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By M. P. Hay

"For a model to be successful it must address the concerns and needs of a target audience. Further, the model must demonstrate the same patterns of behaviour as the real system, and need only be complex enough to meet this objective. If the model is too complex it can become unusable to those who need it most.With this in mind, SUPASIM has been developed for the practical metallurgist requiring only laboratory flotation rate data as input. Some 35+ successful plant simulations have been completed since 1985. The approach of SUPASIM is to characterise an ore, organise information in an understandable way and add structure to the complex flotation situation and hence support the metallurgist to interpret the relationship between variables and optimise the flotation process.The paper describes the basis on which the model was developed and sets out to provide an insight into interpreting laboratory flotation kinetics and their physical meaning in a production plant and the influence floatable gangue has on float performance and plant design. A case study illustrates how the ratio of slow floating mineral to gangue can influence circuit design and improve recovery on a plant scale.INTRODUCTIONThere is an enormous amount of useful data in the results of a laboratory scale rate test. Each variable of fraction and rate, for mineral, metal and gangue has a physical meaning in the plant. The link between float kinetics and the plant in respect of recovery, grade, pulp density, pulp flowrate, residence time, number of stages of cleaning and circuit configuration has been established by the author in the process of developing SUPASIM."

Jan 1, 2005

By Matthew A. Baumann

Tooth-wear on mining shovels requires continuous monitoring. Worn teeth impede excavation performance, increase energy usage, and increase the risk of lost or broken teeth and adapters. A machine-vision-based automated tooth-wear monitoring system is presented. The system employs a rugged boom or stick-mounted camera to capture images of the shovel teeth. An onboard computer processes the images in real-time to determine the length of each tooth. The current wear state is available via a network-accessible log for on-demand status updates. By continuously recording tooth length changes over time, the logs can be used to estimate wear rates and patterns, permitting comparisons between different G.E.T. configurations, operator behaviour patterns, or material types. This detailed, quantitative data permits site-specific optimizations to wear packages and maintenance scheduling. Automating wear monitoring offers the crucial wear information necessary to minimize maintenance costs and reduce unscheduled downtime. A 37-day field trial in a copper-gold mine demonstrated the ability of the system to measure tooth lengths, compute wear rates, and detect differences in tooth wear based on their position on the bucket.

Nov 1, 2011

By J. Nesset, F. Rosenblum, P. Spira

"Sulphide concentrates may exhibit self-heating to various degrees during storage or shipping, the worst cases presenting a serious hazard from fire and SO2 emission. Based on measurements of heating rates on a wide variety of concentrate samples in a special apparatus, combined with field experience, a methodology has been developed which allows concentrates to be rated for their heating potential. This has proven to be very useful in practice, for example, in deciding on the need to take preventive measures. Oxidation under ambient conditions in the presence of moisture initiates heating locally within a stockpile. In the case of highly active materials, such as those that contain abundant pyrrhotite, heating may progress through three stages to temperatures well above 5000C. However, most concentrates show little or no propensity to selfheat. Heating rates were used to estimate values of the heat output, or self-heating capacity (in joules per gram), which sustains the process at each stage. Thermal data from differential scanning calorimetry are also reported. Variables which affect self-heating are discussed and an actual case of heating control on a stockpile by covering is described. A simple apparatus which can be used to simulate stockpiling conditions has been tested successfully and is proposed as a convenient test system.INTRODUCTIONPrevious publications from this laboratory on the evaluation of self-heating in sulphides dealt with tailings backfill (Rosenblum et al. 1982) and waste rock (Rosenblum and Spira 1995). Sulphide concentrates may likewise exhibit self-heating in storage or during shipping. In a comprehensive but dated review, Kirshenbaum (1 968) pointed out the conflicting nature of information on means of controlling the problem, particularly with regard to the application of water and ventilation. Modelling by Simpson (1 97 1) of autogenous heating in stockpiled zinclead concentrate and associated field measurements by Wright et al. (1972) showed that the supply of oxygen by wind and the shape of the piles were the major factors in the development of hot spots. Simpson did not attempt to explain the complex mechanism of self-heating, simply ascribing its onset to oxidation. Pearse (1 980) investigated a potential method of testing for selfheating which consisted of (i) reaction with hydrogen peroxide and (ii) differential thermal anal sis, to characterize the response of concentrates at both ambient and temperatures above 100 C. He found the method sensitive enough to identify the need for careful handling but not to predict ignition. He recommended compacting concentrates and covering stockpiles with plastic sheeting to prevent ingress of air. All these workers recognized the key role played by oxygen and moisture in triggering self-heating."

