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By M. R. Julien, A. Maqsoud, J. Martschuk, B. Bussière

Acid mine drainage (AMD) from mine wastes is one of the most challenging environmental problems currently facing the mining industry. When mining wastes have the potential to produce AMD, the effluents produced have to be managed to meet existing regulations on water quality. The LTA impoundment (property of Barrick Gold Corp.) located near Malartic, Quebec, contains sulphide tailings that have the potential to generate an acidic leachate. The closure option selected by Barrick was to construct a cover with capillary barrier effects (CCBE), in which the moisture- retaining layer is made of non-acid-generating tailings. Since its construction in 1996, the cover has been monitored to evaluate its performance. For that purpose, various parameters have been measured, including the volumetric water content and matric suction in the different layers of the cover. This paper presents some of the main results from the monitoring program that started eight years ago. The results show that the cover is able to maintain a high degree of saturation in its moisture- retaining layer, acting as an oxygen barrier. The actual performance of the CCBE on the flat surface of the 60 ha site is better than expected at the design stage. The only concern with the LTA cover is the effect of slopes that can reduce the performance of the CCBE during dry periods. However, these effects appear only for short periods of time, and are limited to very localized areas, so that they do not significantly affect the overall performance of the CCBE and its ability to limit the production of AMD.

Jan 1, 2006

By Ashley Tews

In 2005, we automated a forklift-based Hot Metal Carrier to be capable of typical metal transfer operations around a smelter. The project was highly successful and the vehicle has demonstrated hundreds of hours of live autonomous operations to thousands of people from industry and the public. As a result of the exposure and success of the project, we have expanded its focus to demonstrate how various technology components can be utilised to gain benefits in other areas of industrial operations. These include asset tracking, vehicle usage analysis, pedestrian detection and infrastructure profiling. Each of these components was derived from the core autonomous vehicle technology suite and has shown a high potential for improving safety and efficiency of vehicle-related operations, and improved diagnostic processes for measuring deformations of bakes and furnaces. The autonomous vehicle project and its extended technologies are described in this paper.

Aug 1, 2013

By D. J. Wesolowski, D. A. Palmer, P. Bénézeth, S. Hilic

The equilibrium solubilities of gibbsite, Al(OH)3, and boehmite, A1OOH, have been extensively studied in our laboratory from 30 to 90°C, and 100 to 300°C, respectively, to ionic strengths of 5 mol.kg-1 (NaC1) over a wide range of pH. The resulting solubility constants have been treated with consistent empirical models that incorporate appropriate experimental data taken from the literature. These studies were initiated in part to understand and quantify scale formation in geothermal fields as a result of fluid re-injection from electric power generating plants. Most of the experimental results were obtained through application of a unique potentiometric method that allows for rapid, precise measurement of the in situ pH and allows the approach to equilibrium to be monitored from under- and super-saturation. The experimental program was extended to deal with more basic solutions (e.g., five molal NaOH), in which the dissolution of boehmite was measured for application to the refining of bauxite by the Bayer process. More recent results in strong caustic solutions at temperatures below 90°C were obtained to investigate the dissolution of aluminum-containing sludge from holding tanks at the Savannah River waste reprocessing site. In this case the solubility enhancing effects (kinetic and equilibrium) of triethanolamine were also established and quantified. Finally, potentiometric solubility experiments were conducted (50°C in 0.l mol-kg-1, NaCl) on aluminum alloy sheets to identify mainly the nature of the aluminum oxide/hydroxide surface layer formed under these conditions.

