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By Ludwig Schmidt

Investigations conducted by the Bureau of Dines pertaining to the reduction of evaporation losses of petroleum have shown that such losses may be reduced 70 to 80 per cent by the use of vapor-tight tanks equipped with vacuum and pressure relief valves, and vapor-tight thief hitches. Additional studies have shown that it is often economical to supplement this type of construction with other measures that will reduce evaporation losses still further. Water-cooling systems, insulation, and light colored paints are the measures most often used in connection with vapor-tight tanks. Painting with light colored paints probably is employed in the greater number of cases. On account of the cost of insulation, or of installing water cooling systems, the use of these methods are restricted to tanks containing gasoline or crude petroleum with a very large content of low-boiling fractions. The effect of cooling systems has been discussed in a previous report.2 In choosing paints for tanks many factors must be considered. Probably the three most important are cost, protective value, and color. Many companies have adopted a standard color for all of their tanks in this way they reduce the initial cost of paint by buying in large quantities. The tank farms of such companies usually have a neat appearance, resulting from the uniform painting of all tanks. This procedure also has advertising value. Unfortunately, most of the paints used to protect steel are of the darker colors, usually red or black. These colors accelerate the rate of evaporation. Several companies have solved this difficulty by using a dark colored metal-protective paint as a primer coat, and a paint of any desired color for the final coat. Special metal-protective primers to be used under light-colored cover coats have been placed on the market by several paint manufacturing companies.

Jan 1, 1925

By F. R. Lee

[THE Bureau of Mines was established in July 1910 to conduct research and to Establish standards for mining equipment and practices which would conserve human life, natural resources, and property in the mineral industries. Several lists of equipment approved by the Bureau as permissible for use in gassy coal mines have a been issued since then. The lists covering all approved equipment except breathing apparatus and explosive have been consolidated info two publications: Bulletin 543, Permissible Equipment Approved to January 1, 1953, and Information Circular 5220, Permissible Mine Equipment Approved By The Bureau of Mines During 1953-62. The purpose of this publication is to supplement Bulletin 543 kind Information Circular 8220 with a listing of permissible equipment approved during 1963 and 1964. The schedules (standards) under which equipment listed herein have born approved are as follows (titles and dates of approval and revision are given in footnotes): Schedule 2F,3 schedule 6D,4 schedule 7C,5 schedule 8C,6 schedule 9B,7 schedule 10C,8 schedule 12D,9 schedule 22,10 schedule 24,11 schedule 25B,12 schedule 28,13 schedule 29A,14 schedule 30,15 and schedule 31.16]

Jan 1, 1966

By P. M. Gruzensky

Several experiments have been carried out in efforts to evaluate qualitatively a variety of electrolytes for refining bismuth. Most extensive work was done with the basic tartrate, hydrochloric acid, and hydrofluosilicic acid electrolytes. Deposits that are smooth and adherent can be obtained from these three electrolytes if low cathode current densities are employed. All three electrolytes were effective in purifying crude bismuth considerably, with additional purification indicated in each instance by a reelectrolysis step. With the basic tartrate electrolyte best results were obtained when the electrolyte was at 40° C, and contained at least 100 grams of bismuth per liter, An apparent disadvantage was depletion of bismuth from this electrolyte, causing the deposits to become spongy and nonadherent.

Jan 1, 1956

By F. P. Haver

A method to recover copper and elemental sulfur from chalcopyrite concen¬trate, using a ferric chloride leach, CuFeS2 + 3FeCl3 ? CuCl + 4FeCl2 + 2S, was reported by the Federal Bureau of Mines in 1971 (Report of Investigations 7474). Since that time, additional work has been done to improve certain steps in the procedure; that is, the recovery of sulfur from the leach residue, the recovery of copper and iron from the leach solution, and the regeneration of the leach solution. It was determined that over 99 pct of the elemental sulfur in the leach residue could be extracted at ambient temperature with an ammonium sulfide solution. Heating the pregnant solution precipitated crystals of rhombic sulfur (99.5 pct purity) and liberated ammonia and hydrogen sulfide for recycle. Copper with a purity in excess of 99 pct was obtained from the leach solution by electrolysis, using a diaphragm cell, with an energy requirement of less than 0.7 kW-hr/lb. Metal was deposited as a weakly adherent powder that could be easily dislodged from the cathode and withdrawn continuously from the cell in the form of a slurry. During electrolysis, part of the Fe(II) was oxidized to Fe (III) at the anode so there was no chlorine evolution. The leach solution was regenerated by direct oxidation of the spent electrolyte with air or oxygen in a turboaerator at 80° C. This precipitated the iron dissolved during leaching in an easily filterable form, Fe203.xH20, and converted the remaining Fe(II) to Fe(III).