Jan 1, 2001

Geology grads mine heated job market Salaries up 44 per cent in three years ?[Geology student] passed up a $100,000-a-year job at a mining company last December when he finished his degree in geology. The 24-year-old Canadian said he?s confident he?ll get a better offer.? Rob Delaney and Stewart Bailey, Calgary Herald, Published: Saturday, March 15, 2008 Massive shortages across the mining industry > Trades and operators are a large component > Technical people are equally hard to find > Students are in an excellent positions to secure exciting jobs > Experience is at a premium. Why?

May 1, 2008

By J. Maheu

Heap leaching is an old technique for the recovery of copper, but a fairly new technique for the recovery of gold.The paper outlines the equipment required for the establishment of heap leaching test facilities and the procedure required to insure meaningful results. Sampling methods, the metal balance, carbon adsorption and stripping and safety procedures are discussed in broad outline.

Jan 1, 1982

By L. E. Djingheuzian

IN 1953, Lewis (1) published an article which brought forth a great amount of discussion by grinding engineers. In his contribution to discussion the present writer (2) suggested that, for the most efficient performance of a ball mill, there must be a .definite relationship between Cn, per cent critical speed, and V p, per cent mill volume occupied by the ball charge. Later, he ( 3) was able to publish some grinding data from Wright-Hargreaves milly which appeared to bear out this contention. It is with this view to establishing a fundamental relationship between Cn and Vp that the idea of this Forum was conceived. Accordingly, a questionnaire was prepared and copies of it were mailed to over eighty Canadian mill operators. This questionnaire did not include a question on dilution on the assumption that each mill operator was using the most efficient dilution for his operation, nor was a question on efficiency of classification included since it was thought that the inclusion of efficiency of dassification in the questionnaire at this preliminary stage might render the forum discussion,. while everybody was trying to find his bearings, too unwieldy. However, it is evident that, as discussions develop, this forum will have to define a uniform method for establishing most efficient classification in grinding circuits

Jan 1, 1957

By F. Hassani, K. Moozar, J. Ouellet, P. Gauthier

"This paper describes a sudden spill of waste rock used for backfilling from a waste pass at an underground mine in Canada, thus causing a major failure/accident. The mine operator immediately launched a detailed investigation to understand the causes of this accident and develop procedures to prevent any recurrence of such events in the future. The authors from McGill University were invited to collaborate with the engineers at the mine to examine this accident. The events leading to the accident were studied, appropriate measurements were taken and samples of the waste material were collected for further testing and analysis.The field visit and the interview of the witnesses allowed the detailed documentation of the events. The sequence of events related to the incident, along with the experimental results obtained in the course of the investigation, are presented. The waste material was characterized in the laboratory with regard to its behaviour in the presence of water. This information is discussed and the failure mechanism involved in the accident is identified. Finally, the full recommendations as well as the immediate operational measures implemented by the mine to prevent the future occurrence of such events are presented and discussed."

