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By Jacqueline H. Jansky

The Mine Safety and Health Administration (MSHA), U.S. Department of Labor, did a linear analysis for a new underground coal mine in Grant County, WV, through the interpretation of LANDSAT imagery and high-altitude, color-infrared aerial photography, to identify areas of potentially unstable roof in advance of mining. The Bureau of Mines included this mine in its ongoing study of the correlation between geologic features and linears. Three years after the analysis, after mining had progressed through the plotted linears, a cooperative Bureau-MSHA study evaluated the effectiveness of the linear plot in predicting areas of unstable roof and defined the geology associated with the linears. Adverse roof conditions at this mine include roof falls, potted-out roof, water inflow, and local areas requiring supplemental support. At the time of this study, 34 pct of the mine workings were within 200 ft of a plotted linear. Fifty percent of the adverse roof area in the mine occurred within this area. The primary geologic anomaly associated with the linears is an increased frequency of jointing. The majority of the plotted linears coincide with the prominent joint orientations. Additional features observed in the linear zones include roof rolls and a sandstone channel that cuts into the coal seam.

Jan 1, 1983

By L Matthews, D O’Dea, P C Hayes, J Manuel, B Monaghan, T Honeyands, D Pinson, J Leedham

Many different approaches have been used in the past to characterise iron ore sinter mineralogy to predict sinter quality and elucidate the impacts of iron ore characteristics and process variables on the mechanisms of sintering. Characterisation techniques include optical image analysis and point counting, X-ray diffraction and scanning electron microscopy. Each technique has its advantages and disadvantages depending on the objectives of the measurement. It is generally acknowledged that silicoferrite of calcium and aluminium (SFCA) is very important to the quality of the sinter produced; however, strict definitions of the phases and textures of SFCA are not generally agreed. This paper summarises the state-of-the-art in sinter characterisation applied in Australia by both academics and industrial researchers. The results from various techniques are compared and the relationships between the measurement results are discussed.CITATION:Honeyands, T, Manuel, J, Matthews, L, O’Dea, D, Pinson, D, Leedham, J, Monaghan, B, Li, H, Chen, J, Hayes, P C, Donskoi, E and Pownceby, M I, 2017. Characterising the mineralogy of iron ore sinters – state-of-the-art in Australia, in Proceedings Iron Ore 2017, pp 49–60 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By Z. T. Bieniawski, E. H. Skinner, R. A. Cummings, F. S. Kendorski

INTRODUCTION Caving Mine Drift Support Design The support of production drifts remains a high-cost item facing the developer or operator of an underground caving mine. Support costs are incurred well in advance of ore production, and there is a strong need to minimize these pre-production commitments of capital. Due to the extensive rock loads that normally develop during the caving process, the support used in caving mines is typically quite heavy and therefore costly. The process of designing this support increasingly makes use of basic tunneling principles, but is hindered by the still-incomplete state of knowledge of rock behavior in caving mines, and high variability of geological conditions in caving orebodies. Caving mines differ from tunnels in that the deformations and rock loads induced are transient and dynamic in occurrence, and are normally large in magnitude, often well in excess of rock mass strength. As opposed to tunnels, caving mine layouts are more intricate, and the methods and effects of construction ordinarily are not as closely monitored. Safety factors in mining tend to be lower and rock masses tend to he weaker. These aspects prevent strict application of tunnel design technology to caving mine drift support, with the result that mine drift supports are commonly designed chiefly on the basis of experience at other mines. Mining procedures at caving mines are evolved in response to site-specific requirements, to the extent that there are really as many caving methods as there are caving mines.

Jan 1, 1983

By Nilo Nogueira da Silva

O objetivo deste trabalho foi investigar os efeitos da temperatura de laminação na microestrutura de um aço microligado ao Nióbio através de simulação por ensaios de torção a quente. Ensaios foram realizados com deformações em resfriamento contínuo para determinar as temperaturas de não recristalização da austenita (Tnr) e de início da transformação austenita-ferrita (Ar3). Foram realizados ensaios de torção simulando diferentes esquemas de laminação a quente em laminador Steckel, variando-se as temperaturas dos passes de acabamento. Foi observado, nas curvas tensão em função da deformação dos ensaios de torção, gradual encruamento da austenita quando a temperatura da última deformação foi inferior à 870°C. Foi também observado que o tamanho de grão ferrítico cresce com temperatura de laminação de acabamento.

