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By Donald Leroux, Colin Hardie

"New or improved mathematical models of mineral processing machines are published almost on a monthly basis. Often, these models can be calibrated from bench-scale test results and programmed using spreadsheet software to simulate different designs and operating conditions in open-circuit configuration. However, since mineral processing plants frequently operate comminution, separation and/or extraction machines in closed-circuit configurations, open-circuit simulations often have limited applicability.The simulation of closed-circuit configurations necessitates the programming of an iterative loop to bring the circuit to equilibrium. This can be done by using spreadsheet software but often requires advanced programming skills. As an alternative, LIMN® software, which simplifies the programming of closed-circuit configurations within spreadsheets can be used. This software was specifically designed to turn a Microsoft EXCEL® spreadsheet into a closed-circuit modeling and simulation platform with minimal programming.During the past few years, the Mineral Processing Group at the Noranda Technology Centre, has used this software for numerous projects which include the simulation of multi-stage cyclone circuits, closed-circuit regrinding and locked-cycle flotation tests. Using these projects as examples, the flexibility and the easy to use nature of the LIMN® software is demonstrated.INTRODUCTIONMineral processing engineers routinely have to make predictions regarding comminution and separation processes. Predicting the appropriate dimensions of equipment and the process response to changes in operating mode are probably the most common situations that they face. In all cases these predictions are expected to be rapid and accurate.Predictions made by engineers are frequently based on mathematical models. Many first principles, empirical, semi-empirical, steady state and dynamic models of mineral processes can be found in the literature. In fact, new or improved mineral processing models are continuously being proposed and in spite of this variety, process engineers often have to either develop their own or tailor existing models to suit their particular needs."

Jan 1, 2003

By J. Dong

"Xanthate is a sulfide collector that has been widely used in flotation for almost a century. It is inexpensive, easy to synthesize and apply, and produces good metallurgy in the right applications. However, a major drawback of xanthate is that it decomposes easily and generates CS2 gas in transportation, storage and operation, which can be harmful to human health. Also, excessive xanthate in tailings pond leads to toxicity of the process water and potential damages to aqua-life systems. New regulations in Ontario require that the TWA (time-weighted-average) value of CS2 in the work place is below 1 ppm, which is 1/10 of the previous limit. The stringent regulation may eventually sweep other regions of Canada with the increased awareness of healthy working conditions and environment protection. Therefore, it becomes very important to find xanthate replacements which will be “green”, i.e., environmentally friendly.In this research work, a systematic procedure is used for collector evaluation using the Sudbury nickel sulfide ores from Vale’s Ontario operations, starting with the collector properties (MSDS) evaluation, followed by batch flotation tests, miniplant tests, plant trials and economic evaluation. It is found that the most promising xanthate replacement is dithiocarbamate.INTRODUCTIONSulfide mineral flotation has been practiced since the early 20th century. Its industrial importance is well recognized as mineral concentrates from flotation can be economically smelted and refined to provide primary metals. Collectors play a vital role in froth flotation. There are reagents possessing both a polar group that binds them to the mineral surface and a nonpolar group that is oriented away from the surface to attach air bubbles. The introduction of xanthate as a sulfide collector in 1925 was a remarkable development in froth flotation (Keller, 1925). It is low cost, easy to synthesize, water soluble, simple to control in application. Most importantly, it has strong capability and usually good selectivity for sulfide mineral flotation, which have been keeping its application prominent for almost a century."

Jan 1, 2011

By S. W. Stogran

"A brief summary of the environmental testing and analyses required to ensure and maintain compliance of mining properties will be discussed. Programs for new and existing properties and for properties which may be purchased will be outlined and potential solutions to problems will be discussed. In addition to the compliance aspects of operations, due diligence will be discussed.1.0 INTRODUCTIONThe impact of mining projects on the environment is an area of major concern to the public, governmental agencies and mining companies. Due to the ever increasing pressure on the government by special interest groups and the public, governments have implemented legislation to control potential environmental impact of mining, from the exploration phase through to close-out. By not planning for environmental issues during all phases of a mining operation, unavoidable delays and retrofitted environmental programmes will be expensive and cause projects to be delayed, which, ultimately, may cause the abandonment of a mining prospect. Most jurisdictions require at least one full year of background environmental data. Therefore, many thousands of dollars are wasted as construction is interfered with or held up due to data collection. This may be avoided by a thousand dollars worth of sample being collected and analyzed early in the project."

