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By John Loui Porathur

Highwall Mining has been recently introduced in India. The first Continuous Highwall Mining extraction in India started operating at Ramagundem Opencast Project-II (OC-II) of Singareni Collieries Company Ltd. (SCCL) in December 2010. A new hybrid empirical and numerical modelling approach has been devised to design web pillars for the initial Highwall Mining sites in India, considering the complex geology, such as existence of thick seams and multiple seams in close proximity. This paper gives the scientific elucidation of a comprehensive design methodology adopted for the above mentioned Indian Highwall Mining sites. The design technology includes web pillar design for multiple seams using hybrid empirical and numerical methods, slope stability assessment, ground movement monitoring, and recommendations for conducting blasting operations in the vicinity of Highwall Mining extractions.

Aug 1, 2013

By L. Jiang

This report investigated the dynamic recrystallization (DRX) phenomenon in magnesium alloy AZ31 billets to understand the deformation mechanisms and microstructure evolution during extrusion and other metal forming processes, Compression tests of coarse-grained as-cast magnesium alloy billets containing lamellar Mg17Al12 eutectic phase and (Al, Mn) particles suggest that temperatures higher than 300°C, strains greater than 0,25 and strain rates above 0,l/s lead to the formation of fine DRX grains in the deformed samples. Microstructural observations also indicate particle-stimulated DRX nucleation (PSN) during hot deformation of the AZ31 alloy, facilitated by the presence of Mg17Al12 and (Al, Mn) particles, While the Mg17Al12 is dissolved into the matrix at about 350°C, (Al, Mn) particles may remain effective for PSN at temperatures up to at least 400°C, This study suggests that alloy design with a proper distribution of second-phase particles can provide the desired microstructure for improved properties and formability in wrought magnesium alloys.

Jan 1, 2004

By G. Shaw

IN recent years, most of the reconnaissance work of the Geological Survey of Canada has been mapped on a scale of 1 inch to 4 miles. Topographic base maps, commonly made from aerial photographs, were available to the geologist for such work. The advent of war curtailed aerial photography for civilian purposes, and by 1941 all areas already photographed had been geologically mapped. Nevertheless, the need for geological maps to assist post-war prospecting was so apparent, and the country to be covered is so vast, that some new method of rapid mapping had to be devised. It was felt that the need would be met if geological maps could be produced at a scale of 1 inch to 8 miles, provided they were sufficiently accurate in topographic detail to serve as guides to travel. Though in such maps there would be considerable sacrifice of geological detail, they would serve to outline, at least approximately, the major geological units, some of which might prove of sufficient interest to warrant later detailed study. It seemed that such mapping would be particularly useful in the northern regions of Canada which the work of early explorers has indicated are underlain largely by granitic rocks. These, so far as is known, are barren of mineral deposits, but within them are known to be areas or bands of 'greenstones' of the type that, in some localities, have been found to contain valuable orebodies. The problem, then, was to devise a method of mapping, particularly of such greenstone bands, that would make it possible to cover a relatively large area-say 30,000 square miles-in one season and at a cost below that of 4-mile mapping, with, of course, some sacrifice of accuracy. The problem seemed to be threefold: (a) to observe as much of the bed-rock as possible; (b) to produce a topographical map of as much of the area as possible, with particular reference to portions of geological interest; and (c) to cover as large an area as possible in a limited time, which meant faster modes of travel than have hitherto been used. The obvious answer to all three phases of the problem was the use of aircraft. If rock types could be broadly differentiated from the air, reconnaissance traverses by air would supply the answer to the first part of the problem. For topography, air photographs taken on reconnaissance flights appeared to be the answer. For the third phase of the problem, the use of aircraft was ideal.

