Search Documents

By Herrmann Flor

In steelmaking process, where up to 70% of variable cost of finished product is already incurred, energy and refractory costs account for 45-50% of the cost of production of crude steel and contribute significantly to the carbon footprint of the end product. Any attempt to control and reduce these costs will automatically lead to more competiveness and reduced carbon emissions. Leading the technology for ECOPLANT (characterized by the fact that the economic and ecological benefits are integral part of our products), SMS has developed innovative solutions which can be applied to both new and existing plants alike. This paper reviews one of the electrical and automation concepts. Tackling the secondary gas cleaning system and hence being applicable to almost all steel plants, the X-Pact® Gas Cleaning Assistant optimizes the control of individual dampers based on modelling of fluid resistances of ductwork in gas cleaning system. It guarantees the best dust removal from work place at minimum energy consumption.

Oct 30, 2017

By W. A. Ahrens, J. H. McNamara, J. G. Franek

"An economical, pollution-free process has been developed for the hydrometallurgical extraction of copper from sulphide ores. The extracted copper, in the form of cuprous chloride (CuC/), is converted by reduction to copper metal. The metal is melted and fire -refined into wire bars which meet the standards of electrolytic tough pitch (ETP) copper wirebars. IntroductionThe successful development of the Cyprus Copper Process has been an evolutionary series of events covering a time span of some nine years. The original process, based on an electrolytic membrane cell principle , was abandoned in 1975 because of technical, economic and pollution problems. During the past four years, the pilot plant has been reconstructed based on a new flowsheet and operated successfully in several campaigns, some for as long as four months. The pilot-plant hydro section operates at a 225-lblhr copper rate. In October 1977, a feasibility study was completed by Jacobs Engineering, Pasadena, California. The study showed favourable economic and technical feasibility. Jacob's studies in 1978-79 revealed favourable comparative economics with other known pyrohydro processes and favourable economies of scale.The Cyprus Copper Process converts copper concentrates of varying composition into copper metal, which has been proven to be equivalent in every way to electrolytic tough pitch copper, suitable for electrical applications. This is accomplished at capital and operating costs which are estimated to be lower than those associated with any other known currently applicable technology. Also, the total energy requirement is equal to or less than any other known process and the process is essentially pollution free."

Jan 1, 1980

By Brad Thrall

"Viceroy Resource Corporation of Vancouver, B.C. has recently developed the Brewery Creek Mine, an open pit heap leach gold mine 55km East of Dawson City in Yukon, Canada. Mineable reserves are 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797000oz) of gold. Ore processing employs the heap leach technology using run of mine ore. 1996 highlights included construction of 158,000 m2 of leach pad, placing 1.9 million tonnes of ore at a grade of 1.46 gpt on to the leach pad, construction and successful commissioning of the ADR plant, and pouring of the first gold bar on November 15th.Permitting this mine has drawn significant attention because the heap leach technology, while proven in other jurisdictions, has not been used in Yukon where winter site temperatures routinely reach -45 C for extended periods.IntroductionFollowing a comprehensive governmental and public review of the proposed project, a Class A Yukon Water license was issued in August, 1995. Construction started in 1995 and leaching commenced in October 1996. The Brewery Creek Mine is in Yukon, the home of the Klondike Gold Rush nearly 100 years ago. This is the only part of Canada not glaciated in the Wisconsin advance so there is oxide ore resulting from about 80,000 years of weathering -unique in Canada. Discontinuous permafrost is present on site and has required special consideration in the design. Winter temperatures dip below minus 50 C, demanding an approach to mining and leaching that is different than in more temperate climates.Project DescriptionThe mine comprises 8 shallow, largely oxidized gold deposits along a 7km corridor. An 8 year mining program will extract 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797,000 oz) of gold. The strip ratio will be 1.35: 1. Overall gold recovery is projected at 78%. There will be 2.3 million tonnes of ore placed on the pad annually, with an average of 2.57 tonnes (83, 000 oz) of gold recovered per year. Because of the cold winters, the mine will operate approximately 210 days per year, while the leaching process will operate on a year round basis. Run of mine ore is placed on the heap 150 days per year. The recovery process utilizes conventional sodium cyanide leaching , carbon adsorption, caustic desorption, and on-site smelting. Peak employment during mining is 145 and winter staff is reduced to 45."

