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By Elwin L. Fisk

The Cordero mine is located in the Nevada portion of the Opalite Mining district that straddles the Oregon-Nevada state boundary. The mercury deposits of the district occur along the margins of the broad east-west graben valley of McDermitt Creek. The only other major producers, the Opalite and Bretz mines, on the northern margin of the graben have thus far exploited only shallow deposits within 100 feet of the surface. Through December 1965, Cordero has produced 94,680 flasks of mercury, the most of which came from the large underground cinnabar deposit. Nearly all of the mercury ore deposits in this district have been found in Miocene rhyolitic intrusives, flows, tuffs, and lake beds. These rhyolites have been argillically altered at depth and extensively silicified at or near the surface. These silicified areas or "opalite" masses were the original cinnabar-bearing outcrops.

Jan 1, 1968

By V. de Macedo Torres

There are technical and commercial limitations on using high fluorine copper concentrates in industrial copper smelters. The presence of more than 1000 ppm of fluorine in copper concentrates affects the sulfuric acid units generally integrated to copper smelters, and penalties are normally applied to high fluorine concentrate prices. Several process alternatives to this issue were studied at CVRD Technology Center (SUTEC): modifications on conventional sulfuric acid plants to use high fluorine concentrates, removal of fluorine containing minerals in flotation using depressants, selective leaching of fluorine minerals and sulfuric leach of copper concentrates. Finally, a hydrometallurgical process of removing fluorine was developed by SUTEC.

Jan 1, 1997

By André Oliveira

The present paper describes state-of-the-art Pulverized Coal Injection technology with focus to Dynamic Distribution guaranteeing highest accuracy on equal distribution and being thus one of the key factors enabling constantly highest injection rates. As an alternative to the construction of a new plant, existing plants may be modernized and upgraded to latest technology. Two recent examples are presented. As a conclusion, two case studies of return on investment are showing that the PCI technology, both for new facilities as well as for upgrades, is very profitable and mandatory for high blast furnace operation effectiveness.

Aug 17, 2017

This Technical Memorandum Report is a collection of three working memoranda, prepared during the course of our work for the bureau of Mines and hound together for convenient reference. These working memoranda present preliminary performance estimates, for baseband voice and narrowband through-the-earth electromagnetic communications systems of principal interest to the Bureau, for operational/emergency mine communications. The calculations were prepared to obtain early indications of the feasibility and governing parameters of such communications systems. They are based on limited, but pertinent, coal mine electromagnetic noise data acquired to-date by Bureau of Mines contractors; and of theoretical signal-attenuation characteristics for two transmitter antenna types of present interest to the Bureau. The memoranda examine the cases of baseband voice and narrowband communications for uplink and downlink transmissions, for frequencies up to 3kHz. Downlink transmissions are via a horizontal wire antenna, up-link transmissions via a vertical-axis loop antenna, for typical mine depths of 300, b00, and 1000 feet. Representative coal-mine overburden conductivities of 10-2 mhos/meter (moderate and common) and 10-1 mhos/meter (high) were used; 10-2 for voice and narrowband, 10-1 for narrowband only. Examples of high, moderate, and low; surface and subsurface; harmonic and broadband-impulsive noise conditions were taken from NBS and Westinghouse (WGL) mine noise data, together with examples of high- and low-levels of ELF atmospheric noise taken from M.I.T. Lincoln Laboratory data.

Jan 1, 1972

By E. L. Evans

The historical development of South Yorkshire mining is traced and note made of the liability to generate spontaneous combustion of some of the seams which have been worked. The liability factor is analysed firstly as an inherent property in the material of a coal seam, and secondly as a circumstance of a situation in which access is provided for the air necessary to sustain oxidation. The geological settings in which incidents of heatings have been known to occur is discussed and conditions favouring a natural pre-disposition to spontaneous oxidation exposed, particularly the effect of argillaceous material overlying the seam. An extensive strata-dynamic study follows to demonstrate the situations in which stray air currents tend to impinge on readily oxidizable material. Prevention techniques are indicated as the identification of strata-dynamic situations in which air access to broken coal is induced and thereafter th operational action to seal off the voids which have been opened up so as to exclude air from the broken coal. Measures to reduce the tendency for ventilating air to short circuit across waste voids, and to obviate deflection of air into packs are outlined. The importance of face and roadway design features is demonstrated and the consequences of practices inimical to good control of spontaneous combustion are related. Discussions on means of detection and also on the sealant materials available are included.