Jan 1, 1943

By C. Stapel, I. C. Tânczos, R. J. De Meijer

"Abstract -In recent years the Environmental Research Group of the KVI has been developing a number of radiometric techniques that may be employed in mineral sand exploration. These techniques involve: radiometric fingerprinting for assessing sand provenances and mineralogical composition; thermoluminescence for dating and provenance determination of sediments; a towed seabed detector to map seafloors for radiogenic heavy minerals and assessing heavy mineral volumes; and simplified transport mechanism models to explain and predict heavy mineral concentrations.All techniques exploit the property that heavy minerals as a group contain concentrations of naturally occurring uranium and thorium that are a hundred to a thousand times higher than in light minerals. In this paper the physics of a number of methods will be described together with a number of results. Based on these results potential applications to mineral exploration and mining are discussed."

Jan 1, 1994

By C. Rocha R.

Petioles is a mining group with integrated operations in the smelting and refining of non-ferrous metals, and is also a chemicals producer. Peñoles is the world's foremost producer of refined silver, metallic bismuth and sodium sulphate and is the leading Latin American producer of refined gold, lead and zinc. The Met-Mex Petioles Zinc Plant commenced operations in 1973 with an annual production capacity of 105,000 t/y. Year after year the production has been increased, and at present, the production capacity is 240,000 t/y. In this paper, the leaching process, particularly the operation of the jarosite circuit and its effective removal of impurities such as arsenic, antimony, indium, selenium and tellurium, is reviewed.

Jan 1, 2006

By H. Lazreg

This paper presents an evaluation of surface resistivity techniques as a tool for delineating salt-water intrusion in Shippegan, N.B. The study consisted of resistivity profiling, resistivity soundings and a limited number of induced polarization soundings in selected areas in the Province of New Brunwick. The results from resistivity profiling indicate that when seawater intrusion occurs in a sandstone formation the resistivity contrast is sufficiently large to allow a precise delineation of the intrusion. A formula is then derived to convert resistivity values to chloride concentration in the "cone of intrusion". The results from resistivity soundings showed that shaly formations may have resistivities as low as seawater-contaminated sandstone. An indeterminacy has resulted from this resistivity overlap. A limited number of IP soundings were performed in an effort to resolve it. The results showed that IP can be of appreciable help in resistivity interpretation.

Jan 1, 1972

By P. Cicmanec

Mining activities in the territory of Slovakia have a long history. Mining techniques have developed rapidly in the last centuries. This paper deals not only with mining history, but also with underground brown coal mining, magnesite mining and other mining activities at present and sustainable developments of the mining industry in the Slovak Republic. This paper looks forward in the context of mineral raw materials in Europe (Global Europe, 2012).

Aug 1, 2013

By G. J. Borbely, E. A. Devuyst, V. A. Ettel

"A new method for oxidative destruction of cyanide in industrial waste waters and slurries, such as gold mill barren liquors, tailing slurries and flotation tailings has been developed at the Inca research laboratories. Rapid decomposition of cyanide and related species is attained by treating the waste waters with a mixture of S02 and air at controlled pH and in the presence of a small amount of copper which acts as a catalyst. The approach selectively oxidizes cyanide and metal cyanide complexes, and also removes iron cyano complexes which are not removed by alkaline chlorination.The new method is shown to be less reagent intensive and therefore more economical than alkaline chlorination for treating gold mill and flotation waste waters. INTRODUCTIONOver 90% of the gold mined in Canada is extracted from the ore by ""cyanidation"". Wastes from the process consist of tailings which contain free cyanide, cyanide combined with heavy metals, thiosalts and thiocyanates. Because of the concern over the effect of toxic cyanides on the environment, all cyanide containing effluents will have to be treated in the future to meet certain government set concentration limits."

Jan 1, 1982

By Zhang Junzhi

This paper relates cross-border mergers and acquisitions (M&A) risk management theory to actual coal enterprises in China. The 3 phases of M&A are preparation, implementation and integration. By using the Analytic Hierarchy Process and fuzzy evaluation methods, we will try to establish a model to assess risks of the cross-border M&A of China?s coal enterprises. We then apply this model to the case of Yankuang Group acquisition of the Felix Company and receive the assessment results. There are significant reasons for quantitative research on risks of cross-border M&A of China?s coal enterprises, such as effective prevention and risk-aversion, and facilitation of cross-border M&As.

