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By J. J. Jonas, G. R. Stewart, N. Pokutylowicz, S. Yue, R. Varano, A. Elwazri

Differing thermal histories in and around a weld can lead to differences in grain size, phase composition and morphology of precipitates; mechanical properties will vary accordingly. Hardness testing gives limited information and the machining and testing of tensile and/or impact specimens that would reveal these variations (which may occur over very small distances) is not practical. Therefore, in this investigation, shear punch testing was applied to measure the variation in the room temperature mechanical properties of a welded pipeline steel.

Jan 1, 2005

"In 2008, the Committee for Mineral Reserves and International Reporting Standards (CRIRSCO) and the Russian State Commission on Mineral Reserves (GKZ) entered into an agreement leading towards harmonization of Russian and international minerals reporting systems. The purpose of the protocol is to define an agreed method by which mineral resources and reserves, reported by companies in Russia according to the current Russian classification system, can be expressed in terms that are comparable to the CRIRSCO reporting codes in Russia and elsewhere."

Jan 1, 2003

By D. A. Karvonen

In 1970, the Government of Saskatchewan instituted a program aimed at resolving the dilemma of excess productive capacity over the market demand which existed for potash produced in Saskatchewan. The two primary elements of the program were prorationing of potash production to market demand and a minimum selling price. The paper reviews the factors, both local and international in nature that led to the introduction of the program. The licensing mechanics and the operation of the program, along with the changes that have been introduced in two and one-half years of operation, are discussed. Attention is given to the results of the controls as they affect the industry and the province. Also discussed is the outlook for Saskatchewan potash in world markets.

Jan 1, 1973

By J. Janeson

Wall control at the Pipe Open Pit is of primary importance in ensuring the long-term stability of the operation, while keeping costs to a minimum. Blasting techniques have been adapted to the variations in competence and structure of the wall rocks. A portion of the perimeter wall is being developed in incompetent peridotite . A recent change in pit slope design provides a wide safety berm on alternate benches. A support program which consists of pinning the crests of wide berms with vertical reinforced concrete dowels and horizontal bolting of walls shows evidence of increasing the stability of the pit walls. This paper describes the blasting and support techniques which are contributing to successful wall control in the Pipe operation.

Jan 1, 1979

By E. O. Lilge

THE USE of the Driessen cone as a heavy-media concentrator involves a mineral dressing process in which many variables inherent in the ore and in the process may have an effect on the efficiency of mineral separation and the operation of the cone. The magnitude of these effects and their possible interrelationships must be known before a full-scale plant can be designed and built. It appears that, among the most important variables, are the following: Ore Variables: The particle size of feed The difference in specific gravity between economic and non-economic minerals The intimacy of mineral association Cone Variables: Cone inlet area Ore to media ratio Cone ratio Size distribution in heavy media Specific gravity of media Viscosity of media Type of media

Jan 1, 1956

By Ken Steele, Pam Sangster, Myra Gerow

Ontario leads Canada in production of structural materials and ranks third in production of non-metallic minerals. The total value of industrial mineral production in 1997 was $1.6 billion. The province is the leading producer of nepheline syenite, salt, talc, clay products, cement, lime, sand and gravel, stone and a major producer of gypsum and silica. Barite, sulphur in smelter gas, elemental sulphur, tremolite, serpentine, gemstones and peat are also produced. Table 1 shows recent actual industrial mineral production levels in Ontario. Other industrial minerals, including phosphate, petalite, diamonds, wollastonite, vermiculite, kyanite, garnet, graphite, silica, kaolin, dimension stone and anorthosite, have been the target of exploration and development projects. Investment opportunities exist at all levels from grass-root prospect through to production level.

