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By Bill Charbonneau

Lumen, lm The measurement unit of light emitted by a light source 60W incandescent840 lumens 32W T8 linear fluorescent3200 lumens 54W T5HO linear fluorescent5000 lumens 400W metal halide24,000 lumens

Oct 1, 2010

By Al Holmes

"In a recent survey of Canadian work values, 89% of the men surveyed and 97% of the women surveyed described the work in a mine as ""not at all auraetive"", Work in a mine, in fact, was rated by both sexes as the least attractive of all of the types of work surveyed. Confronted with this prevailing attitude, Canada's mining industry starts out with two strikes against it in its bid to attract and hold on to its fair share of available work force.Behavioural scientists have, for decades, been seeking answers to the questions:• ""Why do people work?""• ""Why do people choose a particular occupation?""• ""Why do people choose a particular organization?""• ""Why do people leave one organization for another?""• ""Why do some people stay in an organization?""• ""Why do some people work harder than others?""Their answers to these questions, although tentative and often contradictory, are being used by more and more organizations to solve people problems. Few industries can afford to ignore them, least of all, perhaps, the mining industry.Consider the following developments:I. General Motors and the United Auto Workers turn around the car assembly plant in Tarrytown, New York in seven years from the plant with the poorest labour relations and production record to one of the best under a program referred to as ""improving the quality of work life.""2. Shell Canada and the Oil, Chemical and Atomic Workers have designed a new petro-chemical processing plant in Sarnia using a set of principles that seek to optimize both the social and the technical system."

Jan 1, 1980

By Gerhard W. Heinrich, Gerald V. Schroeder, Daniel A. Murphy, Daniel F. Suarez, Jamie B. Beauchamp

"Washwater 'Finger' sprays were installed and tested in the copper/nickel separation circuit at Strathcona Mill to improve flotation capacities and related metallurgical performances. The new spray design features submerged sideways introduction of wash water into the flotation froth through nozzles at the end of vertical pipes which are suspended from a header above the froth. This maximizes the effective cross sectional area of flotation vessels while maintaining effective froth cleaning and a desirably high density of the concentrate slurry. The plant tests gave increases of copper concentrate production rates of 17% to 20% for conventional cells and 16% to 20% in column flotation at target grades of 29% to 30% copper and of less than 0.5% nickel. Basic considerations and concepts of tests and evaluation procedures are described.IntroductionMeeting flotation concentrate grade targets at maximum production rates and recoveries is a challenge all too familiar to operators of base metal ore concentrators. Frothwashing is an option to improve grade/recovery performance by minimizing entrainment of impurities into the concentrate, which is commonly known since the sixties (Kaya & Laplante, 1989). It has been recommended for the flotation of sulphides and industrial minerals alike (Kaya & Laplante, 1989; Miller, 1969; Heinrich, 1989) and has found its ultimate application in flotation columns (Finch & Dobby, 1990). The washwater addition in a flotation column is most evenly distributed over the column's cross-sectional area thus ensuring almost complete displacement of feed water from the froth by a countercurrent washwater flow -provided, a positive bias is maintained. Therefore, flotation columns are ideal for cleaning flotation. However, there is usually less room for boosting the concentrate production capacity by increasing airflow or slurry level then with conventional cells because of the smaller cross-sectional area available."

Jan 1, 1994

By Eric D. Marks

Fatalities resulting from ground workers colliding with objects and construction equipment accounted for approximately 18% of the total construction fatalities experienced in 2010. Current injury and fatality measuring methods have proven to be inadequate due to their use of passive measures of safety rather than a more active approach, such as the use of leading indicator data (also called near misses) of hazardous proximity situations between ground workers and heavy equipment on construction sites. The objectives are to create and evaluate the effectiveness of a reliable algorithm for collecting and analyzing the resulting leading indicator data from hazardous proximity situations. Numerous experiments emulating typical interactions between workers-on-foot and heavy equipment are used to evaluate the proximity sensing and detection technology. Safety leading indicator data (also called near misses) generated by the proximity sensing and detection technology during the experimental trials are used to create and assess the resulting algorithm. Results from the experiments indicate that leading indicator data generated from these systems can be processed and analyzed to identify hazardous proximity situations and incidents on construction sites.

