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By J. K. Brimacombe, F. D. Richardson

Studies have been made of interfacial turbulence occurring in reactions in which indium, zinc and cadmium, dissolved in amalgams, are oxidised into aqueous phases by ferric or mercurous ions. It has been found that this turbulence occurs when the concentrations of oxidising ions in the aqueous phase become sufficiently great. These concentrations are the same as those at which the mass-transfer coefficients in the aqueous phase increase sharply when both phases are stirred by gas bubbles rising through them. The effects of gas flow rate on the mass-transfer coefficients for zinc in mercury have been established, and the oxidation of pure mercury has been investigated. The relevance of the work to processes involving liquid metals is discussed

Dec 1, 1971

By Jarrell C. Grout

The Bureau of Mines has developed a computer program for use in solving nonlinear regression problems. The program is written in a general form so that, regardless of the functional relationship, the unknown parameters may be evaluated by either the Gauss-Newton or the Newton-Raphson methods of iteration. Variances and covariances of the parameters, as derived from the law for the propagation of errors, are also determined.

Jan 1, 1969

By B. W. Gandrud

In 1927 Coghill showed that there is considerable liberation of the iron oxide mineral from gangue when the Alabama red iron ores are ground to a size suitable for classification and tabling but that there is not sufficient to make possible a high extraction and a high grade of concentrate. Coghill states: High extraction and 'high grade of concentrate cannot be obtained without grinding to a size comparable with flotation or cyanide practice. If grade of concentrate be sacrificed the grinding need not be so severe. These ores slime readily during grinding, and in most instances the slimes are only slightly higher grade than the original ore. Not only do they carry a considerable percentage of the total iron in the ore, so that to reject them as tailings would result in prohibitively low extraction, but they are too fine to be amenable to ordinary methods of gravity concentration. In 1929 the Bureau of Mines published results showing that certain Alabama oolitic iron ores could be concentrated by classification and tabling after grinding, with rubber-covered rods. This selective grinding produced slimes of much higher grade than the original ore, and they were considered part of the final concentrate.

Jan 1, 1934

By Harvey W. Parker

Our industry has developed to the skilled, experienced and productive industry that we now enjoy as a result of the visions of great engineers throughout history, but, in particular for their visions in the last 1 centuries. Unfortunately for our forefathers, the technology lagged so far behind that these exceptional visions could not be realized for decades, sometimes for a century. All that has changed in recent time and many bold and visionary projects can now be constructed and operated because of dramatic advances in technology. Before, say, 1950, tunnel technology developed very slowly. However, technology is now developing at such a fast rate that planners and decision makers are challenged to stay ahead. Moreover, new technology will develop during the lifetime of any project that can dramatically improve under-ground space projects. One of the best examples of this technological advancement is that of closed-face TBMs which now make tunneling feasible in previously impossible ground conditions. Since it usually takes a decade or more to plan, overcome environmental and political issues, construct, and put into service major projects, planners and designers are challenged by the changes in technology that occurs during the long time span of planning and construction. This is particularly true of large infrastructure projects such as transportation, water and wastewater systems and other major underground schemes. Also, since the serviceable life of many of these tunnels is often over one century, planners must consider not only lessons learned from the past but also what new concepts and innovations may develop over an extremely long time. These and other issues create a great challenge to planners and illustrate the great importance of careful but creative vision and flexibility during planning of long-term tunnel and underground space projects.

