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By J. W. Horne

The United States Bureau of Mines in cooperation with the State of Colorado at the University of Colorado has conducted experiments to determine the amount and composition of the noncondensable cases evolved when crude shale oil is distilled under pressure. Hydrogen sulphide is one of the components found in the complex mixture of uses produced by the distillation of shale oil under pressure. This paper deals with the apparatus and method used in determining the amount of hydrogen sulphide evolved in the laboratory experimental cracking stills.

Jan 1, 1931

By John D. Sullivan

In leaching copper ores knowledge of the rate of dissolution of the copper minerals and of the impurities is desirable. With knowledge of these two factors and data as to what minerals are present in the ore the metallurgist has an excellent start on planning a leach¬ing cycle to fit that ore. The rate of dissolution is rather difficult to predict, and the time required to leach a given ore may differ markedly from that required by another ore. The whole study as related to mixed oxidized and sulphide ores is one of relative rates of dissolution of the different copper minerals and the impurities in sulphuric acid and in ferric sulphate. The aim of leaching is to choose a cycle and strength of solvents to ex¬tract a maximum amount of copper and a minimum of impurities. The consumption of reagents per unit of copper dissolved is a function of the strength of the reagents used and the relative rates of attack on copper minerals and impurities. An opportunity may exist of ob¬taining the kind of electrolyte wanted for electrolytic precipitation and yet of saving on the consumption of reagents by modifying the strength of ferric sulphate and of sulphuric acid during the cycle to fit the time needed for dissolving the sulphide and oxidized minerals present. Former papers have considered the rate of dissolution of azurite, malachite, tenorite, chrysocolla, cuprite, chalcocite, boruite, and covellite in common leaching solvents. A paper soon to be written will consider some of the less important copper minerals. The present paper considers the rate of dissolution of copper from ores of the Southwest in sulphuric acid of varying strength and the ratio of sulphuric acid consumed to copper dis¬solved. In this study two ores containing the copper principally in an oxidized condition were used. A study of other ores, especially those containing high percentages of sulphide copper minerals, would be desirable, but since consumption of acid has paramount interest,

Jan 1, 1931

By G. W. Jones, F. E. Scott, R. E. Kennedy

Methylene chloride , dichloromethane CH2C12 , a low - boiling and highly volatile organic chlorinated compound, is used extensively as a refrigerant in air conditioning installations , as an intermediate in organic synthesis , and as a solvent for cellulose acetate and other materials . As its vapors are not inflammable in air at ordinary temperatures , it can be used to advantage where it would be highly dangerous to use ordinarily inflammable solvents . The question has been raised as to its inflammable range in pure oxygen and in air enriched with oxygen . To find the answer to this question, tests were carried out with various mixtures of methylene chloride , oxygen, and nitrogen mixtures . It was found that methylene chloride has wide limits of inflammability in pure oxygen . Additional tests were then made to establish the complete range of inflammability of these gases . The methylene chloride employed in the tests was cbtained from the Eastman Kodak Co. It had a reported boiling range of 40.5 ° to 42.0 ° C. and a density of 1.322 at 20 ° C.

Oct 1, 1943

By S. E. Khalafalla

The Bureau of Mines investigated variations in the activation energy for the carbon monoxide reduction of magnetite and ferrous oxide with respect to the state of aggregation of the oxide material. Reduction phenomena can only be satisfactorily explained by including an adsorption step in the reduction process. Summation of the values of the exothermic heat of chemisorption and the variable apparent activation energy for reduction yields a nearly constant value of about 50 kcal for either ferrous oxide or magnetite regardless of whether they are aggregated in pelletized form or coarsely crystalline particles.