Aug 1, 2013

By Z. Farhat

In spite of advances in cutting tool technology, the understanding of the basic wear behavior and failure mechanisms needs further study. Tool wear is the main factor contributing to geometrical error and thermal damage in machined components. Manifested as a reduction in tool life, it also affects the workpiece surface finish, increases cutting forces and induces residual stresses. Furthermore, the emergence of high and ultra-high speed machining processes necessitates the investigation of tool wear under these severe working conditions. Tungsten carbide-cobalt composite material has been used traditionally as wear resistant materials for many years. One main application of this material is in cutting tools. WC-Co tools consist of hard WC particles imbedded in a tough Co matrix, which functions as a binder phase. More recently, Cubic boron nitride (CBN) tool material have attracted special attention due to its high hardness and excellent wear resistance. Boron nitride in its cubic form is known to be the hardest material next only to diamond. In this paper microstructural and tribological properties of commercial grade WC-Co and CBN cutting tool materials are investigated under high speed cutting conditions. The CBN cutting tools were found to be superior to tungsten carbide (WC) tools. Four-fold increase in productivity and significant reduction in chipping and cratering was achieved for CBN as compared to WC. Wear mechanisms are proposed and are related to the observed wear characteristics in the cutting zone.

Jan 1, 2006

By J. W. Senn

A magnesium alloy modeled after commercial alloy WE54 was thermomechanically processed and characterized to understand the mechanisms by which its texture can be randomized, as reported by Ball and Prangnell [1]. Samples were deformed in plane strain compression to prescribed strain levels at temperatures high enough to prevent cracking and then recrystallized. The deformation texture is very similar to that observed after plane strain compression (e.g., rolling) of other Mg alloys, such as common AZ31. However, the texture can radically evolve during recrystallization. Annealing above the precipitate solvus temperature results in a nearly random recrystallization texture where the initially strong basal texture is completely eliminated. Annealing below the solvus temperature produces a recrystallized texture similar to conventional Mg alloys, i.e., a weakened basal texture. If this same material is then annealed above the solvus to promote grain growth, a randomized texture evolves, which is similar that of samples simply recrystallized above the solvus. It is hypothesized that a sort of preferred growth mechanism, whereby grains with random orientation grow faster than those with the original basal texture, contributes significantly to the texture randomization observed in wrought magnesium alloys containing rare earth elements.

Jan 1, 2006

By D. E. M. Plaumann

"The wet grinding of asbestos has attracted the attention of engineers for many years as a means of improving fibre liberation from the ore. Today, added impetus for wet grinding has resulted from a need to minimize worker exposure to asbestos dust in conventional dry mills using air, as well as a need to provide a cleaner, technically superior fibre for use by product manufacturers. However , high viscosities of asbestos slurries create transport and grinding difficulties which have been a factor impeding use of a wet grinding process.Laboratory evaluation of reagents to reduce viscosities of asbestos slurries found that one reagent, XFS-4272.00, reduced the viscosity of a 35% (by weight) slurry by 75%. The impact of XFS-4272.00 on actual grinding parameters were evaluated using a pilot plant rod mill. Slurries containing 78% solids and XFS-4272.00 were successfully milled and asbestos fibres from that milling compared favourably in liberation and relative surface area to asbestos fibres obtained from milling a 4% slurry without additives.IntroductionAlthough the use of asbestos has been declining over the last few years, the large deposits of chrysotile in eastern Canada (Quebec in particular) remain very important. Asbestos production in Canada stands ninth in volume for mineral production with over 740 000 tonnes produced in 1985. Of this quantity, 722000 tonnes were exported with a value of $446 million . Canada is second in world production of asbestos behind the U.S.S.R ."

