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The drill steel' sharpening shop, which stands adjacent to the Chaffers shaft, is built to the dimensions of 110 ft. 9 in. by 58 ft. wide, and is air conditioned in order to maintain reasonable working conditions during the summer months.Figure 1 is a plan of the shop, showing the disposition of the machines and equipment.LIST OF STEEL SHOP EQUIPMENTAir Conditioning Plant comprising:-1 Spray and Eliminator Type Air Cooler, 6' ft. x 7 ft. x 6 ft. with 80 fine sprays.1 No. 36 Keith type ER. Ball Bearing upcast multivane centrifugal fan.20,000 cfm. a in. WG. at 450 r.p.m.Fan motor, A.G.E. S.C. 10 h.p. 1,160 r.p.m.1 Water Pump. 2?!-3-in. Thompson Class G. Single Stage Centrifugal Pump.1 Pump Motor, A.G.E. S.C. 70 h.p. 1,160 r.p.m.Drill Steel Sharpening Equipment:-2 Holman Sharpening Machines, No. 11.1 Ingersoll Rand Sharpening Machine, No. 54.5 Ingersoll Rand Sharpening Machines, No. 50.2 Holman Hot Millers, Type DM. Double Spindle Machines.2 Morgan Hot Millers, Type 1.6 Reamers consisting of motors with Ingersoll Rand Chuck fitted to the shaft and carrying a reamer of i-in. square Ultra Capital Steel Motors, A.G.E. S.C. 1 h.p. 1,160 r.p.m.4 Double-sided Drill Sharpening Furnaces, oil fired with L.P. "Major" 2-in. non-rotary whirl type burners.Combustion Chamber, 2 ft. 4 in. x 6 in. x 12 in. Oil consumption, 3·3 to 3·8 gallons per hour.Furnace Lining, Standard Kyanite.Firebricks, 9 in. x 3 in. x 4 in.2 Moving Frame type double-sided tip hardening furnaces, oil fired using High Pressure Air reduced to 3 lb. per square inch.Combustion Chamber, 3 ft. 5 in. x 5 in. x 16 in.Burners, "Major" L.P. 2-in. non-rotary whirl type.Oil consumption, 3·3 to 3'8 gallons per hour.Furnace lining-bottom and sides, 60 only 9 in. x 3 in. x 4 in. Kyanite bricks.

Jan 1, 1941

By David Reddick

The mining industry is in the midst of dramatic change. Mining activities are moving from industrialized first world countries (Canada, Australia, and the United States) to the third world. This shift is occurring due to depleted reserves, tough environmental standards, and expensive labor in traditional mining countries. During a recent trip to South Africa, I was asked, owing to my educational background in economics and an international involvement in drilling and blasting, what changes could be anticipated in third world blasting practices as labor costs increase. It is from that beginning that this presentation has evolved.

Jan 1, 1997

By H. D. Kline

This paper is one of a series being prepared by the Bureau of Mines on methods, practices, and costs in various mining districts in the United States. The paper describes mining and ore recovery methods common to the Batesville manganese district, Independence County, Ark., and gives the costs of producing merchantable ore by three operators whose methods were more or less typical of those of many other local manganese producers. The operating costs reported were those of Leonard Baxter at mines on Brooks Hill for the calendar year 1958 and Arkansas Mining and Exploration Corp. at Section 16 mine and the Searcy group of mines and Miller-McGee Corp. at the Diener mine during the first 6 months of 1959. Manganese are was mined in the district as early as 1849 and almost continuously thereafter until August 1959, when termination of the Government's domestic manganese purchase program resulted in complete cessation of mining activity. During those years, production came from more than 189 mines and properties, of which only a few produced as much as 30,000 tons of merchantable ore.