Jan 1, 1975

By R. L. Hopkins

Fifteen alkyl cycloalkyl sulfides and three dicycloalkyl sulfides were synthesized to provide reference compounds in the search for these classes of sulfur compounds in crude oils. In synthesizing sulfides by alkaline alkylation the order in which the reactants were added was shown to determine the yield and purity of the product.

Jan 1, 1966

By Foster Fraas

The objective of this research was separation of one highly conductive mineral from a second conductive mineral , a procedure which is impractical in commercial electrostatic separators using metal rolls . Such separators permit separation of nonconductive from conductive minerals . A new technique involved use of carrier electrode rolls specially prepared by anodizing and / or oxidizing at high temperatures to form suitable oxide surfaces . Specific oxides included aluminum , copper , and nickel . The significant result provided by the new surfaces was the extension of the separation range to higher conductivities , an extension in relative mineral conductivity from 10-14 mhos . The results are in accordance with the blocking- layer theory .

Jan 1, 1964

By T. M. Barczak

The term "resultant load vector" is defined as the representation of the forces applied to a longwall roof support element by strata activity through a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield structure prohibits determination of support resistance simply from the summation of leg forces. In the research reported in this Bureau of Mines study, the mechanics of the shield structure were evaluated, and a technique was developed whereby the resultant shield loading could be determined by instrumenting supports with pressure transducers and strain gauges to measure leg, canopy capsule, and lemniscate link forces. This technique has been laboratory tested in the Bureau's Mine Roof Simulator. Functional relationships among variables were assessed, and confidence intervals were established for prediction of the resultant load vector parameters. Resultant load measurements were taken on five instrumented shields on an active longwall face in Colorado. Results were analyzed and found to be consistent with shield mechanics and anticipated roof behavior. Benefits to be derived from this research, future efforts, and long-range goals are discussed.

Jan 1, 1986

By Nan C. Jensen

Silica, the world's most abundant mineral compound, is composed of the two commonest elements - oxygen and silicon. In addition to being the life-giving constituent of the atmosphere and the major element in the waters of the earth, oxygen comprises almost half of all known terrestrial matter and occurs combined with most of the other ninety-odd elements in the solid crust of the earth; however, a large proportion of the oxygen is combined with silicon. Silicon is second only to oxygen in abundance in nature and constitutes more than one-fourth of all known terrestrial matter. The compound of oxygen and silicon, called silicon dioxide or silica, forms 59.08 percent of the earth's outer 10-mile crust. Some of the silicon dioxide exists as

Jan 1, 1942

By B. W. Gandrud

The upper part of the Alabama deposits of crystalline graphite consists of an oxidized ore derived from the underlying unoxidized ore through prolonged Weathering. The degree of oxidation in different sections and at different depths within the bed is not uniform. The original ore is hard and blue-gray; the weathered product is soft and brown and is the only part that has been mined to any extent. Samples of both oxidized and unoxidized ores were obtained from two of the large graphite deposits of Clay County. Three additional samples of oxidized ore were obtained from different portions of a third property in the same region. In this report, ores 1 to 5 are of oxidized material and ores 6 and 7 of unoxidized.

Jan 1, 1934

By E. C. Lane

[This is the eleventh in a series of reports on properties of commercial motor fuels made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data, on motor gasolines sold during the winter of 1935-36.3/ The present report presents analytical data for 2,020 samples, reprecenting the products of approximately 120 companies, which, as in previous surveys, include both large and small suppliers. In addition, the Pacific coast is represented by data averaged the Pacific Coast Technical Group before being submitted and' are published exactly as they were received. As in previous surveys, the data are divided into the three groups of samples of regular-price, premium-price, and third-grade gasoline each group has been averaged separately. The number of samples, items, and old brands comprising each group, exclusive of the of the Pacific coast, axe as follows: Regular price, 1,071 samples, 29 items, and 77 brands; premium price, 608 samples, 235 items, and 72 brands; third-grade gasoline, 341 samples, 196 items, 78 brands. The meanings of these terms as used in tae surveys are as follows:]