Jan 1, 2004

By Minerals Refining Company, Gerald Luttrell, Biao Li, Robert Bratton, Roe-Hoan Yoon, Stan Suboleski, Nikhil Gupta

Flotation is regarded as the best available method of upgrading coal and mineral fines in the mining industry. However, its efficiency deteriorates rapidly with decreasing particle size. Furthermore, ultrafine concentrates are difficult to be dewatered economically. Due to these technological problems, some operators are forced to discard at least part of the ultrafine materials to tailings (or refuse) ponds, causing significant losses of valuable resources and creating environmental concerns. To address these technological issues, a new separation process named hydrophobic-hydrophilic separation has been developed on the basis of the recent advances in the science of hydrophobic interactions. The results obtained to date show that the process can recover and dewater ultrafine particles simultaneously with high separation efficiencies. Following a series of extensive laboratory tests, the process has been scaled up to proof-of-concept and pilot-scale continuous tests. The results obtained with desliming cyclone overflows, screenbowl effluents, and by-zero coal flotation feeds can be cleaned to less than 4% ash and moisture with over 97% organic matter (or coal) recoveries. The results obtained with mineral fines also showed encouraging results.

Jan 1, 2016

By A. J. Ouellet, A. Coulombe, B. Salmon

The no. 7 vein system cuts the Ventures gabbro which has undergone folding and fracturing; the latter, in response to movement on the nearby Campbell Lake fault. It fills a shear fracture which pinches and swells in the upper mine levels but has a more uniform width in the lower levels. The best copper and gold grades in the upper levels occur in the widest parts of this structure. The vein is richer in quartz on upper mine levels and in carbonate on lower levels. The north wall of the vein is more affected by major and minor element wallrock alteration than the south wall. The isocumulative ci;rves for gold and copper show a direct correlation between the two metals in the upper levels and their increased concentration in the wider parts of the vein. Gold grade decreases in lower levels. A proposed structural model identifies the no. 3 and no. 7 veins as second order conjugate fractures, related to the Campbell Lake fault. The fractures pattern suggests that a conjugate system developed between these two parallel veins as a consequence of rock competence and a relatively low confining pressure.

Jan 1, 1984

By Michael Cooper, Eric Konigsmann, A. Moerman

"A paste backfill plant and underground piping distribution system was commissioned at the Brunswick Mine in June, 1998. Concentrator tailings, composed mainly of pyrite and lesser amounts of silicate minerals with a P80 of 37um (45 YO-20 pm), are pumped to the backfill plant. The backfill plant uses conventional thickening and disc filtering to dewater the solids, which are then mixed with binder in twin screw mixers. The paste is discharged through a gob hopper and one of three boreholes by gravity. Approximately 65% of the concentrator tailings will be placed underground at full production. The remaining thickened tailings will be pumped to an existing impoundment area. Application of paste technology will completely replace the use of cemented rock fill in the mine by the end of 1998.The design capacity of the paste backfill plant is a total of 360 dmtph of cemented paste through two parallel production lines. The plant is highly instrumented and controlled via a hybrid Programmable Logic Controller (PLC-5) and Fisher ProVox Distributed Control System that is in communication with the property information highway. Video and audio signals from the underground system are carried to the surface plant via a leaky feeder communications/fiber optic system.The underground distribution system consists of a network of 200mm diameter boreholes and piping. There are approximately 3.5km of boreholes and 5.5km of piping in the system. To minimize pressures, the greatest piping length from any borehole is approximately 400m with all piping being open-ended. There are no valves in the entire paste distribution system.Construction of the plant, including installation of piping to and from the plant and preparation of the underground distribution system, was completed in less than one year from the time of management approval for the $M 22.3 project."

