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By Micheal Mayhew

"This presentation will provide information and facts on the drilling and blasting within a frozen shaft using a full face methodology. The Author will briefly discuss the history of the sinking of a frozen shaft in Saskatchewan, the challenges faced, and the solutions delivered. The case study will include a discussion describing the series of events that led to the decision to adopt a full face blasting methodology. The case study will describe key elements such as the drilling pattern, hole size and depth, explosive products and blast vibration monitoring systems. INTRODUCTION During the shaft sinking process at a project in Saskatchewan, it was recommended that a drill & blast benching method be utilized. Following an evaluation of the site, the geological conditions proved amenable to a ground freezing system that would stabilize the rock formations and prevent inflows of water into the shaft (Table 1).The shaft sinking process required that the ground surrounding the proposed shaft be frozen by drilling several near vertical freeze holes radially at a specified distance from the edge of the proposed shaft excavation. This would allow for the circulation of a chilled brine solution down the freeze holes. The circulation is achieved by means of stainless steel pipes encased within each other to provide a delivery and return conduit for the brine (Figure 1). As a result of this periphery freezing, the ground within the shaft excavation is also predominately frozen.The finished internal diameter of the shaft was 5.5 meters with varying overall excavation diameters to facilitate different liner designs used for various rock formations. For the most part, the fully unsupported/unfinished excavated diameter of the shaft varied from 6.9 meters to 8.5 meters depending on the zone excavated. The challenge was that the proposed drill and blast excavation method posed a significant risk due to the potential to damage the freeze wall and pipes during blasting. The decision was made to commence the excavation through mechanical excavation (i.e. chip and cut) methods then change to a drill and blast method utilizing a split benching design. Through this process, the team encountered five main challenges: 1. Sub-horizontal geological structures and slips that affected blasting performance and sometimes resulted in a sloping surface to the top of the bench; 2. Confined working area for the crews and equipment due to a limited work area as a result of utilizing the split (half) bench drill and blast methodology; 3. Mechanical chipping and cutting of the one-meter buffer zone to the final shaft diameter; 4. Crews working on extremely slippery uneven frozen rock and ice surfaces, which affected safety and efficiency; 5. Establishing a blast vibration monitoring system to determine if the drilling and blasting of the full shaft excavation diameter were acceptable."

Jan 1, 2019

By R. Panchadhara, P. A. Gordon

"A non-local formulation of the classical continuum mechanics theory called peridynamics is used to study driven dynamic fractures in the near wellbore region. The controlled application of pressure on the inner walls of the borehole can create multiple fractures that initiate from the borehole and propagate radially outwards. The number of fractures and their final length is primarily controlled by the loading conditions and the in-situ stress state. It is the objective of this study to use a novel numerical technique called peridynamics to investigate: 1) the influence of loading conditions on the fracture pattern, and 2) the effect of in-situ stress anisotropy on fracture propagation. In peridynamics, the momentum equation from the classical theory of solid mechanics is replaced with the integro-differential momentum equation of peridynamics. As a result, discontinuities in the body, such as fractures, occur spontaneously. The material is represented by a continuum body with material points that interact non-locally with all other points within a specified distance. Fractures evolve using a damage evolution law, wherein, damage at any point is represented as the ratio of the number of broken bonds in the current configuration to the total number of bonds in the undeformed configuration.Simulations are performed on simplified test cases and the results are compared to relevant experimental and numerical studies found in the literature. It is shown that the loading rate significantly influences the number of fractures initiated from the borehole as well as their extent. Low loading rate produces fewer fractures, whereas, high loading rates produce longer and a greater number of fractures from the borehole. The numerical method successfully predicts the fracture pattern obtained from a wide range of loading conditions. Predictions also indicate that the resultant fractures are shorter when in-situ stress is applied. Numerical results show that the fracture extension is largest in the direction perpendicular to the minimum compressive stress for the range of loading rates used in this study."