Jan 1, 1992

By Mike Sapiro

"Heath Steele Mines is a base metal producer situated near Newcastle, N.B. presently treating 3500 TPD of complex Cu-Pb-Zn ore. The ore consists of massive fine grained sulfides averaging I. 1% Cu, 1.6% Pb and 4.5% Zn.The original mill started in 1956 at 750 TPD and was successively expanded through 1500 to 3000 TPD in 1969. In 1972 an expansion to 4000 TPD was initiated. It was planned to obtain the maximum benefit from equipment and manpower by adding some process equipment, instrumentation, an on stream analyser, and a process control system. The benefits from this approach could be greater than normally expected, because of the complex metallurgy of this ore.IntroductionThe crushing plant is of conventional design with two 5 ½ ft, Symons cone crushers with the crushed ore screened to -7/8 inch on a 61 x 16 1 Al I is Chalmers vibrating screen and stored in four 1000 Ion bins. There are two para I lei grinding circuits, each one consisting of the following: one Rod Mill in open circuit, one Ball Mill in closed circuit with two 20"" Krebs cyclones, and one Ball Mill in closed circuit with three 15"" Krebs cyclones, Al I the Mills are 9' x 121 Al I is Chalmers Mills. The secondary cyclone overflow from each grinding circuit is thickened and combined to form flotation feed. The final product is 65% - 400 Mesh. Two regrind mills have been installed as part of the expansion."

Jan 1, 1977

By B. K. Gorain, A. W. Stradling

"The traditional metallurgical scale-up techniques for flotation plants are based on lumped flotation rate constants, dimensionless hydrodynamic numbers and the use of safety factors. Once the plant has been designed, the flotation principles that govern scale-up play almost no role in the optimization of the circuit to meet its metallurgical targets. This deficiency can potentially lead to a plant design incapable of meeting its targets, especially when circuits incorporate large flotation cells. This paper demonstrates the application of the k = PSbRf model in providing a suitable framework for flotation modelling, scale-up and circuit optimization, thus presenting an integrated approach to the problem. Studies were conducted at Teck Cominco’s Red Dog concentrator to characterize cell hydrodynamics, gas dispersion properties, froth flow behaviour, entrainment and ore floatability to obtain the key data necessary to develop a model for the flotation circuit. The findings of these studies are presented in this paper, which provide valuable insights into the modelling and optimization of the Red Dog flotation circuit. IntroductionThe traditional methodology for flotation scale-up and plant design is based on the ruleof- thumb with safety factors and dimensionless hydrodynamic group similitude considerations. With the recent trend toward larger flotation cells with volumes of 150 m3 and greater in concentrators, the problem of scale-up has become even more acute. The scale-up factors that may have been tolerated on smaller cells are not applicable to larger cells. The transportation of froth in these large cells adds further complexity to the problem. Arbiter et al. (1980) foresaw this problem and pointed out that if scale-up were attempted by rule-ofthumb and trial-and-error, the probability of failure would then increase with scale. This problem is confounded by the fact that the design and scale-up considerations used for a new flotation circuit play almost no role in optimization of the circuit to meet its metallurgical target. This results in a plant design, which may be incapable of meeting its metallurgical targets. There have been several instances where new concentrators have required significant circuit modifications and additional capacity to achieve design targets."

Jan 1, 2003

By J. B. Boisvert, P. Oshust

A significant source of uncertainty in the diamond resource contained in kimberlite pipes is the volume of the pipes. Often the material within a pipe will be mined as ore, leaving the actual geometry of the pipe as a significant source of uncertainty. It is desirable to use stochastic techniques, rather than deterministic methods, to model pipe geometry because stochastic techniques generate multiple realizations that are reproducible and can be used to assess uncertainty in pipe geometry. The proposed methodology uses sequential Gaussian simulation of pierce point locations interpreted from drillholes through a kimberlite pipe. Kimberlite pipes are approximately cylindrical in shape; therefore, the data are transformed to cylindrical coordinates to facilitate the simulation of pipe geometry. Rather than using xyz coordinates to define the pierce points, z, ??and pipe radius are used. The radius variable can be simulated in z-??space to generate multiple realizations of pipe volume. Uncertainty in the volume of the pipe can then be evaluated. This methodology is demonstrated with a kimberlite pipe at BHP Billiton’s Ekati diamond mine.

