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This modern plant was installed with the object of treating all oxide ore and payable dump material by the cyanide process.The plant is located on a ridge on the eastern side of Linda Gully. The mill -site has a slope to the south of 1 in 4.The new plant is of steel and concrete construction and was specially designed to suit the climatic conditions which exist at Mount Morgan.THE COARSE CRUSHING PLANTThe ore received from the, mine is dumped into a 600-ton steel bin which is commanded by a 3 ft. 6 in. gauge railway,The mine ore is conveyed by steam locomotives in rakes of five self-dumping 7-ton railroad cars. The dump material is mostly loaded by bull-dozers and conveyed to the binsin large motor lorries. Located on the top of the bin is a heavy railroad grizzly having 12-in openings through which all ore must pass.The flow of ore from this steel bin is controlled by a No. 7D 3-speed Ross chain feeder. It should be mentioned here that, although the bottom of the steel bin is inclined at an angle of 45°, it has been found, owing to the clayey nature of the oxide ore, that the live capacity of the bin is only about 50% of the total capacity.

Jan 1, 1939

By G. S. Scott

[The Duretiu of Kinen, as :) pr<r"Yof its :;encr:rL propan clealini: with the causes, behavior, n.ncl tor-trol of o1:t1?;.?cite-mine fires, hns investic:&apos;lte3 I varionr. Te:.nr, for Je tec tin:: iccj.r)ic:~ t he;, tint; :,:.zqdergro-.:rid and of <~e termining the trend of the hen tir..: once -I i&apos;i re j 7 knnm tr, he nrcsc~t.]

Jan 1, 1938

By G. S. Scott

[The Duretiu of Kinen, as :) pr<r"Yof its :;encr:rL propan clealini: with the causes, behavior, n.ncl tor-trol of o1:t1?;.?cite-mine fires, hns investic:&apos;lte3 I varionr. Te:.nr, for Je tec tin:: iccj.r)ic:~ t he;, tint; :,:.zqdergro-.:rid and of <~e termining the trend of the hen tir..: once -I i&apos;i re j 7 knnm tr, he nrcsc~t.]

Jan 1, 1938

By John Dasher

In 1980, some US cars were designed and built to metric dimensions; wine and gas were sold by the liter; and the March of Dimes Walkathon was measured in kilometers. Although the US Congress has taken a &apos;&apos;soft" approach to metrication, and public resistance to the idea remains strong, the use of metric units is becoming more and more widespread. As the minerals industry becomes more international in scope, US mining companies are converting to the metric system-particularly those companies with business interests overseas.

Jan 2, 1981

Using DEM to Model Industrial Banana Screens

Sep 13, 2010

By M. J. Beus, B. Stewart, S. Iverson

Synopsis U.S. Mine Safety and Health Administration (MSHA) accidents statistics have identified ore-pass hazards as a significant safety problem in U.S. underground metal mines. The statistics show that nearly 75% of injuries are directly or indirectly related to pulling or freeing of ore-pass chutes, the use of hand tools in ore passes, fails of broken rock in ore passes and structural failures of chutes or gates and ore-pass walls. Researchers at the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) are investigating hazards in and around ore passes in hard rock mines. Risk assessment methods, such as fault-tree analysis, have been employed to identify the most probable causes of orepass failures, define research priorities and analyse the factors that result in malfunctioning and unsafe ore passes. Static and dynamic loads are being measured in a laboratory setting with the use of a reduced-scale orepass mock-up. Field tests are being initiated in mine ore passes to determine static and dynamic loads. Data from the test ore passes are being compared with data from the mine to characterize true system behaviour. Computer modelling with the use of closed-form solutions, finite-element analyses and a newly developed particle flow code predicts static and dynamic leads from the flow and the impact of ore and waste in the ore pass. Preliminary results indicate that dynamic impacts from ore and waste rock might be considerably greater than expected. The total static load is substantially less than is typically used fur the structural design of chute and gate support members. It is suggested that damping factors, normal and shear stiffness and mass frictional characteristics have a significant effect on particle flow and resulting impact loads. This is being verified with the use of results from laboratory tests, field tests and particle flow analyses. Ore passes are vertical or steeply inclined openings in a rock mass through which ore and waste are transported and where they mar also be stored. A typical underground mining system is shown in Fig. 1. The arrows indicate the locations of ore passes and loading pockets and their relative configurations. The control of material flow is potentially one of the most hazardous operations in underground mining. According to MSHA data. most of the ore pass-related accidents in the U.S.A. are associated with the loading-unloading cycle and removal of blockages from ore passes. In particular, attempts to free ore hang-ups have resulted in multiple fatalities. The hazards are obvious; there is uncertainty as to when the ore will break loose and miners are unable to escape falling rock to a safe location. Although ore passes and chutes and gate systems for underground metal and non-metal mines roust meet the requirements specified in the U.S. Code of Federal Regulations (CFR). Parts 57 and 75, recent structural failures of ore-pass linings and gates have underlined the lack of adequate ore-pass design standards available to both MSHA enforcement staff and mine engineers. Because of the importance of an ore pass to the safe operation of a mine design criteria need to be assessed and new guidelines developed. Researchers at the Spokane Research Laboratory of the Nationals Institute for Occupational Safety and Health (NIOSH) are investigating hazards in and around ore passes in hard rock mines and studying design criteria for ore passes. The near-term goal is to conduct laboratory and field experiments and computer modelling to evaluate the ore-pass design criteria currently used. Literature searches, field site