Jan 1, 2001

By M. Hajian Heidary

In this investigation, effect of pressure depth on the globulizations of AZ91 magnesium alloy was studied. Cylindrical samples of AZ91 alloy with 1 cm and 2cm in height and 2.5cm in diameter (H/D = 0.4 and 0.8) were prepared, then the samples were hot pressed at 10 and 30% strain at a constant temperature of 200°C; subsequently reheated at 555°C in different times. Results obtained from optical microscopy (OM) showed that the thickness of the samples and consequently, depth of strain affected regions have remarkable effect on the degree of globulization. In addition, it was found that at a constant strain and holding time, structure of thinner samples is more globular than thicker ones.

Jan 1, 2007

By H. M. Roscoe

Fifty per cent. increased lump coal production and at the same time a reduction of from 20 to 40 per cent. in explosive consumption. These results were achieved by the use of the rock-dust cartridge method of stemming shots in the Ruhr coal mines, as announced by Dr. Alfred Stettbacher in the September 1923 number of the Explosive Engineer. Immediately, the explosive and the coal-mining industries on this continent became intensely interested. Considerable experimental work has been carried on in a number of American and Canadian mines during the past year, by which our engineers have become assured that the use of rock-dust cart-ridges for stemming shots increases the efficiency of explosives and promotes safety in coal mines.

Jan 1, 1924

In this paper, the use of electrochemical AC impedance spectroscopy (EIS) for in-situ diagnosis of high temperature PEM fuel cells is described. EIS was performed on single cell hardware, built in-house, using a fuel cell test station modified to operate up to 120°C and 30 psig. Electrode kinetics, membrane resistance, porous-layer and mass transport impedance of MEAs, assembled in-house, were measured at various current densities for the purpose of validating the test station and cell hardware, and for optimizing MEA and flow-field designs. The effect of temperature and humidity on the various impedances was investigated. Impedances obtained at lower and higher temperatures were compared to obtain insight into the issue of water management in operating fuel cells.

Jan 1, 2005

By H. A. Kee

In the mining industry, as in other business, one of the more satisfactory results of sincere but cheerful effort lies in the proper completion of undertakings and problems, which, to be successful, must continually hold the interest of all concerned in the work. In most undertakings, genuine interest and satisfaction is largely dependent on the proper appraisal of opportunities presented, and the opportunity to associate ourselves with sinking operations at McIntyre central shaft, from the surface to a depth of 4,133 feet, was genuinely appreciated. This opportunity was made possible by the previous persistent and successful leadership of Mr. J. P. Bickell, President, with the assistance of his associates, and of the general manager, Mr. R.J. Ennis, in the development of the McIntyre Porcupine mine, and I beg to state that any success in this sinking operation was very largely due to the congenial co-operation and splendid workmanship of Captain Martin C. Horne, his shift bosses, leaders, and all those who worked with us . Our slogan throughout was " Safety First for Pleasant and Efficient Workmanship," and this general policy made it possible to sink and timber 2.,123 feet during the first year without a serious accident.

Jan 1, 1928

By L. M. Dwarkin

Introduction Avital factor in the success of any coal mining operation is the method of roof support employed. A coal seam in? place has been described as the filling in a geological sandwich and the process of mining as the art of snatching the filling from the midst of the sandwich. The difficulty of this task can be appreciated -in the realization of the tremendous weight bearing on a coal seam due to overlying strata; a weight that can exert pressures of several thousand pounds per square inch. Over the years that mining has been carried on, methods have been evolved by arduous trial and error, making possible the successful extraction of billions of tons of coal. However, these time-proven methods are not enough. The constant demand for faster and cheaper production, the necessity of mining under increasingly difficult conditions, and the requirement for higher standards of safety, call for ever better and more efficient roof support. A recent and very promising development in answer to this need is that of Roof Bolting. Roof Support in General Before proceeding to the subject proper, a brief discussion of the older roof support methods is of value in illuminating the difficulties involved and the problems to be solved.