Jan 1, 1997

By C. W. Owings

The number of major coal-mine explosions occurring annually in the United States is decreasing, due mainly to fuller recognition of explosion hazards in coal mines and knowledge of methods to prevent them, which can be attributed largely to the dissemination of information by the United States Bureau of Mines, State departments of mines, and other coal-mining agencies. Conditions vary considerably from one coal field to another; consequently, outstanding causes of and methods of combatting explosions vary, also. The Safety Division of the United States Bureau of Mines is making a critical study of coal-mine explosions in the various coal-mining States, and an analysis of the results is published as each study is finished. It is believed that, with completion of the series enough information will be at hand which, if applied, will prevent all coal-mine explosions. ACKNOWLEDGMENTS The data in this circular are based on records of the United States Bureau of Mines and the Industrial Commission of Ohio. The cooperation and assistance of T. P. Kearns, superintendent of the Division of Safety and Hygiene of the Industrial Commission of Ohio, and of James Berry, chief inspector of the Division of Mines of Ohio, is acknowledged.

Jan 1, 1937

By David A. Summers

The use of high pressure fluid cavitation is investigated as a means of breaking an ore into its constituent grains. This Cavitational Rock Dissagregation (CRD) is found to be possible and effective in breaking down galena ore, both in sandstone and dolomite host material. The technique did not work as well in comminuting and cleaning oil shale, because the cavitation drove the oil into emulsion with the water. The presence of dominant bedding in the rock also caused preferential breakage to these lines, rather than to the individual grain boundaries. This problem was also encountered in tests on igneous ore where weakness plants of the overall ore proved weaker than the boundaries of the individual grains. It was found that the prevailing expression of cavitation erosion dependence on pressure was not absolutely valid. In contrast it was found that CRD is much more sensitive to jet flow diameter, and when this was recognized it was found possible to erode rock with compressive strength of up to 350 MPa with operating jet pressures of 10 MPa.

Jan 1, 1982

By Michael B. Gilbert

The Woodbury L-73 Tunnel involved the design and construction of a 96-inch tunnel driven through 8,080 lf of very difficult ground conditions. Anticipated ground and groundwater conditions consisted of potentially flowing silty sand with cobbles and boulders, mixed face of sand and sandstone and full face of the St. Peter Sandstone. Actual conditions were similar, although the quantities did change from bid quantities. This paper presents the approach used for development of the GBR regarding risk management. The means of arriving at a fair compensation for variances from the baseline values to address the actual encountered tunneling behavior of the soil, boulder count and its effect on production rates are presented.

Jan 1, 2008

By Graham A. Davis

?The ideas of economists and political philosophers, both when they are right and when they are wrong, are more powerful than is commonly understood. Indeed, the world is ruled by little else. Practical men, who believe themselves to be quite exempt from any intellectual influences, are usually the slaves of some defunct economist. Madmen in authority, who hear voices in the air, are distilling their frenzy from some academic scribbler of a few years back. I am sure that the power of vested interests is vastly exaggerated compared with the gradual encroachment of ideas. . . . But, soon or late, it is ideas, not vested interests, which are dangerous for good or evil.? John Maynard Keynes The General Theory (1936) Policy analysts, economists and others have tradition-ally considered mining and mineral wealth a boon, providing rich countries with the resources needed to sustain their modern industrial economies while helping poorer countries generate the foreign exchange, tax revenues and other assets necessary for economic growth and development. Nevertheless, this conventional view has always had its critics.

