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By A. R. Laplante

"In this paper, the performance of the Knelson Concentrator and of the batch and continuous Falcon Concentrators are compared. The units are based on different operating principles, and as such they perform quite differently. The Knelson yields very high free gold recoveries over a wide size range of both the recovered and rejected species. It is ineffective in recovering very fine ( <15 µm) or flaky gold, as encountered in flotation feeds, concentrates or tails. It is the: preferred unit for gold recovery from grinding circuits. The batch Falcon is effective in the fine range, typically less than 37 µm for gold. Its recovery zone is quickly saturated when there is significant heavies in the feed. It works best as a pre-concentration unit. The continuous Falcon is a versatile unit which is capable of recovering fine heavies (density down to 5 g/cm3 ), especially from coarser gangue. INTRODUCTIONThe purpose of this presentation is to describe the mode of operation of two Canadian centrifugal concentrators, the Knelson and Falcon. It is hoped that it will prove informative to prospective users in the selection, testing and optimization for applications of either machine. The work is based on testwork both in Canadian mills and at McGill. I am indebted to many colleagues at these locations. Appropriate references will be made to articles further describing the work, either already in the open literature or in preparation.Although this work is meant to be more practical than scholarly, it is appropriate to begin by considering how the two units achieve selective recovery. This will become useful in establishing a suitable testing methodology, which will then be described, and interpreting typical results. In the last section I will attempt to define appropriate applications for the two units. This is a thankless task, as I am likely to miss some applications or to make projections based on partial results, as much of the work is still in progress. In deference to the reader and both manufacturers, areas where reasonable doubt still remains will be identified."

Jan 1, 1993

By J. Kuipers, R. W. Lawrence, P. B. Marchant, W. Brooks, J. T. Chapman

"Bioleach testing and piloting was conducted on refractory gold sulphide concentrate from Austin Gold Venture in Nevada during 1988. The objective of the test programme was to determine the technical and commercial viability of bioleaching as a concentrate pretreatment step prior to gold extraction by cyanidation. Baseline CIL cyanidation typically resulted in < 20% gold extraction from the Austin concentrate. Bioleaching enhanced gold extraction up to 95% using conventional CIL techniques. This paper summarizes the bioleach test programme and results, including pilot plant studies onsite, and describes the commercial design details for a possible retrofit of the Austin flotation tailings leach circuit to accommodate 20 tpd and 40 tpd capacity concentrate bioleach facilities.INTRODUCTIONBioleach testing on a refractory carbonaceous sulphide concentrate from Austin Gold Venture (AGV), was initiated in late 1987 as part of an ongoing programme at Austin to investigate alternatives to concentrate smelting. Preliminary batch biooxidation tests at Coastech indicated that over 90% gold extraction by carbon-in-leach (CIL) cyanidation of the bioleach residue could be achieved, compared with less than 20% gold extraction on untreated concentrate by similar CIL processing.Subsequently, a more rigorous laboratory study was undertaken at Coastech to establish continuous biooxidation operating criteria on a bench scale. The objective of continuous testing in the laboratory was to provide confirmation of enhanced CIL response based on continuous bioleach products and to determine key process operating and design parameters for pilot testing. The success of the laboratory test program led to the installation of a mobile pilot plant at Austin Gold Venture. The plant was operated by Coastech and AGV during 1988 to provide scaleup data and design criteria for commercial design and feasibility analysis. Based on pilot plant operating data, a detailed commercial bioleach plant was designed as a possible retrofit to the existing 1000 tpd CIL plant. Capital and operating costs were estimated to provide a commercial feasibility study of bioleaching as an oxidative pretreatment for Austin refractory concentrate."

