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By Walter Durst

On October 16, 1978, the Harnback open cut of Rheinische Braunkohlenwerke, the largest open cut ever planned, was officially put into operation. It will outperform all of the large open cuts known at present, both in its dimensions and in its annual output of overburden and coal. Present plans are to commence coal mining in 1983, although target production will only be achieved in 1995when the annual output will be 50 million tons of coal. Considering an overburden: coal ratio of 6: 1, this will involve the removal of approximately 300 million bank cubic metres of overburden. For overburden removal and coal mining, this open cut will use bucket-wheel excavators exclusively. It is planned to employ eight excavators with a daily output of 240,000 bank cubic metres each (Fig. 1). The transport of the overburden and coal to the dump and the power station, respectively, will be effected by 30Q0-mm-wide conveyors, running at a speed of 6 m/sec. The overburden will be dumped by spreaders having a boom length of 100 m, capable of dumping 240,000 bank cubic metres per day (Fig. 2). Such giants, of course, can only be used for extreme conditions . Their employment indicates that huge quantities of material can be handled economically for long periods. However, the use of bucket-wheel excavators is economic when daily outputs of 5,000 bank cubic metres are involved, in particular if direct backcasting of the overburden is not possible.

Jan 1, 1979

By J M. Anderson

The cable belt conveyor installation at Craigmont Mines Limited, Merritt, B.C., has the greatest one-stage vertical fall of any conveyor installed overland in Canada. Since the late summer of 1961, this conveyor has carried more than 5,000,000 tons of copper ore from open pit to concentrator site. When the conveyor is loaded, the drive motor acts as an induction generator, delivering power to an external circuit. This paper covers the selection, the operation, the performance statistics, and the installation and operating costs of this conveyor system. Introduction T HE Craigmont mine is located in the south-western interior region of the Province of British Columbia, approximately 240 miles northeast of Vancouver. A moderate climate, good roads, service by the Canadian Pacific Railroad, power from the British Columbia Hydro Authority, gas from the nearby main line of the Inland Natural Gas Company and close proximity to the village of Merritt provide a favourable location for this mining operation. The ore occurrences at Craigmont have a vertical extent of 1,500 feet,

Jan 1, 1965

By Eric Konigsmann

"Omai Gold Mines is a large scale open pit gold mining operation located in central Guyana, South America with a 12,000 tonne per day milling facility. Mill operations were initiated in December 1992 with commercial production beginning in January 1993. The entire operation employs approximately 120 expatriates and some 800 Guyanese nationals and is expected to produce in excess of 250,000 ounces of gold per year. The total mineable reserves contain 2.5 million ounces of gold with a projected mine life of twelve years.The milling circuits feature an SABC grinding circuit, gravity concentration and a conventional CIP gold recovery circuit. This paper will review the mill start up and ""run-in"" phase during the first year of operation. Emphasis will be placed on descriptions of start up problems and circuit modifications, mill performance trends in 1993, and personnel training and development. An outlook for 1994 is also given.IntroductionOmai Gold Mines is a large scale, open pit gold mining operation located in the Potaro district of Guyana, South America, some 160 kilometers south of the capital city Georgetown. Although there are numerous small scale gold mining ventures in Guyana, particularly with the dredging operations on the rivers, Omai is the first hard rock, open pit mine to be developed in the country. At present, this mining operation is one of the largest gold mines in South America.The Omai gold deposit has been exploited for over one hundred years. In the late 1800's, a German syndicate used hydraulicing with subsequent gravimetric separators such as sluice boxes and trommel screens to recover gold from saprolite, a soft, oxidized, claylike mineral which covers much of the claim area. Through the early 1900's and up until the 1950's, numerous mining companies including Anaconda Mining Co. Ltd. explored and drilled the Omai deposit but the technology and low gold price of the day made the reserve uneconomic to develop."

Jan 1, 1994

By Jean-Marie Fecteau

The gold mine sector is presently facing low gold prices as well as technological challenges. Its competitiveness and survival will depend on new mining methods and equipment to improve ore extraction. In 1999, Natural Resources Canada has invested new funds over a period of three years at CANMET?s Experimental Mine to establish the Narrow-Vein Mining Project. A team of engineers and researchers specialised in mining, mechanics and electronics engineering are working to meet the critical need of ore-extraction technology. CANMET?s program in mechanisation and automation for narrow vein mining had, prior to 1999, realised several important achievements, many in co-operation with a consortium of mining companies (Soredem). The investment of new funds in this area will contribute to develop technologies to improve the productivity, as well as health and safety conditions of the narrow vein mining industry. Several important impacts of this project will be monitored. Specifically, a database of methods and equipment used in narrow vein mining is being developed. A key thrust is to identify operators? needs with respect to the development and automation of mining methods and equipment. Based on those needs, research and development projects will be created. The main problems identified following meetings with mine operators are described with a few elements of solution and the Web site created for the broadcast of the results is presented.