Aug 8, 2018

In several of the States of Australia, mining on private property has been seriously hampered by the fact that large areas of land have been alienated from the Crown before the discovery of gold or other minerals. In Western Australia this difficultyhas only occurred to a small extent, and has largely been overcome by an act entituled "An Act to Permit Mining on Private Property, No. XXIX., 'October, 28th, 1898." Under this act, the holder of a miner's right can apply for a gold mining lease on private land; such applicant may treat privately with the owner of such land as to the amount of compensation to be paid for surface ,damage, or the case may be brought before the Warden who will assess the damages. Private land used as a garden, orchard, or vineyard is exempt from lease, unless the applicant has authority from the owner, or such lease is limited to a greater depth than 100 feet from the lowest part of the surface.No lease shall be granted of any mines under any private land in any municipality unless either the applicant has authority from the owner, or such lease is limited to a greater depth than two hundred feet from the lowest part of the surface.The same regulation applies to leases of private land on which any hospital, asylum, or public building is situated or under or within one hundred and fifty yards laterally of any...

Jan 1, 1901

By A M. Purba and A Sjadat, A D. Wilson

Ongoing mining of the East Ertsberg Skarn System orebody below the Gunung Bijih Timur and Intermediate Ore Zone caves has been relatively successful and a ramp up to 80 000 t/d was achieved in the Deep Ore Zone Mine. However, the distribution of production, the overall drawpoint availability as well as the rate of change of the cave back profile has not followed the anticipated path. Several key factors influencing cave growth and progress, grade variation, fragmentation, wet muck and surface subsidence have been recognised over the life-of-mine that now have to be taken into account for planning the later stages of mining.The paper will discuss the influence of geological controls of lithology and structure – how this as well as other contributing aspects have impacted ore flow, contributing to some of the widespread panel damage, and been a key factor in compacted draw columns and caused an accelerated appearance of water ingress. This in turn has rapidly changed the distribution of wet drawpoints requiring remote mucking and special controls that also affect the call from the remaining dry drawpoints. Comment is also made on the potential final cave profile if it continues along the current trend and some discussion is offered about possible mitigation measures if this were to come about.CITATION:Wilson, A D, Purba, A M and Sjadat, A, 2016. Progressing cave performance into the later stages of the Deep Ore Zone mine, in Proceedings Seventh International Conference and Exhibition on Mass Mining (MassMin 2016), pp 285–292 (The Australasian Institute of Mining and Metallurgy: Melbourne).

May 9, 2016

By John C. Holtz

Interest in the possibility of using Diesel6/ engines for haulage power in mining and tunneling is increasing in the United States, owning largely to the reported successful use of Diesel locomotives in European coal mines and to the comparatively recent development of automotive Diesel engines in this country. The extent of this interest has been evidenced to the Bureau of Mines by numerous requests for information as to the factors that must be considered if Diesel engines are to be used safely underground.

Jan 1, 1940

By John C. Holtz

Interest in the possibility of using Diesel6/ engines for haulage power in mining and tunneling is increasing in the United States, owing largely to the reported successful use of Diesel locomotives in European coal mines and to the comparatively recent development of automotive Diesel engines in this country. The extent of this interest has been evidenced to the Bureau of Mines by numerous requsts for information as to the factors that must be considered if Diesel engines are to be used safely underground.

Jan 1, 1940

By Transfert Environment and Society

Transfert?s added value ? Building bridges between project promoters and communities ? Unique expertise in working toward Social License to Operate through meaningful community engagement ? 25 years of recognized innovation and a systematic approach ? Key mining clients: ? Royal Nickel Corporation ? IAMGOLD - Niobec ? Richmont Mines - Wasamac ? Mine Arnaud ? Managem

Aug 1, 2013

By Everaldo Afonso Fernandes

O cenário tecnológico brasileiro passa por transformações profundas, a indústria em geral faz parte desse panorama, dentro dos segmentos indústrias temos a automobilística, onde novas tecnologias são apresentadas e as demais aprimoradas, nesse segmento temos as ligas não ferrosas de alumínio, que com adição de elementos de liga se transformam em ligas de alta performance, assim como as ligas de aços. Elementos de maquinas de ligas de alumínio sofrem modificações em suas propriedades mecânicas com a variação de temperaturas, deformação, composição química entre outras. O presente trabalho objetiva a comparação das propriedades mecânicas dos resultados experimentais da liga Al-0,05%Cu-[0,35-0,45] %Fe-0,22%Zr e de simulações computacionais de chapas para aplicação na indústria automotiva. A liga foi obtida a partir do Al-EC modificado por inserções de ferro na faixa de [0,35 - 0,45] % e 0,22%Zr. Posteriormente, após a solidificação da liga em molde unidirecional horizontal, os lingotes foram transformados em perfis de 3,0mm e submetidos a ensaios mecânico de tração. Na parte de simulação computacional as propriedades mecânicas foram medidas usando chapas finas de aço e chapas mas espessas de alumínio, as propriedades obtidas nos ensaios reais, foram utilizadas como paramentos das simulações das chapas de alumínio, objetivamente a comparação das propriedades mecânicas com os resultados experimentais da liga estuda. Os resultados dessas análises permitem avaliar que a liga Al-0,05%Cu-[0,35-0,45] %Fe-0,22%Zr pode ser aplicada em componentes estruturais na indústria automotiva que trabalharem estaticamente na forma de fuselagem de automóveis de passeio ou veículos de trabalho com boas propriedades mecânicas.