Jan 1, 1989

By Shila Jafari, Mari Lundström, Aleksei Kritskii, Pia Sinisalo

A typical process adopted at nickel plant is the processing of nickel-copper mattes and converter mattes using the following technology: pressure oxidative leaching (POX), solvent extraction (SX), electrowinning (EW), cobalt recovery, and solutions purification. As a result of multi-stage atmospheric and autoclave process leaching, copper-nickel separation is achieved. Cobalt and nickel are further separated by SX. Copper in the process can be removed as copper cake (Cu-cake), which is a by-product with high content of valuable metals. In the current paper, a method combining atmospheric and pressure leaching of Cu-cake in sulfuric-acid media is discussed. Suggested method allows to obtain high copper extraction (>98%), with leach residue containing precious metals and PGMs. Sulfuric acid media was chosen to make the suggested technology adaptable for the primary POX-SX-EW circuit. The initial Cu-cake was analysed and a range of process parameters (t = 25–190°C; PO2 = 0–7 bar) investigated to achieve the optimal conditions for leaching process at the ambient as well as at increased pressure. As a result, an initial process block diagram for the treatment of Cu-cake with high copper leaching efficiency and low metal losses is provided. INTRODUCTION The conventional technology for nickel sulphide ore processing includes the following main stages: froth flotation, matte smelting and converting. The subsequent processing of nickel converter matte is possible using fundamentally different approaches - hydrometallurgical (Llanos, Queneau & Rickard, 1974; Rademan, Lorenzen & Van Deventer, 1999; Kshumaneva, Kasikov, Neradovskii & Belyaevskii, 2009; Dutrizac & Chen, 2013) and pyrometallurgical (Tsymbulov, Knyazev, Tsemekman & Golov, 2007). Hydrometallurgical approach in comparison with pyro-process has several advantages, such as reduced environmental load, reduced PGM losses, increased copper and nickel extraction. Typically, hydrometallurgical technologies include leaching, solvent extraction as well as nickel and cobalt recovery in metallic form by electrowinning or hydrogen reduction or as valuable metal salts via crystallization process (Crundwell, Moats, Ramachandran, Robinson & Davenport, 2011).

Jan 1, 2019

By D. A. MacFadyen, J. J. Brummer, C. C. Pegg

"The first record of a kimberlite found in Canada (1946) was the identification of thin dykes intersected while drilling for gold in Michaud Township, Ontario.Sampling of the Munro Esker (1964) in the Kirkland Lake area, Ontario, by the Geological Survey of Canada identified the occurrence of detrital grains of pyrope garnets along a length of 35 km of the 113 km tested. A search for the source of the garnets resulted in the identification (1968) of a narrow subsurface kimberlite dyke in the Upper Canada Mine. This discovery resulted in a staking rush. Unfortunately, subsequent work did not identify the source of the kimberlite indicator minerals.During 1978 the Ontario Geological Survey started a multi-discipline study of 29 townships (2560 krn2) in the Kirkland Lake area, to encourage exploration for gold, base metals, and kimberlites. Back-hoe sampling (1979 to 1982), where the overburden was thin, and reverse circulation drilling, in areas of thicker drift, yielded samples of the till. These were analyzed for several elements and a mineralogical identification of the heavy minerals was completed. Pyrope and chrome diopside grains were identified.Studies of the Pleistocene geology indicated only the most recent direction (167 degrees) of ice advance (Matheson) and the associated deposits, out of a possible three advances known to occur in the general region straddling the Ontario-Quebec boundary, is present in the immediate area of Kirkland Lake. Contouring the distribution of pyrope grains (1990) showed a concentration centered over an area of 616 km2 extending down-ice from Gauthier Township. This included a smaller area containing chrome diopside grains. Kimberlite boulders were identified (1981) in gravel pits on the Munro and Misema River Eskers located within this anomalous area. The next step would be to use the airborne geophysical data to locate the kimberlite pipes which yielded the indicator minerals and boulders. The source area is likely to be in the northern half of the Ontario Geological Survey study area."

Jan 1, 1992

By J. F. Perreault, J. Paraszczak

"The profitability of an underground mine depends to a great extent on the production cost.Random equipment failures and their consequences have significant influence on the total operating cost of a mining system. Having this in mind, a reliability study has been initiated for loadhaul- dump machines in an underground mine. The main purpose of this study is to identify the critical machine subsystems, determine their failure pattern and help work out an effective maintenance strategy. In the first part of this study, the failure data of diesel powered LHDs, gathered during an I8-month period have been analyzed. For the purpose of the analysis, the machines have been treated as systems comprising seven subsystems connected in series. The most critical subsystems, i.e. electrical and hydraulic, were further investigated, and analyzed by graphical and analytical methods. Different failure distribution models were applied and discussed. Basic Defmitions and ConceptsIn order to avoid confusion, several terms used in this paper are defined below, as compiled by O&apos;Connor (1991). The acronymsBS and MIL-STD stand respectively for: British Standard and US Military Standard.Failure: the termination of the ability of an item to perform a required function (after BS 4778).Time Between Failures (TBF): the length of time between two consecutive failures.Observed Mean Time Between Failures (MTBF): For a stated period in the life of an item, the mean value of the length of time between consecutive failures computed as a ratio of the cumulative observed time to the number of failures under stated conditions (after BS 4778).Maintenance, Corrective: The actions performed, as a result of failure, to restore an item to a specified condition (after MIL-STD-721 B).Maintenance, Preventive: The actions performed in attempt to retain an item in a specified condition by providing systematic inspection, detection and prevention of incipient failure (after MIL-STD-721B)."

