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By Gopala N. Krishnan

The most promising candidate for the recovery of alumina from non-bauxitic sources is the leaching of clay by HCL acid followed by crystallization of aluminum chloride hexahydrate (ACH) by hydrogen chloride sparging. Hydrothermal precipitation of boehmite ( ?-A100H) from aluminum chloride solution will simplify the process, will reduce energy consumption and will eliminate corrosion problems involved in calcination of ACH to obtain alumina. This report summarizes the results of Phase I of a program to study the precipitation of boehmite from AlC13 solutions. The amount of boehmite precipitation from dilute A1C13 solutions (5 wt%) is . negligible below 200°C. Above 200°C the precipitation increases with increasing temperature approaching 40% at 300°C. Addition of HCl acid to the dilute A1C13 solution even in small quantities drastically reduces boehmite precipitation. Solution impurities such as Fe, Ca, Mg, or Na substantially promote the precipitation of boehmite. No precipitation is observed from concentrated A1C13 solution (30wt%) representing the leach liquor.

Jan 1, 1980

By B. K. Shibler

As a part of the Bureau of Mines' intensive; 'investigation of domestic manganese deposits, ore-dressing studies were conducted on three samples of oxide and silicate manganese ores from various Wyoming properties. The samples wore as follows: 1. A 2-ton sample of ore was obtained by a Bureau engineer during examination of the Caulkins-McGuckin property in the center of Crook County, 10 miles north of Sundance, Wyo. The ore body was described as a vein deposit in rhyolite porphyry. 2. The J. B. C. Mining Co. submitted a 1-ton sample of oxide manganese ore from a property located 44 miles northeast of Rock River in Albany County, Wyoming. 3. A 1-ton sample of oxide-silicate-ore was obtained by a Bureau examining engineer from the Gheen property in the northeast corner of Washakie County, Wyo. The ore body was described as a replacement deposit in a country rock of silicified limestone. As the samples differed widely in physical and chemical characteristics and also in their response to methods of concentration, ore from each property was considered a separate ore-dressing problem.

Jan 1, 1949

By Leonard Obert

The various underground rooms in the Bureau of Mines Oil-Shale mine, Rifle, Colo., have been open for periods ranging from 3 to 5 years. During this time 3 roof falls have occurred; 1 was induced, and the other 2 were unintentional. The three roof falls are described in this report. Two causative factors are discussed -a time-dependent deterioration of the roof rock and an unfavorable system of jointing that occurred in the strata overlying the present roof horizon. Irrespective of cause, the operating life of any stoping area would have been short com-pared with the life of the roof (1 to 4 in the most unfavorable instance), if a high-production system of mining had been employed. The report is concluded with several recommendations that should be considered in planning future mining operations.

Jan 1, 1958

By Robert N. Roby

The Hornsilver lead-zinc property was examined by the Bureau in 1942 and again in 1944. A project was started on the property in April 1946 and completed in January 1947. Silver was first discovered in this district in 1883, and while complete production records are not available, it is known that a substantial tonnage of high-grade silver ore was shipped before 1887. All of the ore was mined from surface or near-surface workings. When the high-grade oxidized ore was exhausted, the district became inactive and remained so until the 1920's. In 1928 and 1929 some activity was shown in the district, but the Hornsilver mine was not reopened until November 1937. Between 1939 and 1946, the mine produced about 16,000 tons of ore of 531 ounces of gold, 283 ounces of silver, over a million pounds of load, and nerdy 2 million pounds of zinc. The property is now controlled by the Era Mining & Development Co., which has acquired the Last Chance and Ella groups of claims, in addition to the Hornsilver mine.

Jan 1, 1948

By E. R. Palowitch

This report stems from a study by the Bureau of Mines of the possibility of reducing coal filter-cake moisture by applying radiant heat directly to the filter cake while under vacuum during the drying phase of the filter cycle. One disk of a 4-foot-diameter vacuum filter was equipped with gas-fired radiant-heat generators and the effect of radiant heating on the moisture content of a variety of filter cakes was studied. The results of this investigation show that this process can best be described as a filter aid capable of increasing the effectiveness of conventional filtration approximately 6 percentage points of moisture. The operating cost of removing water by this method is somewhat lower than the average operating cost of thermal drying and is considerably cheaper when the total cost is considered. Removal of water from coal that has been wet-cleaned is an important part of the overall coal preparation process. Water is a contaminant, and it is foolish to wash coal to reduce its ash content and add inert water in the process. In some instances the removal of water is actually more important than the removal of ash-forming minerals; its weight adds to the cost of transportation, and its evaporation during burning or carbonizing absorbs useful heat. Fine coal that contains more than about 10 percent moisture is notoriously difficult to handle. A problem thus exists for which there are sound practical and economic reasons to seek a solution.

