressure and shock forces than are sheet stop-pings. Where ground movement is a factor, sheet stoppings leak less air than block stoppings.

Jan 1, 1965

By John C. Hartley

Three systems that monitor ventilating fans are described. These electronic monitoring systems automatically perform most of the operations required to conform with the provisions of the Federal Mine Safety Code in the event of fan failure or slowdown.

Jan 1, 1964

By Steven J. Page

Longwall double-drum shearers frequently have difficulty complying with the 2.0 mg/m3 dust standard and, therefore, require the use of effective dust controls. However, before dust controls can be implemented effectively, the major individual dust sources must be determined and their relative severity evaluated. The Bureau of Mines has recently developed a sampling strategy, based upon short-term gravimetric sampling, that can identify the major dust sources contributing to the shearer operator's exposure. This technique utilizes approved gravimetric sampling equipment already available to all mine operators and can be performed by two people in 2 days. Five examples, including data analysis, are discussed with respect to various cutting sequences. In addition, typical dust source contributions obtained from studies of double-drum shearer operations regularly in compliance are included. Mine operators can thereby compare their dust source evaluation results with those from these longwalls.

Jan 1, 1982

By James P. Bennett

In this Bureau of Mines study, portions of four acidproof bricks (two red shale and two fireclay) were exposed to 20 wt pct RCI at 900 C for periods of 30 days. Three different techniques were selected to deter-mine volume expansion of these materials after exposure. Linear expansions ranging from about 0.02 to 0.12 pct were noted from Ta pin and dilatometer measurements. The use of strain gages to measure expansions was not successful. The red shale and fireclay brick with the lowest apparent porosities had the lowest expansions. Expansion data obtained by direct measurement of samples exposed for 30-day periods or by dilatometric measurement of autoclaved samples ex-posed for 2 h were comparable. This suggests the use of an accelerated autoclave exposure procedure for determining volume expansion effects of ceramic materials in acid environments.

Jan 1, 1985

By G. B. Botsford

In August 1943 the Bureau of Mines began an investigation of the West Portal magnetite mines, which comprise the Swayze and Turkey Hill properties. The work included (1) traversing with a dip needle to record magnetic anomalies, (2) diamond drilling, and (3) sampling old mine dumps; it was completed in April 1944. The deposit consists of two parallel veins, which strike northeast and dip southeast. They carry magnetite in gneiss and schist. The Swayze mine was discovered in 1867 and closed in 1889, while the Turkey Hill mine was opened in 1872 and closed in 1887. The dip-needle survey covered 266 acres. The diamond drilling comprised 11 holes totaling 4,910 feet from which 142 samples were taken for chemical analyses. Old mine dumps were sampled at 52 points for chemical and magnetic analyses.

Jan 1, 1948