Jan 1, 2008

By Dave Price

"Canada is scheduled to become the 4th highest diamond revenue producing country in the world by year 2004 with the already operating Ekati Mine and the anticipated operation of the Jericho Mine in 2002 and the Diavik Mine in 2003.This paper provides an overview of worldwide diamond production statistics and a brief introduction to a diamond processing plant. The dense medium separation (DMS) extraction process is presented and this process is discussed in more detail with respect to the extraction of diamonds in terms of feed preparation, dense medium, dense medium cyclones, ferrosilicon recovery and dense medium cyclone operating efficiencies.INTRODUCTIONThe Ekati Diamond Mine in the Northwest Territories started commercial production of diamonds in the 4* quarter of 1998. At full production, the mine is anticipated to produce annually some 3 million carats of diamonds. The Jericho Mine in Nunavut Territory and the Diavik Mine in the Northwest Territories are anticipated to come into production in the 1'' quarter of 2002 and 1st half of 2003 respectively. The combined annual diamond production of these three mines will total approximately 10.34 million carats by 2004, making Canada the 4~ highest diamond revenue producing country in the world.A diamond processing plant initially utilizes crushing, scrubbing and screening in the beneficiation process to liberate diamonds from kimberlite ore and size the product for further treatment through DMS. Alluvial diamond operations do not require initial crushing and scrubbing but incorporate a feed preparation and sometimes a recrush facility with the DMS plant. The heavy sink product from the DMS, which contains diamonds, is further upgraded through x-ray separation and high intensity magnetic separation prior to producing the final diamond product.DMS is a relatively simple separating principle. A mixture of particles of different density is immersed in a dense fluid, so that particles having a density lower than that of the fluid will float while those of heavier density will sink. The translation of the float-sink principle from a laboratory method to continuous industrial practice offers the prospect of very precise mineral separations based on density differences alone."

Jan 1, 2000

By Matthew A. Perras

With growing populations, infrastructure projects are utilizing underground space to expand transportation networks, water supply and sewer disposal systems and hydropower facilities. These new projects require large diameter tunnels to meet the growing demands. As the tunnel diameter increases, not all rock mass properties are scalable and precedent experience becomes less reliable. One such non-scaleable property is lamination thickness. Numerical modelling was conducted to determine the influence of lamination thicknesses on a 16 m diameter tunnel. Five different areas of excavation response were found to exist for laminations ranging between 0.16 to 16 metres in thickness. For this tunnel diameter, critical lamination thicknesses of 6 metre and 1 metre were found to exist. Above 6 metres the excavation response was similar to isotropic models. Below 6 metres the stresses and yield are channeled by the lamination boundaries, increasing plastic deformation. Below 1m multiple lamination units become unstable and the displacements increase significantly and the shape and extent of the yield zone size changes dramatically. The yield zone is controlled by bed deflections and bed parallel shear. As the lamination thickness decreases tensile failure first begins in the haunch area and progressively extends above the crown until a self-limiting plastic yield zone shape is reach at lamination thicknesses below 0.4 metres. Conclusions drawn from observations at the Niagara Tunnel Project are those of the authors.