Jan 1, 2008

By Allan E. Martin, George Glocker, C. E. Wood

"INTRODUCTION As part of a comprehensive investigation of the mechanism of defurization of iron and steel by slags, the Blast Furnace Studies Section, Metallurgical Division, Bureau of Mines, in cooperation with the Institute of Technology, University of Minnesota, has made a study of the forms in which sulfur occurs in blast-furnace slag. This report presents data on the three sulfides most important in iron smelting, namely, ferrous sulfide, manganous sulfide, and calcium sulfide. The tendency of these sulfides to form colloids in the molten slag was determined by an examination of quenched samples with an ultramicroscope.Vogt/ conducted experiments on sulfide silicate melts and examined synthetic blast-furnace slags in a partly crystallized condition. His conclusions were that FeS, CaS, and MnS, or isomorphous compounds, such as (FexCay)S and (MnxCaa)S, were precipitated from the melt, depending on the composition of the slag. In all specimens sulfides were visible and were spherical.Coloration of glass by sulfur also provides indirect information on the nature of sulfur in blast-furnace slags./ There seems to be a general agreement at present among the workers in the field of colored glasses that ferrous sulfide is a strong color producer. Colors that have been attributed to this compound include yellow, orange, brown, blue, and black. Apparently the ferrous sulfide is considered to be dissolved in these glasses. There is no indication that any of them have been examined for a colloidal phase.Lorenz 7/ investigated a single manganese slag in the glassy state and observed a Tyndall beam in an ultramicroscope. His conclusion was that either a manganese compound had precipitated in a finely divided condition or that metallic manganese had volatilized and penetrated into the slag as a vapor and thus formed colloidal particles."

Feb 1, 1941

By Richard Rittenhouse

This program was to develop a new base line system for automated continuous room and pillar type mining. The primary requirement estab¬lished for this machine is that the machine be capable of mining and bolting simultaneously. Additionally, this machine was to provide temporary and permanent roof control, have a productive - full - face semi-automatic mining system, leave a clean entry outby the machine, provide maximum operator protection, provide effective dust suppression and provide air scrubbing to restrict respirable dust to permissible levels. The machine has effectively demonstrated the ability to mine and bolt simultaneously. Additional above ground operation, testing, and time studies are recommended to further verify the machines abilities. Design improvements are recommended for future generation AES machines. These relate to marginal design areas such as side loading on vent duct lift cylinders, etc., that will not impair additional testing of the existing machine.

Jan 1, 1983

By [D. N. ] Naresh

During different activities pile installation like pile boring, concreting etc., it is likely that various problems, depending up on site condition may be encountered. There are possibilities that some of the activities if not correctly followed may affect the pile capacity. This paper describes few problems encountered during pile execution at different sites and presents the remedial measures undertaken to overcome them.

Jan 1, 1996

By P. H. Morris

Nineteen field trials of the co-disposal of fine coal tailings and coarse coal wastes were conducted at the dual Goonyella-Riverside mine in Queensland and at the Hunter Valley No. 1 and Warkworth mines in New South Wales, Australia. The profiles of and the sorting that occurred on the co-disposal deltas are described and an existing theory of subaerial deposition, originally developed for mine tailings alone, is shown to apply to the co-disposed wastes. This enables the dimensionless profiles of large deltas, which may take years to deposit, to be predicted from data obtained from a small delta formed in a few days or even hours

Jun 19, 1905

By William H. Shockley

THERE was an, extensive mining and industrial exploitation of Russia, about 20 years ago, by Belgian, French and British capitalists; but the results were discouraging. It is said that the Belgian and French public together lost approximately $400,000,000, chiefly in the coal and iron industry of southern Russia. This loss is largely accounted for by the fact that most of the companies were formed, as usual in " boom " times, to sell stock; and that thorough investigations were not made. In 1906, renewed interest was taken in Russian mines, especially in those of gold and copper, and a considerable literature is growing on this subject; but as yet I have seen no account of one of the large Russian mining estates. The following notes on such property, where the conditions are so different from those in the mining regions of the United States, should be of interest This inadequate and probably somewhat inaccurate account is made up, partly from my own notes made on the ground, in the summers of 1904 and 1905, and partly from a volume on the geology and resources of the estate issued several years ago, containing surface-and mine-maps, and from a pamphlet published in 1904, giving a general account of the condition and prospects of the property. This pamphlet includes a report made by Arthur L. Pearse, a member of this Institute, in 1899. Both these books are in Russian, and were prepared by the Bogoslovsk Mining Co., which owns and operates the property. Articles in many other languages have appeared dealing with various matters connected with the estate; but I know of no other general account of it. In numerous books and articles on the Urals and Siberia, however, localities are described in which somewhat similar conditions prevail. Recent papers by