Oct 1, 2001

By D. B. Felsher

"Lakeshore Gold’s Bell Creek Mill is located in Timmins, Ontario. The mill has been in operation since 2009 and has undergone several small expansions since then. In 2012 - 2013 the first major mill expansion was commissioned raising the mill capacity from 2,000tpd to 3,150tpd. This was done through the installation of a new ROM ore truck dumping facility, jaw crusher, ore storage dome, SAG mill, leach tank, CIL tank, and electrowinning cell. This paper will cover the equipment installed to raise the tonnage as well as the commissioning of the new equipment including problems encountered and how these problems were solved.IntroductionLake Shore Gold acquired the Bell Creek Mill, along with the Bell Creek Mine, from the Porcupine Gold Mines Joint Venture, a joint venture between Goldcorp Canada Ltd. and Kinross Gold Corporation, in December 2007.The Bell Creek mill, which processed ore from the Bell Creek Mine has consistently achieved recoveries of over 95%, is a conventional gold mill circuit, involving crushing and two stage ball mill grinding, gravity and leaching, followed by Carbon-In-Pulp (CIP) process for gold recovery. The facility had been placed on care and maintenance in 2002. At the beginning of 2009, the mill had been refurbished with an initial capacity of 800 tonnes per day and was subsequently refurbished to a capacity of 1,500 tonnes per day near the end of the third quarter of that year. The Mill was then expanded in 2010 to a capacity of 2,000 tonnes per day.In late 2011, the Company commenced a 50% expansion of its milling facility, from a processing capacity of 2,000 tonnes per day to 3,150 tonnes per day. Phase 1 of the expansion, which mainly involved enhancements to the solution circuit (“back end”) and increased the mill’s capacity to 2,500 tonnes per day, was completed at the end of 2012. Commissioning of Phase 2 of the expansion, to a capacity of 3,150 tonnes per day, commenced at the end of July 2013."

Jan 1, 2015

By Joseph Poplawski, Christian O’Keefe, Robert Maron

"Unique and difficult minerals processing measurement situations will be described and the application of passive array-based technology for performing these measurements will be illustrated. Examples of these situations include volume flow measurements in froth lines and flotation feed lines with entrained air, slurry lines with magnetite and other magnetic ore, slurry lines with abrasive or corrosive materials, high pressure lines, and slurry and non-slurry lines exhibiting scale buildup. Other situations include measurement of entrained air levels in pipes and in flotation columns. These measurements are achieved through CiDRA’s patented passive sonar array-based technology. This technology performs two independent measurements – flow rate and entrained air amounts. Two hardware implementations of this technology have resulted in a non-intrusive flow and entrained air meter which easily is installed on the outside of the pipe, and a submersible version for entrained air or gas holdup measurements which is used in flotation processes. Recent developments in extending this technology to solve other unique measurement problems such as valve movement confirmation will be covered.INTRODUCTIONThe minerals processing industry faces many unique and challenging process control conditions and environments. In terms of flow measurements, many of these situations are not being properly served by traditional flowmeters such as ultrasonic meters, magmeters, turbine meters, orifice plate meters, vortex flow meters, Coriolis flow meters, and venturi meters. A new class of flowmeters has been developed that solves these unique situations and flow measurement problems. This new class of flowmeter technology utilizes sonar-based processing algorithms and an array of passive sensors to measure not only flow, but also fluid composition. It does so accurately, reliably and without making contact with the fluid. These measurements are performed on practically any type of fluid within virtually any type of pipe.PRINCIPLE OF OPERATIONSonar array-based flowmeters are ideal for tracking and measuring the mean velocities of disturbances traveling in the axial direction of a pipe. These disturbances generally will convect with the flow, propagate in the pipe walls, or propagate in the fluid or slurry. First let us focus on the disturbances that convect with the flow. The disturbances that convect with the flow can be density variations, temperature variations or turbulent eddies. The overwhelming majority of industrial flows will have turbulent eddies convecting with the flow, thus providing an excellent means of measuring the flow rate as described below."