Oct 30, 2017

By Raj P. Singh Gaur

Due to high concentration of NaOH in the digested slurry after scheelite digestion, it is diluted to about 4N before filtration to separate sodium tungstate solution from the sludge (residue). However, in practice there may be deviations in the normality of NaOH present in the slurry. There may also be variations in the temperature of the slurry and filtration time. Slight variations in these parameters could cause tungsten losses in the sludge via the back reaction: Ca(OH)2 + Na2WO4? CaWO4 + 2NaOH This paper pertains to the effect of normality, temperature and time on the tungsten losses in the sludge that is separated from ?diluted-scheelite-slurry-in-NaOH? via filtration. Results indicated that tungsten losses in the filtered residue (sludge) were quite significant when the slurry temperature was kept at 70°C or higher. The effect of high temperature was less significant at the slurry normality of 3.6 or higher. Combination of low slurry normality (<3.6) and high temperature (>60°C) resulted into large W-losses in the sludge.

Jan 1, 2006

By R. K. Linn

The New Idria Mining and Chemical Co. owns and operates the New Idria mine in southern San Benito County, Calif. During 1957-59, the New Idria mine was the largest producer of mercury in the United States and its alltime production of over a half-million flasks was exceeded only by one mine. It is one of the oldest and most consistent producers in California. With the exception of 1921-22, the mine has an annual production of mercury dating back to 1854. This paper by the Federal Bureau of Mines describes the exploration, development, mining, and furnacing of mercury ore at the New Idria mine. Figure 1 is a view of the furnace plant of the New Idria mine. The purpose of this report is to promote the development and conservation of our mineral resources by dissemination of technological information on mining and processing procedures, and related practices at operating mines.

Jan 1, 1961

By R Zhou, B J. Monaghan, S J Chew, R J. Longbottom, D J. Pinson, H Li, P Zulli, G Zhang, L Lu

Steelmakers are increasingly motivated to use iron ore resources with a wider range of grades and mineral types that were previously considered unsuitable or uneconomical for sintering. In this respect, specific issues, which now require further investigation and understanding, include the sintering of ore types with:- overall higher gangue content- elements that cause problems in the steel manufacturing operations- distinctive sintering performance compared with traditional hematite-rich iron ores. Laboratory-based investigations of the sintering performance and the behaviour of gangue impurities during sintering is an important step towards the successful utilisation of these resources in steelmaking.In terms of laboratory-based sintering investigations, there are two generally accepted experimental scales utilised prior to undertaking industrial-scale trials, which include: bench-scale tablet (compact) testing and pilot-scale pot testing. The former has the advantages of flexibility and more precise control of sintering conditions; but it is difficult to simulate the heterogeneity of a sinter bed. The latter, which is carried out in pots with diameters between 150–500 mm, simulate the commercial sintering process and conditions quite well, but is time-consuming and labour-intensive due to operational complexity. It is therefore desirable to establish a smaller scale pot testing facility that avoids the disadvantages of the normal sintering pot but can provide comparable information.To explore the feasibility of small-scale pot testing, a ‘millipot’ facility was established to examine the sintering performance of iron ores and other non-traditional ferrous materials. The millipot has a diameter of 53 mm and height of 400 mm. The facility has the capability to monitor the sintering temperature at a number of locations (axial, radial) within the sinter bed and to adjust the suction (‘windbox’) pressure. This paper describes the development of the millipot facility and operational procedures, together with initial tests undertaken in order to match its performance with industrial sintering performance.CITATION:Li, H, Zhou, R, Pinson, D J, Zulli, P, Lu, L, Longbottom, R J, Chew, S J, Monaghan, B J and Zhang, G, 2017. A millipot set-up for sintering investigation of iron ores, in Proceedings Iron Ore 2017, pp 85–90 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 24, 2017

