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By M. H. Bolu

Since undergoing a major mill expansion in 1979, Canada Tungsten Mining Corporation Limited has successfully operated a somewhat unconventional rod mill/rod mill grinding circuit at its mill in Tungsten, N.W.T., Canada. The concentrator employs two rod mills in series, of unmatched size and horsepower, for production of feed to a gravity (tabling) circuit. Cyclones and screens are closed circuited with the secondary rod mill. Outlined in this paper are the rationale behind, and consequences of operation of this unusual grinding and classification configuration.

Jan 1, 1984

By John P. Davis

The use of conventional, circulatory air rotary and fluid rotary, cased and uncased drilling methods in the vicinity of sensitive infrastructure can have deleterious effects on the ground conditions surrounding and supporting structures and the structure itself. Furthermore, the use of these conventional methods offers the engineer or contractor little information about the condition of the subsurface during geotechnical applications. Conversely, sonic drilling measurements and samples can be used to evaluate actual conditions during the progress of exploration and construction across a given site. This paper will discuss the history and properties of sonic drilling and explore case histories of geotechnical applications for the advancement of boreholes within vulnerable structures and on sensitive sites for several recent infrastructure projects ? a tunnel and railroad project, a dam grout curtain project, a bridge micropile exploration project and a tunnel instrumentation project. Project summaries will discuss the advantages realized when the application of sonic drilling techniques demonstrated superior accuracy, quality control, efficiency, productivity, penetrability, waste minimization and adaptability when drilling adjacent to or within existing infrastructure. Finally, the discussion will address the current testing and application of sonic drilling to the installation of micropiles, earth retention anchors, grout injection and instrumentation installation where the quality control benefits provided by the inherent soil cores, measurement while drilling systems, accuracy and non-destructive production drilling features will be advantageous.

Jan 1, 2006

By W. C. Clark, J. B. Schloen

Two papers have been written, previously concerning operations at the Montreal East plant of Canadian Copper Refiners Limited. The first one,' written in 1932, described silver-refinery operations at the time for producing silver and gold bullion from tankhouse anode slimes; the second,Z published in 1933, consisted of a description of the entire plant. Since publication of these papers the refinery has become the world's largest producer of refined selenium. The first selenium was produced in August 1934. Tellurium production on a commercial scale followed in October 1935. This paper will deal with selenium and tellurium production and also with present operations in the silver refinery. Blister cakes from Hudson Bay Mining and Smelting Co., Flin Flon, Manitoba, and commercial anodes from Noranda Mines Limited, Noranda, Quebec, are refined at Montreal East. Both these bullions have unusually high gold, selenium and tellurium content. The average assay of raw slimes produced from domestic and Noranda anodes is about 40 per cent Cu, 3600 oz. per ton Ag, 800 ox. per ton Au, 22 per cent Se and 3.7 per cent Te. Early Silver-refinery Operations From the start of operations in 1931 until July 1934, the raw slimes were oxidiae-roasted at 700' F. in a Nichols-Herreshoff furnace, acid-leached with tankhouse discarded foul electrolyte (20 per cent HzSOa), filtered and charged directly to the dor6 furnace for refining to dore metal. This is the customary method for treating tankhouse anode slimes but was not suitable at the Montreal East plant because of the high selenium and tellurium content of our slimes. In the acid-leaching process about 50 per cent of the selenium and tellurium in the roasted slimes was dissolved in the electrolyte. These elements were recovered with the copper as a sludge in a small electrolytic

Jan 1, 1944

By S. Safak

Europe retains a modest position in world mining activity in terms of scale of production and mineral reserves but maintains a non-negligible role in the world mining industry. The concept of sustainable development resting on three pillars of economics, environment and social development has become an increasingly important factor in the European mining sector and a major influence on the related policies of the European Commission. Members of European mining industry shall conduct their activities according to the principles which promote sustainable development. A successful minerals planning policy should create the legal administrative environment that is necessary to ensure the sustainable supply of minerals to society within the framework of sustainable development. Members of the European mining industry shall conduct their activities according to principles which promote sustainable development. The challenge for sustainability is to find a balance between securing minerals supply, protecting the environment and achieving social progress. The point of balance depends on the range of policies adopted by governments. In this paper the development of the sustainability of the mining sector in EU and the social component of sustainability in the mineral industry is discussed.