Jan 1, 1941

By E. C. Lane

[This is the eleventh in a series of reports on properties of commercial motor fuels made in accordance with a cooperative agreement between the Cooperative Fuel Research (C.F.R.) Committee and the Bureau of Mines of the United States Department of the Interior. The first report contained data, on motor gasolines sold during the winter of 1935-36.3/ The present report presents analytical data for 2,020 samples, representing the products of approximately 120 companies, which, as in previous surveys, include both large and small suppliers. In addition, the Pacific coast is represented by data averaged by the Pacific Coast Technical Group before being submitted and are published exactly as they were received. As in previous surveys, the data are divided into the three groups of samples of regular-price, premium-price, and third-grade gasolines, and each group has been averaged separately. The number of samples, items, and brands comprising each group, exclusive of the of the Pacific coast, axe as follows: Regular price, 1,071 samples, 29 items, and 77 brands premium Price, 608 samples, 235 items, and 72 brands; third-grade gasoline, 341 samples, 196 items, and 78 brands. The meanings of these terms as used in tae surveys are as follows: Sample: The individual sup of gasoline o1 obtained at the filling station and analyzed in the laboratory.]

Jan 1, 1941

By Thomas P. Mucho

Retreat or pillar recovery mining redistributes the overburden weight onto the adjacent coal pillars in a room-and-pillar section. The additional stress and the resultant energy stored in the remaining pillars can become so great that pillars may bump or violently fail. An investigation at the Gary No.2 Mine was conducted to examine the effectiveness of the thin pillar mining method for mitigating bump occurrences. Field observations were made and instruments were installed to monitor pillar behavior during extraction. Stress monitoring instruments and roof-to-floor convergence stations were installed in pillars and entries and crosscuts, respectively. Results indicated that high pillar stress concentrations occurred in these bump-prone geologic conditions. The thin pillar mechanism, the creation and progressive outby movement of an expanded yield zone, was also monitored through the instruments. The expanded yield zone, a result of using thin pillars in a highly stressed pillar line area, mitigates bump risk.

Jan 1, 2010

By W. E. Young

This paper describes operations of the Chief Consolidated Mining Co. at the Chief mine in the Tintic district, Juab County, Utah, where the outstanding problem is water control; the unique pumping methods employed are featured in this report. The ore bodies in this district occur as long, narrow shoots along fault fissures, usually in the Bluebell dolomite of Ordovician age. Oxide ores predominate above the 1800 level, which is also the natural water level. Sulfide ores containing lead, zinc, silver, and gold extend below the 1800 level. The mine is developed by vertical shafts and winzes, from which drifts are driven to the ore bodies. In the lower levels of the mine these drifts extend long distances from the shafts or winzes because of the relatively low dip of the ore shoots. The mine has been worked to the 2800 level and the 18-411 winze extends to the 3080 level.

Jan 1, 1958

By T. E. Howard

The western phosphate field, comprising parts of Idaho, Montana, Wyoming, and Utah, contains one of the world's largest known reserves of phosphate rock. Although phosphate-rock deposits of good-grade have been known since before the turn of the century and production has been recorded since 1906, real development of this important field did not begin until immediately after World War II. Since then fertilizer-manufacturing facilities using western phosphate rock have been expanded, and three electric-furnace plants for producing elemental phosphorus have been installed, resulting in a rise in mine production from 323,955 long tons2/ in 1945 to 1,653,916 long tons3/ in 1953. Interest in the field is increasing, and it is reasonable to expect that the western phosphate industry will continue to expand. Before 1945 all western production was from underground mines. In that year the first strip mine in the field was started near Montpelier, Idaho,~ and in sub-sequent years a number of other open-pit mines were opened in southeast Idaho and western Wyoming. At present the major part of the production comes from surface mines. Underground mining has continued, and new underground mines have been opened in the field, but recent exploration by operating companies has been aimed primarily at developing additional deposits suitable for low-cost surface mining. Preliminary reserve estimates by the Federal Geological Survey5/ indicate that only a very small part of the total resource may be recovered by surface methods and that the industry eventually must depend largely on underground mining. Because one function of the Bureau of Mines is promoting the conservation and development of the Nation's mineral resources, it is appropriate that research be conducted to develop low-cost maximum-recovery underground mining methods applicable to western phosphate-rock deposits.

Jan 1, 1956

By Robert H. Peters

Are the safety rules in your work place effective? Do supervisors enforce them as they should? Do supervisors abide by these rules? Safety rules are an important aspect of many company safety programs, particularly if employees must work in an intrinsically hazardous environment such as a coal mine. However, for various reasons, supervisors sometimes fail to enforce safety rules (Arvey & Jones, 1985; Hartshorn, 1998). This paper presents some findings obtained from interviews with coal miners about why supervisors sometimes fail to enforce an important mine safety rule. It also contains a few suggestions addressing what could be done to help supervisors perform this job function more effectively.