Jan 1, 2008

By C. S. Allbright

This report gives the results of analyzing three groups of crude shale oils by the Bureau of Mines procedure:4/ (1) Oils produced by standard Fischer assay determinations on oil shales from Brazil (Paraiba Valley) and the United States (Colorado); (2) oils produced from Brazilian shale by different retorting methods; and (3) oils from high-temperature retorting of Colorado oil shale in the Entrained Solids retort. It is the second in a series presenting data obtained by analyzing crude shale oils from various sources. The series furnishes information on the general characteristics and compositions of a wide variety of shale oils. Use of a standard analytical method on all samples facilitates comparison of different oils. The 18 oil samples analyzed in this project comprised 3 from assays of Brazilian and Colorado oil shales in the Fischer retort, 9 obtained by processing Brazilian shale in various other units, and 6 from entrained solids retorting of Colorado shale at 1,000° to 1,500° F. The crude oils from Brazilian shale contained about half as much nitrogen as the Colorado oils. Properties of the Fischer assay oils from Colorado shales agreed with some data that relate grade of the oil shale with properties of the crude oil from the Fischer assay. Comparison of results from Fischer assays of oils from the foreign and domestic shales shows that the oil from Brazilian shale contains more low-boiling material and less residuum than either of the two from Colorado shale. This fact is reflected in lower specific gravity, viscosity, and carbon-residue values for the Brazilian oil. Retorting Brazilian shale in the Entrained Solids unit at 1,120° F. produced an oil whose boiling range was generally lower than the boiling ranges of oils obtained by processing in three other retorts at conventional temperatures. The quality of crude oils from high-temperature retorting of Colorado shale in the Entrained Solids process varies with retorting temperature. As the temperature is raised within the range 1,000° to 1,500° F., the amount of the naphtha fraction in the crude oil increases to about 35 percent and the aromaticity to 98 percent.

Jan 1, 1956

By Jr. Denton

This U.S. Bureau of Mines report presents the documentation for HEAPREC, a methodology for calculating reclamation performance bonds for cyanide heap leach operations. HEAPREC is a template developed for use with Lotus 1-2-33 release 2.01 or newer software. The report is presented in step-by-step "user's manual" format. Appendices contain detailed background and reference material on performance bonding, cyanide detoxification regulation, cyanide detoxification methods, general mine reclamation procedures, and an example bond calculation.

Jan 1, 1992

By A. W. Decora

Gas-liquid chromatography has been applied to separating basic nitrogen compounds, such as pyridines and amines. Close-boiling compounds have been separated by exploiting structural and polarity differences, using selective liquid substrates dispersed on specially prepared solid supports. Development of these special supports was necessary in order to obtain symmetric peaks for basic nitrogen compounds; solution of this problem was important in applying gas-liquid chromatography to the analysis of basic nitrogen compounds found in shale oil. Attempts to analyze shale-oil tar bases by conventional gas-liquid chromatographic techniques, using Chromosorb4/ or Celite 545 as the support for a nonpolar liquid substrate, resulted in asymmetric peaks. These asymmetries were caused by adsorption of sample vapors on the solid support. Symmetric peaks were obtained when strongly polar liquid substrates were used on either Chromosorb or Celite. However, a solid support giving symmetric peaks only with strong polar substrates restricts the choice of substrate, and frequently, desired separations cannot be achieved.

Jan 1, 1961

By C. Hendricks

This paper is based upon field studies conducted in a western Canadian open pit coal mine. This work has involved the adaptation of microprocessor-based instrumentation to monitor various operating parameters on-board blasthole drills and mining shovels. A review of instrumentation and monitoring methodology will first be presented. Based upon experience from field-based studies, the paper will subsequently focus on the application of monitoring technology within the framework of an integrated Equipment Monitoring System. Such a system will permit the real-time performance evaluation of key equipment involved in surface mille production.

Jan 1, 1991

By Frederick C. Kohout

An advanced water-in-oil emulsion hydraulic fluid has been developed which meets defined laboratory performance criteria and which has given fully satisfactory results in a one-year underground mine test in two continuous miners. A novel method of monitoring fluid water content was demonstrated and incorporated into a test kit for use at or near the mine site. Test fluid fire resistance integrity as measured by the MSHA Schedule 30 procedure was maintained during the test and important fire resistance test variables identified.