Jan 1, 2014

By C. P. Boddy

One of the most difficult tasks a project manager will have in pre-mine planning is dealing with the mine site's hydrologic regime. Numerous federal statutes passed by Congress in the last decade have made the coal mining industry more responsive to the environmental impact during all phases of the mining process. Permitting these mines has dictated a cradle to grave approach in dealing with water related issues. This paper will attempt to explore the application of these technology- based laws and their direct application to the unique environment found in Alaska's interior regions.

Jan 1, 1985

COAL is perennially -a subject of major interest at. Pittsburgh, but during the week of Nov. 19 to 24 it was especially to the fore because nearly two thousand persons gathered to take part in the second of the international conferences organized by President Baker of the Carnegie Institute. From the opening session on Monday morning when those attending were welcomed by President Baker and T. P. Gaylord, president of the Chamber of Commerce of Pittsburgh, until the party returned from the Clairton coke ovens on Saturday. afternoon, there was something going on all the time, and usually three sessions were in progress at once.

Jan 1, 1928

By Andrey de Moraes Barcelos Casanova, Rebeca Vieira de Oliveira, Juliana Diniz e Castro, Danilo Abílio Corrêa Gonçalves, Patricia Freitas Rodrigues, Thiago Henrique Fernandes Dias Ferrão, Naiara Vieira Le Sénéchal, Rodolfo da Silva Teixeira, Andersan dos Santos Paula

Este trabalho avaliou a efetividade do tratamento térmico de solubilização de uma liga de NiTi com 58,5%at. Ni comparado a uma liga de composição equiatômica, elaboradas por vacuum arc remelting (VAR). A solubilização foi realizada à 950 °C, em forno de atmosfera não controlada, com tempo de encharque de 2 h, seguido de resfriamento rápido em água à temperatura ambiente. Foram analisadas imagens de microscopia óptica e de microscopia eletrônica de varredura, após preparação metalográfica, das amostras fundidas e solubilizadas, bem como, quantificação da segunda fase pela análise de micrografias ópticas. As propriedades mecânicas foram avaliadas pelo ensaio de dureza por microindentação Vickers. O tratamento térmico imposto resultou em alterações morfológicas na liga equiatômica e não foi possível verificar a dissolução completa dos precipitados da liga com elevado teor de Ni. Foi observado a diminuição da dureza com a solubilização do NiTi equiatômico, e aumento na liga Ni58,5%at.-Ti41,5%at.. Logo, para se obter uma solubilização ótima das ligas, se faz necessário um tempo de encharque maior.

Oct 22, 2019

By Daniella Gomes Rodriguesr

"As mudanças que ocorrem ao longo do recozimento na microestrutura e textura foram observadas no aço inoxidável ferrítico estabilizado ao nióbio, tipo ASTM 430 por meio de Difração de Elétrons Retroespalhados. As amostras deformadas foram recozidas com uma taxa de aquecimento de 23,5°C/s. O recozimento foi interrompido nas temperaturas de 780, 830 e 880°C para acompanhar a evolução da microestrutura e textura. Os resultados mostraram que a nucleação dos novos grãos ocorre preferencialmente nos contornos de alto ângulo. No estágio inicial da recristalização a fibra g é dominante na fração recristalizada, com as componentes 111121, 1111 ,1 2 mais intensas. Na fração não recristalizada a fibra a foi mais intensa. No progresso da recristalização as componentes 11112 1 e 1111 ,1 2 permanecem predominantes, a fibra g torna-se dominante em detrimento da fibra a."

Jan 16, 2018

By Jogre A. S Tenório

he aim of the present investigation was to investigate technological features of the Fe-NbC dissolution in liquid Fe-C alloys. Fe-NbC is a Ferro-niobium alloy with 7%C, has a particle size smaller than 150 pm and its micro constituents are polygonal niobium carbides and an iron matrix. The obtained dissolution time was less than one-minute and the yields were in the range of 80-90% at 1873 K. In the Fe-NbC dissolution process, the dissolution occurs at first, and as a consequence the niobium carbides become free to dissolve. These carbides will dissolve until the melt reaches a saturation point. The non-dissolved carbides remain trapped in the liquid or will form a dross. The addition yields decreases when the niobium concentration reaches this limit value, that depends on the carbon concentration. These define a saturation curve.