Jan 1, 2008

By Neri Roux, Chris Budgell, Allan Cramm, Leo Cheung

"Anaconda Mining Inc. is investigating potential improvements and expansions to their operating plant located on the Baie Verte Peninsula in Newfoundland. An extensive batch and continuous bench scale testing program was launched to investigate the efficiency of cyanide destruction under different conditions in order to improve tailings handling. The primary objective of the cyanide destruction study was to apply new technologies to develop a novel cyanide destruction system.Effluent and slurry from Anaconda Mining Inc.’s Point Rousse Project was received at RPC where test work was conducted. Various sodium metabisulfite (MBS) dosages were evaluated and the use of utilizing ozone and ultra violet (UV) light to oxidize cyanide was investigated. All the data was evaluated and mass balances were compiled to develop several flowsheets. Overall encouraging results were found using a combination of ozone and MBS.IntroductionAnaconda Mining Inc.’s Point Rousse project includes an operating gold processing plant located on the Baie Verte Peninsula in Newfoundland which is in the process of improving and expanding. This plant comprises of milling and flotation followed by cyanide leaching in order to extract the gold. The residue from cyanide leaching is filtered by drum filters prior to being clarified for the Merrill-Crowe process. Once the gold has been recovered by the Merrill-Crowe process the effluent is filtered by filter presses and the resulting filtrate as well as the solids from the drum filters are detoxified prior to being pumped to the tailings pond along with the flotation tailings.The entire process is very dependent upon the efficient destruction of cyanide in the effluents and successful tailings handling. Substantial amounts of effluent are delivered to tailings ponds after gold extraction which could create environmental problems if the regulations are not met. Environmental regulations stipulate that final effluents contain no more than 1 mg/L Total CN.The detoxified tailings of the Point Rousse project are produced by the INCO SO2-Air circuit depicted in Figure 1. These detox tailings contain 10 mg/L Total CN at that point of the circuit and this was selected as the target to be matched while reducing overall MBS consumption rates from 3.2 g/L per minute. Prior to detoxification, the filter press tailings contain 520 mg/L Total CN while the drum tailings contain 29 mg/L Total CN."

Jan 1, 2017

By Bernard Dallaire, Jean Cayouette, Sylvain Duchesne

"Louvicourt Mine's concentrator, located near Val d'Or, Quebec, treats an average of 4,300 tonnes of ore per day composed mainly of copper, zinc, gold and silver. An analysis of concentrator revenues and metallurgical losses shows a potential for additional gain, particularly in regards to precious metals (kustelite) where recovery is usually around 67 -70 %. The planning, installation and trial operational period of two Outokumpu SK-240 flash cells at the underflow of the primary cyclones took two years. The use of (( flash flotation )) technology has made it possible to exploit the favourable conditions at the underflow of the primary cyclones such as precious metal concentration and the presence of liberated coarse chalcopyrite. These conditions permit early flotation (fresh surfaces) of the kustelite and the liberated copper. Since the start-up of the flash cells, the metallurgical gains have turned out to be very positive with increases in metal recovery reflected in appreciable NSR gains. Also, significant savings in reagent consumption and a coarser copper concentrate have made it possible to reduce the drying cycle of the Larox filter presses since the cells were put into operation.BACKGROUNDLouvicourt Mine is operated by Aur Resources Inc. (30% ownership) on behalf of its partners Novicourt Inc. (45%, subsidiary of Noranda Inc.) and Teck Corp. (25%). The mine is located in northwestern Quebec about 600 km north of Montreal and about 25 km east of the mining town of Val d'Or. The mine commenced commercial production in July 1994.The massive sulphide ore deposit lies at depths varying between 450 m and 900 m. Mining reserves (2% Cu equi. cut-off) as of Jan. Is', 2000 are estimated at 7.5 million tonnes of ore averaging 3.4% Cu, 1.8% Zn, 28.0 g/t Ag and 0.9 g/t Au. Delineated ore reserves permit the use of a mechanized transverse blasthole mining method. The extraction order is a typical 1.3.5 mining sequence. Primary and secondary stopes are 15 m wide, 15 to 70 m long (25 m long average) and 30 m high. Backfilling for pillar recovery and regional stability is required."