May 23, 1905

By Mohan K. Wali

Soil and vegetation development were studied on abandoned mine sites near Velva in Ward County, North Dakota. The sites studied were 1, 7, 17, 30 and 45 years old since abandonment; unmined sites were also studied to provide measures of comparison. Species diversity was the highest at unmined sites (114) and lowest at the I year old site (26); sites 7, 17,30 and 45 years old had 37, 52, 43 and 68 species, respectively. Stand ordination revealed that site ages were the most important in influencing species diversity and composition. Stand-environ-mental complex ordinations encompassing 53 variables showed topographic variables to be the most important followed by site ages. Rates of nutrient accumulations were as follows: organic carbon 13.1 g m-2 yr-1; nitrogen 2.5 g m-2 yr-1; phosphorus 0.01 g m-2 yr-1; potassium 0.49 g m-2 yr-1. Carbon-nitrogen ratios showed the widest range for 1 year old sites (5-40) but 70 percent of the 45 year old sites showed values below 15 which were com-parable to the unmined mixed grass prairie sites. Species distributional diagrams are provided to show their habitat preferences which may be helpful in formulating species prescriptions for revegetation.

Jan 1, 1982

By R. A. Wyman

"The froth flotation process was patented by E.L. Sulman, H.F.K. Pickard, and John Ballot in 1906 . . . . . . . . . .James M. Hyde installed the first froth flotation process in the U.S., about August 1, 1911, at the Basin Reduction Co. plant, Basin, Montana . . . . . . . . . .By 1914, 42 mining companies were operating or experimenting with the flotation process . . . . . . . . . .The period 1930 to 1960 saw the application of flotation spread to nonsulphide ores and become the key factor in the economic production of many industrial minerals". So states FROTH FLOTATION, 50th Anniversary Volume, published by AIME in 1962. It is interesting, to observe that the Mines Branch, now part of the Canadian Department of Energy, Mines and Resources, was established in 1907 through an act of Parliament entitled, "The Nines and Geology Act". In 1911, a mineral dressing group was formed and a laboratory was constructed. By 1921, an engineer was devoting full time to industrial mineral processing problems.

Jan 1, 1971

By Doris M. Hyde

The Bahama's petroleum-dominated minerals sector constricted again in 1985. The declines were mostly the result of a soft market demand for crude oil and petroleum products. In early 1984, it was a growing unprofitability that prompted Charter Oil Co. to cease using the 350,000-barrel-per-day Bahamas Oil Refining Co. facility that it jointly owns with Chevron Oil Bahamas Ltd. After midyear 1985, because of poor petroleum economics, Chevron announced it would close the refinery, leaving only a maintenance crew. In 1984, the refinery exported less than 26 million barrels of petroleum products. Chevron's throughput was reported as averaging about 8,000 barrels per day at the time of the announcement. The crude oil transshipment terminal also registered declining activity and financial losses in 1984 and 1985. Transshipments of petroleum in 1985 amounted to about 100,000 barrels per day, one-half as much as in 1982.

Jan 1, 1987

By Max J. Spendlove

The Federal Bureau of Mines has been a leader in resource recovery research since it was founded in 1910. Until the early 19601s, most of the projects were concerned primarily with the task of extending and improving conventional technology oriented to secondary metals and minerals upgrading and processing for marketable products of highest value. By the mid-1960's with the passage of the Solid Waste Disposal Act of 1965, all resource recovery research programs were increased in scope and intensity as an effort to solve the growing number of environmental problems and the rapid depletion of domestic energy and mineral resources. Many new materials were investigated including urban refuse, manufacturing, industrial wastes, and stockyard wastes. The objective was to promote maximum recycling as the most practical answer to problems of waste disposal, pollution control, and the short supply of minerals and energy. The new research projects ranged from the conversion of animal manure and other organics to oil, to the recovery of precious and common metals from demolished aircraft and electronic scrap. This profile includes brief descriptions of many selected research projects that typify, the total spectrum of Bureau of Mines research in the important field of resource recovery.