Jan 1, 2015

By Pierre Choquet

"The whole work carried out both in situ and in laboratory by a research group of the West German collieries is presented. This work has led to a design method of steel arch supports for gate roadways that gives full satisfaction in this particular coalfield. The method accounts for mining depth, the mining system (advancing or retreating), thickness of the coal seam and other parameters.Full statistics are then given on gate roadway supports of the ECCS (European Community for Coal and Steel) coalfields. They were collected by the author in order to show that the West German method can be applied to other coalfields as the long wall systems which are generally being used are very similar. Design calculations are conducted for each coalfield's case. They show that the method would have been able to predict in most cases the support actually used.Utilization of the design method is recommended to the Cape Breton Development Corporation 's mine operators because mining conditions, even though different from European ones, present a number of similarities which make it possible to apply the design method to their particular case.This procedure might be profitable in mines facing support problems in their levels and for any planning of future projects"

Jan 1, 1986

By Mohamad Sabsabi, André Hamel, André Moreau, Paul Bouchard

"Laser-Induced Breakdown Spectroscopy (LIBS) is an atomic spectroscopy technique used to measure elemental concentrations. It is well-adapted to in-situ and in-line measurements during materials processing in general, and pyrometallurgy in particular. It is an optical non-contact technique and it can measure nearly all elements, including light elements. Our group has developed a mobile prototype system to measure molten metals. The system includes a tube, also called a lance, one end of which is immersed in the molten metal. An inert gas flows in the tube and bubbles out below the surface. The LIBS measurement is made through the tube and onto the bubble’s surface. This is done to avoid measuring contaminants, slag, or fluxes often found at the surface of the melt. An added benefit is that the molten surface is constantly renewed and thus, more representative of the bulk. An alternative to using our lance is to use a tuyère, such as a gas injection tuyère in a converter, as we did several years ago in a nickel matte converter. In this presentation, we will show various applications emphasizing more recent developments. This includes the simultaneous measurement of the concentrations of Cu, Ni, Fe, Co and S in molten matte at 1125 °C. The more obvious industrial applications of the technology include determining the best time to end oxygen blowing in the converter and elemental concentration measurement during alloying.INTRODUCTIONThe mining industry continually faces challenges in optimizing cost and productivity. Because of the large volumes of materials that are being processed, small improvement can have a big impact on benefits. Better real-time information can help improve this optimization."

Jan 1, 2016

By R. E. Molnar, P. A. Riveros, V. M. McNamara

"This paper describes some recent research done at CANMET in the areas of ion exchange and A VR (Acidification- Volatilization Reneutralization), as applied to the recovery of gold and cyanide, respectively. It also discusses the ways in which these two technologies may be combined in order to minimize the environmental impact of gold milling operations and optimize reagent usage. IntroductionGold milling operations can essentially be divided into those that carry out a liquid/solid separation after leaching and those that recover gold directly from a leach pulp. The former produce a barren solution which may contain considerable amounts of cyanide, either free or cornplexed with metals. The latter produce a similar solution but this is now part of a slurry rather than a clear stream. Due to its toxicity, any excess cyanide must be destroyed before the effluent is discharged into the environment. Ideally, this should be (and sometimes is) accomplished by natural degradation. However, in many cases natural degradation alone cannot remove the last traces of rnetallocyanide compounds from the effluent and , as a result, most Canadian gold producers utilize a supplementary chemical oxidation system. This not only increases the operating costs, but concerns have also arisen in recent years about the formation of ammonia as a result of the chemical oxidation of cyanide (via CN--CNO--HCNO-NH3) ·"

Jan 1, 1993

By S. Jeon, T. H. Kim

"Understanding the frictional properties of discontinuities is crucial to ensure the stability of underground structures. In particular, the frictional behavior at depth depends on the complex interaction among mechanical, hydrological, thermal and chemical characteristics and their coupled effects. In this study, a series of triaxial compression tests were carried out to investigate the behavior of rough shear surface of synthetic rocks. The frictional behavior showed little variation at different confining and water pressures. The test results were analyzed using Coulomb’s failure criterion. In addition, numerical analysis was carried out using PFC2D to simulate the test.INTRODUCTIONUnderstanding coupled behavior of rock at depth is of great importance in design, construction and operation of underground structures such as a disposal facility of radioactive waste, hot dry rock geothermal system and oil reservoir. In particular, many uncertainties are involved in characterizing deep rock mass deformation in the designing process and interactions among fluid flow of groundwater, high temperature and stress disturbance should be considered. Many independent studies have been carried out to investigate the thermal, hydro, mechanical and chemical coupled effects in numerical and experimental methods. They include the researches by Lockner, Summers, Moore and Byerlee (1982), Jafari, Amini Hosseini, Pellet, Boulon and Buzzi (2003), Tembe, Lockner and Wong (2010), Lee, Lee and Jeon (2012), Indraratna, Premadasa, Brown, Gens and Heitor (2014)."