Jan 1, 2001

By Edward I. Renouard

"THE mineral industry is constantly undergoing changes and facing challenges, and today we are in the midst of another serious one -namely, manpower requirement at every level in the mines, shops and plants. In the not too distant past we had a situation where labour was plentiful, although the equipment, by present-day standards, was quite inadequate, and that's easily understandable when you look back at the primitive methods by which our Western mines were first developed and operated, and then improved by the inventiveness and ingenuity of man.I'd like to show you a few slides from drawings made by Buck O'-Donnell which illustrate some of yesterday's methods of mining. Some of you probably had first-hand experience with some of these so you know they were tedious, time-consuming and involved a lot of heavy labour.Taking the Anaconda Company operations at Butte as an example, we can see what has happened in just the past ten years. In August of 1956, the Butte mines had 5,516 day's-pay employees and 976 salaried employees, for a total payroll of 6,492. In August of this year, there were 3,645 day's-pay employees and 605 on the salaried roll, for a total of 4,250. The number of contract miners had gone from 1,347 in 1956 to 606 in 1966 and that of other underground miners from 2,893 ten years ago to 1,149 this year. Along with these changes, however, another change of special significance has taken place, and that is in the number of skilled craftsmen, surface engineers and so on required for our operations. In 1966, we had 1,890 of these people, 600 more than in 1956 and nearly three times as many as just twenty years ago."

Jan 1, 1967

By Frederic M. Langevin

?? Introduction ?? LaRonde ?? History of Seismicity and Rockbursting ?? November 27th 2002 Rockburst ?? April 1st 2006 Rockburst ?? December 11th 2006 & January 11th 2007 Rockbursts ?? Seismic Risk Management Plan ?? Conclusions ?? Located in Northwestern Quebec (Can.) ?? In operation since 1988 ?? Reserves at Shafts #1 and #2 depleted ?? Production now comes entirely from Penna Shaft ?? Deepest single-lift shaft in the western hemisphere (2240 metres) ?? 7300+ tonnes per day ?? 2007 Reserves (proven & probable): ?? By-products: Ag, Cu, Zn ?? Sinking #4 Shaft (LaRonde II winze)

Feb 1, 2008

By M. Nagamori, A. J. Plumpton

"Commercial HCl-leaching of magnesite and serpentine yields highly concentrated aqueous solutions containing 25 mass % to 33 mass % MgCl2. The partial molar enthalpies and heat capacities, the ionic activities of Mg2+ and Cl–, and the Raoultian activity of H2O have been assessed for the concentrated MgCl2-H2O solutions at temperatures of 348 to 373 K. These thermodynamic data are used to calculate the pH of aqueous MgCl2 solutions saturated with a Mg-bearing mineral such as magnesite, serpentine, brucite, forsterite, enstatite or talc. On the basis of these thermodynamic data, technico-economic aspects are discussed as to neutralization with pulverized MgCO3, water evaporation from the MgCl2 solutions, and ore composition including such minor constituents as CaCO3, FeCO3 and Fe3O4. IntroductionA major magnesium electrolytic reduction plant operates in Quebec, where another will begin its production in the year 2000. One uses imported magnesite ore as raw material, while the other will utilize local asbestos tailings (serpentine). Both processes produce a concentrated salt solution of 25 mass % to 33 mass % MgCl2 by leaching the ore with concentrated hydrochloric acid. Thus, the two processes differ mainly in the HCl-leach and related operations. After the HCl-leach of the ore, the serpentine process yields about 25 times more wet cake to filter and wash than the magnesite counterpart. A comparative cost-engineering study with respect to slurry filtration and cake washing has been published elsewhere (Blackburn and Nagamori, 1994). By contrast, the present study considers the thermodynamics and technicoeconomics of the HCl-leach itself for both ores."

Jan 1, 1999

By Dayang Datu Khalil, Charle Amoah, Fred Kock

Abosso Goldfields Limited has been optimizing the comminution circuit at the Damang Mine Operation for the treatment of 100% primary ore. The optimization process started at a base rate of 343 tph when treating primary crushed primary ore, and was increased to above 600 tph with partially crushed primary ore. Abosso Goldfields engaged Orway Mineral Consultants (OMC) to assist with the optimization process in 2009 and the two companies have been working together since, to further refine the process. Continuous improvement was achieved through crushing circuit modifications, changes in operating processes and grinding control system utilization. This paper discusses the improvements developed for the increase in milling capacity and improvements in final product size.