Aug 1, 2013

By J. H. Rickard, D. H. Watkinson

"Abstract - Detailed petrographic and quantitative (electron microprobe, SEM-EDS) mineralchemical analyses of sulfide ore from the 100 orebody at the Copper Cliff North mine, Copper Cliff, Ontario, reveal numerous stages of ore development. Sharp contacts between weakly mineralized quartz diorite and blebby to massive sulfides indicate multiple intrusive events within the Copper Cliff offset dike. A spatial association of sulfides and hydrous minerals, such as amphibole, biotite, chlorite and epidote, suggests that most primary ore has been affected by later hydrothermal fluids. Sulfides are often enclosed or bordered by these secondary silicate phases. The ore consists primarily of pyrrhotite, pentlandite, chalcopyrite, with trace michenerite, cobaltite/gersdorffite, irarsite, hessite, tsumoite, and bismuth tellurides.Geological and petrological comparison of the 100 orebody and the adjacent 900 and 890 orebodies has revealed distinct similarities in ore distribution. Data show that the 100 orebody is depleted in platinum-group elements (PGE) relative to the 900 orebody. Platinum-group elements from the 100 orebody may have been hydrothermally remobilized and partly emplaced in the 900 orebody, in adjacent veins, or in magmatic breccia. Analysis of Cu, Ni, and PGE assay data of ore samples has characterized their distribution among the eight different ore textures in the orebody. There is a strong association between Pt and interstitial sulfide, and to a lesser extent massive sulfide, but little correlation between chalcopyrite-rich ore and PGE in the 100 orebody, unlike many other deposits in the Sudbury region."

Jan 1, 2001

By D. R. Nagaraj, Napoleon Tercero, Raymond Farinato

"Several studies conducted recently have shown that molybdenite flotation from Cu-Mo ores is adversely impacted in sea water at pH >~ 10.0 irrespective of the pH modifier; under the same conditions Cu sulfide flotation is relatively unaffected. This has been attributed to the presence of Mg2+ ions and their hydrolysis products in the sea water which adsorb and precipitate on molybdenite surfaces as Mg(OH)2. However, why and how Mg(OH)2 impacts only molybdenite flotation in the complex flotation pulps containing a multitude of minerals is not understood. The work presented in this paper probes the interface and interphase regions near the edge and basal planes of natural molybdenite (MoS2) in aqueous solutions and flotation pulps, particularly in the presence of copper ore pulp and added Mg2+. Differences in interaction of metal ions and their hydrolysis products (Mg2+, Mg(OH)+) were measured on the two faces of this anisotropic mineral. How those differences relate to molybdenite floatability and the impact of aqueous solution chemistry are discussed.INTRODUCTIONWater resource management is an important sustainability challenge in mineral processing. In view of the shortage of fresh water in many parts of the world, mineral processing plants are evaluating alternative sources. Seawater flotation has received much attention recently and there have been several important studies reported in the literature, particularly for the processing of Cu-Mo ores (S. Castro, 2012; S. Castro, Rioseco & Laskowski, 2012; S. Castro et al., 2012; Laskowski & Castro, 2012; Ramos, Castro & Laskowski, 2013; S. Castro & Laskowski, 2013; Laskowski, Castro & Ramos, 2013; Nagaraj & Farinato, 2014; S. Castro, Uribe, & Laskowski, 2014; Veki, 2013). The main conclusions from these studies on Cu-Mo ores in seawater at elevated pH were: a) flotation recovery of Cu sulfides is either unaffected or only marginally reduced, b) molybdenite recovery is adversely affected in seawater at pH values necessary for rejecting pyrite (i.e. pH > 10 to 10.8 depending upon particular system), and c) the precipitation of Mg2+ in seawater as Mg(OH)2 is responsible for the adverse effect on Mo flotation. In order to further investigate the individual effects of Mg2+ and Ca2+ on molybdenite depression in Cu-Mo ore flotation, Nagaraj & Farinato (2014) conducted flotation tests wherein individual metal ions were spiked into tap water during grinding of Cu-Mo ores. They showed the strong adverse effect of Mg2+ addition on Mo recovery and, to a lesser extent, on Cu recovery when pH > 9.5. Under similar conditions, Ca2+ had virtually no effect on either Cu or Mo sulfide flotation. Figure 1 below shows the previous results for Cu- Mo ores in tap water and the effect of addition of Ca2+ and Mg2+ ions. Note that in seawater the adverse effect of Mg2+ on Cu recovery was much smaller than that in tap water (Nagaraj & Farinato, 2014; Figure 4a and 4b and Table 4 therein)."

