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By J. M. Paxton, R. L. Roscoe, G. A. McCreary, W. W. Muir, T. J. Drown, D. A. Barr, T. W. Law

"This paper reviews the complete cycle of a small mining operation in a remote section of northern British Columbia, including discovery, exploration, development and production. The discovery of high-grade epithermal gold-silver mineralization occurred in 1969 following a regional geochemical reconnaissance program designed to search for porphyry copper mineralization in the Cassiar-Omineca Mountains. Exploration and development from 1971 to 1979 included geological, geochemical and geophysical surveys; trenching, almost 30 000 feet of surface and underground drilling in about 100 holes and cross-cutting, drifting and raising on the principal goldsilver- bearing vein. This led to the delineation of 100000 tons at an estimated grade of0.9 oz gold per ton and 18 oz silver per [on to an average depth of 120 feet below surface. of a 100-ton per day mining operation employing about 50 personnel with all supporting infrastructure transported to the site by a Hercules aircraft. The operation was subsequently supported by its own Twin Otter aircraft with periodic Hercules campaigns supplying major items including fuel.The mining operation included both open-pit and cut-and-fill methods. The milling operation employed conventional cyanide leach process with cyanide destruction initially by alkali chlorination and subsequently by the Inco SOl /Air process.The fly-in operation, initially structured on a 21-day-in and 7-day-out basis was modified to al-t-day-in and Z-day-out basis with no loss in efficiency and with a significant increase in employee satisfaction. The operation, which earned the B.C. Small Mines Safety A ward in two consecutive years in its Ll-month operating history, emphasized safety and process hazard awareness. Wildlife studies in the environmentally sensitive mine area also showed that industry and wildlife can coexist in harmony.Most importantly, the paper compares the feasibility assumptions with actual operating experience."

Jan 1, 1986

By J. G. Peacey

"Canada has a special place in non-ferrous pyrometallurgy because it is the only country in the western world that is a significant producer of all the major non-ferrous metals; aluminum, copper, lead, magnesium, nickel and zinc. This large non-ferrous pyrometallurgy industry has developed because of Canada's abundant mineral wealth and energy resources. Table I summarizes the number of primary non-ferrous production facilities in Canada and their share of western world production.Production of non-ferrous metals is a mature, capital intensive business and its basic processes have been in use for many years. Nevertheless, these processes have continued to evolve in response to changing needs and external pressures; such as the energy crisis of the early seventies; historically low metal prices in the early eighties and the continuing pressure to reduce plant emissions and improve in-plant working conditions. Canada's major metallurgical companies: Alcan, Cominco, Falconbridge, Inco and Noranda have played a leading role in pioneering new process technology and continue to meet the difficult challenge of keeping their operations competitive in the global metals market. This paper will try to give an overview of the major developments in non-ferrous pyrometallurgy, largely from the Noranda and Canadian perspectives, highlighting the current status of process technology and possible future directions.AluminumCanada has the world's second largest aluminum smelting industry and its capacity has expanded rapidly in recent years with the completion of several large projects in Quebec. The location and capacity of the Canadian aluminum smelters are given in Table 2. All these plants use the Hall-Heroult process, that was invented over a century ago but over the last twenty years considerable improvements have been made to increase productivity, reduce power requirements and emissions.The developments in aluminum cell technology can be illustrated by the experience at Noranda Aluminum. In 1971, Noranda Aluminum started its first pot line using Kaiser's P69 prebake cell, which was considered, at that time, the best available technology. The P69 cell was designed primarily for high productivity, operating at 150 000 amps and high current density to produce just over tonne Al per cell-day. The P69 cell is a simple design, typically operating at about 88070 current efficiency and 15 800 kWh/tonne Al. When Noranda Aluminum decided to expand in 1980, the Alcoa 697 cell was selected as it then represented the most proven, stateof- the-art technology. This cell is similar to that installed at Alcan's new Grande Baie and Laterriere smelters and is designed to operate at 180000 amps and 93070 current efficiency, producing about 25070 more aluminum per pot-day than the P69 cell using about 15070 less power. The 697 cell has a much more sophisticated cell design, with very good balancing of the magnetic field giving a flat metal pad and allowing efficient operation at the higher amperage. Alumina is fed via point feeders that provide an almost continuous feed allowing close control of the alumina level in the bath and the use of low-ratio bath composition, giving much higher current efficiencies."