Jan 1, 1961

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 James P. Bennett

The Bureau of Mines investigated the role of imported natural flake graphite in dolomite-carbon refractories used in steelmaking processes. Fundamental engineering data were obtained to enable the evaluation of substitute materials. Changes in oxidation resistance (2,000° F), hot strength (2,750° F), and deformation under load (2,7500 F) caused by 10-wt-pct additions of five different kinds of natural flake graphite and increasing quantities (0 to 30 pct) of a 90-pct-carbon natural flake graphite were studied. Results indicated that carbon purity of 10-wt-pct-graphite additions did not influence hot strength or deformation under load. When the quantity of 90-pct-carbon graphite addition varied between 0 and 30 wt pct in a dolomite-carbon brick, hot strength was highest and de-formation under load lowest with 10-wt-pct additions. As hot strength test temperature was increased from 5000 to 2,750° F, the strength difference observed between 0-and 30-wt-pct additions of a 90-pct-carbon graphite became smaller. Additions of a boron-treated graphite caused significantly higher strength and lower deformation under load at high temperatures, while an addition of ball clay significantly reduced strength and increased deformation.

Jan 1, 1987

By A. W. BELDEN

Among the investigations that the Bureau of Mines is conducting witha view to increasing efficiency in the utilization of fuels belonging to or for the use of the Government is an investigation of the processesthat take place in a foundry cupola during a melt. Some observations on the results of cupola tests of cokes at the Government fuel-testing plant in St. Louis, Mo., the coke being fromcoal from many coal fields of the United States, have been stated in a previous bulletin.s Especial attention was given to the meltinglosses that resulted from the use of different grades of coke, light and porous or heavy and dense. These losses amounted in one instance to 52.5 per cent of the iron charged and showed, in convincing manner, the need of exact information in regard to conditions in the fuelbed of the cupola.b Melting losses of iron have been fully appreciated but little under-- stood. The fact that these losses were possible with either light or heavy coke led to the belief that by using small charges 80 placed that. melting would take place in that zone of the cupola where the highest heat and the smallest percentage of oxygen prevailed and by confiningall melting to this zone these losses would be eliminated and the economical use of practically any coke produced for metallurgical purposes would become possible. This widening of the field from whichcoke might be drawn for foundry purposes would serve to place the foundryman in an independent position as regards his source of supply, and would tend to conserve the better grades of coking coals, which are being rapidly exhausted, by making the poorer grades available for mixing with them. In order to investigate conditions within a cupola, the Bureau of Mines as a first step decided to install a commercial cupola, to sample the gases during their travel from the tuy~res upward, and to determine the temperature of the fuel bed.

Jan 1, 1913

By C. M. Flynn

The solubilities of sideronatrite [Na2Fe(OH)(SO4)2?3H20] and ferrinatrite [Na3Fe(SO4),&apos;3H2O] were determined by the Bureau of Mines in the Na2SO4-Fe2O3-H2SO4-H20 system at 25°, 40°, 60°, and 90° C. The solution compositions investigated ranged from Na+-Fe&apos;+ mol ratios of 0.5 to >100 (Na2SO4 saturation) and H+ -SO4 2-mol ratios of 0 to 1. O. The results are presented in the form of contour plots. The solubilities were determined by seeding supersaturated solutions of known composition with the specified solid phase to precipitate a substantial amount of solid. Water was then added in small portions to the solution until the last portion of the solid dissolved. Equilibration times at 25°, 40°, 60°, and 90° C were 2 days, 1 day, 8 to 16 h, and 2 to 4 h, respectively. The accuracy of the solubility data is estimated to be 1 to 2 pet. Low iron solubilities of <0.36 pct Fe2(SO4)&apos;, or 1 g Fe/kg solution, were obtained in solutions containing at least 8 pet Na2SO4 in the absence of H2SO4 or a total of at least 36 to 38 pet Na2SO4 + H2SO4 at high acidity. The filterability and density of sideronatrite and ferrinatrite in comparison with other iron compounds are reported. These compounds are suitable vehicles for iron removal in Na2SO4-rieh solutions. Additional solubility data on the Na2SO4-H2SO4-H20 system were also obtained.

Jan 1, 1987

By G. S. Scott, G. W. Jones, I. Spolan, R. E. Kennedy

In studies made by the United States Bureau of Mines to determine the causes of explosions in medium-pressure acetylene generators , it was shown that when these are operated at elevated temperatures the acetylene liberated in an acetylene generator carries enough water vapor to heat certain types of carbides to a high temperature , when the acetylene- water vapor mixtures are passed through the carbide . This report contains results of further work carried out to develop an apparatus to show the heating effects or reactivity of various types of carbides in contact with acetylene - water vapor mixtures .