Jan 1, 2004

By E. A. Rychkun

"For the last 700years of recorded economic history, man has been subjected to alternating inflationary and deflationary patterns. Through this period of time, a severe deflationary pattern has developed approximately every 55 years, creating 12recordable occurrences. Through the last two centuries, this severe deflationary phenomenon has come to be known as a depression. As these depressions have repeated themselves regularly, they are cyclic. This in turn leads to the question of whether the 13th cycle will also repeat itself in the form of a depression. As this cycle is now 51 years old, we must consider the possibility at about 1984.In analyzing a 700-year record of consumer prices in Southern England, the 55-year cycle appears to vary in shape and intensity. This varying phenomenon is due to the effect of longer cycles upon which each one ""rides "". Because each cycle effectively rides on the next largest, which in turn rides on the next largest and so on, the combined measured effect of all cycles together at any point in time is always unique. This means that anyone cycle can never repeat itself in an exact identical manner. The combined effect therefore is what we observe in the form of prices and, as cycles interact, variations in deflation are produced . The ""science"" of economics attempts to quantify and develop theory on situations which are never identical and hence can be conservatively classified as a useless predictive tool.This means that more unconventional approaches may be required to predict our economic future. In looking at previous depression cycles, it is possible to recognize similarities in human behaviour patterns and hence the resulting economic movements. These behaviour patterns create major events or influencing factors which set the scene for a major deflationary condition. The way in which these factors occur, however, is not predictable. As more and more of these similar events are identified in each cycle, we can increase our confidence on the probability of the last event occurring (a depression). By also unravelling the set of larger cycles, we can determine the potential combined effect at any point in the future.This paper presents a system of cycles ranging from 800 years to 3 years which appear to operate in our economic system. By so doing, a long-term projection into the next century can be made. Finally, the paper deals with the main controlling similarities within the depression cycle, to show that a comparison with our current cycle implies that a major deflationary collapse in the mid 1980's is virtualy inevitable."

Jan 1, 1980

By J. A. Brusset

Introduction I am indebted for most of the information in this paper to Mr. P. S. Lea, Deputy Chief Inspector of Mines of Great Britain, and Mr. A. E. Crook, Engineering Inspector of Mines, Ministry of Fuel and Power. Other coal-mining men in Canada may be as surprised as I was to learn that there are twenty-five Diesel locomotives in service underground in British gassy coal mines. Many more are in use underground in non-gassy coal mines and in metal mines. Approval has been granted for an additional fifty flame-proof locomotives to be used in gassy mines, and these should be in operation by the end of 1946, or as soon as manufacturing facilities permit.

Jan 1, 1946

By M. Sukhram

In the year 1992, T.A. Utigard published a paper titled "The measurement of the heat-transfer coefficient between high temperature liquids and solid surfaces." In that work, he instrumented an agglomerate of materials with thermocouples to infer the heat transfer coefficient of a high temperature liquid on a solid. The purpose of that research was to help in the design and operation of metallurgical reactors. Since that time there have been many researchers that have worked to characterize heat, mass, and momentum transfer phenomena in high temperature metallurgical processing operations. This paper presents results from the author’s experience with instrumenting thermocouples in copper elements coated with carbon to infer velocity of high temperature liquid metals. It also presents a methodology to determine velocity of a high temperature liquid by inferring the local heat transfer coefficient at a solid-liquid interface

Jan 1, 2015

By Y. M. Zhao, C. L. Duan, Z. F. Luo, X. L. Yang

"Fine coal beneficiation in a dry way is considerably imperative for the efficient utilization and conservation of coal resource in drought regions, especially for China. In this study, a continuous vibrated gas-fluidized bed separator was established and developed based on the results of laboratory batch separation results. The fluidization behavior and the effects of several main parameters including superficial air velocity, vibrational parameters, bed height and separating time were systematically investigated. The results showed that the bed expansion increased linearly with the superficial air velocity and theoretically, higher bed expansion benefited the hindered settling process of fine coal particles. However, larger superficial air velocity would induce intense fluctuation in bed surface and a poor performance of density segregation. The conveying velocity of particles was mainly determined by the vibration angle and a predicted model was established by the nonlinear regression analysis. A theoretical model of bed height distribution was established and this model fitted the measured value well. The beneficiation performance of this separator was evaluated by separating -3+1 mm Wuhai fine coal. The results showed that the probable error, E, is 0.225, indicating a continuous vibrated gas-fluidized bed separator could achieve a satisfactory performance.INTRODUCTIONFine coal beneficiation in a dry way is considerably imperative for the efficient utilization and conservation of coal resource in drought regions, especially for China. Meanwhile, it is also conducive to environment protect and low-carbon, green development of coal sector. In recent years, the increasing academic interest in the field of fine coal dry beneficiation has been aroused in most of big coal countries. In summary, recent processes of fine coal dry beneficiation are, according to their processing principles, mainly classified into two categories: dense medium beneficiation (Dong et al., 2015; Fan, Chen, Zhao, & Luo, 2001; Luo et al., 2008; Macpherson, Iveson, & Galvin, 2011) and improved pneumatic beneficiation (Patil & Parekh, 2011; Yang, Zhao, Luo, Song, & Chen, 2013; Yang, Zhao, Luo, Song, Duan, et al., 2013; Zhao, Zhao, Chen, & Luo, 2015). The former deploys artificial dense medium, such as magnetite powder and fine sand, to form a stable gas-solid suspension with certain density under the function of the upward fluidizing air flow and in some case, the external force field like vibration and magnetic field. Generally, it is believed that the process of air dense medium fluidized bed (ADMFB) is suitable for separation of coarse coal (-50+6 mm) and can't obtain a satisfactory result for fine coal separation (Luo, Chen, & Zhao, 2002; Luo et al., 2008). However, some recent laboratory efforts (Patil & Parekh, 2011; Zhang et al., 2014) attempt to find an improved performance for fine coal beneficiation in ADMFB with some modifications. The point of these works is to use a comparatively shallow bed and finer magnetite powder with appropriate size distribution. It is known that fluidization of finer magnetite powder is prone to arouse adverse fluidization properties such as channeling and slugging. Thus, the external force is introduced to an ADMFB in order to improve the fluidization quality of a magnetite powder bed. Some recent literature on air dense medium magnetically stabilized fluidized beds (Fan et al., 2001; Luo, Zhao, Chen, Fan, & Tao, 2002; Song, Zhao, Luo, & Tang, 2012), air dense medium vibrated fluidized beds (Luo et al., 2008) and Reflux Classifier (Macpherson, Iveson, & Galvin, 2010) reports that the separation efficiency, namely the probably error E value, of dense medium separation of fine coal ranges from 0.066 to 0.07, indicating a good separation performance. But, the main unresolved problems of dense medium beneficiation are located in the processes of product purification and medium recovery and are urgent to be solved befor"