Jan 1, 2016

By J. A. Eisele, D. L. Pool

"The Bureau of Mines has developed a particle agglomeration technique to improve the flow of leaching solution through heaps of low-grade gold-silver ores which contain clays. Benchscale experiments and industrial practice have shown that the percolation rate of cyanide leaching solution is greatly enhanced by mixing the ore with Portland cement as a binder, moistening the mixture, mechanically tumbling to form agglomerates, and aging before heap building and leaching. A slight modification ofthe technique allows its application to precious-metal-bearing tailings, which cannot normally be treated by heap leaching because they are too fine. IntroductionMany low-grade gold and silver deposits and tailing materials from former mining operations in the western United States are potential sources for precious metals. These sources are too low grade or too small to support the capital cost of a conventional cyanidation plant but have stimulated the development of lowcost procedures, such as extraction of the precious metals by heap leaching with cyanide. The Bureau of Mines has investigated methods to improve the recovery ofgold and silver by heap leaching these low-grade materials.For heap leaching to be successful, the crushed and stacked ore must have good permeability so that uniform distribution of the cyanide leaching solution through the heaps can be achieved. Some of the most difficult gold and silver ores to treat by heap leaching are those containing excessive amounts of clays, or fines generated during crushing. Excessive amounts of slimes, generally minus 50-micrometre or 270-mesh Tyler sieve size particles, in the heap feed will slow the percolation of the leaching solution, cause channelling, or produce dormant or unleached areas within the heap, resulting in long leaching periods and low extractions. In extreme cases, the clays or slimes can seal the heap and cause the leaching solution to run off the sides of the heap rather than through it."

Jan 1, 1987

By Stephen Williams

This paper examines manning best practice in the Australian mining industry. In particular, the paper considers a range of mining operations and their manning levels as measured by operational benchmarking. The benchmarking results presented cover 15 open pit and 37 underground studies in Australia. The data was collected as part of AMC?s benchmarking and operational improvement studies conducted between 1999 and 2008. The results examine overall manning levels in mining, processing and administration functions. Manning levels for a range of mining methods, including open pit and underground methods, are segmented. Productivity measures such as ore tonnes per man day and metres developed per man day are presented and where direct relationships can be established, the relationships are described. Finally, the paper considers perspectives on best practice with regard to manning in the Australian mining industry and the limitations in application of this type of analysis in a global context.

May 1, 2009

By B. Jakovljevic, M. D. Soderstrom, T. McCallum, A. J. Quilodrán

Cytec has developed a new organophosphorus based solvent extraction (SX) reagent for rare earth separations. The new product, CYANEX® 572, has been formulated to allow efficient extraction while minimizing the strip acid requirements. The optimization of formulation strength is expected to significantly reduce the operating costs of these circuits. Modeling capabilities for CYANEX® 572 (similar to those used successfully in Cu and Co/Ni SX) have also been developed to aid in the design and optimization of the SX circuits. Simulations will be shown comparing CYANEX® 572 to a traditional rare earth extractant.

Jan 1, 2014

By Mike Anderson

The annual budget for the repair and maintenance of equipment at Syncrude Canada Ltd is in excess of 450 million dollars. Of this amount, a significant portion can be attributed to the loss of material on various pieces of equipment throughout the operation. In order to effectively battle the different wear and corrosion mechanisms that lead to material loss, it is important to understand how materials behave in the environments in which they are used. Through the work carried out at Syncrude, and work conducted with various external collaborators, significant improvements in both equipment reliability and productivity have been achieved. This paper will review some recent field trails where materials research has demonstrated the potential for significant improvements in equipment run life and reduced maintenance costs. These field trails will demonstrate the need for understanding the interaction between various damage mechanisms and the materials used in different services. The paper will also discuss current areas of focus along with future directions for further work.