Jan 1, 2015

By Michael McClintock, Bern Klein

"The high pressure grinding roll (HPGR) is a relatively new comminution technology that is gaining popularity for providing energy efficient solution to hard rock mining operations. A significant barrier to increased adoption of HPGRs is the present requirement for large amounts (excess of 2 tonnes) of sample for pilot testing, which may not be possible for most early stage projects. Three methodologies have been developed at NBK Institute of Mining Engineering at the University of British Columbia that may be used for sizing design optimization of HPGR circuits. All three methodologies use a MTS pistonpress to simulate HPGR comminution. These tests are capable of providing information regarding energy consumption, energy breakage relationship, reduction ratio, and product size distributions. In a period of slow economic development, these methodologies are critical to allow the industry to cost effectively understand the operational benefits of HPGR implementation. This paper examines previous test work done at UBC, as well as the development of an HPGR and piston press database for use in sizing and budgeting of HPGR circuits.INTRODUCTIONCurrently, the mining industry faces several challenges due to falling commodity prices and escalating costs. This has applied pressure for operations and projects to reduce costs and improve project economics. In addition engineering and metallurgical budgets have shrunk as companies try to conserve cash. Improvements and optimization of milling and comminution circuits is one area project economics may be significantly improved. By considering alternative comminution technologies such as the high pressure grinding roll (HPGR), energy operating costs may be greatly lowered. Many have begun to implement HPGR crushing as an alternative to semi-autogenous grinding (SAG) mills, including KGHM and, Sierra Gorda, and Freeport Mc-MoRan’s Cerro Verde operation. However, implementing new technology for companies with little or no HPGR experience may not be practical. An operator must consider both feasibility and economics of a circuit. Currently, consideration of the HPGR requires expensive pilot scale testing for which large sample sizes are needed. In addition, few laboratories are equipped for running pilot scale HPGR test programs. Furthermore, the results of pilot HPGR testing are dependent on the quality of the sample, which cannot represent variations across a deposit. In contrast, ball mills and SAG mills can be sized using the Bond Mill Work Indexes that require a small amount of sample which enable a number of different geological blocks to be tested to allow engineers to have a complete understanding of how the comminution circuit will perform for the life of mine."

Jan 1, 2016

By M. K. Kim

This study presents a framework for quality inspection of precast concrete components using the 3D laser scanning technique. As precast concrete-based rapid bridge construction is getting standardized, quality assessment of the precast concrete becomes critical for preventing any failures during the construction process. Moreover, as Building Information Modeling (BIM) gains popularity in the construction industry, autonomous and intelligent inspection systems are needed. Current method for quality control of precast concrete components, however, heavily relies on visual inspection and contacttype measurements, which are time and labor demanding. Also, storage and delivery systems of inspection information such as the procedures and results of quality inspection are lacking. To overcome these limitations of the current quality assessment technique for precast concrete, this study aims to develop a BIM-based framework for efficient quality inspection of precast concrete with the use of a 3D laser scanner. First, we formulate practical guidelines including detailed inspection procedure, selection of optimized scanner and scan location, inspection criteria, and data storage and delivery system. Second, to investigate the applicability of 3D laser scanning to precast concrete quality inspection based on the proposed framework, a case study inspecting quality of a lab-scale object assumed as precast concrete component is presented for detecting defects.