Jan 1, 1962

By Philip J. Guerney, S. O’ Leary, André R. Laplante

"Concentration of dense mineral phases (s.g. greater than 7) for characterisation of individual particles and mineral grains by electron microscopy is a well established technique for the detection and characterisation of valuable mineral phases. This presentation describes the type of data that can be generated when both the concentration and characterisation steps are carried to higher levels than typical. The concentration step is the gravity recoverable gold (GRG) protocol that has been used for over 100 ore samples. This protocol yields three concentrates that represent three progressive degrees of grinding and liberation. Three ore samples were subjected to the GRG protocol and three size classes of each concentrate were characterised using the mineral liberation analyser (MLA), an automated, EDX-based tool. This presentation briefly presents GRG and MLA technology, and then focuses on the results obtained: photos, images and databank, the latter used to evaluate the extent of particle liberation and particle shape.INTRODUCTIONThe practice of gravity concentration prior to characterization of mineral samples using electron beam microscopy is solidly established. Typically, a dense liquid such as tetrabromoethane (density: 2.97 g/cm3) is used to reject the light phase, typically carbonates and silicates. The heavy phase, mostly sulphides, oxides and precious metals, is then mounted in a polymer matrix and examined using beam microscopy.Both the pre-concentration and the sample preparation/examination steps have seen significant advances over the past ten years, but are not without problems. A major issue of preconcentration is that most dense liquids used are toxic, tetrabromoethane being a prime example. More recently, a dense liquid with little or no toxicity (sodium polytungstate, distributed by Sometu Inc.) has become commercially available, but its use is limited to relatively low s.g. splits around 3 g/cm3. Dense liquids are viscous, and their use is limited to particles coarser than 37 µm, although centrifuge separation can probably lower this limit to around 10 µm. Magnetogravimetric separators can achieve much higher specific density cuts, but upgrading below 100 µm or in the presence of magnetic minerals remains a problem. The use of centrifuge separators such as the 3-in Knelson Concentrator (KC MD3) or the Falcon 4-in SB (SB4) is particularly attractive since these units can easily process large masses (by laboratory standards) and achieve a cut density well above those of dense liquids."

Jan 1, 2003

By N. R. Dixon

This report summarizes all work performed under U.S. Bureau of Mines Contract No. J0395028, "Noise Control of Rubber-Tired Front-End Loaders Used in Surface Mining. " Two loaders, a Caterpillar 988 and an International H-400B, were chosen for this program, and the noise sources and acoustic paths that contribute to the operator's noise exposure were identified. Retrofit noise control treatments were designed and installed on these loaders, and noise reductions of more than 10 dBA at the operator position were achieved on both machines. The retrofit packages are low cost and have been field tested in two mines for more than two years. The results of the program were communicated to the mining industry through a series of noise control workshops and a field manual. The workshops were given in nine states across the U.S. and more than 440 manuals were distributed An audio/visual slide presentation was also developed which the program.

Jan 1, 1983

By M. J. Ankeny, J. J. Forbes

The United States Bureau of Mines often receives inquiries from the mineral , petroleum , and allied industries concerning the essential steps to be taken in the formation of Holmes Safety chapters and councils . The purpose of this circular is to answer in a general way such inquiries and to relate briefly the history and work of the Holmes Safety Association to the present date .

Jul 1, 1931

By Carolina Passanante

Aços Inoxidáveis Supermartensíticos surgiram na indústria petroquímica como um material alternativo para confecção de dutos, devido principalmente ao sinergismo de suas propriedades mecânicas e de corrosão. Com esta nova demanda, tornou-se necessária a caracterização deste material em suas diversas propriedades, destacando-se neste trabalho o efeito da microestrutura na resistência à corrosão. Objetivou-se, portanto, o estudo da resistência à corrosão por pite de um aço inoxidável supermartensítico 13Cr-5Ni-2Mo-Nb em função da fração volumétrica de ferrita-delta (d) presente na microestrutura. A variação da ferrita-delta foi alcançada através de tratamentos de recozimento, a 1.050°C, durante diferentes tempos (de 0,5h a 48h). As amostras foram submetidas a ensaios de polarização potenciodinâmica em eletrólito contendo 3,5% NaCl, naturalmente aerado. Quantificou-se, ainda, a porcentagem de ferrita em cada uma das condições através de ataque eletrolítico com solução 20% NaOH. Os resultados obtidos evidenciaram a diminuição desta fase com o aumento do tempo de recozimento, chegando praticamente à sua eliminação com tratamento de 48h. Paralelamente, a resistência à corrosão por pite deste aço foi melhorada de modo proporcional à diminuição da fase ferrita, resultando em um aumento de aproximadamente 115 mV da pior para a melhor condição, comprovando que, de fato, a presença de ferrita-delta prejudica as propriedades de resistência à corrosão localizada.