Apr 1, 1947

By BUREAU OF MINES

This paper is a revision of Reports of Investigations , Serial 2541 , which was published in November , 1923 , for the benefit of State mining inspectors , safety engineers of mining companies , and others interested in electrical safety inspection in mines . It presents the important points that should be watched by inspectors and briefly reviews the work of the Bureau of Mines in testing of electrical apparatus and equipment to determine their permissibility for use in gassy coal mines .

Jan 1, 1929

By Harold E. Heide

Although the United States has been the largest consumer of tin, only a small quantity of tin was produced or. the North American Continent during peace times, and thy deficiency was made UP by foreign imports. Because the most important sources of tin wore cut off by the war with Japan, it became necessary to increase imports from South America and Africa and, if possible, develop domestic tin reserves. Most of the tin produced in North America has come from the Seward Peninsula, Alaska, and a substantial portion of this was produced from the Potato Mountain area. Tin was first identified as occurring in the Seward Peninsula by A. H. Brooks in 1900, when a part of heavy concentrates from Anikovik River and Buhna Creek, one of its tributaries, proved to be stream tin. 4/ His report was given considerable publicity by the daily press, and the first steamers north in 1901 carried a number of prospectors bound for the Seward Peninsula to search for tin. The deposits of stream tin on Buck Creek in the Potato Mountain area were discovered in the fall of 1901. 2/

Jan 1, 1949

By Janet Torma-Krajewski, Pauline Lewis, Paul Gust, Lisa Steiner, Kean Johnson

Ergonomics processes described in the literature have been associated mostly with manufacturing, financial, electronics, and office settings where working conditions tend to be rather constant and repetitive. The information presented in this document demonstrates, however, that an ergonomics process can also be implemented in a setting such as mining where working conditions frequently change and workers are periodically exposed to extreme weather conditions. This document describes how Bridger Coal Company implemented an ergonomics process at its Jim Bridger Mine from 2001 through 2004. The process developed by the Ergonomics Committee, the promotion of the process to management and employees, and the impacts of the process on working conditions at the mine are reviewed. Barriers overcome and lessons learned are also described. Quotes from Bridger Coal Company employees are included in the document to add a personal perspective. Other industries with working conditions similar to mining, such as construction and agriculture, may find this information useful.

Jan 9, 2006

By G. M. Potter, S. J. Hussey, R. Havens

The Artillery Peak manganese ores , from one of the largest known manganese deposits in the United States , present a difficult problem in concentration because they are low-grade and the association of manganese and gangue minerals is intimate and complex. The known size of this deposit has justified investigation of processes such as leaching, wherein preliminary enrichment of the original feed might be advantageous .. Therefore , the ore-dressing studies on Artillery Peak ores were carried on with the object not only of making directly marketable manganese products but also of removing acid-consuming calcite and raising the grade of ore for leachingplant feed . Owing to the extent of the deposits , test work was carried on at the Salt Lake laboratories in considerable detail on several lots of ore of varying composition . This paper summarizes the results obtained from laboratory testing of four samples obtained by engineers of the Mining Branch from the Maggie Canyon area of the Artillery Peak deposit . Also included are results obtained from testing one sample of Chapin Group ore , which was considered representative of numerous very low-grade ores submitted from the Artillery Peak district . During the course of the investigations , many data were obtained and compiled , but for the sake of brevity , data of secondary importance have been omitted or condensed and only those tests giving the more pertinent results are discussed in detail ...

Nov 1, 1947

By Walter D. Holland

This document is one of a series of instruction guides developed to help instructors present health and safety training courses to workers in the metal and nonmetal mining industry. This course is intended to provide above ground metal and nonmetal mining employees with training which will assist them in performing their work safely and healthfully. A document entitled, "Airborne Contaminants in Above Ground Metal and Nonmetal Mining and Processing Work Areas," is used as a manual for the students during the course. The unique features of the teaching guide are thumb rules for recognizing hazardous situations, candidate contamin¬ants for each work area and descriptions of control devices and work procedures.

Jan 1, 1977

By Paul M. Linebarger

This paper is one of a series of digests of foreign mining legislation and court decisions prepared in advance of a general report relative to the rights of American citizens to explore for minerals and to own and operate mines in various foreign countries. This interpretation of the laws of Mexico has been pro oared from the best information available in Washington but is released subject to correction and amplification, if necessary, by the proper American diplomatic and consular officers, to whom it has been referred through the courtesy of the Department of State. INTRODUCTION Present-day Mexican mining legislation involves, not only the latest minim enactment (August 1, 1026), but many other enactments and regulations, principal among which are the Constitution, the Civil Code, the Code of Commerce, the Foreign Law, the Mining Tax Law, and. the Civil Jurisprudence of Mexico--the last-mentioned being based in Dart on Supreme Court decisions. Ere Mexican Federal Government is supreme in mining legislation because, among other reasons, a large part of the revenue of the Government must come from the fiscal control of the mines. All circulars, decrees, and rulings that affect the mines not only have their origin in the Central Government but are administered thereby. The Department of Industry, Commerce, and Labor is in control of all mines. Attention may here be called, however,