Jan 1, 1999

By Jim Truskoski, Alain Bouchard, Andy Kerr, Germain Labonté, Jim Barrett

"Improving mill grade recovery relationships is always good business. INCO’s Clarabelle Mill has just undergone a $16 million process upgrade that was designed to improve nickel recovery by 2%. The “Mill Redesign Project” was completed on time, under budget and delivered the promised improvement in recoveries.This paper describes the methodology of the Mill Redesign Team, details of the process improvements and the critical success factors that helped the team deliver on its promises.With a payback of under one year, the Mill Redesign Project will play a key role in ensuring a competitive edge as INCO embarks on its second century of operation.INTRODUCTIONIt is not uncommon in milling operations to encounter a crisis. That is the point when the process does not behave as expected and fails to respond to the increasingly desperate efforts of the metallurgists and operators. Flowsheet and process changes are attempted and abandoned. With luck, one or more of the changes achieves some mitigation of the original problem or more usually, the original cause of the problem disappears. Regardless, the metallurgist can sit back and bask in the apparent success of his or her endeavours.Less common is when a problem is carefully diagnosed, a team put together to explore all avenues and recommend a path of action that is implemented on time, on budget and immediately delivers on the promises which are sustained over time. This is one such story. It is the story of the Mill Redesign Project at INCO’s Clarabelle Mill in Copper Cliff, Ontario.BACKGROUNDThe Clarabelle Mill was built in 1971 on the southern rim of the Sudbury basin. At that time it was one of four mills operated by INCO in the Sudbury area. During the 1970’s, 80’s and 90’s, the need for increased process efficiency, higher levels of sulphur rejection to tails and the concurrent development of high capacity mills and flotation cells, resulted in the consolidation of INCO’s Sudbury area milling operations into a single, expanded facility at Clarabelle."

Jan 1, 2003

By L. Li

The backfilling of underground stopes is a common practice throughout the mining industry. The stresses imposed by the backfill on the surrounding rock mass need to be assessed because of their influence on ground stability and on the hydro-geochemical response of the fill material. There is, however, a complex interaction between the relatively soft backfill and the much stiffer adjacent rock mass. In recent years, the authors have presented results from investigations conducted on stress distributions (obtained numerically and analytically) in and around backfilled stopes with (sub)vertical walls. In this paper, the influence of stope inclination and of backfill properties is evaluated. Results indicate that, in general, the vertical and horizontal stresses in inclined stopes are close to, but somewhat smaller than the stresses in vertical stopes. Nonetheless, significant differences can be observed in some cases, especially for the vertical stress along the inclined central line and along the hanging wall. It is further shown that neglecting deformability in limit equilibrium analyses is an acceptable assumption. However, Poisson?s ratio and the dilatancy angle, usually neglected in limit equilibrium analyses, may have significant effect on the stress distribution. Results also confirm that the backfill strength parameters (cohesion and friction angle) are critical factors required to properly evaluate the stress distribution, at least within a certain range of parameter values.

May 1, 2007

By John G. Peacey, Leoncio Sevilla G., Ford. Kevan J. R., Erling Villalobos C.

"Kinross Gold Corporation’s Mantos de Oro (MDO) gold/silver mine in northern Chile currently processes 15,000 tpd of oxide ores through a mill, whole ore cyanide leach plant followed by a Merrill-Crowe refinery. With the expected depletion of these oxide ores in a few years a new sulphide mineral deposit, Ladera-Farellón has been identified to potentially replace existing ore reserves. The deposit contains approximately 0.5g/t Au, 6g/t Ag and 0.5% Cu. The principal sulphide mineral in the deposit is enargite (Cu3AsS4) which hosts the majority of gold and silver and the copper. Direct cyanidation testwork has shown the sulphide mineral is refractory with a low gold recovery of 36% and silver recovery of 45%. Oxidation of the sulphides is required to liberate gold and silver and allow recovery of copper as an important pay-metal. Therefore, at MDO a new metallurgical process route with oxidation as a pretreatment step is required for viable treatment of such new sulphide mineralized material with acceptable recoveries of pay-metals.Analysis of flowsheet options was completed based on bench-scale and pilot scale metallurgical testwork as well as with reference to existing studies and operations. The process options investigated assume concentration of sulphides by flotation, followed by either pressure oxidation, bacteriological oxidation or roasting. Preliminary evaluation of flowsheet options focused on process risk, operability, technology availability and the economics of the project with emphasis on use of the existing metallurgical plant to reduce capital cost. Operating costs for each process option were also included in the relative analysis.The challenges of treatment of MDO sulphides, principally enargite and pyrite for recovery of gold, silver and copper center on fixation of arsenic and sulphur capture with environmentally acceptable disposal of residue tailings. This environmental focus was included in the process option selection and comparative analysis.This paper presents a review of the process options considered and highlights comparative advantages/disadvantages of each process with associated environmental issues. Preliminary conclusions are drawn on roasting as a potentially favorable process option for the treatment of MDO sulphides."