May 1, 2009

By Benedetto Corain

The production and dispersion of metal nanoclusters onto inorganic supports and amorphous carbon rest on well consolidated technologies belonging to the realm of industrial catalysis and of basic catalysis research (1). In spite of the existence of a variety of specific synthetic strategies, their very rationale relies on three main approaches i. e.: A: precursors of both the metal nanoparticles and of the relevant supports (or the support itself) are intimately mixed (even let to react) at ambient conditions and then thermo-reduced according to very controlled protocols (2); B: precursors of metal nanoclusters are let to be adsorbed onto suitable supports from the gas or liquid phase and subsequently thermally decomposed (3); C: metastable size-controlled metal nanoclusters are previously generated in a liquid medium and subsequently transferred onto pre-formed support particles (4). The production and dispersion of metal nanoclusters onto organic soluble supports is also a rather well documented academic praxis (5, 6, 7, 8) able to provide e.g. size-controlled Au0 nanoclusters of 4.4±1.7 nm (5). Our group started in 1997 developing (9) an innovative approach to the synthesis of metal nanoclusters dispersed inside insoluble, albeit accessible (see below) mechanically robust gel-type resins (10), which procedure was tested so far on palladium metal. Metal ions are previously dispersed upon ion-exchange inside of the polymer framework, followed by chemical reduction and by the aggregation of born metal atoms into nanoclusters, the size of which is templated (11, 12) by the three-dimensional intercommunicating meshes that build up the overall polymer framework (Figure 1).

Oct 1, 2003

By Glenn Clarke, Ben Holloway, Barry Lumsden

"BHP-Billiton’s Cannington mine in Northwest Queensland produces a silver-rich lead concentrate and a zinc concentrate. The plant has the capacity to treat 3.1 mta and for the year to June 2006 mean feed grade was 10.3% Pb, 461 g/t Ag and 3.7% Zn. Recovery losses of lead and silver are primarily in the fine fractions. In 2001, the plant was modified when it was determined that splitting the lead feed into two size fractions, and floating the two fractions separately increased fine lead and silver recovery. The fine lead fraction (called the split float) is 80% <16µm and about a quarter of the lead and silver is in the finest fractions. In 2006 to further improve lead and silver recovery a statistical plant trial of magnetic aggregation conditioning of the split float feed was undertaken. While pure galena is diamagnetic the Cannington galena contains iron within the galena mineral resulting in the galena having a paramagnetic, magnetic susceptibility. The trial demonstrated to greater than 98% statistical significance an increase in lead recovery, and to 99% statistical significance an increase in silver recovery, and to greater than 97% significance an increase in the lead in concentrate in the split float circuit. These economic recovery benefits with magnetic aggregation of the split float feed, has led to the incorporation of this technology in the plant.INTRODUCTIONThe BHP-Billiton owned Cannington silver, lead and zinc mine is located in the Australian state of Queensland about 800 kilometres west of the coastal city of Townsville. This is a pastoral area characterised by large cattle farms, low population density and very little infrastructure. The area has two seasons, a wet, hot summer and a dry, mild winter. Because of its isolation and lack of infrastructure the mine has always operated on a fly in fly out basis.Geological drilling defined the resource as 43.8 million tonnes grading 11.6% lead, 4.4% zinc and 538 ppm silver (Walters and Bailey, 1998). At times during its history Cannington has held the crown as the single largest lead and silver mine in the world (Torrisi and Smith 2003). Another unique characteristic of the operation’s history is the rapid progress from discovery to operation. The first drill to intersect the ore body was in 1990 and the mine and plant was commissioned in 1997."

Jan 1, 2008

"Air Products approached LAC Minerals in 1987 to initiate trials with pure oxygen in the leach circuit at several LAC facilities in Canada. This paper gives an overview of oxygen use and covers specific operating data from the Doyon and Terrains Aurifères mills near Val D'Or in northwestern Quebec. LAC also uses oxygen at the Macassa mill in Kirkland Lake, Ontario.In addition to the LAC facilities, oxygen is currently in use for test purposes at the Holt McDermott mine in Kirkland Lake, Ontario and the Camflo mine near Val D'Or.There are two requirements for oxygen in the cyanide leach mill. Firstly, oxygen is required in the familiar gold dissolution reaction as follows:(1) 4 AU (s) + 8 NaCN (aq) + 02 (aq)+ 2H 20(aq) - 4NaAu(CN) 2(aq)+ 4Na OH(aq)Of the reagents on the left side of the equation, the availability of gold is fixed by the ore in question. Obviously, water is available in excess, 1eaving cyanide and oxygen as the limiting constituents in the process. Most mills operate with an excess of cyanide, which is fairly closely monitored. Dissolved oxygen levels, however, are not normally watched very closely and find their own level based on the temperature, the availability of compressed air and the ability of the ore to consume oxygen.Typical D.O. levels are in the 3-8 ppm range, however levels less than 1 ppm are not uncommon for refractory ores.With pure oxygen, dissolved oxygen levels as high as 30 ppm can be achieved. (Figure #1). This greatly accelerates the kinetics of the leach reaction and may also shift the reaction further towards completion thus increasing gold dissolution slightly."