Mar 1, 1908

As a result of early experiments in underground mine illumination, the Bureau of Hines recognized the need for additional experience with the underground lighting of coal mines having low seam thicknesses. There was already experience with tile illumination of coal mines having higher coal seams, and this contract with Ocean Energy Inc. (OEI) was undertaken to contribute to the "low coal" experience. For the purpose of this contract, a "low coal? mine is defined as one having less than 45 inches of overall headroom in the working places. As a practical limit, 26 inches was the minimum coal seam thickness to be encountered in this program. In one instance, the maximum coal seam thickness was eight to ten feet, however, this particular work was at the direction of the Technical Project Officer (TPO) by virtue of the unique type of lighting arrangement that was to be evaluated which would be useful for low coal. At the outset of the contract, three major tasks were established. The first two tasks involved the installation of permissible fluorescent lighting equipment at two low coal mines. The intention was to illuminate mining sections in each case consisting of one or more machines. The third task was to illuminate a variety or mining equipment including a longwall. For the purpose of this report, the fol-owing identifies the particular installations associated with each task.

Jan 1, 1976

By C. Feng, C. Elbaum

Knoop hardness measurements were carried out on large grains of iodide titanium containing different amounts of oxygen. For each oxygen content the hardness is recorded ainingas a function of the crystal orientation and of the angle 4 between the indenter diagonal and the projection of the C (hexad) axis in the surface. The results can be expressed by the following relation; hardness = n-k cos 2ø, where n and k are constants for a given oxygen content and crystal surface orientation. A NISOTROPY of hardness is a well-known phe-nomenon and has been reported for many metals.1-3 At the present time, however, such information is not available in the literature for titanium. Consequently, a systematic study of the simultaneous effects of oxygen content and crystallographic orientation on the hardness of titanium was undertaken in this laboratory. Evaluations of oxygen content in titanium are frequently carried out through hardness tests. Although such procedures may be justified in small grain specimens, the results of the present investigation indicate that the anisotropy of hardness should be taken into account in the case of coarsegrained specimens as well as in the case of pronounced preferred orientation. Materials and Experimental Procedures Iodide titanium, 99.99 pet pure and containing of the order of 0.002 wt pet O, was used throughout this investigation. The metal was arc melted in an argon atmosphere and cold rolled into strips 1/16 in. thick. These strips were subsequently recrystal-lized and strain annealed in vacuum (10" mm Hg or better) at 850°C in order to produce crystals varying in diameter from 10 to 25 mm. Oxygen was introduced into selected large crystals by heating at 700°C in an atmosphere of pure oxygen under an observed pressure of approximately 50 mm Hg. Each sample was subsequently annealed in vacuum at 850°C for 100 hr, in order to homogenize the oxygen content throughout the specimen. It was found that longer annealing was not necessary, for no change of surface hardness in a given direction was detected after prolonged annealing. The oxygen content was determined by the difference in weight of the specimens before and after the oxidation-annealing cycle. The accuracy of oxygen determination is within ±0.1 mg in samples weighing 0.5 to 1 g. A vacuum fusion analysis of oxygen was performed on several samples and gave results in good agreement with the ones obtained by the weight change. It should be emphasized that expected weight losses through evaporation of the metal in vacuum at 850°C' are many orders of magnitude lower than the precision of these measurements. Following the annealing treatment, both oxidized and unoxidized crystals were carefully polished. All detectable traces of surface cold working were removed by repeated polishing and etching. Laue back reflection X-ray patterns were taken for each crystal for the purpose of determining the orientation and ascertaining the absence of substructures detectable by this method. Hardness measurements, using a 1 kg load, were subsequently carried out on a Tukon hardness tester equipped with a Knoop indenter. The Knoop indenter was used throughout this work because indentations obtained by means of a Vickers indenter are considerably distorted due to the anisotropy of the elastic constants in titanium. Such distortions are much less pronounced in the case of Knoop indentations, although for some orientations a cer-