Jan 1, 2012

By G. Bellefleur, K. Stevens, E. Adam, D. Synder, G. Perron, C. Müller

The Downhole Seismic Imaging consortium was initiated by the Geological Survey of Canada and three Canadian mining companies to assess the usefulness of borehole seismic techniques for the exploration of massive sulphide deposits within areas of steeply dipping stratigraphy. Field tests were conducted over two sub-economic massive sulphide deposits located in Norman West, Ontario, and Halfmile Lake, New Brunswick, using various shot configurations and a three-component borehole receiver array. The Norman West deposit, or structures associated with the deposit, produce detectable seismic reflections as far away as 1500 m. However, these reflections are difficult to distinguish from fault reflections and lithological contacts near the base of the Sudbury Igneous Complex. At Halfmile Lake, the rock properties are favourable for direct orebody detection. The Halfmile Lake deposit has a clear but relatively complex seismic signature on the downhole data, showing not only P-wave reflections, but also strong reflected S-waves and modeconverted waves. Such prominent S-waves and converted waves have not been recognized previously in borehole or surface seismic data acquired over massive sulphide deposits. These waves add complexity to the interpretation but provide additional imaging capabilities. Reflected S-waves and converted waves should be considered when designing seismic surveys for mineral exploration.

Jan 1, 2004

By Janos de Warga

"After a short introduction to the history of the semi-conductor theory, the paper describes the principles of electron and hole flow in the semiconducting materials, the operation of the PN junction, and the rectification process in multi-layer devices (diodes and SCR's). The various methods of purification and zone-refining of the silicon are illustrated prior to the discussion on the most commonly used junction-forming processes (alloying, diffusing, etc.). Modern device fabrication and packaging operations are illustrated. Factory testing, evaluation, electrical parameters and guaranteed rating characteristics are listed. It is explained in this paper how the various device parameters affect the electrical performance of the finished unit and how the finished unit characteristics (turn-on, turn-off time, etc.) will influence the equipment rating. In concluding, some typical items of equipment are highlighted, and the applications of these semiconductor rectifiers in the chemical, mining, pulp and paper, and steel industries, etc., are dealt with."

Jan 1, 1967

By Mark Fernald, Christian O’Keefe, John Viega

"In this presentation, the SONARtrac™ technology platform will be described. CiDRA's proprietary clamp-on, passive sonar array-based flow meter technology performs two independent measurements – flow rate and fluid characterization. Firstly, the meter provides the volumetric flow rate of the mixture by measuring the speed at which naturally occurring turbulent structures convect with the flow past an axial array of sensors. Secondly, the meter uses similar sonar-based processing techniques and naturally occurring sound in the process fluid to measure entrained air levels. The result is a unique ability to measure the flow rate and entrained air level of most fluids – clean liquids, high solids content slurries, and liquids and slurries with entrained air.Also to be presented is the application of the sonar-based technology platform in a variety of oil sands processes, hydrotransport, and minerals beneficiation applications. In particular, difficult slurry flow measurement and control in the areas of comminution and flotation such as mill discharge, hydrocyclone feed/overflow, final concentrate, thickener discharge, and tailings will be discussed. In addition new real time maintenance free process measurement capability will be presented in the areas of entrained air in slurry, collection zone gas holdup (?g), and slurry velocity profiling. The operational advantages and value of these measurements, even in the presence of scale buildup, will be discussed.INTRODUCTIONFlow measurements in the mineral processing and oil sands industry suffer from the limitations placed by previously available flowmeters including the commonly used instruments such as ultrasonic meters, magmeters, turbine meters, orifice plate meters, vortex flow meters, Coriolis flow meters, and venturi meters. The desire or requirement to make a non-contact measurement that is accurate and robust, and can be performed on practically any type of fluid within practically any type of pipe has driven the creation of a new class of flowmeters. This new class of flowmeter technology utilizes sonar-based processing algorithms and an array of passive sensors to measure not only flow, but also fluid composition."