Jan 1, 2016

By J. Muralha, L. Lamas

"Given the results of triaixial tests, regressions are commonly used to evaluate the parameters of failure criteria that model intact rock strength and to perform statistical inferences used to evaluate characteristic values defined in EC7. Statistical robustness of these inferences is affected if the basic hypothesis underlying regression are not met, namely homoscedasticity (constant variance of the errors). This paper presents analyses of 23 sets of triaxial tests, starting by the evaluation of the regression parameters of the Mohr-Coulomb linear criterion and of the Hoek-Brown non-linear criterion, followed by carrying several statistical tests to check the homoscedasticity null hypothesis of independence between the variance of intact rock strength and the confining stress.INTRODUCTIONThough rock engineering design is clearly included in the scope of Eurocode 7(EN1997-1), its implementation raised a wide discussion regarding the applicability of structural safety concepts to geotechnical design of construction works in or on rock masses. The basis of the limit state design philosophy adopted in EC7 is that, for each particular design situation, all the possible limit states for a structure, or part of it, shall be considered and that it shall be demonstrated that the likelihood of any limit state being exceeded is sufficiently small. Though EC7 allows the limit states to be verified by one or a combination of methods, use of calculations is by far the most used, and it is often confused with the EC7 itself. It involves using characteristic values of actions, ground properties and geometrical data, as well as obtaining their design values by the partial factor method.Characteristic value of a given material property is defined in Eurocode (EN 1990) as: “value of a material or product property having a prescribed probability of not being attained in a hypothetical unlimited test series. This value generally corresponds to a specified fractile of the assumed statistical distribution of the particular property of the material or product”. As regards the design value of a material or product property, according to the Eurocode it is a “value obtained by dividing the characteristic value by a partial factor”."

Jan 1, 2015

By F. R. Erick Mulder

"AbstractTwo bottom-hole samples have been taken from two new completions in the Turner Valley field, Royalite Lowery No. 8 on the west flank and Royalite No. 73, which was deepened into a lower fault block, on the northeast flank. From the bottom-hole oil of Royalite Lowary No. 8 a synthetic sample was prepared to simulate the original fluid in the reservoir, saturated at the gas-oil contact conditions. The sample from Royalite Lewery No. 8 has been shown to be the original fluid present at this well and represents the oil phase near the oil-water contact in• the reservoir. Complete chemical analysis, P.V.T., and viscosity data have been obtained on these reservoir fluids, which represent the range of saturation from the gas-oil to the oil-water contact in the Turner Valley oil structures. Sampling techniques and the application of the analytical data to reservoir conditions and field operations are discussed. Super-compressibility curves for an average separator tail gas have also been prepared. These data have not been available before. They will be of fundamental value in futu.re reservoir engineering studies of this field and will also serve as a guide in determining operating practices."