Jan 1, 1959

By James J. Neate

The augered cast-in-place pile system came into use in the late 1940's where various techniques were tried using pressure grouting methods. In the early development stages some piles were installed using the preplaced aggregate concrete system. As development continued it became more apparent that placement of coarse aggregate was more costly than making a pile out of a cement and sand mixture only. Various techniques were tried consisting of pumping structural grout into an open hole through a pipe left in the bottom of the hole, drilling or driving a pipe in close proximity to the tip elevation of the auger or in working a pipe down adjacent to the auger fluting. For these techniques the pipe was usually withdrawn after grout appeared at the surface. In 1951 a patent was applied for by Raymond Patterson describing the above techniques along with a technique for placement of grout using a hollow stem auger and a removable plug or lead bit at the tip of the auger. The plug or lead bit was removed by grout pressure and this would be an expendable item for each pile placed. The patent was granted in 1956 and patent rights were assigned to Intrusion-Prepakt, Inc. Shortly thereafter other contractors were granted licenses to utilize the system. Patent coverage expired in 1973 and this method now is in the public domain. Today the method is in wide use throughout the world and is particularly well accepted in Japan and England.

Jan 1, 1988

By R Peden

Recent, detailed mapping, (Allibone, 1986; Peden, in prep.) of north west Stewart Island, has shown that the Rakeahua Granite (Watters et al, 1968), is comprised of a wide range of granitoid bodies ranging from diorite to leucogranite. As a result of the wide variation in granitoids Allibone (1986), suggests renaming of the Rakeahua Granite to the Rakeahua Granitoid Complex. Names were also proposed for the individual granitoid bodies mapped.

Jan 1, 1987

By GEORGE S. POPE

This bulletin is a revision of Bulletin 63 and is published by the Bureau of Mines in order that purchasers of coal for Government, State, municipal, or private use may be informed regarding advances or refinements in sampling coal deliveries and preparing specifications for the purchase of coal. The purchase of coal by the Government under specifications depending on the heating value of the coal, its content of ash and of moisture, and other considerations, rather than upon the reputation or trade name of the coal, was based on the fuel investigations begun by the Technologic Branch of the United States Geological Survey in 1904. The plan was first adopted by the Treasury Department in 1906. Since then the plan, variously modified in form, but the same in principle, has been gradually adopted by other departments until, at present, of the coal used by the Government, the total value of which approximates $8,000,000 annually, more than half is purchased under specifications. The Government publications dealing with the adoption by the Government of the specification plan, the number of contracts awarded on that basis, and the quality of the coal delivered under such contracts in the several fiscal years covered by the reports are given in publioations a listed at the end of this bulletin. Under the authority of acts of Congress making appropriations for analyzing and testing fuels belonging to or for the use of the United States Government, a laboratory is maintained at the headquarters of the Bureau of Mines, Washington, D. C., where samples representing deliveries of coal purchased under specifications for Government use are analyzed and tested. At this laboratory more than 1,200 samples have been analyzed and tested in one month. With the complete equipment and the efficient force employed, the analytical work has been so perfected that the analyses and heating-value tests of the samples received are as accurate as may be reasonably expected in laboratory work of this nature. One of the serious drawbacks to the general adoption of the specification method for the purchase of coal is the difficulty of obtaining at reasonable cost samples of coal that can be considered fairly representative of the commercial product delivered in wagons, railroad cars, or ships. Therefore the method of taking and preparing samples for shipment to the laboratory has been given fully as much care as the making of the analyses and tests, and a general plan of collecting samples fairly representative of the delivered coal has been evolved through various modifications and improvements based on experience and increased knowledge of the physical and chemical characteristics of the various coals that are purchased by the Government. The method that is in general use by the Government is described in the following pages. In connection with studies of the coal deposits of the country, of the best methods of preventing waste in mining, and of increasing efficiency in the utilization of coal belonging to or for the use of the Government, geologists and engineers of the United States Geological Survey and of the Bureau of Mines have visited more than 2,500 coal mines scattered through all of the coal-producing States and Territories. From each mine 2 to 8 or more samples were taken, the number depending upon the size of the mine and its output. The analyses and descriptions of the samples collected up to the end of the fiscal year 1913 are published in Bureau of Mines bulletins 22 a and 85,b and those of samples collected in the fiscal years 1914 and 1915 are presented in a bulletin that will soon be published by the bureau. A study of the analyses of these samples and of the samples taken from cars shipped from a number of the same mines shows that the mine samples are as a rule of higher grade than the average commercial shipments, particularly with respect to containing a lower percentage of ash and having a correspondingly higher heating value. This difference is due to the fact that the Government inspector, proceeding on the basis of what can be done by a good miner, usually removes more of the partings of bone, slate, and other extraneous matter from his mine samples than the average miner does in ordinary practice, the aim of the miner being to get the maximum number of tons past the tipple inspection, as his earnings are based on his output. The average miner, therefore, does not always take as much care as he might in rejecting the impurities. The difference may be caused, too, by the presence of pieces of the mine roof and floor in commercial shipments. The Government inspector can readily