Jan 1, 1965

By M. C. Malamphy

A general description of the activities and results of bauxite investigation by the Bureau of Mines at its bauxite project in Saline and Pulaski Counties, Ark., has been given in Report of Investigations 4251. The factual data obtained during the project are reported in a series of Reports of Investigation beginning with No. 4251, of which this is the thirteenth. The data are accompanied by maps showing the location of holes drilled and the deposits developed. Each area upon which work was done is reported by half townships. Each bauxite deposit investigated was assigned a name and a number for ready reference and identification, and its location and name are shown on the appropriate half-township map. The description of each half township is followed by a description of each deposit developed in that half township. The 14 half-township maps and 77 detail maps of the bauxite deposits in this series of reports give the locations and numbers of all the holes drilled on the project, except the deep holes drilled to test the geophysical anomalies. The locations of those holes show on figure 13 in volume 1. The description of the deposits developed is followed by complete detailed logs of the drill holes. Many of the widely spaced exploratory holes did not discover bauxite of minable thickness and grade. The pertinent information obtained from the widely spaced exploratory drill holes has been summarized and tabulated and a table for each half township is given with the discussion covering that area.

Jan 1, 1948

By Peter Krause

This report provides an overview of the worldwide photographic industry and of the applications of photography. It also covers important technological and market trends, with special emphasis on those factors which may affect the consumption of silver in the future. The text is divided into the following eight sections: 1. Principal manufacturers of silver-based photographic products 2. Major product sectors 3. Structure of the international market for silver-based photographic products 4. Silver-bearing raw materials for the manufacture of photographic products 5. Processing of photographic products: recovery of silver and recycling 6. Methods for estimating the use of silver in photographic products 7. Basic function of silver in photography and alternate image capture and recording systems 8. Brief history of photography Silver- based photographic materials are made for many applications that require different photochemical and physical response characteristics and a wide variety of formats and sizes. All of these products are laminates consisting of a surface-treated support and bonded gelatin layers. Two basic types predominate - films and papers. Films have transparent or translucent plastic supports (mostly cellulose tri-acetate and polyester), while papers have mostly a paper core coated with polyethylene resin layers on both sides (RC type). The front layer contains white titanium dioxide to provide high reflectivity and the back layer a matting agent. However, a few so-called fiber base papers are still supplied. These have a high quality paper base coated with a baryta layer ; i.e. a gelatin layer containing white barium sulfate. The manufacture of photographic film and paper supports requires special procedures and equipment, because of the severe requirements for chemical purity, optical integrity and uniformity (see Table 1 on page 10 for a list of the principal makers of film and paper supports).

Jan 1, 1992

By John D. Sullivan

In leaching copper ores knowledge of the rate of dissolution of the copper minerals and of the impurities is desirable. With knowledge of these two factors and data as to what minerals are present in the ore the metallurgist has an excellent start on planning a leaching cycle to fit that ore. The rate of dissolution is rather difficult to predict, and the time required to leach a given ore may differ markedly from that required by another ore. The whole study as related to mixed oxidized and sulphide ores is one of relative rates of dissolution of the different copper minerals and the impurities in sulphuric aoid and in ferric sulphate. The aim of leaching is to choose a cycle and strength of solvents to extract a maximum amount of copper and a minimum of impurities. The consumption of reagents per unit of copper dissolved is a function of the strength of the reagents used and the relative rates of attack on copper minerals and impurities. An opportunity may exist of obtaining the kind of electrolyte wanted for electrolytic precipitation and yet of saving on the consumption of reagents by modifying the strength of ferric sulphate and of sulphuric acid during the cycle to fit the time needed for dissolving the sulphide and oxidized minerals present.

Jan 1, 1931

By R. D. Brown

There are techniques for separating aluminum alloys from mixed scrap, but there are no efficient ways to separate wrought aluminum from cast aluminum. This Bureau of Mines report describes a novel technique for separating mixed aluminum alloy scrap into cast and wrought aluminum alloy fractions. The technique, which uses conventional heating, fragmentizing, and screening equipment, exploits differences in the mechanical properties of cast and wrought aluminum alloys at elevated temperatures. The cast alloys become brittle at high temperatures owing to intergranular melting of regions of eutectic composition. This melting begins to occur as the solidus temperature for each alloy is reached. Solidus temperatures for casting alloys generally range from 520° to 580° C, but are above 600° C for most wrought alloys. Thus, the casting alloys are easily fragmented while the wrought alloys remain ductile in the proper temperature range. Starting with a mixture containing approximately 80 pct cast and 20 pct wrought alloys, fractions of 100 pct cast and 98 pct wrought have been produced.