Jan 1, 1988

By Jonas Olsson

"The picture of China as an antiquated continent is changing rapidly and fast-forwarding progress is a fact in most infrastructural fields. Mining is not an exception. China is today the largest producer of aluminum, coal, steel, zinc, tin, lead and manganese and the country’s mineral resources comprising approximately 12% of the global reserves ranks them number three in the world after US and Russia.In order to feed the growth industry is needed to take extra ordinary strides to improve supply of raw material and Chinese mines are continuously being upgraded with the latest western technology to meet the increasing domestic demand of base metals.In Anshan located in China’s northeast province Liaoning we find one of the fastest developing mining companies, Angang Iron & Steel Group Co. Ltd. With their six mines that together process approximately 60 M ton iron ore/year Angang Iron & Steel Group Co. Ltd is the largest iron ore company in China. The group’s thorough pre-studies and technical evaluations over the past five years have made them very successful in both plant upgrades of existing operations and green field projects.INTRODUCTIONWe live in a time when the world market is gradually acclimatising to the global consequences of “The China effect”. An effect caused by a formerly sleeping giant nation that during the last years has awakened and developed beyond comparison, primarily because of booming infrastructure projects and demand for capital and consumer goods"

Jan 1, 2006

By K. G. Thorne, D. R. Lentz, A. F. Park

"The Main zone of the Clarence Stream gold deposit is hosted by a shear zone adjacent to the Saint George batholith in southwestern New Brunswick. The mineralization history relates to progressive deformation in the shear zone and the intrusion of the Magaguadavic granodiorite.Of three phases of deformation that have affected the area (D1-D3), D1 is not observed in the Clarence Stream shear zone. Two suites of igneous rocks intrude the shear zone: post-D2, pre-D3 gabbro; and granitic dikes, which crosscut the gabbros. Granitic dikes show a diverse range of relationships to D3 features, from pre-syn-D3 mylonitic fabrics in transposed and highly deformed enclaves, to nondeformed and entirely discordant dikes (post-D3).A variety of veins occur within this shear zone. Zoisite-bearing and later, crosscutting epidote-bearing veins are preserved as relics in quartz-mylonites, and predate quartz veins that host gold mineralization. The epidote-bearing veins are associated with pseudotachylitic cataclasite dikes, consistent with transient brittle failure during ductile deformation.Deformation relates to right-lateral strike-slip motion across the shear zone, and subhorizontal and near-vertical stretching lineations imply transpression. A late (late- or post-D3) dip-slip phase of motion is also apparent, and cooling followed a metamorphic peak early in D2-D3 history. Deformation of the shear zone, and more localized transient brittle failure, provided the permeability for fluid movement and vein emplacement. This scenario is similar to the findings of other studies, in which geochemical, tracer isotopic, and age-dating (U/Pb, 40Ar/39Ar) results suggest that the adjacent Magaguadavic granodiorite provided heat and metals. La zone principale (Main zone) du gisement d’or de Clarence Stream est encaissée par une zone de cisaillement qui longe le batholite de Saint George dans le sud-ouest du Nouveau Brunswick. L’historique de la mise en place de la minéralisation accorde un rôle important à la déformation progressive dans la zone de cisaillement et à la mise en place de la granodiorite de Magaguadavic.Des trois phases de déformation à avoir affecté la région (D1-D3), les effets de D1 ne sont pas observés dans la zone de cisaillement de Clarence Stream. Deux suites de roches ignées se sont mises en place dans cette zone de cisaillement : un gabbro post D2, pré-D3 et des dykes granitiques qui recoupent le gabbro. Les dykes granitiques montrent une grande diversité de relations avec les structures D3, allant de précoces à synchrones aux fabriques mylonitiques D3 dans des enclaves transportées et fortement déformées à des dykes complètement discordants et non déformés (post-D3).On note diverses veines dans cette zone de cisaillement. Des veines contenant de la zoisite ainsi que des veines d’épidote sécantes plus tardives, lesquelles sont préservées comme reliquats dans les mylonites à quartz et sont plus vieilles que les veines de quartz contenant la minéralisation aurifère. Les veines d’épidote sont associées à des dykes de catacalasite à texture de pseudotachylite, compatibles avec une rupture cassante épisodique durant la déformation ductile.La déformation résulte d’un mouvement décrochant dextre le long de la zone de cisaillement et les linéations d’étirement subhorizontales et quasi-verticales impliquent de la transpression. Une phase tardive (tardi- ou post-D3) de mouvement selon le pendage est aussi apparente, et le refroidissement succède à un pic métamorphique tôt dans l’histoire D2-D3. La déformation de la zone de cisaillement et la rupture cassante épisodique ont fourni la perméabilité nécessaire au mouvement des fluides et à la mise en place des veines. Ce scénario est similaire à celui proposé par d’autres études, dans lesquelles les résultats de géochimie, de traceurs isotopiques et de géochronologie (U/Pb, 40Ar/39Ar) suggèrent que la granodiorite de Magaguadavic avoisinante a fourni la chaleur et les métaux."