Jan 1, 1977

By Balmer Neilly

To one with so little experience in matters pertaining to currency, international finance, and foreign trade, this is surely an ambitions venture on my part. However, this is a subject of prime importance to all seriously minded Canadians and, if we are to obtain any clear understanding of the factors involved, we must study the facts and debate such points as may remain at issue. During the last few years, the world' s better known economists have described the gold standard in all its ramifications and in such detail as to leave many of us even more confused than before. If we, then, are to acquire any real conception of its meaning and use, I think we must reduce it to its fundamentals and start from there. To my way of thinking, gold in ? trade and commerce is the symbol of honesty. When you seek to discharge a debt by tendering paper you hand the recipient an I.O.U. which may or may not be good, for the purchase of goods or services to the extent of its face value. When, however, you discharge a debt by the payment of gold, it constitutes a complete and final discharge. There are no reservations - no ifs and ands - and the transaction is definitely closed to the satisfaction of all concerned. Gold, then, is evidence of accumulated and transferable wealth that is immediately acceptable in practically every part of the world. However, there is not nearly enough gold to meet the demands of world trade, and. many years ago this deficiency gave rise to what we now describe as our banking system.

Jan 1, 1949

By R. P. Killmeyer, W. W. Wen, B. K. Parekh

A continuous pilot-scale test of the GranuFlow Process was conducted using a screen-bowl centrifuge for the dewatering and reconstitution of column -flotation concentrate at a coal preparation plant in Virginia. In this test, a slipstream of the fine clean-coal slurry from the column flotation con¬centrate was treated with a bitumen emulsion before dewatering. The treated products from the screen-bowl centrifuge appeared to be dry and in a free flowing granularform, while the untreated products were wet, sticky and difficult to handle. Test results indicated that the average moisture contents of the dewatered coal products were 35.7%, 35.5%, 32.6%, 29.9% and 26.5% (by weight) with Orimulsion additions of 0.0%, 0.7%, 3.2%, 4.8% and 6.4% (by weight), respectively. The handleability and dust reduction of the dewatered coal products were also vastly improved.

Jan 1, 2000

By Tapio Ahokainen, Asmo Vartiainen

"Outotec's portfolio contains a wide variety of smelting solutions for non-ferrous metals. Some of these include flash smelting for primary copper and nickel, flash converting for copper, Ausmelt technology for primary and secondary copper, nickel, tin, lead, and zinc residues and waste, Kaldo technology for secondary copper, lead, and precious metals recovery. Outotec also offers slag cleaning technologies and much more.Company provides complete process solutions tailored to each customer's individual needs. Decades of experience have resulted in extensive metallurgical know-how that ensures the most profitable process choice and optimal performance. Outotec's life cycle technology partnership with their customers spans from the early stages of process solution design through the supply and commissioning of the entire process chain. They include integrated process control and holistic service and support concepts. Continuous research and development ensures that the customer is provided with the latest advancements in process and equipment solutions.IntroductionOutotec develops and provides technology solutions for the sustainable use of the Earth's natural resources. Solutions are ranging from various processes and special equipment needed for metallurgical extraction and mineral processing of ores to the production of refined metals and minerals. The processes include not only the grinding and physical separation of ores but also the smelting and leaching of base metals and precious metals. The company provides engineering services for whole projects as well as life cycle services on the equipment and products that they supply."

Jan 1, 2012

By R. V. Higgins

This report presents computer instructions for calculating the performance of three-phase flow of gas, oil, and water. The calculated results for an illustrative example are presented. The example is the waterflood of a reservoir containing free gas in the reservoir as a result of the partial depletion of the oil by the expansion of the gas initially in solution. The flood pattern for the example is a 5-spot.

Jan 1, 1967

By L. J. Barnes, R. O. Koch, J. H. Versteegh, C. J. N. Buisman, P. J. H. Scheeren

Several water treatment options have been studied and piloted. A process based on activity of sulphate reducing bacteria combines sulphate removal and heavy metal removal in one process step. The anaerobic bacteria reduce the sulphate to sulphide and consequently metal sulphides will precipitate. The final design for the commercial scale plant is described.