Jan 1, 1994

By Malcolm Scobie

"This paper reviews the evolution of Canadian surface and underground mining automation, principally relating to: advances in communications, initial development of machine teleoperation from line-of-sight remote control, and islands of automation. The eventual role of teleroboties and minewide robotic mining remains to be resolved. The progress and approaches adopted have tended to vary within each sector of the mining industry. Recent information technology advances have made possible the Digital Mine; in which information associated with all mining processes, however dispersed, would be integrated with support systems using new communications technology. The Digital Mine will provide the information infrastructure to serve as the foundation for minewide automation. This paper concludes by reviewing the issues likely to govern implementation success, relating to: mining process design, machine design, machine intelligence, and mine planning and control.IntroductionSignificant advances have recently been made in underground hardrock mine communications and teleoperation. Subsequent R&D efforts are mainly focussing on control systems for various types of machines. In underground potash mining, the realization of automated continuous mining systems appears to be imminent. Recent advances in surface mine dispatching, machine monitoring and global positioning systems (GPS) have tended to reactivate some of the initial R&D enthusiasm developed in the &apos;70s for surface mine automation. Mines at large are approaching a major milestone: the implementation of comprehensive communications infrastructure which proves to be sufficiently reliable and economical to support the automation of routine mine production, either using teleoperated or autonomous machines. This then should motivate a deeper commitment to real time monitoring and management. The communications advances make possible the Digital Mine; in which information associated with all mining processes, however dispersed, would be integrated with support systems using information engineering. The Digital Mine will provide the information infrastructure to serve as the likely foundation for a wide range of automation scenarios. This paper surveys the status and directions of automation development in both surface and underground Canadian mines, pointing to what are seen to represent key technology development issues."

Jan 1, 1995

By Wei Zhang, Jinhong Zhang

"The adsorption of ethyl xanthate on copper sulfides, i.e., chalcopyrite, chalcocite and bornite, has been studied in situ in aqueous solutions by applying an atomic force microscopy (AFM). AFM images show that xanthate, such as potassium ethyl xanthate (KEX), adsorbs strongly on chalcocite and bornite mainly in the form of insoluble metal xanthate, which binds strongly with the mineral surface without being removed by flushing with ethanol alcohol. This adsorption mechanism is totally different from the one obtained with chalcopyrite/xanthate system, during which oily dixanthogen is the main adsorption product on chalcopyrite surface. The findings obtained from the present AFM study suggest that an AFM image analysis is a powerful tool for the study of the collector’s adsorption on mineral surface and as well the development of novel collector for copper sulfide flotation.INTRODUCTIONIn mining industry, copper sulfide minerals, i.e., chalcopyrite, chalcocite and bornite, are usually separated selectively from non-valuable gangue by froth flotation, which treats the highest throughput and produces the maximum economic outcome of any surface chemistry process. In flotation, collectors are added into the pulp (mixture of water and fine-grained minerals) to selectively adsorb onto the target mineral and render its surface with high hydrophobicity, which is generally beneficial for a strong mineralbubble attachment and thus a high flotation recovery.The adsorption of collector on mineral surface, therefore, is vital for a successful flotation process and it has been studied by applying various surface analysis techniques, such as IR (Infrared Spectroscopy), CV (Cyclic Voltammetry) and XPS (X-ray Photoelectron Spectroscopy). (Poling, 1963; Allison et al., 1972; Mielczarski et al., 1984; Leppinen et al., 1989; Kartio et al., 1996) These studies have revealed a lot of information, such as the reaction, product and mechanism, of the adsorption of chemicals on mineral surface. It is also of great interest to directly get the image of adsorbed collectors on mineral surface changing with pulp chemistry, such as pH, redox potential, ionic strength and chemical’s dosage."