Jan 1, 1979

By Xuemei Zheng, Aiyuan Ma, Chao Liu, Guojiang Li, Chenyu Sun, Jinhui Peng, Libo Zhang, Yongguang Luo

In this paper, the removal of fluorides and chlorides from blast furnace dusts by water vapor enhanced microwave roasting was investigated, combined with the advantages of microwave selective heating and based on a thermodynamic analysis of zinc and lead halides. According to proposed reactions in the process, detailed experiments were systematically conducted to study the effect of roasting temperature, holding time, air flow, water vapor flow rates, and stirring speed on the efficiency of the removal of F and Cl. The results show that 97.26% of F and 64.23% of Cl could be separated when the condition of the roasting temperature of 650°C, stirring speed of 80 rpm, holding time at 60 min, air flow of 350 L/h and water vapor flow rate of 8 mL/min was optimized.

Jan 1, 2016

By Elisa Araujo Santos Darsie

A busca na melhoria da qualidade dos aços, principalmente no caso de aços limpos, fez com que o distribuidor de lingotamento continuo também seja empregado para a remoção das inclusões responsáveis por prejudicar as propriedades mecânicas dos aços. Uma melhor eficiência desta função do distribuidor pode ser atingida com o conhecimento das características do escoamento do banho metálico de modo que se possam propor modificações na configuração do distribuidor. Esses fenômenos de escoamento e remoção de inclusões podem ser simulados mediante a utilização da modelagem física. O objetivo deste trabalho é avaliar quatro configurações internas de distribuidor por meio da qualificação do escoamento via ensaio de linhas de fluxo e quantificação de inclusões passantes pelo veio com o ensaio de remoção de inclusões. As variáveis de controle utilizadas neste estudo são: velocidade de lingotamento, presença de barreiras e presença de tubo longo. Os resultados apresentados para o distribuidor em questão mostram que para os casos com o tubo longo, o uso da barreira torna o escoamento predominantemente ascendente eliminando o curto-circuito e favorável a remoção de inclusões passando de 29,76 para 24,29% de inclusões passantes pelo veio. Enquanto que para os casos sem tubo longo, o uso da barreira proposta diminuiu o contato do aço com a escória sobrenadante, aumentou o curto-circuito e aumentou também o percentual de inclusões passantes pelo veio de 2,56 para 3,01%.

Aug 8, 2018

By Margarete Kalin

"Difficulties arise in implementing environmental technologies in the mining sector because important fundamental processes, which lead to the environmental degradation, are ignored. Weathering rates, the role of bacteria in the process and the incomplete application of the matching principle of accounting at the time the mining disturbance take place. Mining is a multi-stakeholder activity and the environmental problems have multivariate dimensions also effecting process.The limiting factors in the contaminant generation process are the transport of oxygen by advection, convection or diffusion in air or water and the associated microbial activity. Weathering products are transported from the mineral surface by atmospheric precipitation to surface and groundwater. This contamination takes place at different rates, requiring a long time to evaluate technological choices.Restoration efforts have to focus on slow reaction rates in the contaminant generating processes. Technology, which does not address the reaction rates and is selected based on inappropriate time scales, will not provide long-term solutions. Natural approaches to reduce acid generation, based on Ecological Engineering principles have required decades of research and field testing, but now show promise in addressing the cause of AMD and ameliorating its effects."

Jan 1, 2005

By F. A. Rutledge

The Bureau of Mines Investigated the Copper Bullion claims at Rua Cove on the east coast of knight Island in Prince William Sound, Alaska, during November-December 1948 and March-April 1949. This project was part of the Bureau of Mines program for developing critical and strategic minerals in Alaska, Mineralization at the copper deposit on the Copper Bullion group of claims is mainly pyrrhotate and chalcopyrite, confined to a northeast-trending shear zone in the greenstone 2,000 feet northwest of Rua Cove. The property has been partly developed by two adits, by a number of crosscuts from the upper adit, and by several diamond-drill holes.