Jan 1, 2009

By R. J. MacLeod

"INTRODUCTIONThe removal of water or liquid from slurries and solutions is a procedure generally present in many process industries. This has prompted the development of many mechanical and thermal devices with which, I have no doubt you are al1 familiar.In the mining industry, beneficiation of ores necessitates ' the removal of water or other 1iquid from the concentrate material. The most common method of accomplishing this is by means of thickeners, vacuum filters and rotary dryers, generally all three and in that order;The use of spray drying techniques to obtain the same end has many advantages and these will be outlined here.THE PRINCIPLE OF SPRAY DRYINGA Spray Dryer consists of a cyclone shaped chamber where hot air and atomized concentrate are introduced in the upper section. (Sec figure No. 1). Efficient mixing of these two streams produce dry concentrate and moist spent air, both of which are removed from the base of the chamber.Thermal dewatering involves the product ion of heat and spray drying has no special requirements in this area. Generally a direct fired air heater is used and the products of combustion whether they stem from the use of gas, oil or coal fuel go into the spray dryer along with quench or dilution air which is used to reduce the combustion gases to the desired temperature. This generally lies in the range of 1,000 to 1,600° F. In spite of these relatively high inlet temperatures, the spray drying process eliminates the need for refractory lining or indeed any special heat resistant metals except on the air inlet ducting. Waste heat may also be used even if a significant amount of contamination is present."

Jan 1, 1972

By J. Ling, L. Racine, P. Cousin, A. R. Laplante

"The problem of gold recovery by gravity from high density gangues is first discussed from a fundamental perspective. Three potential difficulties are presented: poor liberation and fine gold particle size, concentrate bed erosion by coarse dense particles, and slow percolation of gold particle through the high density gangue bed. Two case studies are presented to illustrate the impact of these three problems on circuit performance and the feasibility of gravity recovery. It is concluded that careful testing can determine the scope of the first problem and feed preparation can limit the extent of the second. The third problem is clearly the most serious and results in lower gravity recoverable gold recoveries than would be achieved with the same recovery effort on a low density gangue application.IntroductionSince the commercialisation of the Knelson Concentrator in 1980, gold gravity recovery has experienced a surge in interest, in Canada and the United States first, then Australia, Zimbabwe and Russia, and finally worldwide. Table I details number of units sold in various countries, which corresponds approximately to their importance as gold producers 1. Exceptions. such as the low rank of South Africa or the importance of Zimbabwe, despite the much higher gold throughput of the former, are generally the result of differences in the effectiveness of the local marketing strategies, as well as a reflection of the ""philosophy of recovery"" prevalent in the country.The impact of the Knelson has not been felt equally in all plants. Typically, a highly successful application falls into the following categories: (a) alluvial or hard rock recovery for which gravity is the sole recovery method, (b) hard-rock free gold milling with ores which have a very high gravity-recoverable gold (GRG) content, (c) low grade sulphide copper-gold ores which include flotation ahead of cyanidation and (d) free-milling gold ores ahead of Other applications can be successful, but are not as common. The ""explosion"" of centrifuge concentration, of which the Knelson is the most successful but by no means the sole model, has created a certain euphoria which can be summarized as ""gravity recovery will improve the profitability of gold milling, no matter what."" This presentation is about applications that are not so successful, or even downright unsuccessful. The rationale is not to down-play gold gravity recovery, but to set it in its rightful position: metallurgically, it is not appropriate all of the times; it can become inappropriate if poorly designed; and it can be metallurgically possible but economically unjustifiable. In this paper, this will be illustrated and explained rather than demonstrated, with the use of both industrial plant surveys and laboratory test work. Alternate gravity approaches will be suggested."