By David J. Baxter

Use of bored displacement piles has experienced significant growth in the UK piling market sector, largely due to their environmental advantages over other piling methods and through cost benefits. Bored displacement piles are a cast-in-situ construction which can be formed with minimal production of spoil and offer low noise and vibration compared to driven displacement piles. A large variety of bored displacement piles have been developed. This paper describes a standard system for their classification. The development of the different types is described along with the factors which have led to their increased use. Consideration is given to processes undergone by the soil during pile installation and design approaches for bored displacement piles are compared. Comparisons are made between the different classifications of bored displacement pile. Comments are also made on the installation of such piles. It is concluded that complex changes occur in the stress states of the surrounding soils. Such effect of the pile installation on the soil should be accounted for and there is a need, therefore, to further refine the design process for these piles.

Jan 1, 2006

By D Wyatt, J Domenico, W Kow

Over the past few years developments in heavy minerals processing have concentrated on the mineral separation portion of the business. The best example of this would include new developments in rare-earth magnetic separators and associated flowsheet modifications. Except for some minor modifications in spirals, the æwetÆ side of the separation business has lagged behind the ædryÆ side. Basic concentrator design has not changed in 20 years. Recent pilot trials by Outokumpu Technology have shown the benefits of a new gravity flowsheet that combines density separation and spiral concentration on a variety of heavy mineral deposits. This concept is already well utilised within the iron ore industry. The synergistic combination of these two technologies allows smaller, simpler, and controllable gravity concentrators to be built while providing equivalent or better grade and recoveries of valuable heavy mineral. This is contrasted to the all spiral flowsheet characterised by the diminishing returns of multiple stages of spirals and associated recirculating loads. Examples of the flowsheets and associated benefits will be presented from a variety of cases.

Jan 1, 2001

By M. I. Brasileiro

The use of experimental design to the study of mixtures has found a wide range of applications, even in laboratory scale or in industrial development works. The aim of this work was to maximize granite sawing waste content in ceramic tiles using experimental design. Based on the raw materials, specific formulations were developed using the experimental design. The raw materials were mixed and sample bodies were produced using uniaxial pressing. The sample bodies were fired and characterized in terms of water absorption, mechanical strength and X-ray diffraction. Regression models were adjusted relating the water absorption and mechanical strength with the amount of raw materials. The results showed that the methodology of experimental design maximize the content of wastes incorporated in ceramic tiles formulations. Formulations containing up to 40% of waste can be used for the production of ceramic tiles.