Jan 1, 1994

By Paul L. Matrin

This paper will discuss the recent and on-going drill and blast optimization measures at the Sparkhule Limestone Quarry, which have resulted in a 44% reduction of drill and blast unit costs per ton of broken limestone. This amounts to approximately $240,000 of drill and blast saving per year at current annual production rates of about 2.5 million tons (2.3 million tonnes) total material shot. The reduction of drill and blast costs were accomplished by a detailed and controlled in-the-mine drill/blast experimentation and cost evaluation using 8 different blast pattern designs and shots totaling approximately 267,000 tons (242,200 tonnes) of shot and mucked material. A careful review of the geology of the deposit was performed to determine the different rock classification/strengths/structural properties and to adjust blast designs to optimize fragmentation for the different rock types. Equipment loading productivity and crusher throughput performance were monitored as part of the evaluation process to assure that an optimal fragmentation of broken rock was achieved with the new blast designs. The study included the review of bulk explosive and accessory selection criteria (ammonia nitrate/fuel oil mix - ANFO, mini prills (high density ANFO), sensitized and un-sensitized emulsions at a 30% emulsion/70% ANFO blend), blast pattern design, charge diameter and the cost of drilling. Laser profiling technology was used to assure proper bench heights, stemming and sub-drill footage and front row burdens. High speed photography, video and still photos were taken of the different designed shots to assist in the evaluation of the performance of each blast. Powder density checks, size distribution, back break, detonation velocity and pressure measurements were taken. Different borehole diameters were used for the drill optimization study and drilling cost and productivities determined. A detailed cost comparison between in-house blasting and complete shot service was prepared to evaluate if shot service is a cost effective alternative to current in-house loading and blasting including a review of the new and pending United States Bureau of Alcohol, Tobacco and Fire Arms (ATF) regulations and associated owner costs/risks and potential benefit of shot service.

Jan 1, 2004

The paper point out the testwork has been carried out with real process solutions from the Chambishi cobalt plant in Zambia, showing that the ISEP® continuous ion exchange system can effectively remove nickel from cobalt sulphate electrolyte. Laboratory testing confirmed published data, and was subsequently verified on site at Chambishi in a pilot test program. Based on the testwork data, a commercial unit is being installed at Chambishi.

Sep 13, 2001

By George R. White

"The Phalen Colliery, the Cape Breton Development Corporation's flagship, is now producing thermal and metallurgical grade coal in Eastern Canada's Sydney Coal Field. The colliery is a drift mine operating under the waters of the Atlantic Ocean. Improved mechanization, including a 2200 tonne per hour cable conveyor, and the introduction of modern retreat longwall mining methods as part of the Phalen concept are now paying off in better productivity and low operating costs. Geological conditions within the coal field are consistent with plans for ever greater outputs in the 1990s. Although much of the current production improvement is related to uprated machine capacity and simplified mines planning there is potential for even further development in the areas of maintenance, process control and engineering. Human resource development will also be a key factor. These programs are now well under way and Phalen Colliery is poised for top results in the 1990s. Comparison of the CBDC's top producer with similar operations elsewhere in the world, quantifies that potential.IntroductionAn exciting new mining project which has recently started production on Canada's East Coast has been conceived and designed to be one of the most modern and productive coal mining operations in North America.As with all mining operations, the business is basically that of material transportation. Daily, the product is transported many kilometres from the underground face to the surface and then to washing facilities. Men, materials and equipment are transported to and from the surface and the operating faces and services, such as electrical power, ventilating air, fresh water, discharge water, communications and compressed air are supplied throughout the operation to cover operating requirements. On all accounts the operation has been designed to take advantage of the latest proven technology."