Jan 1, 1997

By Trevor Yeomans

"NVI Mining’s Myra Falls Operation is a forty year old underground mining operation feeding a 4000 mtpd concentrator.The current Mill, built in 1985, was designed to process a large massive sulphide ore-body. This ore-body, known as the “HW”, contains about 50% pyrite. Value minerals are chalcopyrite, and sphalerite, with precious metals occurring in all mineral types.By 1997, mining of a new ore-body, known as “Battle-Gap” commenced. Mineralogically complex, the new orebody contains about 15% pyrite, copper minerals including primary chalcopyrite, secondary bornite, chalcocite and tennantite, combined with increased galena and sphalerite.Flotation performance generally decreased with increasing amounts of Battle-Gap ore types, with both copper concentrate quality (increased lead and zinc content) and copper recoveries being affected.Following significant metallurgical testwork, a new fully sequential copper-lead-zinc flotation flowsheet and reagent scheme was developed.This sequential flowsheet was progressively installed and commissioned during 2006.Copper concentrate lead and zinc smelter penalty contents have been reduced by some 40%, whilst increasing copper recovery by 10%.INTRODUCTIONNVI Mining operates the Myra Falls Operation near Campbell River on Vancouver Island, BC. The complex has been in operation since 1966 with mining being predominantly underground. One unique feature of Myra Falls is that the mine operates within a BC Provincial Park.In 1985, a new large massive sulphide ore-body (HW) had been defined, and metallurgically tested. A new concentrator was built based upon this massive pyrite, chalcopyrite, and sphalerite mineralization producing copper and zinc concentrates by conventional flotation methods."

Jan 1, 2008

By K-A. Adamson

If fuel cells and hydrogen are to become a mass market reality a substantial amount of further research and development needs to be undertaken. Work in hydrogen storage, production, the economics of all aspects of fuel cells and hydrogen, materials balances, and product integration are just a few of the areas that are under focus. Setting R&D targets, and providing R&D funding are therefore areas that are central to the long term development of the market, and areas in which a number of governments worldwide are highly active. Some governments, such as Japan and Korea, have set a number of very ambitious, highly focused, long term targets and are backing this up with substantial funding, others such as the EU are working on a more integrated approach, wrapping some fairly fundamental R&D into large integrated projects which run in combination with a number of other market aspects, such as public acceptance and roadmapping. The US is slightly different, in that although is has a number of long term programmes and targets, FreedomCar and SuperGen being just two, the levels of funding are set annually with the passing of each years Fiscal Budget. This paper takes three high profile regions and analyses the R&D targets and funding levels for fuel cells and hydrogen. Criteria that will be looked at include: Time frame of target(s), level of ambition, funding issues, including: Funding windows, levels available, funding barriers, overall programme goals. The added value to this paper is that it will provide a clearer picture of where each region is heading, what are its strengths and weaknesses, in terms of R&D and where there may be areas for potential international collaboration.

Jan 1, 2005

By X. M. Zhou, T. Wu, He X. N.