By H. Krogerus, P. Niemelä, P. Oikarinen

High carbon ferrochromium is produced by carbon reduction. No replacement for carbon as reductant has yet been developed. The reduction creates a considerable amount of CO-gas. In open and semi-closed furnaces the gas is burned when leaving the burden. In closed furnaces the formed gas is sucked out by a fan, washed and utilised as fuel. The formation of carbon monoxide is presented briefly starting from thermodynamic considerations up to solid and liquid state reduction. The volume, composition and energy content of the furnace gas are discussed, focusing on the raw materials and pre-treatment processes of the furnace feed as well as on the process equipment and control. Outokumpu has been using closed and sealed furnaces and utilising the CO-gas in its Tornio Ferrochrome Works since 1968. Today in Tornio with an annual ferrochromium production of 260 000 t CO-gas production is 186 million m3, representing 68 MWh an hour. At the same time the furnace power input is 95MW. About 98 % of the CO-gas is utilised, whereof 30% in the ferrochrome production itself. This paper focuses on the characteristics and utilisation of CO-gas. CO-gas is secondary energy, which on one hand saves primary electric and fossil fuel energy in ferrochromium production and, on the other, replaces other fossil fuels at the adjacent steel works. The characteristics of the fuel, requirements for utilisation as well as health and safety aspects are discussed. Utilisation of the gas has a high impact on the total dust and gaseous emissions and on the energy optimisation at the ferrochromium and steel works.

Jan 1, 2004

By J. T. McCartney

OPTICAL PROPERTIES of U.S. coals of differing rank have been investigated by the Bureau of Mines, for about 20 years. These investigations have been remade to further the development of an objective basis for petrographic analysis of coal and to add to knowledge of the structure and composition of coal and coal components by determining their optical constants in various regions of the electromagnetic spectrum. Various experimental techniques have been used in these studies, including determination of reflectance from bulk specimens and transmittance of thin and ultrathin sections, interferometry, electron microscopy, and election diffraction. Similar studies leave also been made of graphite, the end product of coal metamorphism. The bureau of Mines conducted the first U.S. investigation of reflectance properties of coal components, laying the foundation for petrographic analysis based on arbitrary reflectance classes and for automated reflectance analysis of coals. Optical constants of coals of differing rank and of graphite have been determined in the ultraviolet-visible-near infrared spectrum. Maxima in the optical constants of graphite were observed in the ultraviolet region and were interpreted to be related to transitions of electrons between the valence and conduction bands. Similar maxima for coals, especially high-rank coals, appeared to be characteristic of the presence of graphitelike layers. A special application of optical theory to absorbing, anisotropic materials like graphite and high-rank coals has been developed. Electron microscopic and electron diffraction studies of coals have revealed various ultrafine structures in coal components and have shown the evolution of an oriented, crystalline graphite structure in high-rank coals.

Jan 1, 1967

By Cabrera M. Manuel C

A fines de 1980, la empresa Minero Perú construyó una operación piloto de monitores y planta de lavado con una capacidad de 1,500 m3/día, incrementando la producción de oro a un 80%. En este sentido, el presente texto señala la producción de oro de esta minera peruana, utilizando dichas herramientas mencionadas. Para ello, se describe la geología, minado, características del monitor seleccionado, características de la bomba de alta presión, metalurgia y las plantas de lavado.