Jan 1, 1991

By L. R. P. de Andrade Lima, D. Hodouin

The paper presents a survey of the possibilities of the simulation techniques for improving the design and operation of gold processing plants. The procedure to construct kinetic models that are used in simulators is first reviewed, and examples are given for cyanide gold dissolution and gold adsorption on carbon. Then, an overview of the structures of the plant simulators is proposed, and the simulation equations formulated for a carbon-in-leach process. Finally, the potential of simulation methods is illustrated by four examples. The first one shows how it is possible to use a simulator to design a cascade of leaching tanks while optimizing an economic performance criterion. The second one illustrates the role of simulators for optimal tuning of the cyanide addition strategy in a leaching circuit. The third example focuses on the power of simulation to design carbon transfer strategies in a carbon-in-pulp process. Finally, the last example shows the role of on-line simulators for optimally supervising the automatic control of cyanide addition into leaching tanks.

Jan 1, 2005

By G. J. Kipouros, P. W. Kingston, W. F. Caley

"Current practice in advanced materials processing has involved the dispersion of a second-phase, commonly SiC, glass, or other non-metallic fibres/whiskers/particulates to enhance physical characteristics of the matrix. These matrices may be either ceramic or metallic but in either case it is important that the physical and chemical properties of each phase be compatible. The dispersed, finely divided second phase is often both expensive and foreign-produced and may exhibit chemical instability at elevated temperatures. Thus, it would appear that certain naturally-occurring industrial mineral fibres/whiskers/particulates might offer an attractive and low-cost alternative. Suitable candidates, such as wollastonite and sillimanite, are available in Canada and may be milled to produce particles whose shape is appropriate for this application. It is suggested that wollastonite, in particular, may be a useful modifying agent in metal matrix composites utilizing AI, Al-Si, Zn-Al or other light metals and alloys. In addition, the possible use of these minerals in ceramic matrix materials is also addressed, with reference to a preliminary thermodynamic analysis of the systems involved.IntroductionBackgroundA composite material may be thought of as consisting of a matrix component, the properties of which are improved by the addition of a second component or dispersed phase which forms a distinct three-dimensional interface with the matrix. This matrix is commonly either metallic or ceramic, which leads to the two most popular types of composites: metal-matrix composites (MMC); and ceramic-matrix composites (CMC).Such materials are by no means new. Early composites include fiberglass, mixtures of plaster and horsehair in wall plastering, as well as use of natural materials such as bamboo in fishing rods. Some of the newer applications include high strength, low-weight bicycle rims, as well as the more familiar role in aircraft and automobile engine components."

Jan 1, 1993

By James E. Fisher, Roger Cotton

"The legal background f or environmental issues, and the growing emphasis both from government and private concerns of corporate and management liability for environmental problems provides one of the driving forces behind the growing concern with environmental law for the future. One prime objective must be the identification and minimization of potential liability, both for the corporation and its officers, directors and employees.This paper will identify the basis for liability of individuals and corporations for environmental matters, focussing on current legal requirements, and the appropriate legal response to events of such potential liability. It will also consider the reduction of liability through the implementation of management systems and environmental policies in order to ensure due diligence both with respect to corporate responsibility and the responsibility of the individuals within the corporation.IntroductionConsolidated Professor Mines Ltd . and its predecessor have been exploring in northwestern Ontario for about sixty years . During the last twenty years, the company has been interested in developing a gold mine, the Duport Project, on Stevens Island in Shoal Lake . The lake straddles the border between Ontario and Manitoba and is a drinking water supply for Winnipeg and environs.The Duport Project involves the mining of 450 t/day grading an average of 0.35 oz Ault of ore . At the minesite, located on Steven s Island in Shoal Lake, only preliminary processing of the ore will take place, to produce gravity and flotation concentrates for final gold recover y at a mainland plant well removed from the Shoal Lake watershed. No hazardous chemicals will be used at the island site."