Jan 1, 2007

By W. J. Farley

Location and History The Sherritt Gordon mine is in northern Manitoba, one hundred miles north of The Pas and forty miles northeast of Flin Flon. The original discovery was made by a Cree indian, Philip Sherlett, in 1922. The claims lapsed in 1924 to be re-staked and optioned by various mining groups who carried out a certain amount of development work before relinquishing their options. In 1927 the present Company, Sherritt Gordon Mines, Limited, was formed to take over the property. Production commenced in 1931, but in the following year operations were suspended and it was not until 1937 that the prevailing price of copper pemitted resumption as an economic operation. The mine has operated continuously from that time to the present. Total production to the end of 1947 has been: Copper . . . . . . . . . 301,813 . .,345 pounds Zinc . . . . . . . . . . . 112,636 tons of concentrat (50% zinc) Gold . . . . . . . . . . 83,070 ounces Silver . . . . . . . . . 2,651,317 ounces General Geology The consolidated rocks in the vicinity of the mine, all of Precambrian age, are a series of gneisses and form a part of a great area of what are known as the Kisseynew gneisses. The Sherritt is the only known economic base-metal deposit to occur within the Kisseynew series. Extreme metamorphism has produced recrystallization that has imparted a decided igneous-like texture to many of the units. However, the gneisses are predominantly of sedimentary original although the most basic member, a hornblendegarnet gneiss, is considered to be an altered basic flow. Figure 1 illustrates the intricately folded structure and the succession of roe types. The footwall enclosing members are of sedimentary origin and represent quartzite and arkosic and greywacke derivatives. The contact footwall member is gneissic quartzite, a medium to coarse grained rock composed mainly of quartz with minor altered feldspar (orthoclase and plagioclase), muscovite, chloritized biotite, and magnetite. Most phases of this unit show varying degrees of granitization.

Jan 1, 1949

By Harold L. Gibson, Don H. Rousell, Ian R. Jonasson

"Abstract - The Sudbury Structure consists of three major components: 1) the Sudbury Basin; 2) the Sudbury Igneous Complex which surrounds the basin as an elliptical collar; and 3) an outer zone of shatter-coned and intensely brecciated footwall rocks. Although the Sudbury Event which formed the structure may be unique, the area has, in fact, been shaped by a series of tectonic, magmatic and mineralization events which can be considered in terms of two Wilson cycles of continental extension and closure. The first cycle, from 2500 to 1700 Ma, included the following events: doming (uplift of Levack Gneiss Complex); NE-SW extension (Matachewan dikes); N-S to NW-SE rifting (faults, mafic intrusions, sedimentation, and Ni-Cu-PGE and U mineralization); NW-SE extension (Nipissing diabase, and Ni-Cu-PGE, Ag, Co mineralization); and NW-SE and NE-SW closure (Penokean Orogeny, 1900 to 1700 Ma) with superimposed meteorite impact (1850 Ma, Ni-Cu- PGE, Zn-Cu-Pb deposits). The second cycle, from 1700 to 1000 Ma, included: N-S extension (alkali metasomatism, Au); N-S extension (hornblende diabase dikes along the Murray fault set); NNESSW extension (olivine diabase dikes); NE-SW extension (Fecunis Lake fault set); and NW-SE closure (Grenvillian Orogeny).The rich and diverse Ni-Cu-PGE and subordinate Zn-Pb-Cu and Au mineralization of the Sudbury region is related to endogenic and impact-triggered crustal extension and magmatism. The Sudbury Structure apparently was the site of a triple junction or hot-spot. The Sudbury ores, although located within an impact structure, are analogous in terms of age and tectonic setting to Ni-Cu-PGE and Zn-Pb-Cu ores elsewhere in the world. Meteorite impact accentuated on-going ore forming processes and magmatism at Sudbury."