Jan 1, 1950

By R. J. A. Fricker

IT is the purpose of this essay to give a reasonably complete description of shaft sinking under a rock pentice in a small Northern Ontario gold property. Hallnor is in many ways an exceptional mine, but the sinking operations here described are but typical examples of the excellent practice for which Canadian mines and mining engineers are justly famous the world over. The worth of the subject lies, therefore, nor in its originality, but in its soundness; not in the spectacular, but in the economical and safe. Attention is particularly drawn to the excellent safety record and to the exceptionally low overall sinking cost. INTRODUCTION Prior to April, 1939, the Hallnor No. 1 shaft had been sunk vertically to a depth of 997 feet below the surface. It is a three-compartment shaft, 19 ft. 10 in. by 7ft. 7 in. outside the timbers (see Figure 1).

Jan 1, 1941

By Ashu Garg, Anirban Bhattacharya

"Friction stir spot welding of aluminum alloy AA6061-T6 sheets was performed with circular (plunge depths 0.4 and 0.6 mm), square and triangular tool pin (plunge depth 0.4 mm) with constant 0.2 mm shoulder penetration to characterize various zones of weld nugget. It was observed that the depth of the stir zone formed below the tool pin is comparatively similar for different tool pins but wider for circular tool pin. The size of another stir zone formed at the interface of tool pin and a tool shoulder is observed to be larger for triangular and square tool pin due to the higher swept rate. Predicted strain from finite element analysis, calculated strain rate using Zener-Hollomon relationship and experimentally measured grain size distribution indicates severe amount of plastic deformation in-and-around the nugget/spot region. Finer grains in various stir zones were observed than thermo-mechanically and heat affected zones. Grain size (at distribution peaks) in stir zones varied around 2.54 µm to 3.69 µm for different tool pin profiles as compared to base metal grain size of 20 µm. Microhardness results indicate that the welded region is quite softened than base metal and maximum hardness is mostly observed around the thermo-mechanically affected zone.INTRODUCTION Friction stir spot welding (FSSW) is widely used for joining the sheets of materials like aluminum, copper, magnesium, etc. The process begins by plunging a rotating tool (generally having a pin and a shoulder) into the sheets to be welded. Continuous stirring of the tool and downward plunging force generates localized heat due to friction at the tool-sheet interface and plastic deformation of the sheet metal. The material gets softened and the plasticized material adjacent to the tool pin starts flowing due to the action of tool rotation and tool plunge thereby causing intermixing and bonding between the overlapped sheets. The tool stirring also promotes grain refinement in the weld nugget associated with high strain, strain rate and thermal cycle. The formation of new microstructure also affects the mechanical properties and efficiency of FSSW joints. Studies also showed that the tool pin design and tool shoulder feature exerts a noteworthy influence on the material flow and intermixing during the FSSW process (Reilly et al., 2015; Hirasawa et al., 2010). Sarkar et al. (2016) studied the material flow and intermixing during FSSW using tracer material method and reported that the size and width of flow zone increases with tool penetration depth. The influence of tool rotational speed on microstructure and stir zone temperature was investigated during FSSW of dissimilar AA6061-AA5754 alloys (Gerlich et al., 2007). They reported that the average grain size in stir zone of AA6061 weld increases with increase in tool rotational speed. In another work, Gerlich et al. (2008) studied the local melting and tool slippage during FSSW of Al alloys. Tool slippage was investigated by calculating the strain rate using Zener-Hollomon relation. Garg and Bhattacharya (2017a) studied the effect of dwell time, tool pin profiles and tool rotational speed on shear strength, microstructure, temperature and strain distribution during FSSW of AA6061. In another work, Garg and Bhattacharya (2017b) analyzed the effect of different tool pins and pinless tools on the shear strength and microstructure during similar and dissimilar FSSW of AA6061-T6 and pure Cu. Chang et al. (2004) proposed mathematical relationship between the average grain size and Zener-Hollomon parameter during friction stir processing of Mg alloy. Solhjoo (2010) presented a mathematical approach to determine the critical strain as a function of peak strain required for initiation of dynamic recrystallization in austenitic stainless steel. Fratini and Buffa (2005) also proposed the numerical model to determine the grain size during continuous dynamic recrystallization phenomenon."