Jan 1, 1985

By R. V. Higgins

Tarner (1),3/ Muskat (2), and Schilthuis (1) have presented methods of calculating oil recovery by the expansion of dissolved gas with and without return of gas to the reservoir. Although electronic computers have eliminated the tedious and time-consuming calculations (4) required by each of these methods, many petroleum engineers do not have access to electronic computers. For these engineers a short method is presented that uses the Tarner method as a base. Moreover, for engineers who have access to computers and have not as yet prepared a program, the short Tamer method requires less computer time than the long iterative methods. In the proposed short method, no plotting of the calculated data is required to determine a point of intersection described in the original Tarner presentation, as only one calculation is needed to determine the value sought, or two calculations if greater accuracy is desired.

Jan 1, 1960

By Herbert R. Babitzke

As part of a project to develop refractory metal alloys suitable for high-temperature structural applications, the Bureau of Mines applied solid solution and precipitation-hardening techniques to columbium and tantalum alloys. Thirty-three alloys were evaluated to determine their formability, strength, and oxidation resistance. Three alloys had tensile strengths near 40,000 psi at 1,200° C: Cb-1N-5W-5V-10Hf (No.4), Cb-15Hf-5W-0.5B (No. 31), and Cb-15Hf-SW-IB (No. 32). Oxidation resistance of the high-strength alloys was good. Alloy4 gained only 34 mg/cm2 at 1,200° C, and 21 mg/cm2 at 1,000° C in 2 hours. Hot forming was done without any protection from oxidation.

Jan 1, 1968

By W. H. Rinkenbach, C. A. Taylor

"Among the recently patented detonating compounds that have been suggested as substitutes for the commonly used fulminate of mercury is the normal lead salt of trinitroresorcin, or styphnic acid. As no data concerning its use or practi¬cability were available, a study of its properties was made in the explosives laboratory at the Bureau of Mines experiment station at Pittsburgh, Pa. This paper embodies the results obtained.Normal lead trinitroresorcinate was first prepared and patented*** by Herz; it probably found some use during the World War, but no record of its performance is available,Preparation of Lead Trinitrpresorcinate.In his patent specifications, Herz states that the normal salt may be obtained in a quantitative way by precipitating a multiple of the equivalent weight of the lead salt of a strong inorganic acid - such as lead nitrate - in the presence of a weak organic acid - such as acetic acid - by heating with a Teak solution of the alkali-metal salts or alkaline-earth salts of trinitroresorcin. Herz gives the following example: 245 grams of dry trinitroresorcinand 290 grams of crystalline sodium carbonate are dissolved in in 18.8 liters of boiling water, to which 77 c.c. of glacial acetic acid is added. The toiling solution is mixed with a boiling solution of 650 grams of lead nitrate in 1.4 liters of water, stirring rapidly; and the mixture is boiled for two minutes, after which it is cooled quickly with constant stirring. The precipitated crystals are then filtered off, washed several times with cold water, and dried."

Oct 1, 1923

By Engelmann. William H.

In pursuit of innovative methods to improve mining productivity, the Bureau of Mines is investigating the use of inorganic salts as drilling fluid additives for penetration enhancement. Laboratory diamond drilling tests were performed on Westerly Granite with aluminum chloride solutions and on Sioux Quartzite with aluminum nitrate and aluminum, calcium, sodium, and zirconium chloride solutions as drilling fluid additives. These drilling results were compared with the average drilling performance using distilled, deionized water on Sioux Quartzite (12 replicate tests) and Westerly Granite (3 replicate tests). Maximum in-creases in penetration per given time and bit life were obtained when drilling with zero point of charge (ZPC) concentration solutions of each additive. For Sioux Quartzite, maximum increases in penetration and bit life ranged from 96 to 115 pct and 64 to 99 pct, respectively. For Westerly Granite, maximum increases in penetration of 155 and 165 pct and bit life of 109 and 136 pct were obtained at or near ZPC aluminum chloride concentrations of quartz (7.3 x 10-7 mol/L AIC13) and alkali feldspars (1.1 to 1.5 x 10-6 mol/L AIC13), respectively. This simultaneous increase in penetration per time together with extended bit life should result in increased productivity and reduced bit costs.