Aug 7, 2018

This report has been prepared in response to a request by the Bureau of Land Management (BLM) Fairbanks Alaska District Office that the Bureau of Mines quantitatively assess the potential supply of minerals from undiscovered deposits in the White Mountains National Recreation Area (WMNRA) and the western part of the North Steese National Conservation Area (SNCA) in Alaska. The assessment will be used to assist in future land-use decision-making. Resource Management Plans (RMPs) for the WMNRA and the SNCA were approved by the BLM in 1986. These plans imposed significant restrictions on new mineral development in the two areas. The level of public concern regarding these actions, especially on the part of the mining industry, has spurred BLM to seek additional information about the potential supply of minerals from the two areas with assistance from the Bureau of Mines. The assessment focuses on an area within the WMNRA and the SNCA which has been administratively closed to mineral entry. The study area encompassed approximately 1.24 million acres and included all of the WMNRA and the western portion of the North SNCA (fig. ES-1). Three quantitative estimates of the potential supply of minerals from the study area were developed: 1) For all lands in the study area, assuming that they are open to mineral entry-the baseline analysis; 2) For those lands which have been closed to mineral entry; and 3) For eleven prospective mineral activity areas, assuming that all are open to mineral entry.

Jan 1, 1989

By J. P. Jarrell

Environmental considerations are of increasing importance in determining the acceptability, schedule and cost of expansion ofCanada's uranium processing industry. Environmental considerations must be addressed in the early stages of facility planning. This results in a dilemma, as the process data needed to predict physical environmental impacts are not yet available from process design activities. Hence, a business risk is incurred if plant design is carried forward to meet these requirements prior to project (or site) approval. On the other hand, project scheduling normally mitigates against leaving process design engineering until such time as project approval is obtained. This paper examines the experience gained in Eldorado Nuclear's proposed expansion of refining capacity as viewed by an environmental engineering consultant. The history of the project and the relationship to process design functions in the two-year period prior to the Port Granby environmental hearings are reviewed. During the Port Granby public hearing, there was a consensus that normal operation of the proposed refinery could be successfully integrated with the site's natural environmental constraints. Moreover, the radiological impact from plant operations was demonstrated to be inconsequential. However, concerns were raised relating to plant upset and accident situations. These concerns are summarized. Process data requirements identified during the environmental hearings are discussed. Finally, the concerns for on-site burial of radioactive waste are reviewed. These concerns focussed on long-term stability of the waste in the presence ofgroundwater transport, erosion and glaciers. The AECB's position on waste management with regard to this project is reviewed in light ofthe implications for design.

Jan 1, 1979

By W. C. Babcock

This report covers Phase V of .a continuing program to apply a new liquid membrane process called coupled transport to the recovery pf metals from hydrometallurgical leach solutions. During this phase of the program, a membrane system of moderate scale was constructed and field-tested at the Exxon Highlands Mine and Mill Co. site near Douglas, Wyoming. The test unit contained four hollow-fiber membrane modules, each with 100 ft2 of membrane area. In the field tests, about 1000 gallons per day of leach solution was processed. The unit was operated on the leach solution for about 50 days. Leach solution entering the unit contained 100 ppm uranium. This concentration was reduced to about 5 ppm by coupled-transport treatment, and the uranium was concentrated to about 2 wt% as a uranyl carbonate product. Under these conditions, a transmembrane uranium flux of about 2.5 lb/ft2-year was obtained. An economic analysis showed that the cost of recovering uranium from this leach solution via coupled trans-port is about $1.20/lb. At higher concentrations of uranium in the leach solution this cost is reduced. For example, at 1000 ppm the cost of uranium recovery is about $0.30/lb.