Jan 1, 2018

By Z. Ren, M. Tomlinson, E. Asselin

"Organic carbon blinding is a common, yet often partial, solution to the reduction of preg-robbing. A quantitative method to assess the extent of adsorption of a given blinding agent is presented herein. The adsorption of several blinding reagents on various carbon samples is quantified using electrochemical impedance spectroscopy (EIS). EIS results showed that kerosene is more strongly adsorbed on carbon than sodium lauryl sulphate (SLS), while SLS can hinder the charge transfer process of the oxygen reduction reaction on the carbon surface more effectively. The effectiveness of SLS is pronounced when its concentration is higher than 100 ppm. Raman spectra are presented for selected carbon samples: as the area ratio of the disordered peak to the graphitic peak increases, blinding agent adsorption increases.INTRODUCTION The presence of naturally occurring constituents in gold ores may adversely affect the extraction of gold in cyanide leaching since the gold cyanide complex, Au(CN)2–, can be adsorbed by these constituents (M. Adams & Fleming, 1989; Afenya, 1991; Miller, Wan, & Díaz, 2005). Such ores are known as “preg-robbing”. Preg-robbing behavior may arise from natural carbonaceous materials in the ore (M. Adams & Burger, 1998). In the past decades, a number of pre-treating methods have been developed for refractory carbonaceous ores (Arriagada & Osseo-Asare, 1984; Beer, 1994; Dunne et al., 2007; Jiang, Liu, Xiao, & Yang, 2012; Kohr, 1997; Kulpa & Brierley, 1993; Menne, 1992; Menne & Revy, 1994; Moyes & Houllis, 2010; Petrie, Craw, & Ryan, 2005; Simmons, 1996). The method known as blinding is one of the most effective and economical pre-treatment methods (M. D. Adams & Burger, 1998; Albert, 1923; Darrow, 1924; McQuiston & Shoemaker, 1975; Van den Berg, 2000). Blinding, also referred to as blanking or passivation, uses a chemical reagent to passivate the preg-robbing carbon by selective absorption or wetting (Bas, Altinkaya, Yazici, & Deveci, 2012; Brierley & Kulpa Jr, 1993; Dunne et al., 2012; Van den Berg, 2000; Yang, Qian, Song, & Dong, 2013; Yen, Amankwah, & Choi, 2008; Zhou, Jiang, & Choi, 2014). Organic reagents, which selectively adsorb on the surfaces of activated carbon and “smother” the surface, have been used for blinding carbonaceous matter in gold ores prior to cyanidation. Two comprehensive studies by Abotsi and Osseo-Asare and Adams and Burger have been published on this topic (Abotsi & Osseo-Asare, 1986; M. D. Adams & Burger, 1998)."

Jan 1, 2017

By John H. Morris, R. Gwilym Roberts

"The Upper Beaver Mine, Kirkland Lake, Ontario, is a copper-gold deposit in mafic flows and sedimentary rocks. The deposit consists of a number of orebodies of two types: copper- and gold-bearing chalcopyrite-pyrite-magnetite ore; and gold-bearing quartz veins. Chalcopyrite-pyrite-magnetite ore occurs in two structural forms: as cherty interflow material in coarse clastic roks underlying flows; and as veins. Both sedimentary and vein ore occur in each orebody. The goldbearing quartz veins occur in interflow sedimentary units and at the contacts of oligoclase porphyry dykes.The deposit is in a localized, volcanic-sedimentary basin which began to develop during the emplacement of the upper units of the pyroclastic and sedimentary Gauthier Group, and continued to the early mafic flow activity of the overlying Kinojevis Group. The formation of the volcanic-sedimentary basin is ascribed to the D0 deformation. The deformation is significant in terms of the structural configuration in the mine area, and may be significant regionally, but this has not been demonstrated. The early deformation was followed by two tectonic deformations. D 1 is associated with a penetrative mineral foliation, axial planar to upright mesoscopic folds and striking parallel to the trend of regional fold structures. Mesoscopic flexural-slip folds, kink folds and fracture-crenulation cleavage are attributed to the D2 deformation. It is probable that no large-scale fold structures are associated with the D2 deformation. The gold-bearing quartz veins were folded during the D1 deformation.The close spatial relationship of copper-gold, chalcopyritepyrite- magnetite veins with chalcopyrite-pyrite-magnetite in cherty inter flow material is strong evidence for the derivation of the veins from the sedimentary ore by hydrothermal, metamorphogenic processes. By analogy, it is suggested that the gold-bearing quartz veins were formed by similar processes."