Aug 1, 2013

By Jean-Yve Tremblay, Michel Prud'homme

"IntroductionIndustrial minerals include a group of more than fifty minerals which are marketed into almost all the sectors of industry; they are the backbone of many manufacturing industries. Table I shows major end-uses for industrial minerals in manufacturing sectors.At Energy, Mines and Resources, industrial minerals are divided in three major categories: (I) agro chemicals and chemicals, (2) construction mineral s, and (3) ceramics and specialty minerals. A listing of the major groups of minerals is shown in Table 2.Agro-chemicals and chemicals are sold on the basis of their chemical content and purity. Construction minerals or structural minerals are distinguished by their performance as low cost and bulky commodities. Ceramics and specialty minerals are performance-specific and are sold for their property on imparting functions on end-products. Industrial minerals have unique characteristics that are useful in many stages of processing; from crushed size to micronized fillers a single mineral ca n serve a broad range of industries because of its intrinsic properties.The Industrial Minerals Industry in CanadaCanada has a large industrial minerals base and is a world leader in the production of some of them. The total value of product ion of these minerals has grown by 115% over the last 10 years despite the misfortune of asbestos.Industrial minerals have shown remarkable growth in the past 20 years at an average annual rate of 9.2%, compared to 7.8% for metallic minerals. In 1986, the value of industrial minerals rose to $4.9 billion, or 14% share of the Canadian mineral production. Figure I shows the value of production of the mineral industry for the period 1966-1986.The leading segment in industrial minerals segment since 1976 is the chemicals and agro-chemicals sector which has an average annual growth rate of 5.75 % in terms of value of production. During the same period, the growth rate for the whole Canadian mining industry was 1.37% per annum. The chemicals and agro-chemical s sector increased its contribution to the total value of production of 2% to 6070 despite the growing share of fuel minerals with 59%."

Jan 1, 1988

By Chri Langille, Dougal McCreath, Samantha Espley

"In 1993, trials of two innovative applications of liner support involving the replacement of bolts in the ground support system were undertaken at Inco mines. The first trial involved an evaluation of the effect of dynamic loading on mesh-reinforced boltless shotcrete in a sub-level cave mining area on 2400 level at Stobie Mine. The second trial involved an evaluation of the MIROC Mineguard spray-on liner as a replacement for bolts and screen support, or as a replacement for screen support alone, in a topsoil heading of a bulk, VRM (vertical retreat mining) stope on 3240 level at Lower Coleman Mine.In the Stobie Mine trial, an uppers retreat heading was supported using a two-pass system. First, shotcrete was applied 2 inches thick, followed by pinning of mesh screen to the back and walls. A second pass of another 2 inches of shotcrete was then performed. For recovery of the ore zone, a vertical slot was created using a Borepak blind boring machine. The uppers rings were blasted, one or two rings at a time, starting at the slot and retreating out of the heading. During blasting of the production rings, blast monitoring was used to record the ppvs (peak particle velocities). For a series of 5-ring blasts, the maximum ppvs were measured to be 0.4 m/s (16 in./s) with a maximum charge weight per delay of357 kg (800 Ib). Six 5-point convergence measurement stations were set up and after each blast the total rockmass convergence was measured using a tape extensometer. Although a maximum displacement of 100 mm (4 in.) was measured, the shotcrete still managed to provide some support junction. A support damage assessment was also done to try and relate blast vibration to effectiveness of the mesh reinforced shotcrete liner. This trial demonstrated the effect that blasting has, on a support system, and it also demonstrated the necessity of having the mesh reinforcement properly placed within the shotcrete."

Jan 1, 1995

By Marek Mika

This Paper has been prepared to be presented at the 23rd World Mining Congress & Expo ? Montreal 2013. It presents the idea how to carry out the shaft sinking operation, going through highly water-bearing and very weak rock strata, giving as an example one specific shaft sinking project which is being executed for one of the Polish collieries by our Shaft Sinking Company Content 1. Introduction. 2. Hydrogeological conditions within the area of the shaft. 2.1. Hydrogeological conditions assumed at the stage of designing. 2.2. Hydrogeological conditions encountered in the course of sinking. 3. Designed shaft lining. 4. Procedures for the shaft sinking. 4.1. Designed procedures of the shaft sinking. 4.2. Procedures for preservation and strengthening of the shaft lining and the surrounding rock strata. 5. Technological guidelines for proceeding with the shaft sinking ? selection of special methods. 6. Options for mechanization of work for the selected method. 7. Conclusions.