Jan 1, 1991

By R. A. Rabnett, G. Paget, Patrick Walsh

"Tumbler Ridge, Canada's newest resource community, has been developed differently than have been other resource communities.Since its conceptualization, emphasis has been placed on the establishment of a traditional municipal government at early a stage as possible.Planning f or the community goes back to 1977. By then, extensive study by provincial agencies had shown a new resource town would be required to exploit north east coal. The Ministry of Municipal Affairs, in conjunction with a consultant named R.A. Rabnett began the extensive Tumbler Ridge conceptual plan.The results of the conceptual plan are evident in the organizational and planning goals of Tumbler Ridge. In every aspect from the election of officials to some financial matters, the town functions as a normal municipality. With the resource companies of the North East Coal Development within its municipal boundaries. Tumbler Ridge has been able to debenture its capital projects against its municipal tax base.The town's ability to function as a normal municipality is enhanced by its control over Crown land it has purchased from the province. This gives it further control over the development of the community and helps in establishing agreements with the resource companies and the provincial government to ensure that housing and service needs are met. While resource company representatives sit on certain municipal committees, their roles are advisory in nature.The community continues to move toward full municipal status and will have a fully elected Council by 1986.BackgroundPlanning for the development of northeast British Columbia coal resources began in 1976 under the aegis of the provincial Cabinet Committee on Coal Development. A series of subcommittees were established including a Townsite/Community Development subcommittee. The Ministry of Municipal Affairs chaired this subcommittee and continued as the lead agency for the provincial settlement planning effort over the period 1976 to 1981."

Jan 1, 1983

By V. G. Papangelakis, G. P. Demopoulos

"Recovery of gold from refractory ores and concentrates presently constitutes one of the most important, challenging, and exciting areas of R&D activity in the gold processing industry. New technologies are being tested for the treatment of refractory gold materials, some of which have been advanced to the level of commercial operation. In this paper, some recent technological developments in the hydrometallurgical processing of pyritic matrix-refractory gold ores are highlighted. Key operational steps of each of the alternate hydrometallurgical technologies are analyzed and potential advantages and drawbacks are identified. The processes which are reviewed are: hydro chemical oxidation, biochemical oxidation and pressure oxidation. INTRODUCTIONOver the years the term ""refractory"" has been applied in gold ore processing to denote situations in which straightforward cyanidation failed to yield high gold recoveries. A number of mineralogical and chemical factors may be responsible for this ""refractoriness"" problem. A systematic classification of the different options for their treatment has been discussed in a recent review paper. In this paper, the pretreatment of the submicroscopic gold encapsulated within the matrix of pyrite and arsenopyrite minerals is considered. This type of gold is the ultimate refractory material because complete breakdown by reaction of the host mineral structure is required.The method which has been traditionally applied for the treatment of pyritic-type refractory gold ores is an oxidation roast (single stage or double stage depending on the As content) of a flotation concentrate to produce a porous calcine, the latter being more amenable to cyanidation. Despite its established practice, oxidation roasting is not considered particularly attractive with today's standards for high product recovery and clean environment. Roasting is known to be very sensitive to heating parameters and feed composition and deviation from optimum conditions can result in reduction in permeability which is translated to incomplete gold liberation."

Jan 1, 1989

By A. Galibois, R. Singhal

"This paper highlights some of the potential application areas of knowledge-based systems in the mining industry. The basic theoretical principles associated with knowledge-based systems are discussed and the justification for mining applications is given. The paper concludes with a brief description of a prototype knowledge-based system applied to scraper selection that was developed at Université Laval on a LISP machine. IntroductionThe beginning of Artificial Intelligence coincided with the conception and development of the first computer systems some thirty years ago. At that time researchers were euphoric about the possibility of modelling the human reasoning process. Soon, however, they discovered that the combinatorial aspect of the set of possible solutions to a particular problem did not permit an in-depth evaluation.In the mid-60s researchers started to look at the heuristic approach because it was more suited to human behaviour with its congnitive abilities (i.e. representing, reasoning, problem solving and advising). The heuristic approach allows possible results rather than exact solutions and it is more rapid and cost effective than the exhaustive combinatorial analysis. The heuristic approach did allow some noticeable progress in the seventies with the development of the first expert system called MYCIN with the objective of diagnosing blood infection diseases."

Jan 1, 1988

By Leslie McHattie, Sadek E. EI-Alfy

"The Maintenance Engineering Department at Carol Mining and Concentrating is currently in the process of introducing reliability concepts such as failure analysis, rework elimination, predictive maintenance, computerized maintenance history analysis, etc. to improve the over-all maintenance function in the mine and concentratormaintenance areas. Some current initiatives include:• Implementation ofan infrared thermographic scanning program.• Ultrasonic inspection of shafts for all critical equipment in the mine and concentrator areas.• Non-destructive testing of all major welds done by maintenance personnel.• Development of an effective vibration monitoring and analysis program for the production equipment in the mine (shovels, drills, haulage trucks, locomotives).• Failure analysis performed by maintenance engineers to identify the root cause of component failures on critical production equipment.• Computerized breakdown analysis to identify the recurring component failures which contribute significantly to high maintenance costs and production loss.• Implementation of a computerized maintenance management information system.This paper will outline the planned implementation ofthese initiatives, and others, and will also cover the status and results obtained to date."