Jan 1, 2016

By Erwin L. Zodrow

"For 25 chemical elements in electrostatically precipitated fly ash (Lingan coal-fired power station), concentration changes are studied as a function of increasing proportions of fines (ash particle diameter less than 45 micrometres). Elements that are involved when concentrations increase as the proportions of fines increase are likely to escape into the atmosphere. These are Th, U, As, S, P, Sb, Na, Ag, Zn, Pb, Ni, Ba, Sc, AI, Mo (and Bi, Ge, Ga, F and Li), i.e., more or less highly volatilized elements. Of the less volatilized metals such as Fe, Ca, Cu, Ti, K, Co, Mn (and lanthanides), certain portions presumably also escape as stack emissions. Diadochy and spinel formation in bottom slag is presented as an emission-reducing agent for certain metals.IntroductionThe Lingan coal-fired power generation plant, owned and operated by the Nova Scotia Power Corporation, produces annually about 140,000 metric tons of ash (the residual mineral content after burning coal). The tonnage is based on a 15 per cent average ash content of Cape Breton coal.For purposes of this report, samples of the hard, fused slag (bottom slag) that is accumulated at bottoms of boilers, and electrostatically precipitated fly ash (ep ash), were collected and investigated. Bottom slag is a minor component of the produced ashes.The ashes were surveyed and the presence of over 75 major, minor and trace elements is reported. From this survey, 25 elements were selected to establish elemental enrichment/depletion trends when the proportions of the less than 45 micrometre <45µm) fractions in ep ashes increase. The results are significant in that, taking the case of elemental enrichment, the elements involved are likely to escape into the atmosphere, i.e, highly volatilized elements. Depletion trends for elements are presumably associated with less volatilized elements during coal-firing. Quantification of the emission of atmospheric pollutants is not considered part of this work. ""Igneous"" minerals generated during coal combustion include spinels (found mainly in the bottom slag), quartz, glass and mullite."

Jan 1, 1982

By P. E. Weidmark

"PART I - Published PapersBallivy, G., and Dupuis, M., ""Laboratory testing for the design of grouted rock anchors""; Proc 6th Pan Am Conf Soil Mech Found Eng; Lima; 1:277-291; 1979.Ballivy, G., Ladanyi, B., and Gill, D., ""The effects of moisture content on the strength of fissured rocks""; Proc 1// 1ntnl Congr 1.A.E.G.; Madrid; //:2:7-16; 1978.Baumgartner, P., and Stimpson, B., ""Development of a tiltable base friction frame for kinematic studies of caving at various depths""; Int J Rock Mech Min Sci Geomech Abstr; 16:4:265-267; 1979.Bawden, W.F., and Roegiers, J.-c., ""Discussion and interpretation of the mathematics governing radial flow in a single horizontal rock fracture""; ISBN 07727-7002-6; Dept Civil Engng publication 79-11; Univ Toronto: 134p;1979.Chatterji, P.K., Smith, L.B., and Insley, A.E., ""Construction of Saline Creek Tunnel in Athabasca oil sand""; Can Geotech J; 16:1:90-107: 1979.Coates, D.F., and Gyenge, M., ""A case history of pit slope design""; Proc 4th ISRM Congr; Montreux, Switzerland; Sept 1979; 1:Theme IV:591-596; 1979.Crawford, A.M., and Curran, J.H., ""A dynamic direct shear machine for determining the time-dependent behaviour of rock joints"": Dept Civil Engng publication 79-08; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A displacement discontinuity approach to modelling the creep behavior of rock and its discontinuities""; Dept Civil Engng publication 79-09; Univ Toronto; 1979.Crawford, A.M., and Curran, J.H., ""A higher-order displacement discontinuity element""; Dept Civil Engng publication 79-10; Univ Toronto; 1979.Cruden, D.M., ""A computer-based system for rock mass description""; Proc 1// Intnl Congr I.A.E.G.; Madrid; //:2:155-159; 1978.Cruikshank, D.J., and Curran, J.H., ""A.B.LE. approach to modelling of fluid flow in fractured rock masses""; Proc 7th Cdn Congr Appl Mech; May 1979; Sherbrooke, Que; 887-888; 1979."