Oct 14, 1980

By T. R. A. Davey

The fundamental principles by which bismuth may be removed from lead by pyrometallurgical processes are enumerated. Qualitative discussion of the phase diagrams concerned is followed by presentation of quantitative diagrams. Brief mention is made of the practical aspects. Data presented show how chemical lead (<0.005 pct Bi) may be produced by the Jollivet, Dittmer, and Kroll-Betterton processes. BISMUTH is an element whose properties are very similar to those of lead, and its minerals are associated to a greater or lesser extent with nearly all the major lead ore deposits of the world. In consequence, the lead produced contains bismuth unless a special debismuthizing process is practiced. There does not appear to be any published comprehensive review of the effect of bismuth as an impurity on the properties of lead, and there is some uncertainty as to the beneficial or detrimental effects of small amounts of bismuth in lead used for particular applications. Standard specifications of most countries stipulate a maximum bismuth content of 0.005 pct for chemical lead. With one exception, this specification is met only by lead producers whose ores are relatively bismuth-free, or whose refineries are electrolytic. In lead for certain applications a higher bismuth content is preferred by some fabricators.&apos; In contrast to the refining for silver, copper, and antimony, the refining for bismuth does not usually result in a large overalil economic gain from the sale of byproduct. Thus, debismuthizing is customarily practiced only if market conditions demand a lead with a bismuth content lower than that produced by classical refining; i.e., softening, desilverizing, and zinc refining. Until this century, debismuthizing was carried out only a:; an incidental result of desilverizing, as later described. This century has seen the development of the Betts electrolytic process—the only successful one of many electrolytic processes proposed and patented —and a number of precipitation processes based on the pioneering work of Kroll,&apos; although only one of these, the Kroll-Better ton process,&apos; is in wide commercial use today. It is proposed in this paper to deal only with the pyrometallurgical processes, excluding those based on aqueous electrolysis. Historical Background Prior to 1833 silver (and incidentally bismuth) could not be removed from lead. To recover silver from rich bullion, the only course available to lead refineries was to cupel the bullion, forming a slag of litharge. The first slag tappings or skimmings, on reduction, yielded soft lead of very low silver and bismuth contents. Intermediate skimmings yielded a lead of somewhat higher silver and bismuth contents, which could if desired be recupelled. The last skimmings yielded a litharge very high in bismuth, which could by successive oxidation and reduction cycles be separated into high purity bismuth, and lead returns. This oxidation reduction process, with modern operating techniques, can still be used today to produce a portion of a lead refinery&apos;s output of very low bismuth content, as discussed later. In 1833 Pattinsone discovered that lead bullion could be purified of silver and bismuth by fractional crystallization, the primary lead crystals formed by partial freezing being purer than the melt. Repeated processing in pans produced a lead containing as little as 0.02 pct Bi. The simple explanation of this

Jan 1, 1957

Excavations in rock are commonly supported with wire mesh, shotcrete, wire mesh and shotcrete in combination, and shotcrete reinforced with various types of fibres. Wire rope lacing and various types of straps are additional forms of support installed over the above types, to cope with severe conditions. These support systems are very important items of ?membrane? rock support. With the recent development of several types of thin sprayed linings, the importance of membrane support is likely to increase in the future. In this paper, a wide range of mechanisms of membrane behaviour and mechanisms of loading of membranes, is described. The concepts of membrane components, which are single membranes that may be used on their own as rock support, and membrane systems, which are combinations of more than one membrane component, are introduced. Different situations have different requirements of membrane support, and differences between civil engineering and mining requirements are highlighted. With the different basic requirements in these two areas, the requirements of rock support are correspondingly different. A thorough understanding of the mechanisms of behaviour of the different types of membranes, and the different mechanisms by which the membranes are loaded, is essential before a selection of appropriate support can be made, before appropriate design methods and calculations can be determined, and before appropriate performance test methods for membranes can be defined. The material in this paper contributes towards the understanding of membrane support behaviour.

Jan 1, 2001

By A B. Phillips

This paper details the approach adopted to upgrade the current metallurgical facilities at both the Driefontein and Kloof Gold Mines in the Republic of South Africa. Goldfields Ltd operates eight metallurgical plants within South Africa of which three have recently been upgraded to replace the older technology previously installed, with modern equipment. This upgrade was undertaken with a view to improving extraction efficiencies and to reduce operating costs. The upgrade was undertaken in a phased approach with the first phase focused on the replacement of the filtration/zinc precipitation processes with modern pumpcell carbon-in-pulp technology. Included in this upgrade phase was the installation of an automated hands-free electrowinning cell, which represents the first commercial application of its kind in the industry. The second phase of the upgrade entailed replacement of the multiple comminution stages previously installed with large SAG and SAG/Ball mill combinations. Due to the rapid return on these projects, a fast-track approach was adopted which necessitated the purchase of available good conditioned second-hand mills from both within South Africa as well as in Australia. Goldfields Ltd is a large mining house with gold mining operations in South Africa, Australia and Ghana. A well advanced PGM exploration project is underway in Finland- Arctic Platinum.

Jan 1, 2003

By Thomas Prietl

The use of gas stirring systems through the furnace bottom is common for anode and holding furnaces in the copper industry The first implementation of a gas stirring COP KIN® system in a Peirce-Smith converter was performed at the New Boliden smelter, Rönnskar, Sweden. In addition to other benefits, a decrease in process time and a decrease of the oxygen content in the blister copper were observed. To determine the effects of the gas stirring system and the process endpoint, an optical production control ?Semtech OPC system? was used. The light emission of the converter flame as an optical process parameter provides qualitative on-line process information, and is also used for endpoint determination of the slag making process, on-line control of iron content in white metal, quality control of slag etc. The results, benefits and risks of using the COP KIN® and OPC system for a Peirce-Smith converter are reported.

Jan 1, 2005