Aug 1, 2013

By L. A. Melis, J. W. Rowson

"Cluff Mining has successfully operated a gold recovery plant at its Cluff Lake operation in northern Saskatchewan to recover gold f rom Phase 1 uranium leach tailings. The operating circuit consists of tailings repulping, grinding, cyanidation, carbon-inpulp, gold recov ery, and cyanide destruction by acidification, volatilization and re-neutralization. The process is described and operating data and metallurgical results from the operation are provided.INTRODUCTIONCluff Mining, a Saskatchewan partnership, is owned 20 per cent by Cameco and 80 per cent by Amok Ltd. /Ltée. (Amok), manager and operator of the partnership.The current operation includes the Phase II uranium mining and milling facilities, located at Cluff Lake, 700 km north of Saskatoon, capable of processing 300 000 tonnes o f ore to produce about 4 000 000 lb UPs (1500 tonnes of uranium) per year.The Phase I operation was initially established to process the very high grade ""0"" uranium orebody from 1980 to 1983. The leach tailings from the Phase I mill operation were found to contain elevated level s of gold . These high gold values were partially due to the gravity pre-concentration step included in the uranium recovery circuit, and to the naturally high levels of gold associated with the uranium mineralization in the""0"" orebody .During the Phase I operation some 6475 tonnes of leach tails were produced and stored in a total o f 2916 large concrete containers (vaults). This method of storage was, at the time, deemed to be the preferred method of temporary storage for the tailings.This temporary storage of high-grade gold tailings facilitated the reclamation and reprocessing of the leach tail s for gold recovery. The primary reason for reprocessing the Phase 1 leach tails was to provide for long-term permanent disposal of the material as an admixture with Phase II tailings in the Cluff Lake tailings disposal area. Although there was limited tonnage, the high gold content in the material made the in stallation of a gold recovery circuit economically justifiable."

Jan 1, 1989

By T. T. Wang, T. H. Huang, S. S. Zhan

"Fractures with diverse features dominate the hydraulic behavior of fractured rocks and are one of the major subjects for hydrogeological characterization of a site. This study investigates curve patterns obtained by packed tests, and as well the influence of fracture features based on 59 sets of in situ packer tests with different fracture combinations and fracture features. The result shows that, in the example of Heshe site, neat and tidy fractures usually provide stable channel for water flow during testing, and the hydraulic properties of fractures infilled with breccia and mud may change during testing because of leaching and/or washed out of infilling breccia and mud. Different combinations of fractures with diverse features in packed test sections lead to different curve patterns for in situ hydrogeological tests. For groundwater flowing predominately through neat and tidy fractures, the pressure-discharge curve of modified Lugeon tests are usually linear curve pattern, and the pressure decrease while the discharge increase in pressure-discharge-time curves of single-hole double packer tests, which benefit statistically determining the transmissivity of dominant fracture sets. INTRODUCTIONFractures interlaced in rock masses are major channels for groundwater flow and generally account for the anisotropic and heterogeneous characteristics of permeability for fracture rocks. To describe reasonably the permeability of a fracture rock, the Discrete Fracture Network (DFN) approach and others with similar ideals have been developed. Many methodologies and associate equipment, for instance, the televiewer and the in situ hydrogeological test, have been proposed to investigate the spatial distribution and the transmissivity for different fracture sets, which are two main parameters necessary for the DFN or similar model simulation (Pearson & Money, 1977; Barker & Black, 1983; Hsieh et al., 1985; Bernard et al., 2006; Quinn et al., 2012). However, diverse outlooks for the pressure-discharge curves and the temporal pressure and associate temporal discharge curves often confuse the investigation results by significant deviations on derived permeability (Houlsby, 1976; Zlotnik, 1994; Royle, 2009; Camilo, 2010).Aiming on technical development for in situ hydrogeological tests and fracture investigation, an experimental well site with 10 wells has been established in Heshe in central Taiwan since 2011 (Wang et al., 2011; Song, 2012; Zhan et al., 2013). Extensive geological survey and well-hole scanning by a televiewer provide spatial distributions and outlooks of fractures in detail. Additionally, a series of Lugeon tests, double packer injection tests and pumping tests have been performed to investigate the permeability of fracture rocks, and dominate fracture sets as well. Based on the results obtained from the Heshe site, this study classifies the curve patterns of hydraulic packer tests. The features of fractures involved in packed sections for packer tests are then inspected in detail. Relationship between the curve patterns of hydraulic packer tests and associated features of corresponding fractures in rock are discussed and addressed accordingly."