Jan 1, 1990

Taking Up the AFN Corporate Challenge ?? About MAC ?? ?Towards Sustainable Mining? ??Mining and Aboriginal Peoples Framework ?? AFN-MAC Relationship ?? A New MAC Northern Initiative ??Social and Economic Progress ?? A View to the Future?

May 1, 2009

By René Lefebvre

Numerical simulations of the physicochemical processes related to acid rock drainage (ARD) in the Sugar Shack South rock pile of the Questa Mine were performed with the TOUGH AMD simulator. The objectives were to 1) identify the main processes responsible for observed present-day conditions, 2) provide an estimate of gas phase humidity transfer, and 3) give a preliminary indication of the potential impact of closure involving the installation of an alluvial soil cover. Modeling results indicated that the mine rock geometry (thin layers placed along steep mountain slopes) favors the onset of strong thermal air convection. Simulations also indicate that resloping the piles would not significantly reduce convection and oxidation. For simulation purposes, a potential cover with the permeability range of a local alluvium was investigated and found to be of questionable effectiveness since its permeability can exceed the value of 3x10-13 m2 required to prevent thermal air convection and reduce ARD.

Nov 1, 2002

By F. C. Lendrum

"This paper had its origin in a panel discussion organized by the Canadian Uranium Producers Metallurgical Committee (CUPMC) at their Annual Meeting in Blind River in May, 1964. The reason for the panel was the formation of the National Uranium Tailings Research Program funded in the amount of ten million dollars by the Federal government. According to the bureaucrats in charge the program would seek to solve the perceived problems as well as any actual problems they believed existed with uranium tailings. Dr. Allan Ashbrook of Eldorado Nuclear chaired this panel and his summation of the panel's purpose was set out as ""Regulation and the Regulatory Process in the Nuclear Industry, Where Have We Been, Where Are We Now and Where Are We Going""?"" This paper will try to relate these questions to the whole mineral industry.The Canadian Mining Association has been telling us our natural resources are today required only if they are competitively priced with those produced in so called ""third world"" countries where labour rates are lower, environmental restrictions may be less and every effort is made by the local government to sell their product. It is in this hostile economic climate that the Canadian mining industry now finds itself. Before going further I want to stress these comments apply only to: a) Mines financed by private capital in a free enterprise society.b) Mining companies want to operate in an environmentally safe manner. However, they must earn a profit because no company financed with private capital can borrow money ad infinitum.WHERE HAVE WE BEENNone of us today would want to return to the days when the mill waste management system consisted of pumping the tailing to the nearest slope and letting nature's law of gravity do the rest. This was the way it was in early gold mines in Nova Scotia, tin mines in Cornwall, England or silver mines in Cobalt, Ontario and survives today in countries where climate, customs and methods of doing business are far different from Canada. As mill tonnage rates increased, more sophisticated systems evolved often designed for mining areas with different climates. Systems imported from arid climates such as south-west United States retained the solids but allowed bacterial oxidation of the sulphides promoting acid drainage. Environmental regulations were introduced and Canadian mines learned to handle tailings in our climates."