By Wallace W. Roepke

Research to evaluate the lubricity effects achieved by spraying water on the cutting bit of a mining machine or spraying water on the coal during cutting has shown that neither practice affects cutting forces, as had been believed. However, when water was supplied to the cutting zone axially through the bit at 3,000 to 5,000 psi pressure, tangent'ial cutting forces were reduced an average of 30 pct at a I-in depth of cut while normal bit forces were reduced an average of 65 pct. Lower normal forces mean reduced bit wear, faster advance with greater depth of cut, and fewer coal fines.

Jan 1, 1985

By John Durkin

A computer model has been generated to evaluate speech intelligibility of individuals wearing conventional and electronic hearing protectors. For speakers talking at normal levels in noise levels of 65 db(Lp) or less, it was found that conventional hearing protectors significantly reduced speech intelligibility. Under the same conditions, electronic protectors provided scores equal to those for the unprotected individuals while providing protection from high noise levels. Therefore, electronic hearing protection is valuable in areas where high noise level is intermittent.

Jan 1, 1979

By B. W. Madsen

The Bureau of Mines conducted a large-scale (6.4 t), long-term (2,165 days) test to gain a better understanding of the leaching characteristics of chalcopyritic ores. An ore sample containing 0.77 pct Cu was leached in a fiberglass column by downward percolation of acidified ferric sulfate solutions. Three sets of leaching conditions were investigated: (1) ambient temperature leaching, (2) elevated temperature (50° to 60° C) leaching, and (3) elevated temperature leaching after inoculation with thermophilic bacteria. Leaching at ambient temperature resulted in a copper extraction rate of 0.44 pct per 100 days. Increasing the temperature to 50° to 60° C resulted in decreased activity of natural mesophilic bacteria, and the leaching rate decreased to 0.22 pct per 100 days. The pH was lowered from 2.0 to 1.6, and nutrient solutions that contained thermophilic bacteria were added. This procedure resulted in an increase in the ferric-to-ferrous iron ratio and an increase in the copper leaching rate. However, the increased leaching rate was not sustained, and 120 days after inoculation the bacterial activity declined, the ferrous iron content increased, and the copper leaching rate decreased.

Jan 1, 1983

By E. E. Maust

The present work is part of an ongoing Bureau of Mines effort to provide a better understanding of the fundamental phenomena involved in sulfide flotation, the role of oxygen in xanthate adsorption being one essential issue. Galena was chosen as the material around which to develop a conceptual model, partly because of its demonstrated oxygen sensitivity and partly because information on its properties and flotation behavior constitutes the largest part of the fundamental information available on sulfides of commercial importance. The model is formulated primarily in terms of surface electronic energy levels produced by oxygen and xanthate and is further developed using existing experimental evidence and its implications. Four major functions of oxygen are elucidated, and the relationship of these to the formation of lead xanthate, dixanthogen, and a surface compound is discussed. Though yet incomplete, the model provides a useful framework within which the results of diverse experiments can be related to one another in their proper perspective, as shown by a brief discussion and resolution of some apparently discordant results reported in the literature.

Jan 1, 1976

By D. E. Shanks

As part of its goal to help maintain an adequate supply of minerals to meet national economic and strategic needs, the Bureau of Mines, U.S. Department of the Interior, is investigating a fused-salt electrolytic procedure for producing zinc metal. A previous report described preliminary, small-scale work on the fused-salt electrolysis of ZnC12. The present report covers a more detailed investigation of the properties of ZnC12-alkali metal chloride electrolyte systems in relation to the production of zinc metal and also discusses electrolysis in largescale, internally heated cells. The effect of composition on bath stability, current efficiency, cell voltage, and liquidus temperature was determined for the ZnCla-NaC1-KC1, ZnC12-NaC1-LiC1, and ZnC12-KC1-LiC1 electrolyte systems. An electrolyte com-posed of 38 mole-pct ZnC12, 31 mole-pct NaC1, and 31 mole-pct KC1 gave the best overall results. Sludge (ZnO) formation in the ZnC12-NaC1-KC1, ZnC12-KC1-LiC1, and ZnC12-KC1 systems was investigated during prolonged electrolysis. The ZnC12-KC1-NaC1 electrolyte showed the least sludge formation. A 1,500-amp cell was operated using the ZnC12-NaC1-KC1 electrolyte at 500° C. Zinc metal was produced at the rate of 4.0 lb/hr with a current efficiency of 95 pct.

Jan 1, 1979