Jan 1, 1990

By V. T. Stringfield

ONE of the earliest investigations of ground water in Florida was made in 1513 when Ponce de Leon arrived at St. Augustine in search of the Fountain of Youth. The history of the development of the water resources of the State shows that the large artesian reservoir that underlies Florida was discovered in the latter part of the last century. Part of that history is given by L. C. Johnson1 who states that the first successful artesian well in Florida was drilled at St. Augustine between 1880 and 1882. After the City of Jacksonville failed to obtain a flow of artesian water at a depth of nearly 400 ft and abandoned the drilling, R. N. Ellis, City Engineer, and L. C. Johnson, using Johnson's knowledge of the geologic structure of the artesian reservoir, estimated correctly that artesian water could be obtained at a depth of about 500 ft. Thus began the development of the large artesian system in the northeastern part of the State. In 1908, the Florida Geological Survey issued its first report on the ground water of central Florida.

Jan 6, 1951

By Jim Gebhardt

Douglas W. Fuerstenau (DWF) grew up on a farm and in several small communities in rural South Dakota during the depression years, where he learned the value of hard work. Working hard can produce results but being clever and hardworking will give you a bright future. In his later school years, Fuerstenau’s family moved to Rapid City where his intellectual curiosity and capacity helped him graduate with a B.S. in Metallurgical Engineering from the South Dakota School of Mines and Technology in 1949. His technical interests led to graduate studies and completion of a master’s degree from the Montana School of Mines in 1950 and Sc.D. degree from the Massachusetts Institute of Technology (MIT) in 1953.

By N. A. Pace

This is one of a series of papers being published by the Federal Bureau of Mines for the dissemination of information on methods and practices used in the mining and preparation of crushed stone for market requirements. Performance in terms of units of work or tons produced per machine and per operator man-hour are given whenever that information is available. Direct operating costs are useful for comparing different methods, and are, therefore, included if possible. In addition to the factual description of equipment and methods used, it is desirable to discuss the engineering reasons for the choices that have been made. This paper is particularly concerned with the opertions at the Columbia plant of Palmetto Quarries Co. of Columbia, S.C. The plant is about one-half mile east of the Congaree River and adjacent to the southwest corner of the city of Columbia. Rail access is by the Atlantic Coast Line Railroad, and by a spur strack of the Seaboard Airline Railroad.

Jan 1, 1962

By N. I. Basuki, E. T. C. Spooner

"Abstract - More than 2800 published fluid inclusion data (primary inclusions) from eighteen typical Mississippi Valley-type (MVT) Zn-Pb deposits and districts were examined to study possible relationships between MVT fluid properties and metal tonnages and ore grades. The mean Th and salinity values for fifteen MVT deposits and districts are 122°C ± 21°C and 20.7 ± 2.6 wt% CaCl2 equivalent, respectively. In general, temperatures increase from pre-ore to ore stages, and salinities decrease from ore to post-ore stages. From post-ore to late calcite stages, salinity and temperature decrease with various trends within specific districts.Several conclusions are drawn: first, results show that Hanor’s (1996) salinity threshold for metalrich basinal fluids applies to typical MVT ore fluids (~16 wt% CaCl2 equivalent). Second, the lower limit of mean Th values of measured MVT deposits and districts (n = 15) of ~75°C is similar to Hanor’s (1996) observed temperature threshold for metal-rich basinal brines of ~60°C (n = 224). Third, there is no statistically significant relationship between fluid inclusion homogenization temperatures (Th) and metal tonnages or ore grades. Fourth, there seems to be a tendency for large tonnage districts/deposits to be associated with mean fluid salinities that are relatively low (~16 to 21 wt% CaCl2 equivalent) within the overall range of salinity means (~16 to 26 wt% CaCl2 equivalent). There is also a correlation between higher ore grades and higher salinities. Finally, comparison with other sedimentary rock-hosted Zn-Pb deposit types shows a trend of salinity decrease and temperature increase from MVT, sandstone-hosted and diapir-related Pb-Zn deposits, to vein-type and Irishtype Pb-Zn deposits, and then to sedex deposits. However, more data are needed for sedex deposits. The salinity threshold for significant Zn-Pb transport decreases to =~10 wt% CaCl2 equivalent at ~250°C. This study suggests that fluid inclusion analysis during exploration may be useful in assessing ore-forming potential (threshold salinity) and possible ore grades (salinity)."