Jan 1, 1992

By Doug Barnstable

"Quinsam Coal Ltd. is assessing the potential of developing a thermal coal deposit near Middle Quinsam Lake on Vancouver Island. The coal reserve outlined is classified as a high-volatile, bituminous ""A” steam coal and is composed off our separate seams of varying quality within the Late Cretaceous Comox Formation.Open-pit mining methods will utilize a walking dragline and a truck / shovel module as the primary stripping tools. Following washing and mechanical drying in a Baum jig preparation plant, the coal will be transported to the proposed dock at Campbell River for shipment via 55, OOO-DWT vessels to world markets. The paper will outline the development and status of the project to date. IntroductionQuinsam Coal Ltd. is a joint venture of Weld wood of Canada Ltd. and Luscar Ltd . The participants propose to develop a thermal coal mine in the Middle Quinsam Lake area, 17 miles inland from Campbell River on Vancouver Island (Fig. I). By acquiring all the assets of Canadian Collieries in 1962, Weldwood also came to own the coal rights of the area proposed for development. Luscar Ltd . ha s been designated as project manager until completion of construction and thereafter will act as operator of the mine.Surface mining methods will be used to produce approximately 1.0 million short tons of coal annually from the Quinsam property. Seven separate mining pit s will be developed along with the supporting minesite facilities, including a proper paration plant. Transportation routing to Campbell River and the establishment of docking facilities will be required. The initial economic life of the mine is 12 years, with the provision to extend this in the future by developing higher-ratio, auger or underground reserves."

Jan 1, 1980

By Derek J. Barratt

This paper compares a number of operating conventional and semi-autogenous grinding circuits and analyzes them in regard to operating and capital costs, specifically as applied to porphyry copper ores.

Jan 1, 1979

By F. Goodarzi

"The nature and distribution of the inorganic components and the concentration of certain environmentally sensitive elements, such as, As, Sb, B, Hr, Cd, CI, F, Mo, Pb, S, and Se, or elements detrimental to the utilization by industry such as B, Na, P and S are very important in determining coal quality. The concentration of elements in coal is controlled by the following factors: (1) frequency of occurrence of partings; (2) nature and habit of occurrence of minerals in coal; (3) environment of coal deposition; (4)rank; (5) geological setting; and (6) weathering.Selective mining of coal can reduce the input of undesirable elements such as As and S by eliminating the part of the seam which is enriched in these elements. IntroductionCoal is a sedimentary rock of plant origin and consists of two components: an inorganic component (minerals) which is formed by influx of clastic sediments into the coal-forming environment and also by activities of groundwater, and an organic component (macerals) which is formed from plant debris deposited in the original coal-forming environment. However, coal is a generic term with a broad range of utilization characteristics. A coal that is attractive for use in one market - such as generation of electricity (combustion) - may not necessarily be acceptable for use in another, such as for production of coke (Davis, 1978).The elements in coal are associated with both macerals and minerals. The elements associated with coal macerals, such as C, H and N are termed elements with organic affInities. The concentration of elements with organic affmities (including B, Br, CI, F, I, S, and Mg) often decrease with increasing ash content of coal (Nicholls, 1968; and Finkehnan,1982). FIgure 1 shows such a trend for chlorine. Some of these elements may also be incorporated in coal maceral as very fine mineral grains (Finkelman, 1982). The elements with organic affmities are often volatilized during combustion and carbonization of coal and emitted in the vapour phase. Emission of some of these elements (C, 0, Br, N and S) is of major environmental concern (Lim, 1979)."