Jan 1, 1980

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 Noel Billette, Jean-Luc Chouinard

"An analysis of the number of industrial injuries shows that the mining sector is particularly affected, since mining is one of the most dangerous industrial activities in Canada. This has led to numerous inquiries, and supports the need for an in-depth study aiming at the identification of factors responsible for these accidents. One possible factor often pointed at is the small crews incentives and this paper presents a scientific approach applied to check a potential link between bonus and accidents at two mining companies located in northwestern Quebec.The data required to do so were the accidents, the salaries and the number of hours worked at each mining site by the hourly paid personnel for the period from June 1979 to January 1982. The analysis of the results derived from the initial information shows different behaviours of the frequency rate vs the bonus rate at these mines. The number of days lost per accident is independent of the bonus rate at both mine sites, as shown by Khisquare tests on contingency tables.IntroductionA wide variety of opinions has been pinpointed by a survey of the literature related to individual or small crew incentives and industrial accidents in sectors of activity where it applies. In addition, various formulae of mining contracts take place in the industry on one part, and statistics from this sector indicate a high accident frequency rate on the other part. These fact s have lead to this scientific investigation which does isolate the direct impact of the bonus on workers&apos; accidents. This study was undertaken with the full support of the Quebec Metal Mining Association.The conclusions of this preliminary phase of the researchproject are presented for two mining complexes in northwestern Quebec. The procedure is somewhat similar to the approach of the Belmoral Commission, with the underlying assumption that bonus has a direct impact on accidents."

Jan 1, 1986

By Todd S. Harris

"IntroductionThe western region of North America has long been considered a dynamic market supporting such diversified industries as lumber, agriculture, cement, and electronics. In recent years however, the region has also been the focus of a great deal of activity in the extender and filler mineral s business from companies seeking to position themselves to take advantage of the large demand for these materials both here and abroad.Extender and Filler MineralsExtender and filler mineral s include 15different products used in numerous end uses. The nine most important extenders and fillers are listed in Table I. These products range in price from under $50 a ton to over $4,000 a ton and basically represent the following three different types of minerals:Particulate products-Calcium carbonate; Kaolin; Silica.Platy minerals-Talc (Montana, Canada); Mica.Fibrous minerals-Talc (California, Eastern U.S .A.);Wollastonite.What distinguishes these products from other industrial minerals? For one thing, an important feature of extender and filler minerals is that they are used primarily in such consumer non-durable good s as paper, paint, plastics, sealants, and rubber which traditionally do not react as violently to swings in the economic cycle. In addition, these minerals are sold principally on key physical properties, usually brightness, particle size and shape, oil absorption, and hardness. As part of the physical minerals segment of industrial minerals, extenders and fillers are traditionally the most stable group and typically the most profitable. Studies by C.H. Kline over the past decade on extender and filler minerals has revealed historic average profitability (expressed as a percentage on sales) nearly double that of most other industrial mineral s.The demand for these minerals in the western region (Fig. 1), closely follow s the areas of greatest population concentration. These markets include pulp and paper, mainly in the Pacific Northwest, and paint, around Los Angeles and San Fran cisco. Other significant markets for extender and filler minerals in western North America include joint cements, carpet backing, and plastics, mainly PVC pipe."

Jan 1, 1986

By Leonard A. Wolff

"The 1980sfor the mining industry can be characterized as the survival of the fittest. High interest rates, low commodity prices, foreign subsidized competition and decreasing ore grades have contributed to a streamlining of the domestic mining industry in the United States, leading to the shutdown of operations or large cutback of work forces. The purpose of this paper is to look at the impact of a layoff on the employees of what was once a major uranium producer in south central Wyoming, twenty months after the final layoff and mine shutdown. INTRODUCTIONDecember 19, 1985, was the date of the final of three successive layoffs over a two-month period, leading to the complete shutdown of Petrotomics Company, a subsidiary of Getty Minerals Company. The final shutdown was due to a combination of depressed U3O8 prices and the takeover of Getty Oil Company by Texaco in January 1984.The layoffs affected 104 employees and included mine personnel, mill personnel and staff. Both hourly and salary workers were involved. The operation was considered non-union, however, a few mill hourly employees were unionized. At the completion of the layoffs. only a handful of employees remained for administrative and miscellaneous functions.For Getty employees, the terms of the merger agreement provided a generous level of separation benefits. The terms that were insisted upon by Mr. Petersen, Chairman of the Board for Getty Oil, stipulated that employees receive one month of severance pay, for each full calendar year of employment up to a maximum of two year&apos;s pay. This was the forerunner of what is now commonly known as the ""tin parachute”. All but the union employees of Petrotomics received these separation benefits. Union employees were covered by their separate, less generous, contract.Much of the literature that has been published in recent months has centred around the effects of layoffs on remaining employees, or the psychological effects on the severed employee. This study will emphasize the economic impact and ramifications due to a layoff, using the Petrotomics employees as a case example."