Jan 1, 1987

By Peter D. Lohn

The Bureau of Mines conducted both laboratory and field investigations to study the effectiveness of medium-pressure (up to 30,000 psi) water jets in controlling the generation of airborne respirable dust during the hydraulic fragmentation of coal. Laboratory studies were conducted at the Farmington High Energy Test Site of the Twin Cities Mining Research Center, and field studies were carried out at the Humphrey No. 7 mine, Mount Morris, Pa., in the Pittsburgh coalbed. The water jets were produced by commercially available triplex pumps. The dust samples were collected by midget impinger samplers, and analyzed by electronic and optical counting techniques. Respirable dust concentration for a full-scale production model was projected at below 2 mg/m3, the maximum exposure allowed by the Federal Coal Mine Health and Safety Act of 1969.

Jan 1, 1975

By J. R. Hauger, P. A. Romans, W. J. Niebuhr

With suitable instrumentation and techniques it is possible to determine the presence of tantalum in columbium to 20 ppm . This paper discusses the selection of X- ray spectrographic instrumentation and describes a technique for accomplishing the low level determination of tantalum . An ion- exchange method of separating tantalum from columbium is also described .

Jan 1, 1964

By G. M. Kintz

From 1895 to 1932, inclusive, 1,0163/ men were killed in and about New Mexico coal mines. Of these, 473 (approximately 47 percent) were killed in the 17 explosions listed in this paper. The second largest explosion of record in the United States, in so far as fatalities are concerned, occurred in New Mexico. The data in this circular were taken from publications of the United States Bureau of Mines and published annual reports of the State inspector of coal mines of New Mexico. The tables included are complete only with regard to major disasters. The Bureau of Mines considers as a major disaster one in which 5 or more men are killed. A few minor disasters are included, however.

Jan 1, 1934

By W. P. Yant, H. C. Fowler

"INTRODUCTIONHydrogen sulphide is probably the most toxic gas associated with crude oil. Hydrocarbon (petroleum) vapors themselves are harmful to the human system, but hydrogen sulphide, when present, is usually more important from the standpoint of health and safety. These conclusions were reached in an investigation of the toxic gases encountered in the transportation end refining of high-sulphur petroleum. The results of that investigation are presented in Bureau of Mines Bulletin 23l. although the writers of Bulletin 231 paid no direct attention to the production of oil in the field, they attributed to hydrogen sulphide reports of accidents caused by gas in the oil fields of Mexico.During the development of oil fields in Texas, a ""poison gas"" was encountered that constituted a decided health and safety hazard. The present report discusses an investigation of this gas made in July, 1926.The major portion of the investigation was conducted in the Panhandle field of Texas, but the study also includes the Big Lake and McCamey fields.Scope of WorkThe work undertaken in each field included:Examination of the gas-coming from representative wells at various locations in the field; also analyses of the gas-air mixtures to which the workmen were or might be exposed.Observation of symptoms of poisoning and severity of these symptoms."

Oct 1, 1926

By Louis C. Brichta

The rapid depletion of known deposits of high-grade ore and the need for development of additional reserves, together with increased interest in open-pit mining of low-grade zinc-lead ores in the Tri-State District, led the Bureau of Mines to examine likely mining sites. Underground operations failed to remove all of the ore in a number of areas, and it appeared possible that some of them might be reworked successfully by low-cost open-pit methods. The South Carthage or Hull tract in Jasper County, Mo., was selected by Bureau engineers as favorable for the development of an open-pit mine.