Jan 1, 1983

By M J. Gillespie, P D. Erskine

Mine site rehabilitation generally includes the re-shaping of overburden to create a final landform, manipulation of substrates and subsequent revegetation. Due to the wide range of environmental variables that influence rehabilitation progression, having clearly-stated final land-use goals and ongoing significant contributions to the planning process, from prefeasibility through to mine closure, is essential for achieving stable landforms and sustainable rehabilitated communities. Two examples of rehabilitation processes in the phosphate rich region of North West Queensland are used to illustrate some of the possible benefits of early planning and communication of rehabilitation requirements.Approximately 160 km south of Mount Isa, Incitec Pivot Limited operates a 35 year old open cut mine at Phosphate Hill. Monitoring of rehabilitation areas and selected analogue sites is undertaken annually, but the initial landform design, substrate management and species selection has created a difficult environment for revegetated areas to successfully establish. Constant management input (such as weed management, erosion control, supplementary seeding, etc) will, therefore, be required over a long time frame.The second example uses exploratory drilling and historic costean pits at Legend International HoldingÆs Paradise South site, 135 km north of Mount Isa, to determine the success of natural vegetation colonisation on waste rock and compacted soils, and the effects of cattle grazing on recolonisation. This information can be used by planners of the mine life to inform possible end-land use decisions and proposed completion criteria.In a semi-arid environment such as North West Queensland, the creation of a post-mine landscape suitable for nature conservation and/or grazing can be an arduous task. The input from environmental personnel at all stages of the mining process will positively impact upon the quality of the resulting rehabilitation and ensure undesirable legacy issues are minimised.CITATION:Gillespie, M J and Erskine, P D, 2012. Importance of early rehabilitation planning - Case studies from North West Queensland, in Proceedings Life-of-Mine 2012 , pp 187-196 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 10, 2012

By D. van Heerden

In the mining industry abrasion caused by both sliding and impact have over the years resulted in costly damage to installations such as ore passes and silos. Good geotechnical practices combined with the use of a high quality abrasion resistant concrete can prolong the life of such an installation and minimize problems associated with abrasion. In order to maximize the life of an abrasion resistant concrete, the choice and combination of the correct raw materials (cement, aggregate and fibre) and overall mix design needed to make up such a concrete are important. This paper presents technical data and practical experience showing that concrete formulated with calcium aluminate cement resists severe abrasion conditions better than similar OPC-based concretes.

Jan 1, 2005

A good deal of experimental work has been done from time to time on the application of compressed air to the elevation of wet pulp. On account of the flat nature of most of our mill sites elevation of the pulp has to be provided for, and the various methods in vogue show considerable loss of time, in the replaceing of wearing parts. During the last two years the writer has carried out a great many experiments with a view of devising an elevator that will give continuous work with a minimum of wear.The results do not show a high efficiency for the power employed, but the lift is continuous in operation, very cheaply installed, and possesses no wearing parts. The lift was tried working in a bore hole of 8 in. diameter, but in many cases it is more convenient to sink a small well for the purpose. The result to date showed that the most efficiency was obtained when the depth of the wellwas not less than the height of the lift required. The pressure of air required in pounds per square inch was (approximately) half the number of feet to be lifted.In the majority of cases the lift required varied between 20 ft. and 50 ft. and the air pressure required between 10 lbs. and 25 lhs. per square inch. In most existing installations the air compressors in use were delivering air to the receivers at about four times that pressure, and when air so compressed was expanded to perform its work at a reduced pressure, it was apparent that the power exerted in origInally compressing the air above the working pressure required at the lift was absolutely lost.