Jan 1, 1989

By John F. Gartner

"New terrain maps provide information on the ground conditions in northern Ontario. This information has a relevance to mineral exploration because it assists the user in determining ground conditions prior to entering the area. The prospector, geologist, geophysicist and geochemist can then plan for the optimum use of exploration techniques best suited for theseground conditions.These terrain maps are the result of the Northern Ontario Engineering Geology Terrain Study-a program carried out by five consultants under contract to the Ontario Geological Survey of the Ministry of Natural Resources. The area mapped is 370,000 km2 and more than 100 basic data maps at a1:100,000 scale will be published.An unique terrain legend was derived to facilitate the mapping and it allows the derivation of specific user information. Examples of some of these uses are described. Introduction""Where did all the boulders come from Charlie?"", asked the student, as the prospector and his young assistant clambered through the bush. "" Why son, they were brought down here by the glacier"", the prospector replied. ""But where is the glacier now Charlie? "", persisted the young man. ""Gone back up north for more boulders son!""An old story, but one that illustrates the importance of overburden to the prospector. The use of overburden as a prospecting technique is not new. In fact, the principles have been known in the western world for at least 235 years (Shilts 1976). More recently, Dreimanis&apos;s classic work on boulder tracing (1957) and Lee&apos;s work (1971) emphasize the role of glacial geology in prospecting. In addition, papers by Smee and Sinha (1979), Averill (1978), Bereton (1978), and Gleeson and Hornbrook (1974) all describe the importance of drift in mineral exploration programs. The discovery of the copper deposit in the northern Ontario township of Currie (Thompson, 1979) is attributed in part to till prospecting methods. So the significance of the overburden is firmly established, both in the literature and in the minds of today&apos;s prospectors, geologists, geophysicists and geochemists."

Jan 1, 1981

By Robert B. Parsons

"While it might seem like heresy to suggest that ""taxation"" can be a source of financing, never the less some generous tax rules can considerably enhance the tax savings pertaining to a particular expenditure or project. A basic tax knowledge, and careful tax planning, can optimize government participation in a project. INTRODUCTIONIn trying to identify sources of financing for a project, ""government"" as a source of funding is normally thought of in terms of government grants, loan guarantees, interest rate buy downs, property tax waivers, hydro subsidies, and so on. Generally, such concessions are somewhat difficult to obtain, especially in the current period of apparent fiscal restraint. One source of government funding which should not be overlooked is the income tax regime, and, at the provincial level, the various provincial mining tax regimes.While the taxpayer would not normally view a tax system as a potential source of government financing, nevertheless various federal and provincial rules applicable to the mining industry can offer attractive tax deductions - and tax savings - with respect to particular expenditures. In fact, it is not unusual for a civil servant to refer to a tax deduction as a tax ""subsidy"". For example, in the right circumstances, the cost of a smelter expansion in New Brunswick would cost the operator only 31 cents on the dollar, with the federal and provincial governments paying for the other 69 cents by foregoing tax revenues (Table I). In a sense, such tax savings could be compared to a government grant equal to 69% of project costs. Of course, not every project expenditure will generate that degree of government funding. The fact of the matter is that the percentages of tax savings attached to different expenditures cover a wide range, depending on a complex mix of factors. The point to understand is that the tax rules can offer some valuable savings, even after tax reform, and that a basic knowledge of the tax rules can yield some fruitful rewards."