Jan 1, 1982

By R. D. Brown

On November 16, 1978, Finance Minister Chretien delivered his second formal budget in the House of Commons. Over-all, the provisions of the budget should provide moderate stimulus to the Canadian economy. With respect to the mining industry, the budget offers some welcome changes in the form of' improved write-offs for development expenses and social assets; higher investment tax credits; and a reduction in federal sales tax. On the other hand, income bond financing of new mineral ventures may be restricted.

Jan 1, 1979

By E. Swartzman

"DURING 1951, experimental cleaning studies on both fines and larger sizes of certain Canadian coals were conducted on a relatively large scale in two pilot plants in the United States, large enough to be considered as small commercial units, and in one commercial plant in Canada.One of the pilot plants was a wet washer of a type which apparently has never been .used in Canada, nor has any Canadian coal been tested in it before. In the other pilot plant and in the commercial plant, dry cleaning equipment was used. The commercial plant is the first of its kind to be employed in Canada, and this type is used only to a limited extent in the United States.Fine-Coal Cleaning ExperimentsTest PlantsHydrotator and Hydrotator-Classifier combination pilot-plant with a capacity of about twenty tons per hour. This is a classifier type washer adapted for cleaning fine coal as well as certain intermediate sizes. The Hydrotator deals with that portion of a coal retained on approximately a 24-mesh Tyler sieve, whereas the Hydrotator-Classifier deals with the minus 24-mesh fines."

Jan 1, 1952

By P. Hubert, J. P. Ildefonse, F. Qafssaoui, J. Poirier

Corrosion tests by corrosive alumina-lime slags were carried out on commercial high alumina bricks used in steel ladle linings and model refractories (with different raw materials : bauxite, andalusite, and different microstructures). Using (SEM) scanning electron microscope and (EDS) energy dispersive spectroscopy, microstructures of slag-corroded refractory interfaces were studied in detail. The monomineral and glassy phases, the composition of reaction products and chemical profiles were determined. A thermochemical analysis based on phase equilibrium diagrams has permitted to estimate the proportion and the composition of the high temperature intergranular liquid phase. These data were compared to the experimental microanalysis results. The viscosity of the high temperature liquids were calculated according to Urbain 's model and the relationship between the viscosity and the penetration of liquid phases were discussed. These theorical and experimental results were used to understand the complex phenomena of slag penetration and corrosion of andalusite and bauxite refractories at high temperature and to propose new ways of improvements for the formulation of high alumina refractories.

Jan 1, 2004

By J. M. Ríos

"Without conscious effort and understanding, a number of factors unique to mineral exploration often hinder building sustainability in host communities. These include the episodic and transitory presence of an exploration team in the community and the inherent uncertainty of outcomes— most projects fail from an exploration perspective. Experience in rural communities across Mesoamerica, however, has shown that it is possible to go beyond pragmatic philanthropy and infrastructure improvements to promote positive, sustainable outcomes in communities. Examples are provided of lessons learned and proven practices that improve quality of life and support a strong social license to operate.RÉSUMÉ Sans une compréhension et un effort réfléchis, de nombreux facteurs uniques à l’exploration minérale nuisent souvent à l’établissement d’un développement durable dans les communautés d’accueil. Ces facteurs comprennent la présence épisodique et transitoire d’une équipe d’exploration dans la communauté et l’incertitude inhérente des résultats – la plupart des projets échouent après l’étape de l’exploration. L’expérience dans les communautés rurales à travers la Méso-Amérique a toutefois démontré qu’il est possible de dépasser la philanthropie pragmatique et les améliorations des infrastructures pour promouvoir des résultats positifs et durables dans les communautés. Des exemples qui améliorent la qualité de vie et soutiennent un solide permis social d’exploitation sont présentés; ils sont tirés de leçons apprises et de pratiques éprouvées."