Jan 1, 1949

By Paul Hatmaker

Lime was a highly useful commodity thousands of years before the simple chemistry of its manufacturing process was known. The employment of lime for agriculture, building, and even certain essentially chemical purposes is so old that its origin is among the unrecorded details of man's first ventures into the manufacture and use of prepared substances. Lime is a most versatile material and consequently has come to be widely utilized in modern civilization. Immediately before the depression of the early 1930's the annual production of lime in the United States was more than 4 million tons, valued at 33 to 42 million dollars. This output was sold to many industries, so many that mere enumeration becomes tedious. In addition to agricultural and building lime the sales statistics compiled annually by the Bureau of Mines include lime sold to the steel and other metallurgical industries as refractory and fluxing material, as well as that used by paper mills, glass works, tanneries, and water-treatment plants. These major uses normally consume about 86 percent of the domestic sales. The remaining 14 percent includes lime sold for use in the manufacture of alcohol, alkalies, bleaches, calcium acetate, calcium carbide, coke gas and byproducts, glue, insecticides, oils and fats, paints, and rubber, in the refining of salt, in the manufacture of sand-lime and slag brick, in the disposal of sewage and garbage, in the manufacture of silica brick, in the refining of sugar, in the textile industries, and in wood distillation. Many other uses are also known for which complete sales data are not available.

Jan 1, 1934

By John Nagy

Large-scale tests in the U.S. Bureau of Mines Experimental Coal Mine show that the explosion hazard of coal dust on shuttle-car roadways can be con-trolled by proper application of water, dry rock dust, a saturated solution of ammonium phosphate, or mixtures of water or the water-phosphate solution with rock dust. The experiments were made with loadings of 1.0 and 5.0 pounds of mine size coal dust per linear foot of entry, and with a 3-or 4-inch-thick layer of coal rubble on the floor, The data from the tests with mine-size coal and rubble are comparable. The water contents of the dust loading were determined from samples collected just prior to initiation of a gas-air mixture in an ignition zone at the face Dust samples were collected 1 inch deep from the coal-rubble deposit. One experiment was made with the dust in the coal rubble bound with latex applied as a water solution by spray. The binding action was inadequate and explosion propagation was obtained.

Jan 1, 1970

By George S. Rice, J. W. Paul, E. H. Denny

Data assembled by the Bureau of Mines , coupled with requests from coal companies , have emphasized the desirability of establishing standardized specifications for brattice cloth with particular respect to durability and fireproofing . Brattice cloth is a canvas or other material , often covered with some fireproofing composition , which is used extensively in coal mining for temporarily deflecting air into pillar workings and maintaining ventilation at the working faces . These specifications will be established , it is planned , through a cooperative program in which the U. S. Bureau of Standards will make a series of tests of various brattice cloths treated with respect to fire- resisting qualities and the U. S. Bureau of Mines will continue to assemble field data on the use of brattice cloth . Plans now are being made for this cooperative work. Without attempting to make a complete survey , the Bureau of Mines has made preliminary studies and investigations , and verious representative coal - mining companies have furnished detailed information . The information thus gained will be used as the basis for the cooperative investigation , but the Bureau of Mines would welcome additional information from mine operators on the character and weight of brattice cloth , conditions of use , durability , quantity employed and price . Such information should be sent to the Director , Bureau of Mines , Washington , D. C. The mine operator is interested in procuring at reasonable cost a brattice cloth with lasting fireproofing quality and of as great durability and strength as possible . There has been a lack of assembled data and knowledge regarding the subject , but the Bureau of Mines feels that this lack of knowledge may be overcome if the coal -mining companies will lend their hearty support to the cooperative investigation and submit information relative to the use of brattice cloth in their own properties . Information contained in this report is based on data obtained from coal operators in bituminous districts of Pennsylvania , Alabama , Utah , Indiana , Illinois , Colorado and Nova Scotia .

Feb 1, 1923