Jan 1, 2008

By A. O. Dufresne

A Step which, it is believed, will prove extremely beneficial to the Quebec asbestos-mining industry was taken during 1931, when the asbestos mine operators of the Province assembled to work out a uniform method of naming the products of their mines. The outcome of several meetings was the drawing-up of a classification which defined, limited, and designated anew the numerous grades of asbestos marketed. It entailed no drastic departure from the existing processes of grading, nor any revolutionary changes in methods of testing, but aimed rather to perfect existing methods. The classification proposed has been accepted by all operators in the Province, who, from January first of this year, began introducing the new nomenclature. Unless one is conversant with the properties and mode of occurrence of chrysotile asbestos, with the unique milling methods devised for its recovery, and with the history of the development of their technique, he may not readily understand the basis of the new classification. For information on these and other data concerning the industry, the reader is referred to a recent publication, Chrysotile Asbestos in (Canada, by James Gordon Ross, issued by the Mines. Branch of the Department of Mines, Ottawa. The object of this paper is to present briefly some of the phases in the evolution of the classification of Canadian chrysotile asbestos, in the hope that the recent effort to standardize the marketable products of one of Canada's most important non-metallic mineral industries will open a field for discussion, fruitful in new ideas and constructive suggestions. The necessity for the grading of asbestos results fundamentally from the fact that the price per ton depends on the length of fibre. At all times in the history of the industry, the very limited available supply of the longer grades, as well as the requirements of the trade, have caused relatively very high prices to be paid for fibre over half an inch in length, while for the shorter grades the price decreases rapidly, and at a rate which bears no proportionate relation to the length of fibre.

Jan 1, 1932

By Jack G. Hazan

The Critical Path Method is the modern scientific answer for solving the planning and scheduling problems inherent in today's complex projects. With this method, nothing is left to chance. All resources are controlled and kept to the minimum. The various phases are properly planned and strategically determined. Optimum conditions are evaluated for the most economical and fastest way to complete a definite project. The method must be fully understood and implemented with positive data and continuous feedback to obtain the best results. This paper covers the various aspects of the Critical Path Method and mentions some of its applications in the mining and metallurgical fields. T 0 progress to a higher state of human welfare necessarily involves sacrifices. The greatest sacrifice is to relinquish social freedom in favour of economic freedom. In the old days, for example, a cobbler was free to work at whatever time of the day he chose; today, he can't. He is now forced to adapt himself to environment and to work at stand-

Jan 1, 1965

By D. F. Sherwin

"THE AREA which is described in this paper (Fig. 1) includes the continental margin of eastern Canada extending from the Gulf of Maine to the north edge of the Grand Banks, which, including the continental shelf, slope and rise, comprises an area of about 600,000 square miles. The paper is intended to give a background of the geological setting of this region in the context of its ultimate potential for oil and gas reserves in close proximity to the Nova Scotia energy market.HISTORY OF EXPLORATIONThe history of geological exploration of this area really began in 1878, when U.S. fishing boats brought back samples of rock recovered in trawls from their expeditions to the long-famous fishing banks off Canada's East Coast. Tertiary and Cretaceous fossils recovered from these samples indicated that the eastern Canadian continental shelf was actually the submerged northern extension of the Atlantic Coastal Plain."