Jan 1, 1986

By A. Himsley

"There is an ever-increasing demand these days for efficient methods of removing metals from solutions especially for selectively recovering a particular metal from a mixture of metals in solution.Up until the mid l 930's the only methods widely practiced for such separations involved precipitation techniques or electrolysis. Both these methods have limitations and indeed can only be used for certain metals.It is only within the last 40 years or so when synthetic ion exchange materials became available that chemists in industry and universities have been able to apply ion exchange techniques to a wide variety of separations that not only would be impossible by precipitation methods but which are now achieved with much greater efficiency.Ion Exchange TechniquesIon exchange is a unit process that can be applied using either liquid ion exchangers or solid resin particles. Liquid ion exchange - or solvent extraction as it is often referred to - is used in a number of special areas dictated mainly by the nature of the separation.On the other hand, ion exchange resins are much more widely used and consequently a great deal more is known about their application to a variety of metal separations.In both systems there is a loss of the ion exchange material which in the case of solvent extraction results in hydrocarbons going to waste. The ion exchange resin systems lose resin in the form of small particles, referred to as ""resin fines"", and these are insoluble.The loss of liquid ion exchanger is due to the fact that it is slightly soluble in water and consequently the loss is a function of the volume of liquid with which it comes into contact and is not related to the amount of metal processed."

Jan 1, 1975

By Alain Dorval

"''Purification of marine sands from Les Iles-de-la-Madeleine''This paper presents the results of the work that has been done at CRM pilot plant for «Les Silices du Golfe Inc.». Essentially the purpose of this piloting was to demonstrate, on a semi-industrial scale, the process of purification of marine sands from Les Iles-de-la-Madeleine; that had been developed by CRM Process Development Service. This purification is necessary to produce silica suitable for the glass sand and the foundry sand markets.Introduction«Les Silices du Golfe Inc.» is a company who intends to dredge marine sands around the «Les Iles-de-la-Madeleine» coasts. The material will be transported to Gaspesia where electricity, water supply, and a convenient site is available to treat it. A high purity silica intended for glass sand and foundry sand markets will be produced. The objectives of this purification process are to remove organics, calcium, feldspars and iron.Material ReceivedCRM received 50 tons of sand with Si02 varying between 80,6 and 99,3 % (see Figure.1). The highest variations in impurities were the calcium and lost on ignition. We notice direct relation between% SiO2, % CaO and % L.O.I. as you can see on the following Figures 2, 3 and 4."

Jan 1, 1994

By Joe Pease

"The demand for minerals and metals is increasing. Head grades of ore bodies are dropping. Remaining ores are becoming finer grained, more complex, and more logistically challenging. Mineral processing – in particular comminution – already consumes a huge amount of energy. But in 20 years’ time, it will require about six times as much energy as today to meet the world’s mineral demand.Unless we do something different.As minerals professionals, it is our job to find that “something different”. The world is relying on us. Of course, we must look for new breakthrough technologies and techniques. We must find them, and we will find them – most likely in surprising areas.But what if we also already know how to make 30-50% improvements to efficiency? Just by using existing technologies, by applying modern analytical techniques, by custom designing our plants, by applying manufacturing principles, by breaking down our management silos between disciplines.The thing is, industry professionals already know this. Yet – in spite of a lot of intelligent people trying very hard – we just can’t seem to make it happen.This discussion considers why, despite our best efforts, we don’t get the best out of what we already have. Why we are wasting energy and money. Once we understand why, we can set about unlocking that value and improving industry productivity and energy efficiency. We will discuss the role that professionals and volunteer professional organisations like CMP and CEEC can play in catalysing the changes."

Jan 1, 2015

By A. G. Doll

"Multi-stage crushing plants, including high pressure grinding roll (HPGR) circuits, require more materials handling equipment than SAG and ball mill circuits. A temptation exists to neglect the energy consumption of materials handling when doing desktop comparisons of HPGR versus SAG milling circuits because estimation of materials handling power requirements can demand significant general arrangement drafting that is not available when performing preliminary scoping or ""desktop"" studies.The largest component of materials handling power is consumed by conveyors when lifting material between stages of crushing, meaning that a simple potential energy model can be used to evaluate conveying specific power consumption. This potential energy consumption for conveying can then be factored to provide overall materials handling specific energy consumption suitable for desktop studies of HPGR and other multi-stage crushing circuits. The technique also permits different crushing circuit flowsheets to be evaluated, at a preliminary level, by simply counting the number of times a conveyor must ""lift"" ore from ground level up to a bin or other equipment mounted up high.INTRODUCTIONTrade-off studies of multi-stage crushing plants involving high pressure grinding rolls (HPGRs) versus semi-autogenous grinding (SAG) mill circuits typically focus on the operating cost savings of crushing plants versus the capital cost savings of SAG mill plants. Very high-level (or desktop) studies of this type do not include a great deal of engineering work, meaning that the details (and costs) of ancillary systems are often not captured when doing the comparisons. The more complicated nature of the multistage crushing plants means there are more ancillary systems than a SAG mill plant, risking a skewed analysis of the operating costs, benefiting the HPGR option.One of the ancillary systems that may be overlooked is the more complicated conveying systems inherent in multi-stage crushing plants. Due to the mass of material being handled in large mining operations, these conveyors become a significant portion of the operating costs. A simple way to estimate the specific energy consumption of conveying systems without requiring engineering drawings and a site layout would allow high-level studies to capture this operating cost."