Jan 1, 1901

By H. F. Silliman, Daniel R. Hull, Earl W. Palmer

THE brass-rolling industry has not had a great deal of experience with antimony in its product. There have been some recent excursions with antimony as a corrosion inhibitor in tubes, but in sheet brass it has been regarded with apprehension and generally avoided. This is not to say that [ ] contaminations have never occurred, and probably a great many brass mill men have had their own ideas on the effect of such contamination. Our own views were based upon certain experiences some years ago with strip castings that split lengthwise in the early stages of rolling. The nature of this splitting is shown in Fig. I, from a photograph taken in 1922 as a record of 20 bars of 65-35 common brass made with an antimonial brand of copper. These bars were cast 6 ¾ in. wide by 1 in. thick by 45 in. long. In the first pass through the rolls, 19 of the 20 split lengthwise throughout their length, while each half curved outward in a wide arc as it emerged from the rolls. [ ] In those days, if splitting was not a frequent occurrence, it was not unfamiliar. One can recall periods of short duration when large amounts of common brass would behave in this way. There was nothing imaginary about these spells. The affected metal would split lengthwise in the breaking rolls, and no maneuvering of mill practice made any difference. The condition would descend like a plague, demoralize the mill for several days, and disappear. It is doubtful if anyone knew the cause-however many explanations may have been current. In 1921 a quantity of split brass was traced to the use of fired small-arms

Jan 1, 1943

By Robert J. F. Goodfellow, William A. T. Meakin, Kevin Clarke, Eric Cole

INTRODUCTION New York City Water Supply—Background and History Since the 1840s New York City has been developing the largest, and perhaps, the best urban water supply and distribution system in the world in terms of quality and reliability. One of the engineering marvels of the modern world, the New York City water supply and distribution system serves a population of almost nine million, including residents in nearby Westchester, Putnam, Ulster, and Orange Counties of New York State. The average daily supplies presently are running at almost 60 m3/sec(about 1,350 million gallons per day). The watershed for the New York City water supply system, under the jurisdiction of the New York City Department of Environmental Protection (NYCDEP), consists of19 reservoirs and three controlled lakes, and covers an area of approximately5,000 square kilometers (about 2,000 square miles) north of New York City. The watershed total available storage capacity is about two billion cubic meters (560 billion gallons) and is divided into three reservoir systems: the Catskill and Delaware watersheds located West of the Hudson River; and the Croton watershed, located east of the Hudson River, see Figure 1. The first element of the system, the Croton Aqueduct, started operations in 1842.Through several updates and expansions, the present-day Croton system was in place by 1911, providing a potential maximum supply of about 15 m3/s (about 340 mgd). The system includes ten reservoirs and three controlled lakes. In the late 1800s, with the tremendous growth of the City, New York City water engineers began to look for additional sources. Between 1907 and 1929, the City acquired water rights and constructed a new 148 km (92 miles) Catskill aqueduct to convey water from the Ashokan Reservoir to the City. The Catskill system also included the construction of the Kensico and Hillview Reservoirs just north of the City,

Jan 1, 2005

By S. J. Macnaughton

The Olympic Dam deposit in South Australia contains 2% copper and 0.06% uranium, which are present as bomite, chalcocite, chalcopyrite, uraninite, coffinite and brannerite. The copper is principally recovered using flotation. The flotation tailings, which contain the bulk of the uranium, and typically 0.3% copper, are leached using sulfuric acid and an oxidant at atmospheric pressure. This paper describes the results from a detailed investigation of the leaching behaviour of this ore. The influence of acid strength, Fe3+ concentration, redox potential and temperature on the dissolution of uranium and copper minerals was studied. Experimental data were obtained from extensive batch leach tests. Mineralogical studies, including SEM analysis of individual mineral grains, were also carried out. The maximum extraction of uranium determined experimentally was in good agreement with that predicted from SEM determination of the proportion of refractory brannerite in the ore. The leaching rate of copper was found to be independent of acidity over the range 20 g L-' to pH 2.0, but was strongly dependent on temperature and Fe3+ concentration. Uranium extraction showed a weak de endence on acidity, Arrhenius temperature dependence and a complex co-dependence on F>+ concentration and redox potential. A kinetic model has been developed, which predicts copper and uranium dissolution. This model will be incorporated into a more comprehensive model that can be used to predict leach performance and reagent consumption for specific ore samples.