Jan 1, 1994

By Kosta Fytas, Nour-Eddine Chaouai

"Selection of the appropriate kriging plan during indicator kriging estimations is of a paramount importance to the precision of ore reserve estimation. However, very little is known on the sensitivy of indicator kriging results when changing the kriging plan parameters (mainly search distance and number of samples). This paper evaluates the effect of the search distance and number of samples on indicator kriging results using a gold deposit as a case study.IntroductionBlock estimation using kriging is based on the autocorrelation function (variogram) on one hand and on the kriging plan on the other. As far as the variogram is concerned it is more or less subjectively adjusted and this is reflected on its parameters (range, sill, nugget effect and anisotropy). The effect of a poor estimation of these parameters on the kriging variance of ordinary kriging has been proven very important (Brooker, 1986). Choosing a kriging plan is generally a difficult matter depending on the estimation type (global or local). Generally there is not a unique kriging plan be cause there is not a unique structural analysis (variogram). There are no rules or dogmas in choosing a kriging plan but it is rather a function of the sampling pattern (David, 1982).Structural analysis requires the hypothesis of quasistationarity but very often either the data available within the zone of quasi-stationarity are too many so that the search distance is reduced during kriging or the data are too few to satisfy a stationary kriging system (Journel and Huijbregts 1978). As a rule, the larger the neighbourhood, the more precise the estimates should be , but for large neighbourhoods the hypothesis of stationarity does not always hold (Rivoirard 1987; Armstrong and Champigny 1989)."

Jan 1, 1991

By Gene O. Cowie

"Zinc, which once enjoyed an unchallenged position in the field of decorative applications, has lost a substantial share of its markets to other materials, particularly plastics. This turn of events has led the zinc industry to explore new market areas, particularly those applications where the engineering properties of zinc can be utilized. This paper gives an overview of the zinc industry's efforts to develop the data base and product development technology which have enabled zinc alloys to emerge as engineering materials. It also indicates those areas in which the research facilities of the zinc industry must be employed to ensure that zinc alloys keep pace with developments in competitive materials and processes.The Materials RevolutionThe development and utilization of new materials and manufacturing processes progressed for centuries by evolution. Recently it erupted into a revolution, which may become as significant as the industrial revolution. The materials revolution has impacted upon many industries, but none has been affected more traumatically than the North American automotive industry. The plight of that industry is of great importance to us because their problems have, to a great degree, become problems to the zinc industry.Much of the impetus behind the automotive trauma came from the battery of motor vehicle regulations promulgated by the United States government in the 1970s. These regulations required that the efficiency of passenger cars, in terms of miles per gallon, be approximately doubled in ten years. In view of the fact that major changes in the automotive world require three years of lead time to implement, the industry was left with only seven years to perform the task. The automotive industry was simultaneously required to make progress in other areas, such as reduced emissions, reduced cost of repairs and increased levels of occupant safety. These added demands not only diverted some of the available resources away from efficiency goals, they often ran in direct conflict. For example, when you are required to provide a front bumper which will absorb the energy of a 5-mile -per-hour barrier collision, you must add both hardware and structure to the vehicle. This adds weight, and increased weight reduces miles per gallon."

Jan 1, 1983

By O. Garg

This paper summarizes the computer applications in open-pit mine planning at the Iron Ore Company of Canada (IOC). A brief history of the use of computers at IOC is given, and a description of the existing facilities is outlined. The following systems are discussed: storage and retrieval of geological data; geotechnical data analysis; long-term grade and tonnage forecasting; ore grading; and open-pit mine design. Justification for using computers in open-pit mine planning is given, and possible future areas of application are considered.

Jan 1, 1979

By Stephen G. Hardcastle, Michel G. Grenier

"Safety and health issues are and have been in the last decade a very high priority item with all parties involved in the Canadian mining industry. As a result of this high level of concern for workers' safety and health, Canadian mines are at the leading edge of environmental control technology. For the most part, the occurrence of pollutants in mines is unavoidable. Dust from mining operations, airborne radiation, gases and heat from the strata as well as gases and particulate from diesel engine emissions will undoubtedly be found to some level in most Canadian mines. A lot of work remains to be done, however, in order to bring all Canadian mines at the same level of proficiency when it comes to safety and health. Also, more work is needed in order to maintain our status as world leaders in this field.CANMET's Mining Research Laboratories (MRL) in Elliot Lake and Bells Corners, Ontario, with the cooperation of the mining industry, have contributed to improving environmental conditions in underground and surface mining and milling operations. The extent of collaboration and efforts vary widely from long-term, multi-million dollar projects between several interested parties to smaller projects involving one laboratory and a single mining operation. This paper gives examples of such collaborative efforts and potential future directions as they apply to: mine ventilation analysis using tracer gas techniques, optimization of mine ventilation network efficiency using real-time monitoring and controlled recirculation (heat saving), respirable dust and radiation sampling and control techniques, diesel emission control using regenerative ceramic filters and, finally, the control of sulphide dust explosions and resulting sulphur dioxide production."