Jan 1, 2015

By Philip Thwaites

"Automatic flotation control in varying degrees of sophistication is practiced at a number of concentrators throughout the world. Practically, the variable conditions in the flotation circuit and the difficulty in maintaining accurate instrumentation information all add to the complexity of automatic control.Further development at the Kidd Creek concentrator has resulted in a 3075 mtpd copper flotation circuit capable of running twenty-four hours a day under the direct control of an optimizing supervisory computer.Three main streams, continuously monitored by an XRF analyzer, supply circuit information to the optimizing computer. Circuit efficiency calculations (from smelter contract terms) and target setpoints allow the computer to determine the economic optimum direction to move the circuit based on the grade/recovery relationship. Circuit manipulation is accomplished by precise pumping of collector and frother reagents together with accurate control of flotation bank pulp levels. The former uses computer controlled diaphragm pumps and the latter is achieved by control loops utilizing a float type level transmitter, variable position dart plugs and a process computer working to setpoints determined by the optimizing computer.The development of a fully automated flotation circuit is by no means complete, but increased knowledge and major hardware improvements have allowed its progression to a higher level of sophistication.IntroductionThe Kidd Creek concentrator is located twenty-six kilometers east of Timmins, Ontario, within a metallurgical complex including a 109,000 mtpy zinc plant and a 59,000 mtpy copper smelter and refinery. The concentrator treats two ore types, a copper-zinc ore and a copper-silver-Iead-zinc ore, at a combined rate of 4,500,000 mtpy. Flotation of the crushed and ground ore yields copper and zinc concentrates from the copper-zinc ore and copper, lead and zinc concentrates from the copper-silver-lead-zinc ore."

Jan 1, 1983

By S. J. Cook

The system of mining statistics for Canada, as it exists today, represents the result of long years of progress, first by the Geological Survey, later and more comprehensively by the Mines Branch of the Department of Mines, and now by the Mining Branch of the Dominion Bureau of Statistics-all supplemented by the very comprehensive reports published by the several provincial departments of mines. It is the purpose of this paper briefly to state the development and present status of Canada's statistical service, more particularly in regard to information on mineral production, and to show that in its evolution continuous progress has been made in the elimination of factors tending to duplication and overlaping, with the result that the construction of an adequate statistical service has been carried out with the least possible expenditure of .public funds. For the purpose of this discussion, the subject of mineral statistics may conveniently be considered from two points of view. The technical difficulties in obtaining satisfactory and complete data from the variety of industries represented in the mining fields of Canada must be apparent to all. Methods of record-keeping are almost as numerous as mines and even the larger concerns which maintain elaborate records for their own information, often find it difficult to compile the statistical reports required of them, because the specific form of inquiry differs from the method in use in their offices.

Jan 1, 1924

By C. Chapman, P. Cowx

"INTRODUCTIONTetronics Research and Development Co. Limited has installed several plasma torches for steel heating in continuous caster tundishes. An extensive demonstration program on a 14 tonne tundish reported the following advantages of plasma heating.• close control of steel temperature to ± 5°C;• a reduction of the furnace tapping temperature of up to 20ºC, leading to savings in energy and refractories costs ;• improvement in steel quality, to produce a slab product with an equi-axed crystal structure and a reduced number of large sub-surface slag inclusions;• the virtual elimination of oxygen pickup in the tundish; and• the capability of making ferroalloy trim additions to the tundish to permit a change of steel grade during casting, greatly decreasing inventory costs.The Need for Tundish HeatingIn the continuous casting of steel, the function of the tundish is to transfer the molten metal between the ladle to one or more continuously fed casting moulds. Figure I shows a typical temperature profile of molten steel in the tundish over the first cast cycle. It is observed that a rapid drop in temperature occurs both at the start of the cast, due to the tundish refractories absorbing heat, and also during ladle changeover. In addition, as a result of thermal losses through the ladle sidewalls, there is a gradual decline in the bulk steel temperature over the entire heat cycle. Consequently, in normal tundish operation, it is necessary to cast with a high superheat (25°C to 30°C + above steel liquidus temperature) in order to prevent freeze-up of the strand. Problems of high temperature variation and the potential of the steel solidifying in the tundish are greater for small caster units of low thermal mass . A high steel superheat increases the steelmaking vessel process time and refractory wear and prevents the formation of a uniform equi-axed solidification structure in the cast steel, resulting in centre line segregation and porosity. The large drop in the casting temperature that occurs during unsteady state operation causes an increase in the number of sub-surface inclusions, reducing the value of the product. Accordingly, plasma heating may be employed to maintain the molten steel at an optimum temperature to produce a slab of consistent quality."