Jan 1, 2009

By Phillip Allender, Wolf Karo, Knox Van Dyke, Lixin Wu, Ali Ardekani, Jorge Garcia, Jaime Gutierrez

"We report that two different micropolystyrene round beads linked to either luminol or lucigenin have been developed. The 1-µ.m-diameter beads arc useful reagents that allow one to perform chemiluminescent (light producing) phagoeytic reactions without opsonization. It is known that luminol reacts with peroxidases (e.g., myeloperoxidase) while lucigenin reacts mainly with superoxide anion. Luminol and lucigenin beads produce cellular chemiluminescence (CL) with neutrophils, macrophages, monocytes, and differentiated human promyelocytic leukemic cells (HL60). When myeloperoxidase (MPO) is present luminol beads evoke higher CL from neutrophils, but when little or no MPO is present, lucigenin beads produce higher amounts of light. Lucigenin beads appear to be active inside these cells where unbound lucigenin does not enter freely.INTRODUCTIONA variety of cells, e.g., neutrophils (Ns) and macrophages (Ms), can engulf foreign particles (1). This engulfing or phagocytic activity is used by the body to kill bacteria and to eliminate foreign particles such as respirable dusts, e.g., coal, silica, or cotton. The neutrophil engulfs or phagocytizes bacteria which are coated with plasma antibodies and/or complement proteins (Fig. 1). The coating or opsonization allows the neutrophil to recognize foreign substances. Usually the absence of opsonization prevents the cell's recognition of a foreign particle and the particle is not phagocytized. Macrophages, particularly the alveolar Oung) cells, do not require opsonization for phagocytosis. Ms should not be selective toward individual dusts because they serve a major role in eliminating a variety of these.Particle size can also be a factor. Usually a particle with a diameter of 0.5-5 µ.m is considered in the respirable range. Larger particles are trapped before they reach the alveoli Oung spaces where oxygen exchange with blood occurs), ·and smaller particles do not generally settle, and are not engulfed by macrophages (2). Tabato and Ikada (3) found that maximal phagocytosis of microspheres takes place when their diameter is in the range of 1.0 to 2.0 µ.m. In addition, they found that beads with hydrophobic surfaces were more readily phagocytized than hydrophilic surfaces."

Jan 1, 1990

By D Porta, E Grigolato, K Behrens

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Aug 12, 2013

By M. Clair Smith

This report is one of a series describing exploration, development, mining methods, and costs at United States open-pit mines; the Bureau of Mines prepares and publishes them in cooperation with the mining companies. Their purpose is to promote development and conservation of our mineral resources by disseminating technologic information on mining methods and practices at various United States mines. The exploration, development, equipment, and mining of a large, oxidized-copper ore deposit by open-pit methods, the leaching of the ore with sulfuric acid solution, and the recovery of the copper as cement copper are described herein.

Jan 1, 1958

By R. Agius, A. Nacu

"Adoption of the International Cyanide Management Code, regulatory requirements and community concerns have increased the need to implement suitable cyanide destruction processes at gold operations to meet ever more stringent discharge limits. As standards set for the allowable concentrations of cyanide, cyanide compounds and other contaminants may vary from country to country, jurisdiction to jurisdiction, and even from site to site, there is no “one size fits all” technological solution. Currently the most common cyanide destruction processes used in industry are sulfur dioxide/oxygen, hydrogen peroxide and Caro’s acid. Regardless of the process used, cyanide destruction plants must be reliable and achieve permit guidelines at all times. The selection of the most appropriate cyanide destruction process for an operation depends on several factors, including permit discharge requirements, tailings chemistry, location, site-specific climatic conditions and size of the operation. Only after considering all these factors together can the most effective approach be selected to achieve the permit guidelines economically and technically feasible. Finally performing the correct test work program is the most important step to ensure that the correct process design criteria can be determined to accurately calculate capital and operating costs.IntroductionThe adoption of the International Cyanide Management Code in 2005, stricter regulatory requirements and community concerns prompted by environmental incidents involving cyanide have increased the need to implement cyanide destruction processes at gold and silver operations.Process solutions associated with the extraction of gold and silver contain several forms of cyanide. The most toxic form of cyanide is free cyanide, which can be present as a dissociated cyanide anion (CN-) or gaseous or aqueous HCN. Weak or moderately stable cyanide complexes such as those of zinc, copper and nickel are classified as weak acid dissociable (CNWAD). Although less toxic than free cyanide, weak acid dissociable cyanide complexes are considered “ecologically sensitive” forms of cyanide and are regulated in most jurisdictions. In practice, reported WAD cyanide values are comprised of both free cyanide and weak acid dissociable cyanide complexes. Cyanide complexes with gold, mercury, cobalt and iron are referred to as strong acid dissociable complexes (CNSAD) and are much more stable even under mildly acidic conditions. Another term commonly used in cyanide chemistry is total cyanide, which represents all cyanide compounds present in solution, with the exception of cobalt complexes. Total cyanide levels in solutions are in most cases higher than WAD cyanide values and the difference between the two usually indicates the presence of iron-cyanide compounds. Typically, in Canada CNTOTAL levels cannot exceed 1 mg/L in solutions."