Jan 1, 1951

By Eugene Larochelle

The serpentine of the Eastern Townships of Quebec is more or less seamed and impregnated with chrysotile asbestos, of which we note two types: the cross-fibre and the disseminated fibre. The cross-fibre type always appears in fibres or crystals arranged parallel to one another, and disposed at right angles to the walls of the matrix serpentine. The length of fibre of these veins, which run in every conceivable direction, even crossing ?one another, varies from microscopie dimensions to three and sometimes four and even five inches. It is the principal form of asbestos found in the serpentine of Thetford Mines, Black Lake, Coleraine, and Asbestos. The disseminated-fibre type, which is the main product of the serpentine of Broughton township, in which ate located the mines at East Broughton, does not form veins, but occurs in the serpentine without any definite arrangement. There is a difference in the toughness and hardness of the rock of the two types, the Broughton serpentine being softer than that at Thetford. The disseminated-fibre section of the serpentine belt is probably more regular in its content than is the cross-fibre section. Nevertheless, it contains no 'crude,' which is the most valuable of asbestos, and the fibre is usually shorter than the cross-fibre average.

Jan 1, 1928

By F. Doxey

Introduction In order to improve outputs and to reduce or hold mining costs, many attempts have been made to mechanize the getting and loading of coal in the major coal producing countries, and machines of various kinds and sizes have been designed and manufactured. Some of the most important are: Joy Continuous Miner Joy Coal Auger Goodman Mining Machine Lee-Norse Koal-Master Jeffrey Colmol Cardox Hordsecg Recovery Drill German Coal Plough British Coal Plough with agitated blades M. & C. Samson Stripper AB Meco-Moore Cutter Loader Joy Gloucester Getter The three last named are the chief longwall machines in use and the AB Meco-Moore and the Samson Stripper are doing a good job in their respective applications. It is understood that the Gloucester Getter recently installed in a British colliery also shows reasonable promise. It was felt, however, that to meet the conditions of the mines in Nova Scotia, any machine developed must have certain distinctive characteristics. It must: ( 1) Be able to cut and deliver coal in quantity and of the right sizes ( 2) Be easily manoeuvrable ( 3) Be suitable for longwall operations ( 4) Not interfere with timbers already set ( 5) Cut its own stable (6) Work on reasonably heavy gradients

Jan 1, 1951

By Ralph W. Edie

"IntroductionTHIS PAPER presents some analyses of diabases from a number of metallogenic provinces in Canada and the United States. It is intended as a contribution to the literature on the genesis of mineral deposits associated with diabase.As it has been in the past, opinion today on the origin of the cobaltnickel- native silver and associated pitchblende type of deposit is sharply divided. Some geologists hold that this type of deposit is in some way genetically related to intrusive diabase; others are of the opinion that the deposits are related to granite. The controversy, like others of a similar nature, probably will not be settled satisfactorily for many years to come, •but in the meantime it is recognized that, with respect to most deposits of the type referred to, altogether too few facts are known for accurate conclusions on genesis to be drawn. To contribute in a small way to factual data on this whole .problem, the writer analyzed diabase from several districts in Canada in which deposits of the aforementioned type occur. For comparative purposes, the copper, cobalt, and nickel content of diabase from Cornwall, Pennsylvania, and of norite from the Sudbury basin of Ontario, was also determined.Insofar as is known, none of the analytical work undertaken had been previously carried out."

Jan 1, 1953

By D. S. Robertson, G. E. Nutter, T. P. Podolsky

"IntroductionBasal Proterozoic quartz-pebble conglomerates are found both west of Elliot Lake, in Duncan, Jarvis and Aweres Townships, north of Sault Ste. Marie and to the east and northeast of Sudbury, Ontario. Locally, while well packed and pyrite-rich, they carry little to no uranium. Locally, they carry gold. These features generally are ascribed to variations in the source areas of the rocks.In two other areas of Canada, similar basal Proterozoic units contain quartz-pebble conglomerate beds with uranium.Sakami LakeLocation and HistoryThe Sakarni Lake uranium deposit is found in a narrow, northeast-trending, Archean greenstone belt located 95 miles southeast of Fort George, on James Bay, and 240 miles north of Matagami, Quebec (Fig. 1).The deposit was detected by Inco in 1971, during an airborne EM survey which carried a newly developed Inco spectrometer system flown at 450 feet. Ground investigation, in 1972, resulted in the discovery and sampling of quartz-pebble conglomerate which yielded assays as high as 0.19% U3O8.Extensive field exploration was conducted between 1972 and 1975. Sixty-five diamond drill holes, to a total of 13,969 metres, served to define the extent and economic potential of the conglomerates which extend over a total strike length of about eight kilometres."