Jan 1, 1990

By G. Pouskouleli, T. A. Wheat

"The role and benefits of using statistical methodology in the development and optimization of materials and processes is examined. It is shown that considerable benefits accrue from the use of an appropriate design in which a number of factors (process parameters) are varied simultaneously while the system response such as percent recovery, degree of separation, purity, etc. is monitored and ultimately optimized.Compared with the commonly encountered one-factor-at-a time approach, this schema exploits reduced experimentation (thereby requiring reduced resources [staff, time, dollars, etc.]) yet yields quantitative information on the significance of each factor and their combinations on the measured response."

Jan 1, 1992

By Andrew L. Mular, Robert P. Edwards

"The operation of flotation circuits is often regarded as a combination of art and science. Expert systems offer a method by which the art may be captured and supervisory control of flotation circuits fully realized. Operating knowledge, the art, can be consistently employed to enhance regulatory control through the judicious application of an expert system. Using an expert system, a supervisory control routine was developed, and success- fully implemented, in the copper flotation circuit at Brenda Mines Ltd.The expert system ran in conjunction with regulatory PI controllers on a personal computer. The expert system received assays via an on-stream analyzer and adjusted regulatory loop set points as required in real-time. From its commissioning in November, 1989, to the end of the mine 's operation in June, 1990, it was enthusiastically embraced by the operators and attained operating levels superior to those achievable manually.IntroductionExpert system (ES) software springs from research into artificial intelligence and is currently making significant inroads into business and industry. ES proponents make many attractive claims; they are a means of capturing the knowledge of experts and they can be programmed by non-programmers. To date, most uses of this software in the process industry are in off-line applications, meaning that the applications are not tied directly to operating (on-line) environments. Moreover, in on-line environments, they are typically employed as advisors and only suggest changes. Human operators are required to close-the-loop to the process. Yet, an ES should be applicable to operating environments and, if the claims of the proponents are valid, should also be better than existing tools. As an intelligent controller an ES must use the knowledge of experienced operators, apply it directly to a process and do this without the intervention of human operators. On-line applications have been successfully employed in the closed loop control of SAG circuits (Herbst et al., 1989) and flotation circuits (Hales, 1989). Harris and Kosick (1988)detail an implementation for flotation control at the Polaris Mine."

Jan 1, 1992

By Seunghoon Lee

The increase in the number of higher and larger buildings is expected to require the buildings' outer wall maintenance process, which includes cleaning, painting and monitoring, still depends on manpower. In this study, we proposed the robotic building maintenance system and aimed to reduce the jerk effect through the motion control of the system, improve the performance of the maintenance task, and ensure longer life and safety by improving the stability of the building structure and robot system. Through the results of the motion control and field-test with the proposed system, in specific, horizontal sliding module (HSM) showed that the jerk oriented by impact force was significantly reduced, feasibility of the proposed method was verified, and the robotic challenges were explored.

Aug 1, 2013

By T. Grammatikopoulos, A. Jordens, C. Gunning

"Exploration activity for rare earth element (REE) deposits (i.e., alkaline complexes, carbonatites) has increased significantly in the last decade. A number of deposits have been evaluated around the globe. However, new mines have not been commenced in the last few years with the exception of Mount Weld (Lynas) and Mountain Pass (Molycorp).Resource estimation of REE can follow similar guidelines to other metal projects. However, the inherent mineralogical characteristics of the REE deposits, despite their complex nature, have been generally overlooked by many exploration companies. These include variability of the ore, liberation and association of the REE minerals, and grain size, all of which can affect the processing of the ore. Each deposit appears to be different in terms of matrix and REM (rare earth minerals). Light REE bearing minerals such as allanite, monazite, bastnaesite, synchysite, and HREE bearing minerals such as fergusonite and xenotime can vary widely in composition, grain size and association (e.g., carbonates or hard silicates). On the other hand, although not really REM, zircon, Zr-silicates, titanite, fluorite, apatite, and in some cases many other common silicate minerals can carry trace to significant concentrations of REE.The evaluation of REE deposits should include an appropriate mineralogical characterization in order to quantify the REM, distribution, liberation and association by quantitative mineralogical techniques (i.e., QEMSCAN, MLA, TIMA and others); chemistry of the REM by electron probe micro analysis (EPMA), Laser Ablation ICP-MS or ToF SIMS.These techniques provide valuable data for geological purposes such as: defining quantitatively, the variability and distribution of the REM; differentiating between LREE and HREE zones to delineate ore; and metallurgical purposes to predict minerals/REE behaviour during processing. The lack of a comprehensive mineralogical characterization often leads to the wrong processing path and ultimately affects the elemental/mineral recovery."

Jan 1, 2016