Jan 1, 2017

By Murillo Romero da Silva

Ligas com memória de forma (LMFs) são ligas metálicas capazes de recuperar o seu formato e tamanho original após deformação plástica quando aquecidas acima de uma temperatura crítica. Diversos casos de possíveis aplicações paras as LMF têm sido justificados no campo científico, com alguns poucos casos identificados para aplicação em massa, existindo uma ausência na literatura de uma análise crítica da aplicabilidade das mesmas que leve em consideração aspectos industriais e de mercado. Dessa forma, se faz necessário um estudo mais aprofundado que correlacione as ideias científicas geradas com a produção industrial e com a comercialização de LMFs. Nesse contexto, o trabalho visa através de levantamento e análise de patentes e artigos científicos, assim como por contatos industriais, estabelecer uma relação entre o desenvolvimento científico e o comercial das LMFs. Mais de 11 mil artigos e mais de 7 mil patentes foram produzidos nos últimos 16 anos, sendo observado uma tendência crescente da criação de conhecimento de LMF, o qual já vem sendo aplicado na indústria, justificando assim os esforços observados no campo científico. A área biomédica se destaca como a mais bem estabelecida no campo das LMF, com destaque para a utilização das ligas a base de NiTi.

Aug 17, 2017

By Roney Eduardo Lino, Loyslene Rabelo Fernandes, Gustavo Henrique Sousa, Athos Fernandes Araujo, Wallace Crisólogo Souza Gonçalves

Nos processos de refino dos aços, as ferroligas exercem um papel muito importante. E deve-se conhecer o comportamento do rendimento dessas ligas para que não sejam feitas adições desnecessárias que possam elevar os custos de produção ou até mesmo acarretar em perdas de corridas por composição química fora da faixa de especificação. Nesse trabalho foi utilizado o simulador de refino secundário do Steel University para avaliar o comportamento do rendimento das principais ferroligas em estação de rinsagem com banho metálico desoxidado ao alumínio e em banho não desoxidado. Foi possível avaliar que o comportamento do rendimento das ferroligas tende a ser mais positivo quando se é feita a desoxidação do banho metálico utilizando Alumínio briquetado. Com isso feito um comparativo do custo de produção que mostrou que, quando se conhece o comportamento dos rendimentos, é possível gerar economia para o processo.

Oct 1, 2019

By C. L. Emery, A. V. Corlett

"The stress equilibrium is disturbed in a body of rock by a mine opening and is restored by a redistribution of the stresses around the opening. The pattern of the redistribution of unilateral stress around an opening has been established by mathematical analysis and photoelastic measurements. The pattern for multilateral stress is found by superimposition of unilateral fields. The mathematical analysts do not use the elastic moduli as parameters and they are not significant in photoelastic work. The medium is isotropic. The concept of unilateral stress from vertical loading and the classical pattern of its stress distribution around openings does not explain commonly observed failures around the perimeters of mine openings. They show evidence of compression where tension is postulated.When it is recognized that few minerals and perhaps no rocks are Hooke Solids, most rocks must be St. Venant Solids. The components have varying degrees of elasticity and viscosity. The assembly will be-have elastically to rupture under shock loading, but when loaded short of rupture will adjust viscously to equilibrium. Similarly, the highly elastic components may initiate rupture before equilibrium can be established when stress is instantaneously relieved. Polycrystalline adjustments may produce permanent deformation. The mechanics of consolidation, especially in sedimentary deposits, ac-quire a stress component normal to the direction of compaction which can exceed that of the loading. It is one source of prestress. There are others. The principles of prestress design are based on the normal beam reactions, modified by a built-in compression in the lower chord. When the beam is loaded to design limits, the lower chord retains some compression and the whole beam depth is effective in compression. Some of the . common evidences of failure in compression over a mine opening can be duplicated in a prestressed experimental model.When the triaxial stress pattern is recognized and suitable measuring techniques are devised, mine design can be done on a rational basis."