Jan 1, 1986

By F. F. Roberto, E. Kirby, A. R. Marchbank

The application of biologically assisted methods for metal extraction in the mining industry has a long history, but development of modern techniques has been relatively slow. There is, however, a resurgence of interest in the industry with the recent development of methods to successfully treat base metals concentrates. Two major pilot plant programs for treatment of chalcopyrite concentrates have been initiated in the past year and results from one are beginning to be released. This paper provides an overview of methods that have been applied in the past, from the earliest deliberate applications of the technology, through the copper and uranium heap and dump leach applications, the more highly engineered agitated tank leach gold applications and the developments currently taking place in the industry.

Jan 1, 2003

By Andrew R. Marchbank

The application of biologically assisted methods for metal extraction in the mining industry has a long history, but development of modern techniques has been relatively slow. There is, however, a resurgence of interest in the industry with the recent development of methods to successfully treat base metals concentrates. Two major pilot plant programs for treatment of chalcopyrite concentrates have been initiated in the past year and results from one are beginning to be released. This paper provides an overview of methods that have been applied in the past; from the earliest deliberate applications of the technology, through the copper and uranium heap and dump leach applications, the more highly engineered agitated tank leach gold applications and the developments currently taking place in the industry.

May 1, 2002

By Tom Brady

A major focus of ground control research presently being conducted by the Spokane Research Laboratory of the National Institute for Occupational Safety and Health (NIOSH) is to incorporate weak rock masses (such as are associated with operations in the Carlin Trend in Nevada) into existing design relationships. The original database that led to most of the empirical design relationships presently employed in hard-rock mining was derived from fair-to-good-quality rock. In this study, the relationship between weak rock quality and opening design (nonentry/entry methods) is being investigated. The common factor in all mines is a weak back or wall. This work attempts to provide tools that will enable a mine operator to make economic decisions that will also ensure a safe working environment.

May 1, 2003

By R. Butar-Butar, J. Mosher, G. Banini, J. Hollow, A. Villanueva

The effect of High Pressure Grinding Rolls (HPGR), as a preceding stage to a conventional ball mill circuit at PT Freeport Indonesia’s C1/C2 concentrators, has been studied in terms of downstream grinding efficiency and circuit performance. When milling the product from the HPGR, mill capacity increased by 21% for the same product grind size, when compared to processing similar ore from a conventional crushing circuit. This achievement is a result of several reasons, among them: reduction in feed size (F80), fines generation beyond the proportional reduction in F80, reduction in ore hardness induced by HPGR comminution mechanism, optimization of the recycle system of the HPGR and ball string optimization in the ball mill circuit given the new feed to the mill.

Jan 1, 2012

By Brendan Parker, Tyron Rees, Steven Hart, Abba Manesh, Ian Mcgaffin

"In September 2009, Newmont began the commissioning of a 3 stage crushing and milling circuit at its Boddington Gold Operation in Western Australia. The Boddington ore has been recognized as one of the hardest and most abrasive ores treated to date and this played a pivotal role in the selection of crushing and HPGR technology for this operation as opposed to the more conventional SABC circuit.This paper will examine the scale up from laboratory to pilot plant and full scale operation of the crushing circuit. There have been many challenges to overcome in the first 18 months of operation; however, the HPGRs have in general met design expectations and performance is expected to improve further with ongoing design changes"

Jan 1, 2012