Jan 12, 1992

By Paul E. Lamoureux

Introduction The Author As the pail of smoke and wartime destruction gradually rises from the surface of the earth, from all countries, statesmen assemble to discuss and prepare pacts and treaties which are designed to, once more, bring people of all nations to understand each other and live in harmony. Scientists and engineers throughout the world are also undergoing a drastic reconversion in their ideas and objectives. No longer do they think only in terms of destruction and twist their brains to develop more devastating weapons or to surpass production records of war machinery. They have turned their eyes and ambitions to more pleasant tasks and are taking stock of wartime developments in materials, fabricating procedures, and equipment, many of which had been carefully shrouded with a veil of secrecy, and are applying their new knowledge to the fabrication or improvement of the tools of peace. The next few years will see the gradual elimination of scores of substitutes and makeshifts, expedients which the constantly changing law of supply and demand' under wartime stress necessitated. The universal search for satisfactory substitutes, however, has resulted in a general awakening of plant engineers to the possibilities of materials with which they were relatively inexperienced, with the result that, in many instances, what was considered a substitution at the outset turned out to be more satisfactory than the original material, and, in reality, can be considered a worthwhile development. Not only have materials been explored, but existing fabricating processes have been reviewed, and others, built around the properties and characteristics of new materials, created.

Jan 1, 1947

By Jean Wehbe, Daniel C. Brahana

"The new Mercedes-Benz Stadium (MBS), home of the Atlanta Falcons, is part of a new era of stadium construction in the U.S. These new-age stadiums are larger and have more amenities than their predecessors. Many of the MBS’s features, including its innovative retractable roof, result in extraordinary structural loads. The roof structure is supported by a series of mega columns that bear on eight large caps, six of which are supported by drilled piers. Each of the pier caps contains between 8 and 16 drilled piers that bear in the underlying bedrock. The design pier diameters are 6 and 6.5 ft (1.8 m and 1.9 m). Augercast piles were used to support two of the mega column caps. Drilled piers, augercast piles, aggregate piers and spread footings were used to support the more lightly loaded portions of the structure.The focus of this article is the construction aspects of the drilled pier foundations. Initially, a fairly extensive drilled pier load test program was performed. Load testing included a Statnamic compression test, two Osterberg Cell tests and two lateral tests. Production pier installation included over 3,800 linear ft (1,158.2 m) of earth excavation and over 1,350 linear ft (411.4 m) of hard rock excavation. The piers contain more than 6,600 cu yd (4,587.3 cu m) of concrete and 1,100 tons (998 tonnes) of reinforcing steel. Drilled pier installation took about 4.5 months. ABE Enterprises was the specialty foundation subcontractor and Bauer-Pileco was the equipment provider.Site and Subsurface ConditionsThe project site is in downtown Atlanta and was originally occupied by residential buildings. A portion of the site was later developed as a rail yard, and other areas contained light manufacturing, warehouses and other relatively light structures. For the past 15 to 20 years the site had been used for surface parking.Beneath a surficial layer of manmade fill, soil test borings at the site generally encountered residual soil, partially weathered rock and the parent bedrock. The bedrock at the site is highly variable, both in elevation and in hardness/quality. The depth to rock is reasonably uniform within the western two-thirds of the site at about 20 to 50 ft (6 to 15.2 m), with a few exceptions. In the eastern third of the site, the rock drops off dramatically to the north and east. In one mega column cap, there was almost 80 ft (24.3 m) in elevation difference. In two borings in the cap that were 20 ft (6.1 m) apart, the top of rock varied in elevation by 34 ft (10.3 m)"

Jan 1, 2016

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

By C. W. Davis

During the fiscal year 1935-36, the Ore-Testing Section has been active in carrying out a program designed to attain the objectives that have been set up for it. For the Purpose of standardizing important testing methods, an attempt has been made to develop a rationalized scheme for ore testing, starting with preliminary investigations to determine the physical and chemical properties of the ore, following this with a logical selection and trial of processing tests to find out how the ore may be most effectively treated, and concluding with a discussion of what interpretation may be placed on the results in terms of plant design and operation. A selection of Procedures that appear well-suited to the ore-dressing problems under investigation is included in the following paper of this report so that other experimenters may be enabled to verify our findings and to offer criticisms and suggestions for improving our practice. A tentative scheme for the evaluation of flotation reagents is being investigated, and some progress has been made in a study to determine the significance of small-scale testing. These projects have required 899 analyses. Papers on these and others on ore testing, such as testing for amalgamation and for cyanidation, will be included in future annual reports.