Jan 1, 2015

By Kevin Bell

About Beltek Inc. For more than a decade Beltek, Inc. has been working with national and international organizations to harness and deliver solutions which gain real ebusiness advantages in today's world. Our objectives are to partner with our customers to achieve maximum results, while reducing costs. At Beltek, we provide a commitment to you and your organization's needs. Whether that be delivered by ensuring our services and products are state of the art or by providing a level of personalized service, which makes you feel like the center of attention, Beltek is about adding value to every job we work on. The individuals who work at Beltek quickly become your friends because we share your passion and enthusiasm for the business we are in. That's why every person is a leader in his or her respective fields. Having these individuals as apart of our business ensures you get the best out of our equipment, receive the very latest in advise, problem solving and support. We also pride ourselves on our ability to remain flexible at all times because we know deadlines and schedules can change quickly, so we always go the extra mile to deliver exactly what you need.

May 1, 2004

By R. A. King, B. G. Hunt, C. E. T. White

"This paper reviews the history, occurrence, properties, and uses of indium, and describes the commercial production and fabrication of that metal by The Consolidated Mining and Smelting Company of Canada, Limited (Cominco), at Trail, B.C'. Indium is produced commercially at Trail from dross retreatment furnace D.R.F.) slag, a complex by-product of the lead smelting operations. Furnace feed prepared from this slag is smelted with coke and limerock in an electric furnace. The e1ectric furnace bullion is parted electrolytically, producing a market-able lead-tin alloy containing about 8 per cent tin, and leaving the indium in the anode slime. Recovery of indium from the anode slime involves roasting the slime with sulphuric acid, followed by leaching with water, purifying the leach solution, recovering the indium by sponging with zinc or aluminum, and re-fining electrolytically. This process yields standard grade (99.97+ per cent) indium which is either sold or refined •to high purity ( 99.999 per cent) indium for special uses requiring higher purity metal."

Jan 1, 1959

By Y. Champoux, N. Atalla, R. Oddo, C. Lesage

"Percussion drills are the source of the most serious noise problems in mining activities, due to their extremely high noise levels(114-122 dB(A)) and widespread use(Bartholomae and Stein, 1988). Percussion drills will continue to be widely used to drill small diameter holes in hard rock because no other method seems to be economically avail-able to replace them (Boillat et al., 1993).Many studies (Danière, 1991; Hawkes etal., 1977a; Jensen and Visnapuu, 1972;Leblond et al., 1976; Milette, 1989) were con-ducted to determine the major noise sources of percussion drills. The exhaust air of pneumatic drills, the hammer, the bit in contact with the rock and the drill rod have been identified as the major noise sources. A muffer can be used to reduce the exhaust noise and the hammer can be enclosed. The bit noise is considered to be of concern only at the beginning of holes. When all the available methods are used to reduce the noise of a percussion drill, the drill rod vibrations become the dominant noise source (Hawkes and Burks, 1979). However, the noise levels generated by this source remain high and future efforts should concentrate on reducing its radiation.Works by Hawkes and Burks (1979) and Hawkes et al. (1977b) for the U.S. Bureau of Mines provide the most complete description on the noise and vibration of percussion drill rods.The longitudinal and bending waves are the two most important types of elastic waves generated in drill rods. Among these, only the longitudinal waves contribute to the drilling rate. The bending waves are caused by non-centralized impacts, drill rod curvature and non-uniform bit/rock interface. Drill rod noise is generated by Poisson’s ratio expansions and contractions of the rod as the longitudinal waves travel up and down it and by transverse rod motions induced by bending waves. The radiation efficiency is much higher for bending waves than for longitudinal waves. Most of the impact energy is transformed into longitudinal waves, as expected for axial impacts. The evaluation of the relative contribution of longitudinal and bending waves to noise generation poses a very difficult problem for experimental, analytical and numerical approaches. It is, however, an important issue because the relative contribution of these two waves will guide future noise reduction efforts. It seems that very little can be done to reduce the noise radiation of the axial waves without affecting the drilling rate. The main difficulty that analytical and numerical approach-es face, in the evaluation of the relative contribution of the two waves, is that there is no adequate theory for predicting the bending vibrations from the factors that cause them. The experimental approach has, thus, been limited to test fixtures that do not adequately represent the boundary conditions, as well as by measurements obtained under real operating conditions from which it is difficult to establish the relative contribution of the two types of waves. For example, Hawkes and Burks (1979) and Hawkes et al. (1977b) used a test fixture with free-free boundary conditions and made no clear link with measurement under real operating conditions. Rather, they have based their discussion on a simple model. Many authors assume that fexural waves are the main noise source on drill rods. However, measurements have been somewhat contradictory and researchers are still unable to state with certainty that this is indeed the case (Lednik et al., 1988)."

Jan 1, 1997