Jan 1, 1989

By Lynne Bowen

"On the da y shift in Number One Mine at Nanaimo on Vancouver Island, on May 3, 1887, William Griffiths, a coal miner with many years experience, fired a shot to advance the face of the crosscut. A flame ran out for a distance of fifteen feet along the roof and then extended up the slope for ten to twelve feet, and although many would have called this a blowing out shot, Griffiths said it was just a feeder. ""A blower"", he said, ""would have caused an explosion."" 1There was no explosion. Griffiths reported gas and the area was cleared for three hours and then work resumed. When the shift changed at 3:00 p.m., the fireman reported all places clear of gas and the ventilation good.2The ventilation in Number One Mine was the best anyone had ever seen. The air in the mine was almost too cold. The current was so strong that it sometimes blew out the flame on the miners&apos; fish oil lamps. It delivered five to six hundred cubic feet of air for every man and animal working in the mine. The law required only one hundred cubic feet 3The miners considered Number One to be relatively safe. The manager was proud of the mine and its up-to-date equipment"". Recently, there had been reports from France and America about the explosiveness of coal dust, but the manager did not think his mine was sufficiently dusty to be dangerous.5 The dust lay thick on the floor of the mine. Sometimes when a shot was fired the dust rose in great clouds. When a miner was shovelling it, the dust would billow up and be carried off by the current of air. The dust was also in the roof and in the stopings, put there intentionally to fill up the spaces and prevent the accumulation of methane gas."

Jan 1, 1992

By G. Macfarlane

"In 1985, a crushing plant, located in the feed preparation area of Kidd Creek&apos;s copper smelter, was modified. The plant, which originally had treated only copper-bearing materials for the smeller, at a rate of 10 tonnes per hour, was expanded to 40 tonnes per hour capacity and modified to treat silica ores to meet the smelter’s flux requirement and also gold ores from the company&apos;s Hoyle Pond property. In the storage area adjacent to the crushing plant a 300 tonne per day gold mill was constructed.This paper outlines the construction and first year of operation of the crushing plant and gold mill with emphasis placed on the capital and operating advantages to be gained by utilizing an existing metallurgical infrastructure.IntroductionThe Kidd Creek Mines Ltd. copper-zinc-silver orebody is located 24 km north of Timmins, in Northern Ontario . Mining of this massive sulphide de posit commenced in 1966 and, in the ensuing years, a concentrator and zinc plant were constructed at the metallurgical complex, approximately 17 km by rail from the mine site . At this same site, in 1981, a copper smelter and refinery were commissioned. The smelter which utilizes the Mitsubishi smelting process for the continuous production of blister copper from copper concentrate, has been comprehensively described in previous papers.At the time of the smelter construction, a small (10 tonnes per hour) crushing plant was installed in the smelter&apos;s feed preparation area. This plant was used to treat the copper-bearing revert material produced by the smelter, and, apart from periods when slags and matte were produced through furnace drainage at the end of each operating campaign, it was generally under-utilized. This fact, together with the requirement to devise a more cost effective method of providing silica flux for the smelting operation, was the basic rationale for modifying and expanding and crushing plan t. At the same time, development at Kidd&apos;s Hoyle Pond orebody had progressed to such a stage that a gold mill of 300 tonnes per day was warranted."

Jan 1, 1988

By P. A. Mascaró, N. Chacon, A. A. Cecchi

"This document shows the development of a system called the “On-line charge level determination in SAG mills” (abbreviated as Jc). The Jc variable has certainly been difficult to measure due to the relevant number of factors and variables that affect the grinding phenomena inside semi autogenous (SAG) mills. To assess the feasibility stage of the proposed system, it was necessary to carry out two tests in different sized SAG mills, 38´ × 22´ and 36´ × 15´, respectively. In each test, the system was configured with a battery of sensors of the following types: (1) strain gauge, (2) accelerometer, and (3) gyroscope. The first step involved for charge level determinations was to determine kidney foot and shoulder by means of a study of the energy-impacts on shell structures. The second step consisted of correlating the measured grinding operational variables with the actual charge levels obtained from SAG mill crash stops. This system development is extremely useful and relevant for providing approximations about mass balances inside SAG mills. It will be a suitable tool for explaining “tonnes per hour” variations and determining optimal points under various operating conditions.INTRODUCTIONThere has been a growing necessity for technologies capable of obtaining “on-line data” of the main comminution variables in order to increase throughput. Computer systems have taken an important role in providing important solutions by means of processing on-line device signals (commonly referred to as monitoring). In semi autogenous (SAG) milling, there are many examples of monitoring devices that allow the operational staff to obtain detailed information both mechanically and electronically inside a grinding circuit. In this context, a new technology has been developed to obtain “Jc total charge (%) online” in two different SAG mills called Vibro-Energy® System.As part of the analysis performed by JKsimMet® the Jb/Jc was estimated because it has an important impact on SAG mill throughput. Different scenarios were simulated and contrasted at various theoretical Jb/Jc values in a baseline circuit (Figure 1)."