Jan 1, 2015

By G. Major-Marothy

"INTRODUCTIONA beneficiation plant to upgrade earthy iron ores is being installed by the Iron Ore Company of Canada in Sept-Iles, Quebec.The crude ore for the plant will come from the Knob Lake area, located in Northern Quebec, where mining has been in progress since 1954.Some 170 million tons of ""direct 11 ores have been mined and shipped in the past eighteen years, with an overall silica content of 7 to 8 percent. No beneficiation - except the reduction of the top size to about 2 inches - took place during this period, but extensive research work has been carried out, in order to find a feasible process.Since “washing"", gravity separation, roasting and magnetic separation experiments did not indicate positive enough results, flotation was tried and found to be feasible.The beneficiation complex being installed will consist of grinding, flotation, dewatering - i.e.: thickening, filtering and drying - balling feed preparation, and agglomeration - i.e.: balling and induration.This process will result in a product superior to the ""direct shipping"" ores and will also expand the ore reserves by allowing material with a higher silica content to be utilized.THE OREThe Knob Lake ores are grouped by mineralogical composition and by grade.BLUE ORES, representing roughly two thirds of the reserves, carry their iron content mostly in the form of massive, blue hematite and martite.YELLOW ORES, about one sixth of the reserves, have predominantly hydrated iron oxides as the iron bearing minerals.RED ORES, the other sixth of the reserves, carry the iron mostly in the form of red hematite.The gangue in all ores is mainly quartz, but aluminum oxides and hydroxides are also present, particularly in the red ores."

Jan 1, 1972

By Cecilia Arrue, Dominic Fragomeni, N. O. Lotter

"A statistically designed benchmark mill survey was carried out in July 2005 at the Kidd Creek Concentrator, D Division circuit, which processes Ni/Cu ore from the Montcalm deposit. A structured statistical survey approach was followed, together with defined quality controls, which would assign a 95 percent level of confidence in the result.A set of six surveys were completed over a limited time; the corresponding stream samples of the surveys found acceptable were combined to obtain high confidence composite samples. The head grade of each survey is compared to two distributions to test its acceptability; surveys that fail to conform to these trials are rejected. The accepted set of surveys, which is a robust representation of the process, is prepared into a composite for QEM-SEM analysis and mass balance purposes.Where the above practice is a standard procedure in Falconbridge for QEM*SEM purposes, in this case each individual two-hour survey unit was measured and analysed for a mass and value balance. It is shown that none of the individual mass and value balances close as well as the composite set of accepted two-hour survey units. This founding is in keeping with the averaging properties of the Central Limit Theorem.INTRODUCTIONMontcalm OperationsNi/Cu bearing ore from the Montcalm deposit is being processed at the Falconbridge, Kidd Creek Concentrator in a modified D Division circuit. The circuit was commissioned in the fall of 2004. Ore is crushed at the minesite to –19 mm and trucked to Kidd for delivey into the 4 parallel fine ore bins.Ore is milled in a rod mill followed by cyclones and 2 parallel ball mills. The grinding circuit treats Montcalm ore at an average feed rate of 100 wet tonnes/hour (750,000 tonnes/annum) and produces a flotation feed particle size of 83% -53 um. A simple flowsheet including bulk Cu/Ni roughing and 2 bulk cleaning stages followed by Cu/Ni separation in 2 stages is practiced. Soda ash is used as a pH modifier in bulk flotation. SIBX is the collector. Lime and Dextrin are added into Cu/Ni separation for the depression of pentlandite."

Jan 1, 2007