"In order to study the support effect of concrete in the surrounding rock of a metal mine, the concrete and surrounding rock were comparatively studied. Firstly, the general situation of the ultra-kilometer deep shaft in Xincheng, surrounding rock and geological conditions are introduced. Secondly, the experimental scheme of material mechanical properties of surrounding rock and shaft lining concrete based on same standard dimension and shape are examined, and the mechanical tests of rock and concrete based on different shapes and sizes are carried out. The study shows that the compressive strength value and elastic modulus of the rock cube are 1.28 times and 1.78 times that of the cylinder, and the Poisson's ratio is 0.77 times. The dimensional effect law of the concrete cube and cylinder test data is consistent with the rock law. However, the test results of the concrete are less discrete than the rock; the test also shows that the strength and elastic modulus of the concrete lining of the main shaft of the Xincheng are much smaller than the surrounding rock that is also used as the concrete aggregate, which indicates that the support of concrete lining in the surrounding rock shaft behaved weakly. Based on the development of the modern NATM rock support theory, it is suggested that the mechanical test standard of artificial support materials should be unified into the mechanics test standard of natural rock, which will help to improve the accuracy and practicality of scientific calculation of geotechnical engineering.INTRODUCTIONConcrete and rock mass are usually attributed to a class of materials called frictional materials or geotechnical materials, of these two kinds of materials, the first is man-maded and the second is natural. The attentive scholar can find that there are many differences in the test criteria for the mechanical properties of the two kinds of materials among different industries or departments, reflecting the differences in their sources, tradition, and the application thoery of material strength among them.There is a situation wordwide, that there are many testing standards of the same material mechanical parameters such as elastic modulus, compressive strength, etc. The cube with a side length of 150 mm is adopted as a common sample in the architecture department in China, while a cylinder with a diameter of 50 mm and a height of 100 mm is as a standard specimen in geotechnical department.Knowing that mechanical parameter values are strongly affected by the the size, shape of specimen and loading rate etc, that is to say the mechanical parameter values of the same material are completely different when obtained from different test with different standards. However, such a problem has been long neglected in geotechnical engineering."

Jan 1, 2019

By Paul Staples, Chris Morley

"The development of the Cerro Verde, Amplats Mogalakwena and Boddington projects over the last few years has helped to establish the use of high pressure grinding rolls (HPGR) in comminution circuit designs in large-scale hard-rock applications. The increasing acceptance of this innovative and sometimes controversial technology has had the natural effect of prompting many other new projects to examine HPGR as an alternative to the established, usually SAG-based, comminution circuit design approach.At the current stage of development of the technology, HPGR-based circuit capital costs are generally higher than for the equivalent SAG-based circuit, so that HPGR must offer sufficient operating cost benefits to offset the additional capital costs over an acceptable pay-back period. It is usually necessary to undertake comprehensive project-specific trade-off studies to quantify this effect.This paper describes the processes involved in the execution of a typical SAG-HPGR trade-off study, from the preliminary assessment of ore characteristics and project criteria, through testwork, circuit modelling, equipment selection and cost estimates, to a project-economics comparative assessment of the options. The trade-off study determines both the technical feasibility of the respective technologies and their commercial viability in the given project setting.The paper concludes with a cautionary note to the effect that, while HPGR has many potential benefits, it is not a panacea, and that, for some ore types and project conditions, the more established conventional technologies are often more appropriate."

Jan 1, 2010

By J. E. Nesset

"I had been requested earlier this year by MetSoc, our sister society of CIM, to contribute a chapter on technical developments in Canadian mineral processing over the past 50 years to their 50th Anniversary volume. Accepting the challenge of assembling such a chapter seemed at first a reasonably straightforward task, until one realises that the list of contributions by Canadians to mineral processing over this period has been more than just significant. It turns out to have been an extraordinarily fertile time for innovation and impact for Canadian-based technology. The list is necessarily a subjective one, however I had no trouble identifying twenty technology developments that are clearly outstanding, and there are undoubtedly others. As much as possible, I approached the individuals themselves who played key roles in each technology and asked that they tell the “story”. Without exception, all who were invited accepted eagerly and delivered more than I had hoped for. The technologies have been grouped into those that are truly Canadian innovations, such as the Knelson gravity concentrator and the McGill gas dispersion sensors in flotation, and technologies where Canadians and Canada played a very significant role in their success and implementation, such as AG/SAG grinding and ion-beam surface analysis. Also included are what may be termed technology transfer initiatives and institutions that have risen to a world class level, such as SGS Lakefield and the Canadian Mineral Processors Society of CIM. The challenge is now for the coming generation to continue this record of innovation and contribution to the industry, and that includes the (mostly) Canadian mining and metallurgical companies who have taken the longer term view and supported many of these initiatives, through their critical early years, with both financing and project sites for these ideas. Let us hope that the current trend of mining company globalization will not dampen their enthusiasm to participate. This plenary presentation will highlight many of these technologies, the individuals behind them, and their significance to the mineral processing industry."

Jan 1, 2012