Jan 1, 1916

By Stephen Gerard Sawyer

This report presents a Fortran IV computer program for the structural analysis of space-frame protective canopies used in underground mines to protect equipment operators from falls of roof, face, or rib. This program entitled CANOPY permits rapid calculation of the elastic strength of a canopy for a variety of static loading conditions. Stresses in, and displacements of each structural member are computed and printed out. Additionally, identification of all members that have commenced yielding, weight of the canopy, total loads on the canopy, and maximum loads that the canopy can sustain elastically are output. Program description, input instructions, program listing, and two example problems are included.

Jan 1, 1972

By Michael M. Hamilton

In 1984 and 1985 the U.S. Bureau of Mines performed a mineral survey of the South Jackson Mountains Wilderness Study Area covering 60,211 acres of mountainous terrain of Humboldt County in northwestern Nevada. Approximately 550 lode claims have been located within or adjacent to the study area from 1900 to the present. Total recorded production for the area is 28.19 ounces gold, 1,105 ounces silver, 959 pounds copper, 6,016 pounds lead, and 12,446 pounds zinc; an additional two carloads from one mine contained an unknown amount of metal. In early 1986, there were eight active properties with a total of 126 claims. Wescord Resources and Long Lac Exploration (Texas) Inc. are involved in a joint exploration of the Jackson Mountains for volcanogenic massive sulfide deposits. Development at the Claudia mine continues in 1986. Results of the survey indicate that there are no identified mineral resources or reserves within or adjacent to the study area. Twenty-two properties have mineral occurrences containing gold, silver, copper, lead, zinc, iron, antimony, vanadium, and cobalt, with silver, copper, and iron being the most abundant.

Jan 1, 1987

By Thomas C. Shapiro

This is the final article in a three-part series on microcomputers and application software in the mineral industry. The first article covered microcomputer terms and concepts. The second discussed exploration and mining software. This article will examine plant, administrative, and geotechnical software. Every effort has been made to be current in the latest software developments. Rapid change, however, is a fact of life in the computer world and any omission is inadvertent. Introduction Geotechnical disciplines have received considerable attention in software programming. Calculations are repetitive and the formulas needed to solve them are not extremely complicated. These programs are ideally suited to the microcomputer and the microcomputer is ideally suited to the consulting geologist or engineer, due to its low cost and reliability. In fact, the advent of the Apple (a registered trademark of Apple Computer Inc.) and, more recently, the IBM personal computer has caused an explosion of inexpensive software programs available to the microcomputing public. Another area that has benefited from computerization, although not in the same way, has been mineral beneficiation. Here, process control for start-up or phase-down operations has been used in newer plants for some time. Programs to perform various calculations are becoming more common as micros increase in number. Tappi Journal has a section with solutions to handheld-calculator and microcomputer problems. Process Modeling Most process modeling is still done only on mainframes. One such program is called ASPEN PLUS (a registered trademark of Aspen Technology), and a one-week course is recommended so the user can best use the program. This program is available through timesharing from University Computing Co. Programs to find an optimal solution using Linear Programming (LP) have been around for some time. Also, plant process simulation has been possible using simulation programs. Both simulation and LP are expensive to program and run. Although there are LP programs available for some micros, the user must be fairly knowledgeable about how to set up the problem. This is because each problem must be set up as a unique program that typically requires custom programming. There are some programs that can handle blending of mine crudes and examine economic parameters over the life of the mine. Plant Applications Areas relating to mine and plant applications with programs available for micros are maintenance, production reporting, inventory, accounting, and personnel scheduling. Maintenance Maintenance typically requires that certain jobs be performed in a particular sequence and parts be ordered with enough lead time for maintenance to take place on time. There is, therefore, a critical sequence of tasks that must be performed or the scheduled maintenance will not take place. Two answers needed for maintenance project scheduling are: what is the lead time needed

Jan 4, 1984