Jan 1, 1999

By Martti Hagfors

The Finnish Defence Forces Technical Research Centre (PVTT) studied the effect of shape of boost-er to its ability to ignite insensitive (IM) plastic bonded explosive (PBX). Therefore an explosive fac-tory produced 20 insensitive (IM) plastic bonded explosive (PBX) charges for the tests. The mass of each of the charges was exactly 9.2 kg (20.3 lb). The charges were equipped by two different type of boosters; RDX and PETN. Both the explosives contained some parts of plasticizers. The weight of all the boosters was exactly 300 g (0.66lb). On the bases of their shape, the boosters were also divid-ed into two different groups, cylindrical and “pancake”. In the middle of the “pancakes” there was also shaped a small cone in such away that the detonation could accelerate to its full speed after the charge was ignited. The following shots were exploded;

Jan 1, 2013

By K. H. Brandt

A standard planning system for the development of roadways was adopted for German coal mines based on the results of geotechnical and rockmechanical investigations. Its goal is to provide for sufficient support systems under conditions of multiple seam mining at great depth. The report points out the required determination of geotechnical parameters and the basis for achieving a high level of planning reliability and resulting high performance in roadway development and longwall mining. The instrumentation and the planning procedure for selecting the support design most appropriate for the geotechnical conditions are described and demonstrated by examples.

Jan 1, 2004

By Charles Henrique Xavier Morais Magalhães

Os Aços Inoxidáveis Duplex possuem uma estrutura constituída basicamente por ferrita e austenita na proporção aproximada de 50%. Este trabalho estudou a influência da temperatura de um tratamento térmico na morfologia e fração de ferrita e austenita no aço UNS S32304. Os tratamentos térmicos realizados consistiram no aquecimento das amostras, desde a temperatura ambiente até a temperatura de 1250°C, seguido de um resfriamento lento em um segundo forno estável em uma determinada temperatura. As amostras permaneceram neste segundo forno por um intervalo de tempo necessário para que suas temperaturas atingissem exatamente um valor desejado, sendo então imediatamente retiradas e resfriadas em água a 20°C para preservar a estrutura resultante do ciclo térmico aplicado. As amostras foram metalograficamente preparadas, atacadas e analisadas com o auxílio de um microscópio ótico. As frações de fases medidas por MO se aproximaram dos resultados obtidos por simulação utilizando o software Thermo-Calc. A morfologia das fases variou significativamente com a diminuição da temperatura de tratamento, uma vez que a austenita se mostrou mais fragmentada nas temperaturas mais baixas, porém o bandeamento não deixou de existir na estrutura.A transformação da ferrita em austenita se mostrou fortemente dependente do tempo.

Aug 16, 2017

By Vivas

Goldcorp is one of the largest gold producers in the world with projects in South, Central and North America. Goldcorp?s flagship operation is Peñasquito, a world class, polymetallic deposit that started production in 2010 and is one of the largest mines in Mexico. Since the early stages of the project, Goldcorp has used the most advanced technologies available to maximize its value. However, the implementation of optimum mine plans has been challenging to put into practice. This is due to the fact that the mine operation involves more complexity than the plans usually reflect. This challenge is an industry-wide issue that presents opportunities for improvement. This article discusses the mine planning methodologies and procedures used to connect long-, medium- and short-term planning strategies in order to bridge the gap and produce optimum mine plans that can be practically implemented in the field.