Jan 1, 1959

By D. F. Cooper, J. G. Paterson, K. H. Pang

"Effective control of metallurgy by manual adjustment of cell levels is common flotation practice. With an on-stream XRF analyzer interfaced to a process control computer it is possible to program the computer to carry out this function automatically. This paper describes the development and implementation of closed loop control of the concentrate and tailing grades at the Clarabelle Mill of the International Nickel Company of Canada, Limited, The XRF analyzer was used as the sensor, cell level as the control and the computer as the controller.IntroductionThe International Nickel Company of Canada, Limited recently brought on-stream Clarabelle Mill having a rated capacity of 35,000 tons per day. The plant was required to increase milling capacity in the Sudbury area by 9,000 tons per day and to improve milling efficiencies by replacing the obsolete crushing and grinding equipment at the Copper Cliff Mill. This represents the fourth mill built since 1959 and incorporates the latest thinking in a continuing evolution of instrumentation and control concepts. Table 1 illustrates control progress at Inco since 1959.In 1967 Frood-Stobie Mill came on-stream incorporating a central control room, an on-stream analyzer, a data gathering computer, and a significant change in instrumentation from direct-contacted pneumatic to miniature electronic. The computer successfully controls the analyzer but has very limited process control capability. Based on this experience a process control computer system was installed at Clarabelle Mill with the objective of carrying out extensive supervisory control and a limited amount of direct digital control."

Jan 1, 1973

By Phillip N. Yasnowsky

This Bureau of Mines publication tabulates State taxes levied on nonfuel minerals that have the characteristics of a severance tax.

Jan 1, 1978

By G. Papachristodoulou, O. Trass

"Performance data for both wet and dry grinding of materials have been obtained in this novel, planetary ring-roller mill over wide ranges or operating conditions. The Szego mill consists of a stationary cylindrical shell inside which grooved, radially mobile rollers rotate, driven by a central shaft. The mill has several internal design variables such as number, diameter and length of rollers as well as size, shape and pitch oi helical grooves. It is compact, has a high specific capacity, modest power consumption, and can grind many materials down to ultrafine powders. Illustrative data on product fineness and mill power consumption are given along with results from studies on grinding kinetics.INTRODUCTIONThe extensive use and importance of grinding as a unit operation, coupled with the rather low energy efficiency of conventional equipment provide a challenging incentive to investigate novel methods of comminution. Yet, most current development work is taking place in mill performance modelling and optimization, or with various detailed improvements rather than in the field of new equipment development.This paper is a report on the development of a ring-roller mill invented by the late L.L. Szego which embodies several novel concepts. The mill has a broad range of applications, may be operated wet or dry, and can grind materials down to ultrafine sizes with modest energy consumption. It has been developed by General Comminution Inc. in close cooperation with the University of Toronto."

Jan 1, 1986

By Breno Delgado Silva

O conceito de Fast Track é a retirada das manutenções leves de dentro de oficina, migrando-as para realização em pátios, enquanto os vagões ainda estão no trem. A mudança de estratégia de manutenção para englobar este conceito aumenta o espaço disponível nas oficinas para realização de reparos pesados, reduz a quantidade de manobras para separar os vagões avariados dos em bom estado, reduz o número de vagões retidos e, consequentemente, aumenta a disponibilidade de ativos, melhorando a capacidade de escoamento do corredor. Através do projeto piloto no corredor Centro Leste a VLI conseguiu reduzir em 45% o envio de vagões para oficina, gerando um ganho de 0,44% na DF de vagões graneleiros.

Oct 30, 2017