Jan 1, 1989

By John H. Schloen

"The object of this paper is to review electrolytic copper refining as it was in 1954(1), as it is now in 1984, and to comment on the many improvements which have been made in the last thirty years.In 1954, and even in 1984, the ASTM specification B 115 for cathode copper was 99.90% minimum copper plus silver content and 100% minimum electrical conductivity, IACS standard. However, to meet competition and to satisfy the requirements of the fabricators and the electrical industry, the electrolytic refinery must supply a product of 99.95% to 99.96% minimum copper content, and 101fJlo minimum electrical conductivity.The range of cathode impurities reported by 20 major copper refineries in 1954 are given in Table I.The much more rigid British Specification, DD 78, for high-purity cathode copper, specifies individual elements, as well as groups of elements, as shown in Table 2.The Svenska test has been replaced by a similar procedure which uses 2.r mm diameter wire. The ISO test is the one listed in the DD 78 specification. In Table 3, corresponding values for the Svenska and ISO test s are given for various wire bar coppers."

Jan 1, 1986

By Denis Raymond, Yvon Trudeau

"Abstract-The Orion gold mine, located 7 km northeast of the town of Malartic, Quebec, was discovered in mid-1985. Underground exploration was undertaken in 1986Ieading to commercial production in 1988. The upper part of the orebody was exploited above the 125 m level and a total of 131 090 t at an average grade of 5.31 g/t gold were extracted.This paper describes the authors' current knowledge and interpretation of the geology, gold distribution, and structure of the Orion No. 8 ore zone deposit. The deposit is an epigenetic lode gold occurrence somewhat unique in that both quartz-vein type and pyritic type of gold ore occur side-by-side. It is located within the Marban-Norlartic Deformation Corridor (MNDC) formed during a first deformation stage (D1). The MNDC is a well-defined regional structural feature in the Val d'Or- Malartic mining camp. Primary gold mineralization is associated with the D1 event and is represented by pyritized , silicified and brecciated basaltic lavas enclosed by ultramafic flow units. The ore zone is concordant with the MNDC. Felsic intrusions are spatially related with the ore zone, but their role in the genesis of the ore has yet to be defined.A second deformation event (D2) resulted in local folding, a second schistosity (S2) and reverse faulting. Gold remobilization, the formation of the gold-bearing quartz breccia and the emplacement of the main quartz vein at the No . 8 zone deposit were associated with this event."

Jan 1, 1992

By A. Y. Smith, R. J. Allan, E. H. W. Hornbrook, R. W. Boyle, W. Dyck

"HYDROGEOCHEMICAL METHODS in the Canadian Shield can be based on analyses of the following :(1) spring waters and their precipitates;(2) stream and river waters;(3) lake and muskeg waters;( 4) ground waters from drill holes, wells, faults, etc.;(5) waters issuing from diamond drill holes, faults, shear zones, etc. into mine workings and open pits; also analyses of precipitates associated With these waters.The first four can be utilized in both reconnaissance and detailed surveys. The last is suitable only for detailed work.For hydrogeochemical methods of prospecting to be effective, the following conditions must be present. 1. Natural waters must come into contact with mineral deposits and remain in contact with them long enough for the solution of detectible amounts of ore, gangue or indicator elements. 2. Dispersion patterns must be present in the hydrologic systems in order to trace the elements back to their source. These patterns may take the form of trains (e.g., increasing amounts of elements upstream toward t he source (s), Figure 1 ) or halos (e.g., increasing amounts of elements in bodies of water toward the source (s), F igures 2 and 3)."

Jan 1, 1971

By D. Laguitton

The basic chemistry of a1•senic related to its dissolution and subsequent precipitation in gold-mine waste waters is discussed. The lime addition methods provides the most economic treatment of arsenical slurries, but requires a careful control of the oxidation of Asm into Asv, of the pH (>12) and the filtration of the precipitate. If arsenic levels below 0.5 mg/ l are required, a modification of the method by phosphate addition must be considered.

Jan 1, 1976