Jan 1, 2016

By A. McLean, D. K. A Donyina, R. S. Segsworth

"Various aspects of processing ferro-manganese fines generated during the crushing of standard ferro-manganese have been studied in laboratory-scaleplasma furnaces. These laboratory furnaces are based on the use of conventional graphite electrodes rather than water-cooled non-consumable torch devices. The reactor system has separate, distinct zones for pre-healing, melting and smelting. This unique feature assists in the removal of undesirable elements from the molten alloy. Ferro-manganese alloys containing over 82% manganese, 0.004% sulphur, less than 0.01% silicon, 0.006% nitrogen, 0.001% oxygen and 0.0006% hydrogen have been produced from the offgrade ferro-manganese fines.IntroductionThe major application of manganese is as an alloying additive to numerous metals such as steel, aluminum, copper and magnesium. Manganese is mainly consumed in the ferrous industry in the form of ferro-manganese and silicon-manganese, or in its pure state as electrolytic manganese when certain impurities inherent in the manufacture of ferro-manganese and silicon-manganese alloys must be avoided. Before being sold on the market, ferro-manganese is crushed and during this process alloy fines are generated. Due to the nature of the casting process, the fines produced are contaminated with silica sand. In addition, due to segregation effect s, the pho sphorus content of the alloy fines is higher than that found in the bulk of the material produced. Because of the smaller particle size and the higher impurity content, there is only a limited market available for the alloy fines. For this reason, there has been increasing attention directed toward the development of processes for recycling fines through the conventional smelting furnaces. The fines may be charged to the furnace either directly or after agglomeration. The detrimental effects of charging the fines directly include:(1) decrease in gas permeability, causing irregular gas flow;(2) increase in the amount of dust produced;(3) packing and bridging; and(4) intensive reactions due to sudden flow in hot zones."

Jan 1, 1982

By D. C. Fuller

"CoaLiquid, Inc. (CLI) has been in the coal-oil-mixture (COM) business for over five years. The initial pilot processing facility was replaced by a 2000 barrel per day commercial production facility in August 1979. For over two years CLI has been expanding its efforts and conducting large-scale production and combustion demonstrations successfully in many locations across the United States. To facilitate the marketing effort, CLI has recently constructed a special trailer containing all equipment needed for a temporary COM retrofit.CoaLiquid has conducted commercial-scale combustion demonstrations in the following types of combustion units: kilns, calciners, industrial boilers, blast furnaces and driers.IntroductionCoaLiquid, Inc. officially dedicated its plant on August 31, 1979, at a ceremony presided over by the then Governor of Kentucky, The Honorable Julian Carroll. The dedication marked the culmination of over three years of research and development work and marked the beginning of a new era of coal-oil-mixtures as a commercial commodity in the marketplace. As the first such plant in the United States, it set the tone for construction to follow.CLI was originally owned and managed by a group of entrepreneurs from Kentucky who had developed the process and constructed the plant on purely private investment and conventional financing. Beginning in late 1976, with a pilot-scale operation, also located in Shelbyville, Kentucky (near Louisville), CLI began producing a stable mixture of 50070 coal, 30% to 40% oil and 10% to 20% water by weight. The technology employed was developed by Eric C. Cottell of Long Island, New York and is covered by U.S. Letters Patent No. 3,941,552. Since the pilot plant operation, CoaLiquid has made many refinements to its process and in fact has added new technology to its portfolio of patents and patents pending. Further refinements to the product now produce a stable mixture of 50% coal, 40% No.6 fuel oil and 10% water by weight."

Jan 1, 1985