Jan 1, 1972

By S. V. Burr

"A 28-year study of cross folds leads to the conclusion that the northwest-southeast folds recognized in many areas of North America are part of a regional pattern. Detailed examination of over 650 geological maps and reports of Ontario indicates that this folding can be traced across the province. Evidence is presented that this fold pattern played an important part in determining the pattern and scale of intrusion, that its recognition in the field can aid in defining stratigraphy, folding and faulting, and that it may have played an important role in channeling hydrothermal or magmatic mineralization. IntroductionThe concept of regional cross folding in Ontario is not new. W.H. Gross (1955) discussed regional cross folds in the Archean of Northwestern Ontario, and A.M. Goodwin (1961) referred to regional cross folds in the Archean of Ontario and Quebec. However, the interpretation in this paper is new.The writer saw a cross fold for the first time, underground, at Little Long Lac Gold Mines in Geraldton, Ontario, in 1951. This recalled the ""transverse folds"" on E.R. Faribault's classical maps of Nova Scotia, published by the Geological Survey around the turn of the century; M.E. Hurst's cross fold(s) at Timmins, Ontario (Figure I); and the cross folds mapped by A.W. Jolliffe in the Yellowknife area of the Northwest Territories. All these mapped cross folds had one thing in common with the fold at Little Long Lac: A northwest-southeast axial trend. Were such cross folds of purely local extent, or might they be indicative of a widespread regional fold pattern? If so, has such folding any significance for mineral exploration or potential?By 1959, based on a study of about 1000 Canadian geological maps and reports, including 291 in Ontario, the writer reached the conclusion that cross folding trending northwest-southeast is so widespread as to constitute a pattern of folding, and that such cross folding should produce changes in plunge along pre-existing greenstone fold belts."

Jan 1, 1980

By M. Beech-Jones

The increased emphasis on the efficient utilization of capital and mineral resources has led to several new advances in the science of mineral separation. One example of a recent development is the application of high-capacity high-intensity wet magnetic separators to fine hematit e recovery by a leading Canadian iron ore producer. The iron ore recovery feasibilit , flow-sheet development, circuit operation and metallurgical performance are reviewed.

Jan 1, 1979

By Chris Larsen, Ian Orford, Marilene Renaud, Mike Cooper, Lud Strah

"An AG/SAG mill was commissioned at the Brunswick Mine concentrator in October 1998. This paper discusses the original liner design for the bi-directional AG/SAG mill, observed liner wear, subsequent liner design modifications, and benefits. The mill liners consist of steel top hat shell liners, steel end liners, rubber grates and rubber lined pulp lifters.Lifter profile and plate thickness measurements were made on monthly shop days. Trends of wear rates were used to project when liners required replacement. Wear profile information was also used to determine where liner re-design would improve wear life or minimize scrap loss. Charge motion simulation modeling was used as a tool to assist liner design modifications.INTRODUCTIONThe Noranda Inc. Brunswick Mine, located near Bathurst, New Brunswick, is a large underground lead/zinc mine with a nominal production rate of 10,000 tonnes per day. The Brunswick concentrator commenced operation in 1964 with conventional surface crushing followed by rod and ball milling to reduce run of mine ore to the required size to feed two parallel flotation circuits. In 1998 the AG (autogenous grinding) mill was commissioned for a nominal production rate of 9,000 tonnes per day replacing two surface crushing plants, three rod mills and three primary ball mills. In May of 1999 the mining rate was increased and the service of the AG mill was changed to a SAG (semi-autogenous grinding) mill with the addition of 4 inch steel balls (4% volume). The mill operates in closed circuit with 0.66 meter horizontal cyclones to produce a ground product of 90 micron nominal size (K80).The AG/SAG mill liners are steel (Norsteel, chrome-moly steel) with rubber grates and rubber lined pulp lifters.The original liner design was based on studying other AG/SAG mills and recommendations by the liner supplier, Norcast. Design factors taken into account were total cost of lining (including material and labour), protection of mill shell and impact on operating performance."

Jan 1, 2003