Jan 1, 1937

A knowledge of airway friction factor (K-factor) is necessary to designing mine ventilation systems for least cost and optimum effectiveness. The friction factor used must be accurate and reliable to estimate correctly roadway resistances and pressure sources for required flows. Though the resistance to flow offered by mine airways has been an object of study over the last half century, no accurate relation has yet been established from which the prediction of the resistance of a projected airway can be made. In Kentucky, only limited and incomplete data on local K-factors are available. Therefore, there is a need for field investigations to determine these values in-situ for existing mining conditions. The author describes a study concerning K-factor that was carried out in ten coal mines, located in eastern and western Kentucky. The results of these investigations are presented in both tabular and graphical form.

Jan 1, 1991

By J. B. Coher, M. B. Bever

COLD work destroys long-range order, as was first observed by Dehlinger and Graf.1 Dahl2 showed that the mechanical disordering caused by cold work produces changes in those properties that are affected by long-range order. The existence of order has a marked effect on tile manner in which an alloy deforms and therefore on its mechanical properties.L' The relation between order and deformation behavior however, is only beginning to be understood. Seemann and G1ander4 suggested that cold work reduces an ordered alloy to a kind of gruel of antiphase domains. According to Cottrell,5 superdis-locations and pairs of dislocations in a slip plane connected by a strip of anti-phase domain boundary provide deformation mechanisms which do not change the state of order. In general, however, slip may be expected to produce new domain boundaries and destroy order if dislocations move on intersecting planes or cut through existing domain boundaries. The yield strength of an ordered alloy may pass through a maximum with decreasing domain size.5"7 The reduction of domain size resulting from cold work may, therefore, lead to a maximum in strength properties. Flinn8 suggests that dislocations can climb by short-range diffusion during deformation and thus can generate domain boundaries not only on slip planes, but also on other planes which will be those with the lowest domain-boundary energy. It has long been known that the rate of strain hardening of an alloy in the ordered state is larger than in the disordered state.3'9 Also the slip bands in ordered CU3, AU10 and Ni3Mn" are finer than in the disordered alloys. The stress which causes initial yielding in Cu,Au passes through a maximum with decreasing domain size.6'12 A maximum has also been observed in the hardness of ordered Ni3Mn as a function of strain.' These observations suggest, but do not prove, that domain size reduction occurs during deformation. According to Fisher13 slip destroys short-range order and thus the strength of an alloy is related to the degree of short-range order present. Rudman and Averbach14 and Averbach et a1.,15 demonstrated that cold work reduces short-range order in copper-gold and gold-silver alloys. Destruction of long-range and short-range order by cold work implies slip on an appreciable fraction of planes. Yielding of an alloy in which short-range order exists or antiphase domain boundaries are present should be discontinuous because the first dislocations moving across the slip plane meet with the largest resistance.5 Such discontinuous yielding has been observed in CU3AU6,16 and Cuzn.l7 This phenomenon, however, can also be explained by mechanisms not involving order.b The published investigations of the effects of cold work on alloys with long-range or short-range order have not been covered thoroughly in reviews of order-disorder phenomena. These investigations, therefore, will be listed here. They have been concerned with strength properties> 2,3,6,8,9,12,16-21 electrical resistivity,2,4,18,19,21-26: thermoelectric power, magnetic properties,2,18,21,26 and X-ray strain'1,2,14,15,27,28 The slip systems and the appearance of the microstructure after deformation in ordered and disordered alloys have also been investigated. 6.10.ll,l7,23,29,30 The alloys used in these investigations were copper-gold. 1-4,6,9,10,14,16,18 23-26,28,29 copper-zinc. L7. 19. 20,30 nickel-manganese,2 11,21 iron-aluminum. iron-nickel,' copper palladium,4,18,22 gold-silver.4,18,22 and palladium-silver-copper.4 In the work reported here. the changes in properties of polycrystalline Cu3Au were investigated as functions of strain in wire drawing and rolling. Specimens were heat treated before deformation

Jan 1, 1961