Jan 1, 1953

By M. J. Adam

The Bureau of Mines is investigating the feasibility of partitioning complex sulfide minerals to simpler sulfide phases by sulfidation reactions. Such partitioning can afford opportunity to improve selective extraction of mineral constituents of value. This report describes research involving sulfidation partitioning of byproduct chalcopyrite concentrates from Missouri lead ore processing, and a Utah chalcopyrite concentrate from Cu ore processing. Small chalcopyrite samples were sulfidized with elemental S in glass capsules sealed after evacuating and backfilling with He, by heating for 1 to 24 h at specific temperatures in the range of 250? to 500? C, extending from below to above the boiling point of S (-4450 C).

Jan 1, 1987

By Wilfrid Comeau

The RICHTER scale is used in classifying earthquake severity. It is an energy scale giving the estimated energy liberated at the source of the earthquake. Earthquake damage on the earth’s surface, for example at the epicenter - spot on the earth’s surface directly above the earthquake, for a given RICHTER number can vary. This depends on the depth of the earthquake focus. Deeper earthquakes will generally cause a lower level of damage at the epicenter but the damage will be spread over a greater area. As mentioned by Randy Wheeler on Blastserve, each successive RICHTER number represents about a 30-fold increase in energy. This scale is open at both ends with “0” RICHTER equal to about 104 Joules. The lowest level detected by sensitive instruments is about 2 on the RICHTER scale or about 107 Joules. The highest-level earthquake detected at 8.9 RICHTER represents a release of about 3 x 101 7 Joules.

Jan 1, 2003

By Anderson Azevedo Agra

O Pó de Aciaria Elétrica (PAE) é um resíduo sólido gerado durante a fabricação de aços em usinas com Forno Elétrico a Arco (FEA). Esse resíduo contem quantidades apreciáveis de metais, tais como ferro e zinco, tornando sua reciclagem interessante não só do ponto de vista ambiental como econômico. Assim, esse trabalho teve como objetivo avaliar a autorredução de misturas de pó de aciaria elétrica e coque verde de petróleo (CVP). Para isso, misturas e pelotas de PAE:CVP, com variados teores de redutor, foram submetidas a ensaios de autorredução em termobalança e, na forma de pelotas autorredutoras, numa retorta aquecida em forno elétrico vertical. A redução das amostras foi analisada a partir da perda de massa das misturas. Além disso, a redução das pelotas autorredutoras foi observada através de análises de difração de raios X. Nestas análises foi possível verificar decomposição da Franklinita e a redução dos óxidos de Ferro e Zinco.

Aug 17, 2017

By C. E. Wyndham

The occurrences of manganese In Alabama were reported to be widely scattered over the northeastern section of the State, and these were examined before a development project was started.2/ The most promising and available showings were chosen for further investigation, which include 1 deposit in Goshen Valley, 6 in the Rock Run area, and 2 in the northern section of Calhoun County. The work was performed by the Bureau of Mines from July 29, 1949, to February 17, 1950. The work consisted of power auger drilling 69 holes 3-1/2 inches in diameter and totaling 2,548.4 linear feet. The accuracy of samples from auger drill holes in this type of deposit was determined by sinking two shafts a total depth of 68.17 feet, from which channel samples were cut. Sixteen rotary core holes totaling 1,048.7 linear feet were drilled with a 3-inch, double-tube core barrel. Twenty-two diamond core holes were drilled with a 2-1/8-inch, double-tube core barrel and NX diamond bit. In addition to the above drilling 220.8 cubic yards of soil and rock was excavated by hand from 403.9 linear feet of trenches and 69.7 feet of test pita. A total of 206 samples were taken and analyzed for manganese, iron, cobalt, nickel, and insoluble.