Jan 1, 1929

By James F. O'Neill

Brown iron ore deposits in Quitman County , Ga . , were investigated by the Federal Bureau of Mines in cooperation with the State of Georgia , Department of Commerce , and the University of Alabama . Ninety- one holes were drilled , having an aggregate footage of 2,188 feet ; seventy- one holes penetrated 248 feet of iron mineralization . Average thickness of the ore zone was 3.5 feet under an average thickness of 14.7 feet of overburden . The drilling developed inferred reserves containing nearly 30 million long tons of crude ore with an average analysis of 28 percent iron plus minor quantities of manganese . Test work done by the Bureau on the crude ore samples indicated that they would upgrade by current log washer practice , with the use of a 1 /8 - inch screen , and yield 4.4 million dry long tons of concentrate with an average analysis of 52.1 percent iron plus manganese . The weight recovery obtained was 14.7 percent . Research studies made by the Bureau showed that the weight recovery would be increased by changing the screen size without any appreciable sacrifice of grade . The average weight recovery was increased to 18 percent with a 10 - mesh screen and 22.8 percent with a 20 - mesh screen . Screen tests studies indicated that there was no appreciable interlocking of the iron and manganese minerals and the clay and silica waste particles of the materials retained on a 200- mesh screen . Clay was prominent in micron - size slimes . Silica was deleterious in the minus 20 - mesh size .

Jan 1, 1965

By M. J. Kirwan

[There have been large increases in the oil production and casing-head gas production of certain wells on the Quinn dome (northern part of the Lyons-Quinn field of Oklahoma) caused by large volumes of gas under high pressure entering Vie productive oil sand, The oil production of sore of the leases in this part of the field temporarily increased over 100 per cent within a few days after gas entered the oil sand among the leases that had the greatest increases in oil production wore those on which no gas wells were drilled but which were located up-elope on the structure in reference to gas wells on adjoining properties. It is conservatively estimated that 1,444,000,000, cubic feet of gas entered the productive oil sand and, up to January 1, 1924, caused an increase of about 950,000 barrels of oil from this sand. The casing-held gas volumes of a number of wells producing between 25,000 and 75,000 cubic feet of gas per day increased to several hundred thousand cubic feet and a few walls increased to nearly two million cubic feet per day after extraneous gas entered the oil sand from which the wells were producing.]

Jan 1, 1924

By T. Bieniawski

"INTRODUCTION The Congress theme ""Improvement of Mine Productivity and Overall Economics by Modern Technology"" is probably beat: addressed by the subtheme allocated to this Plenary Session. It is appropriate that .Theme 1 emphasizes the simple point that effective use of geotechnical information is the key to improving mine productivity. In essence, this means that: (1) geological and geomechanics, (rock mechanics) data must be collected in sufficient quantity and of high quality; (ii) data interpretation must be performed specifically for purposes of engineering design; (iii) innovative design approaches should be used to bring about Improvements in productivity and safety.While, each of these three aspects .may: seem obvious to any mining engineer it is a fact that the above sequence is seldom followed and as a result, mining engineering not infrequently lags, behind other branches of engineering when it comes to design creativity, efficiency and safety.. . After all, mining is still-one of the most hazardous occupations and we are gathered here to discuss, at the highest world professional forum, how to use more effectively the modern technology. This however, does not mean that mining engineers are less capable than other engineers or that their achievements are any lesser; far from it! Mining engineers are the cream of the engineering society on whose efforts depends the welfare of mankind. Moreover, they have produced minerals and coal evergrowing quantities against evergrowing difficulties. Yet, we must and can become even better because we are not making full use of the modern technology and rock mechanics knowledge already at our disposal, and. we are not being innovative enough to the full extent of .our capabilities."

Jan 1, 1989

By H. Kenworthy

The objective of this investigation was to evaluate the technical feasibility of smelting certain low-grade domestic iron ores in an electric furnace. Laboratory-scale experiments showed that a high recovery of iron in the form of pig iron can be obtained from east Texas ores containing less than 25 percent iron. The pig iron was amenable to standard-or electric-furnace-refining methods for producing steel. Car-bon, silicon, and phosphorus were the primary impurities removed in refining. Overall recoveries of iron as pig iron exceeded 95 percent, in contrast with commercial mineral-dressing recoveries on these particular ores of 50 percent of the iron as a 45-to 50-percent iron concentrate.

Jan 1, 1958