Jan 1, 2002

By K. G. Thorne, M. J. McLeod, D. Hoy

"Throughout the Paleozoic, a variety of gold depositional environments were created in the New Brunswick segment of the northern Appalachians because of the complexity of arc and continental plate collisions and subsequent erosion of the orogen. In southwestern New Brunswick, recent exploration and research has focused on deposits and occurrences that can be broadly classified as intrusion-related, generated by late- to post-orogenic felsic to intermediate plutonic rocks emplaced during the Early to Middle Devonian. This work has led to the establishment of models for gold mineralization and guidelines for exploration in this area, which might also be applicable elsewhere in the southern part of the province and, perhaps, throughout the northern Appalachians. The deposits in the vicinity of Clarence Stream in southwestern New Brunswick exemplify this deposit type, and highlight the emergence of a possible major gold district in the region. Durant le Paléozoïque, une grande variété d’environnements aurifères ont été créés dans le segment néo-brunswickois des Appalaches du nord en raison de la complexité des collisions entre arcs et plaques continentales ainsi que durant l’érosion subséquente de l’orogène. Dans le sud-ouest du Nouveau Brunswick, les travaux d’exploration et de recherche récents se sont tournés vers les gisements et les indices appartenant à la classe des gîtes associés aux intrusions, générés par des roches plutoniques felsiques à intermédiaires tardi- à post-orogéniques mises en place au Dévonien précoce à moyen. Ces travaux ont permis d’établir des modèles de mise en place pour la minéralisation aurifère ainsi que des guides d’exploration pour ce secteur, lesquels pourraient aussi être appliqués ailleurs dans le sud de la province et, possiblement, dans l’ensemble des Appalaches du nord. Les gîtes aux environs de Clarence Stream dans le sud-ouest du Nouveau Brunswick sont un exemple de ce type de gisement, mettant en valeur ce qui pourrait devenir un district aurifère majeur dans la région."

Jan 1, 2008

By Jean-Guy Levaque, Robert Ethier, Ron J. Elliot

This paper presents data gathered during a comprehensive study on the impact of improvements to fragmentation in a major Limestone quarrying operation. The full impacts of gains in fragmentation are tracked through the mucking, crushing, and grinding phases of the operation.

Jan 1, 1999

By Sidney Katell

The reaction of coal, oil, or natural gas with air and oxygen and/or steam yields a gas containing varying amounts of impurities. Depending on the raw material and the end use of the product, these impurities include solids, such as dust or slag, and gases, such as hydrogen sulfide, carbon dioxide, and nitrogen. Considerable effort has been expended in developing and operating purification systems, and the literature is replete with equipment data and operating results. The research problems, the design, and the operation of the various systems have been the subjects of patent applications, journal articles, and textbooks.

Jan 1, 1959

By Y. Nara, N. Aramaki, M. Maruyama

Evaluation of three dimensionally non-uniform strain distribution in rocks under various conditions such as in water or under freeze-thaw cycles is of significant importance to understand their complex deformations and fracturing mechanisms. For this purpose, we developed an image analysis method which can evaluate or “measure” the three dimensional (3-D) strain distribution in rocks. The proposed method utilizes the 3-D images of rock under initial and deformed configurations, which are obtained by some imaging techniques such as X-ray computed tomography (X-rayCT). In the proposed method, the obtained 3-D images are divided into multiple sub-regions of interest. For each sub-region, the strain is evaluated utilizing 3-D affine transform with unknown coefficients to be determined. In the first step, 3-D voxel level displacements at multiple representative points in each sub-region are computed by 3- D digital volume correlation technique between the comparison images and the initial-guess of the transform coefficients are obtained. In the second step, referring to the initial-guess of unknown transform coefficient, they were optimized in sub-voxel level by finding optimum digital volume correlation between the comparison images, which can evaluate the transform coefficients with higher precision. From the calculated transform coefficients, the strain was directly obtained through the spatial derivative of displacement based on affine transform. In this paper, along with the description of the proposed method, the evaluation of deformation in a lignite specimen due to immersion in water was presented as an application example. As the 3-D imaging technique, micro-focus X-rayCT was applied. The result showed that the induced dilatational strain field due to the initiation and extension of cracks in the specimen was clearly captured. Therefore, authors believe that the proposed method can be applicable to various problems in rock mechanics.

Jan 1, 2015