May 1, 2003

By I. Osvath, I. Gombköto, G. Mucsi, Z. Molnár

"In the present research, a deposited brown coal fly ash was used as raw material for geopolymer. The reactivity of the fly ash was altered using mechanical activation, which is one of the promising methods to improve bulk and surface reactivity. The mechanical activation experiments were carried out in a high energy density mill using 5 m/s circumferential speed, and various residence times (1, 3, 5, 10, 15 and 60 min). The effect of mechanical activation on particle size distribution was measured by a laser particle size analyzer and structural changes using FT-IR. Geopolymer samples were prepared from mechanically activated fly ash with an alkali solution. The progress of geopolymerisation was monitored using an Isothermal Conduction Calorimeter. The heat flow curve obtained indicated that reactions were more prominent and started much earlier in the mechanically activated samples. This observation is further supported by the compressive strength results which also improved in geopolymers using mechanically activated fly ash. Based on the obtained results, it can be inferred that mechanical activation is a possible way to enhance the reactivity of fly ash and consequently properties of resulting geopolymers.INTRODUCTIONCoal fired power plants generate fly ash and slag in huge amount worldwide, about 780 million tons/year (Heidrich et al. 2013). Due to the relatively low utilization rate, enormous quantities of these wastes are landfilled in ponds. The fly ash is the finest grained particle fraction of the solid ash, which is transported with flue gas, and removed by electrostatic or bag filters. The fly ash has pozzolanic activity, it does not react with water, but in the presence of calcium hydroxide solution hardens and solidifies, producing a reaction product practically insoluble in water (Opoczky, 2001). The most important property of the fly ash regarding geopolymerization is its reactivity, which depends on the chemical and phase composition, the dispersity (specific surface area, particle size distribution), and the morphology of the fly ash particles, and determined by the physical properties and chemical composition of the fly ash. Geopolymers concerning their chemical structure are polysialates, where the sialate (silicon-oxoaluminate) network is built up from the bonds of Si-oxide and Al-oxide by sharing oxygen atoms (Davidovits, 1988)."

Jan 1, 2016

By Rufus L. Chaney

A new technology is available to the Ni mining and remediation community to “phytomine” Ni from mineralized or contaminated soils using rare plants which hyperaccumulate Ni to over 1% of shoot dry matter. Research has identified useful plant species, and even bred improved cultivars of Alyssum murale and Alyssum corsicum for commercial phytomining in temperate regions. All agronomic practices (fertilization, soil amendments, planting and harvest methods) needed for economic phytomining were identified to attain high yields and high Ni concentration in the biomass. In tropical regions, other species are available such as Phyllanthus which accumulate over 1% Ni in dry shoots. These species are perennial so they regrow after annual cutting to harvest biomass. Expiration of our patents on the technology opens the opportunity for other organizations which control Ni rich natural soils or contaminated soils requiring remediation to commercialize the technologies. Inexpensive methods to remediate/revitalize Ni contaminated phytotoxic soils using agronomic approaches have also been developed and demonstrated at Port Colborne, Ontario, but adoption is delayed until formal agreements with government are completed. These new simple remediation and profitable phytomining technologies can obtain Ni from soils which contain Ni well below levels considered economic for current mining technologies, and the plants biopurify the Ni so it is easy to recover Ni metal from plant ash by pyrometallurgical or hydrometallurgical technologies. Although increasing pH decreases the solubility of Ni in all soils, raising pH increases Ni accumulation by Alyssum species. Hence usual chemical extraction methods for phytoavailable soil metals such as the DTPA- or NH4-OAc-extraction cannot predict Ni accumulation by Alyssum species.

Jan 1, 2016

By M. Lahtinen, H. Takala, B. Saxén

Oxidic zinc fume dusts are formed in electric arc furnace (EAF), Waelz furnace operations, and also in the Top Submerged Lance (TSL) furnace of Outotec Ausmelt. These dusts are normally considered as secondary raw materials for zinc metal production, as they are mainly originated from steel scrap recycling or zinc plant residue processing. The latest development in zinc fuming is direct smelting of zinc concentrates in the Ausmelt TSL furnace and hydrometallurgical treatment of produced fume dust. This technology is for primary zinc production like roasting and concentrate direct leaching, as concentrates are directly treated. The various oxidic zinc raw materials differ in composition and content of impurities. Thus, they require different hydrometallurgical processes to produce pure zinc metal. In addition to zinc these dusts typically contain also lead, silver and indium, which can be recovered and can increase recovered metal value significantly. From the impurity point of view the most relevant elements in the fume dusts are iron, arsenic, fluoride, chloride and cadmium. This paper describes hydrometallurgical processes to treat Ausmelt TSL fume dusts to extract valuable metals at high recovery and also to control and separate various impurities efficiently.