Jan 1, 1997

By Harold L. Gibson, Don H. Rousell, Ian R. Jonasson

"The Sudbury Structure consists of three major components: 1) the Sudbury Basin; 2) the Sudbury Igneous Complex which surrounds the basin as an elliptical collar; and 3) an outer zone of shatter-coned and intensely brecciated footwall rocks. Although the Sudbury Event which formed the structure may be unique, the area has, in fact, been shaped by a series of tectonic, magmatic and mineralization events which can be considered in terms of two Wilson cycles of continental extension and closure. The first cycle, from 2500 to 1700 Ma, included the following events: doming (uplift of Levack Gneiss Complex); NE-SW extension (Matachewan dikes); N-S to NW-SE rifting (faults, mafic intrusions, sedimentation, and Ni-Cu-PGE and U mineralization); NW-SE extension (Nipissing diabase, and Ni-Cu-PGE, Ag, Co mineralization); and NW-SE and NE-SW closure (Penokean Orogeny, 1900 to 1700 Ma) with superimposed meteorite impact (1850 Ma, Ni-Cu- PGE, Zn-Cu-Pb deposits). The second cycle, from 1700 to 1000 Ma, included: N-S extension (alkali metasomatism, Au); N-S extension (hornblende diabase dikes along the Murray fault set); NNESSW extension (olivine diabase dikes); NE-SW extension (Fecunis Lake fault set); and NW-SE closure (Grenvillian Orogeny).The rich and diverse Ni-Cu-PGE and subordinate Zn-Pb-Cu and Au mineralization of the Sudbury region is related to endogenic and impact-triggered crustal extension and magmatism. The Sudbury Structure apparently was the site of a triple junction or hot-spot. The Sudbury ores, although located within an impact structure, are analogous in terms of age and tectonic setting to Ni-Cu-PGE and Zn-Pb-Cu ores elsewhere in the world. Meteorite impact accentuated on-going ore forming processes and magmatism at Sudbury."

Jan 1, 1997

By Sam Palombo, James José Varela

"Washing can be defined as the process used to eliminate or reduce the dirt (presence of fines or slimes) of one material. It is also the basic and oldest process applied to ore preparation for further concentration. This process, in combination with commnution and screening, form the so called washing plant and in many cases produce end products. This work describes the factors that influence the performance of the washing process and main washing technologies used in the mineral processing industry.The Hydro-Clean represents, since 1998, a state of the art technology in this area and is comprised of one of the most innovative solutions developed at HAVER & BOECKER. HAVER & BOECKER design and manufacture technology for mining and related industries. Today the Hydro-Clean is manufactured and sold throughout the Haver Screening Group (HSG) which is comprised of HAVER & BOECKER Maschinenfabrik Münster, HAVER & BOECKER Latinoamericana – Brazil and W.S. Tyler Canada.The Hydro-Clean is a washing technology based on utilization of high pressure water jets. To follow we will discuss how the Hydro-Clean’s different modes of operation result in several advantages related with mine waste reduction, recovery of saleable product, lower capital costs, superior washing results, less stress for the material, a wider range of application and less maintenance cost. Aside from these positive factors, its lower operation costs related to the consumption of energy and water are presented. It is important to note that the quantities, tonnages, data and management concepts presented in the paper are accurate for the time of writing and are subject to change and modification as operations progress."

Jan 1, 2009

By N. Saeidi

"For a mine section comprising 100 different stoping activities, there are ~10158 different possible stoping sequences to explore in the mine schedule optimization search and this figure is indicative of the challenge posed in maximising profitability through mine schedule optimization. Any viable excavation timetable must satisfy all conditions that will constrain feasible sequences. In general, consideration of additional constraint will tend to reduce profitability. Geomechanical constraints on mine schedules, introduced with the aim of avoiding excavation instabilities, can be established for underground mine schedule optimization processes but, currently, this is done only rather crudely; precedence relations between excavation activities (stoping or development) are encoded to produce particular stope sequence patterns (e.g. ‘chevron’ or pyramidal sequences).The work reported aimed to investigate automated processes for formulation of such geomechanical constraints. The timetable optimization approach to the problem precipitated a fresh look at time dependent, and excavation sequence dependent, deformation. Abundant evidence emerged that supported the notion that any methodology developed that failed to account for such time and sequence dependencies was itself bound to failure. Yet, it was also recognised that any deviation at all from an assumption of linear elasticity for geomechanical numerical modeling, adopted to inform geomechanical constraint formulation, would rapidly lead to impractical levels of computational effort.Thus the approach presented here represents a compromise: the elastic stress fields induced by individual mining activities are computed for each activity, independently considered within a computational domain identical to that of all other activities. These are stored in a database. Instability risk for a specific sequence of mine activities can be assessed through superimposition of stress fields drawn from the pre-computed database. Time stamps allocated to events corresponding to the excavation processes permit the conversion of the sequence of elastic stress fields into a time table of stress fields. For specific locations within the computational domain, the aggregate effect of the sequence of mine activities leads to stress-time histories having a castellated appearance, a result of the near instantaneous response of an elastic medium to the excavation perturbations. Time dependent deformation responses are crudely allowed for through the re-profiling these castellated histories through graphical construction of curved responses, where the curve gradients are related to a viscous parameter. Such curves form the basis for a geomechanical constraint formulation to be adopted for mine schedule optimization."

Jan 1, 2015