Jan 1, 1953

The Bureau of Mines is responsible for a broad spectrum of programs for meeting the diverse and changing mineral resource needs of the Nation. These programs are managed by the Director and two Deputy Directors, who formulate general policy and program direction from the Washington, D.C., headquarters. Bureau program activities are classified into two major functions, minerals research and minerals information and analysis. A senior advisory staff, consisting of the Chief Staff Officer and Chief Scientist, provides advice and consultation to the Director on a wide range of scientific and technical matters and acts on behalf of the Director to maintain liaison with other government agencies, both foreign and domestic, mineral industries, and professional societies. The Minerals Research Directorate Technological research and development in minerals have long been cornerstones of the Bureau of Mines. The Minerals Research Directorate performs this work. Re-search functions cover the extraction, processing, use, reuse, and disposal of mineral materials; the reduction of health and safety hazards in mining and processing; and minimizing undesirable environmental effects. The production, conservation, sale, and distribution of helium is also conducted under the Research Directorate.

Jan 1, 1981

By W. W. Adams

"The fifth annual National Safety Competition conducted by the United States Bureau of Mines to determine the best safety records at mines and quarries during the calendar year 1929 has been concluded, and the general results of the contest are presented herewith. To the winner in each of the five groups into which the contestants were divided there has been awarded the bronze trophy 'Sentinels of. Safety,' donated by the Explosives Engineer magazine. The trophy for bituminous coal mines was won by a mine in Alabama; that for metal mines by an iron-ore mine in Michigan; that for nonmetallic mineral mines by a salt mine in New York; that for quarries and open-cut mines went to a limestone quarry in Michigan;. the trophy provided for anthracite mines was, of course, won by a mine in Pennsylvania, as all of the anthracite mines participating in the contest are situated in that State.Winners of the trophies were selected by a committee of sward in accordance with rules governing the contest and on the basis of accident records furnished by the various companies to the Bureau of Mines. These records were summarized by the bureau and the results submitted to the committee. Members of the committee are W. H. Cameron, managing director of the National Safety Council. William Green, president of the American Federation of Labor; James F. Callbreath, secretary of the American Mining Congress; T. T. Read, Vinton professor of mining of Columbia University and editor of 'Mining and Metallurgy'; C. B. Huntress, executive secretary of the National Coal Association; A. J., Curtis, assistant to the general manager of the Portland Cement Association; A. T. Goldbeck, director of the engineering bureau of the National Crushed Stone Association.Thirty-four States were represented in the l29 contest. Among the plants which participated were 68 bituminous coal mines, 29 anthracite mines, 54 metal mines, 19 nonmetallic mineral mines, all of the foregoing being underground mines, and 141 quarries or open-cut mines. A total of 106,533,006 man-hours of work was reported by all of the companies. Accidents during the year numbered 7,008 and represented a period of disability equal to 986,306 man-days. Hence the accident-severity rate for all plants combined represented 9.3 man-days of disability for each thousand man-hours of exposure to hazard. Similarly, the combined accident-frequency rate for all plants showed that 66.3 accidents occurred for every million man-hours of exposure to hazard. Both of these rates indicated an improvement over the combined rates for all plants in the previous year's contest. The reduction in the accident-severity rate centered chiefly in the metal mine group, though all except the quarry and open-cut mine group shared in the reduction; the improvement in the accident-frequency rate was in all croups except anthracite and metal, the rate for the former having increased while that of the latter remained unchanged."

May 1, 1930

By HARRINCTON EMERSON

UNEMPLOYMENT is the most ominous shadow ahead of the industrial nations today. Only two great industrial countries are free from unemployment, France and the Soviet Commonwealth. In France the social unit is the family, not the individual. This has saved France. In the Soviet Commonwealth, development is proceeding so rapidly from agricultural to industrial that there is still a dearth of muscle workers in the non-agricultural enterprises. In the other industrial countries unemployment results both from acute temporary recession in industrial activities and from the rapidly increasing substitution of the machine for the man. Temporary recessions can be mitigated, alleviated by makeshifts, often ill considered. Secular recessions due to a fundamental change in the way of accomplishing physical, chemical results cannot be cured by any makeshift. There must be a period of transition. There is therefore before us the three- fold problem, immediate, prosimate and ultimate.

Jan 1, 1930