Jan 1, 2014

By Ian Sherrell, Michael Pirie, Riddhika Jain

"Conventionally, direct reduced iron (DRI) mixed with char from rotary furnace discharge is cooled down before separating the char via magnetic separator. The DRI must then be reheated for further downstream processing (i.e. smelting). Outotec has developed the PyroMagTM specifically to conserve thermal energy during this separation process. DRI is cleaned by feeding hot particles directly after reduction onto a rotating surface just above a stationary magnet assembly. This allows hot feeding of the clean DRI to the downstream equipment which renders the entire process more energy efficient.Continuous testing of the PyroMagTM was performed to verify design and separation. Because the use of DRI/char was not practical for test use, the pilot plant testing was conducted using a magnetite/sand mixture heated up to and beyond the Curie temperature of magnetite. The separation was efficient for both cold and hot processing with recoveries varying from 98.6% to 99.74%. As expected, the recoveries decreased to as low as 83.99% as the temperature was increased beyond the curie temperature of magnetite (585°C). Long term separation was thermally efficient and sustainable.INTRODUCTIONMagnetic drum separators are widely used in the mineral processing industry. These low to high intensity magnetic separators are used to concentrate various magnetic material, such as iron ore, and less magnetic materials, such as ilmenite and garnet from silica and other contaminantsThere are multiple classes of magnetism based on the effect that each material displays while in and out of a magnetic field. In a simplified fashion, which is more appropriate for mineral processing, the magnetic susceptibility of a mineral is used to define it as being ferromagnetic, paramagnetic or nonmagnetic. In this respect, minerals with varying degree of magnetic susceptibility can be selectively separated with different types of magnetic separation equipment in different stages of a process flow sheet. The lower strength magnets are employed early in the process to remove highly magnetic fractions. Later stages utilize greater magnetic fields for capture of less magnetically susceptible material."

Jan 1, 2016

By N. Bartie

Realising the circular economy (CE) is faced with some significant challenges. Process metallurgy and its infrastructure play key roles at the heart of making the CE work. Therefore, the enabling role of process metallurgy within the CE will be central to the discussion in this paper, touching among others on product and system design as well as the key metallurgical and other process fundamentals that need to be investigated and understood to make the CE a reality. The central role of materials and its processing will be discussed in an integrated circular cities perspective. A key focus will be a discussion on designing a resilient “Smart Materials Grid” using and innovating metallurgical process engineering tools, which will manage the flows through Sustainable Circular Cities. The discussion will be using copper as leitmotiv of the discussion i.e. from copper ore, to metal, to complex products, recycling, product design and simulation and its impact. INTRODUCTION The transformation of our economies from linear to circular models in which waste materials become resources is the focus of the Circular Economy (CE) paradigm. Its important intentions: to take control of the damage we have been doing to the planet to ensure its livability and the welfare of future generations. This can only be achieved through careful utilisation of human, natural and economic resources. The concept is derived from several others (Beaulieu et al., 2015), of which Cradle-to-Cradle, Extended Producer Responsibility (EPR), Industrial Ecology, and Life Cycle Thinking are just a few. Other relevant concepts include resource efficiency (RE), design-for-recycling (DfR), and various others discussed by Blomsma and Brennan (2017) and Homrich et al. (2018), as well as various R-hierarchies e.g. Reduce, Reuse, Recycle (3R). However, does society comprehend these concepts, the actors and actions that influence them and how they interact? Do we know the limits of CE? Does society understand the key role of Copper and other metals to rendering the CE operable? True life cycle and systems thinking, focussed on simulation-based, process and metallurgical design are required to answer these questions. Lieder and Rashid (2016) identify nine widely-varying fields that study the concept ranging from sustainability sciences and engineering to economics, business, law, and social sciences. Overlap between questions addressed highlights the need for interdisciplinary collaboration (Nanz et al., 2017) in the assessment of the current status, and further steps needed to transform to CE. This doesn’t apply just in academia, but also in industry where concrete implementation of CE needs to occur at multiple levels, thus necessitating cooperation between government, civil society and other stakeholders (Beaulieu et al., 2015).

Jan 1, 2019

By S. B. Mishra

Ni-20Cr metallic coating was deposited on a Ni-based Superalloy (3Fe-19.5Cr¬0.3Ti-Balance Ni) by a shrouded plasma spray process; NiCrA1Y was used as a bond coat. Erosion studies were conducted on uncoated and plasma-spray coated superalloy specimens using an air-jet erosion test rig at a velocity of 40 m/s and impingement angles of 30° and 90°. The coating has been characterized for porosity, microhardness and microstructure and X-Ray Diffraction (XRD). An electron probe micro analyzer (EPMA) was used to obtain X-ray elemental mappings of the coating along the cross-section. Scanning electron microscope (SEM) with EDAX attachment was used to analyze the eroded surfaces.

Jan 1, 2005

"During the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests.In the current case, a composite sample of gold ore is dedicated to a Gravity Recoverable Gold (GRG) test. The properties of interest are the head grade of gold, the size distribution of the material, and the gold assay per size class. The sample is mixed and a sub-sample is taken to measure the feed properties: the size distribution and the gold assay per size class. The remaining material of the sample is subject to the first stage of concentration using the laboratory Knelson concentrator. The concentrate is analysed in its entirety, while a sample of tailings is taken for the same analysis. The remaining part of tailings is subject to grinding to feed the second and third stages of concentration. Similar sampling is performed at each stage.The concentration performances are analysed in light of these measurements. But what is the accuracy of the measurements of the properties? Pierre Gy’s theory of sampling, associated with a heterogeneity model built using the GRG test results, will answer this question. The current paper presents, through a real example, the calculation of the errors of the measurements of size distributions and gold assays performed during the GRG test. The uncertainties of the concentration performances and liberation size estimate are then calculated and their impact on the results interpretation is analysed.INTRODUCTIONDuring the development of a mining project, samples are taken for metallurgical tests. The sample can be a composite sample made of material from a selection of various drilling products or a sample from a mining test. It can be also a sample from an existing plant in order to investigate process enhancement. This sample can represent several tonnes of material which are analysed and split for use in various tests. In order to take into account the ore variability in terms of gold deportment, it is recommended to perform variability studies (Dominy, Murphy, & Gray, 2011, Dominy, 2013) using samples representing various horizons or years of production. But for a given ore type, it can be necessary to perform many tests with different operating conditions (Brochot, 2012a). In that case, the variability of the samples is not due to the heterogeneity of distribution of the deposit, but only on the heterogeneity of constitution of the primary sample. The level of confidence associated with the estimated performance parameters is directly linked to the overall error (including sampling error) of the measurements performed during the tests."

Jan 1, 2016

By R. Browner, J. Collard, D. Ibana

The extraction of cobalt from synthetic pressure acid leach solutions of nickel laterite ores by the direct solvent extraction route using ESPLIM is reported. It first explored the use of gaseous ammonia as pH modifier and then the variables that affect the dispersion of the aqueous phase in the organic phase such as ionic strength, viscosity of the phases, initial droplet size, etc. were explored so that phase hold-up and thus extraction can be effectively controlled. The results show that the technique allows better control of phase dispersion circumventing one of the main weaknesses of conventional solvent extraction.

Jan 1, 2005

By F. P. Hassani, J. F. Boily, A. M. O. Mohamed, M. Hossein

The optimal geochemical parameters required to form ellringite in a lime-remediated site have been investigated with the use of thermodynamic modelling. The speciation of sulphate and 10 metals analyzed in samples of a mine tailing from northern Quebec was calculated with a computer model. The model also includes calcium, which would result from the addition of lime to the system. Two speciation calculations were done. The first one is a hypothetical speciation before the onset of precipitation and was used to devise the stability fields of minerals susceptible of forming in high pHs. The stability fields were determined by building activity ratio diagrams with sulphate, aluminum and calcium species concentrations for pHs ranging from 4 to 14. The investigation was carried out for a 25°C solution with an ionic strength less than 0.12. Thermodynamics predict that an optimal stability field for ettringite in the mine tailing samples containing 10-3 mol/L SO4-2,10-2 mol/L of AI(OH)4 requires at least 10-2mol/L of Ca+2 and a pH larger than 11.6. The sulphate contents of the mine tailing samples, however, limit the precipitation of ettringite and monosulphate could be an end-precipitate. The second speciation is in equilibrium with precipitates and provides information on the speciation of the residual metals. If ellringite could be precipitated as a stable form, it could serve as a sorptive agent for residual metals, and, due to its binding properties, consolidate tailings.

Jan 1, 1995

By Andrew Bamber

Outline ?Background to Mine-Mill Research at UBC ?Mine Mill Integration ?In situ mining methods ?Underground Pre-concentration ?System Design and Supporting Technologies ?Case Studies: ?INCO -McCreedyEast Mine ?Placer Dome ?Porcupine JV ISL Study ?Musselwhite, South Deep ?Falconbridge ?Fraser Copper ?Thayer Lindsley ?Wayside Gold, other scoping studies? ?System Designs ?Summary ?Future work ?Conclusion

May 1, 2006