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By W. K. Smith, V. P. Krueger, D. C. Mulder

"AbstractThis paper describes the geological procedures used to evaluate two mineable high-volatile C bituminous coal seams at Coal Valley , located in the outer foothills belt of the Rocky Mountain Eastern Slopes in west-central Alberta. Lexco Testing Ltd., the exploration arm of Luscos: Ltd., owns and operates an all -weather geophysical logging system which provides gamma, focused density , single-point resistance and caliper logs in a single pass. A mathematical analysis for a theoretical interpretation of the single-point resistance log confirms empirical research that bed boundaries are located at a point 10% from the bottom of the curve. A unique and efficient triple-tube, wireline rotary coring system cuts an undisturbed 0.076m- diameter core in a plastic liner at recoveries exceeding 90% . Although only 10% of the total footage is cored, it provides vital analytical and geotechnical data, and, when integrated with the geophysical logs, improves the quality and extends the usefulness of interpreting both sets of data. All data are programmed to produce computerized structure contour, isopach, isoratio and isoquality maps, and volume calculations.General IntroductionTHE COAL VALLEY AREA is located in the outer foothills belt of the Rocky Mountain Eastern Slopes, 60 miles (96 km) by road southwest of Edson, Alberta. Luscar Ltd. holds leases which total 49,000 acres (19,830 ha) , of which 18,300 acres (7,410 ha) have been assigned to the Coal Valley mine area (Fig. 1 ) . There are two Paleocene high-volatile C bituminous coal seams initially developed for mining within a total stratigraphic interval of 750 feet (230 m ) (Fig. 2 ). These seams strike generally NW, and in the undisturbed areas generally dip westerly from 10 to 30 degrees."

Jan 1, 1977

By J. Currie, J. McManus, R. Chenier

"Cominco Copper Division's Valley Mine is located in the Highland Valley of British Columbia, approximately 275 km by air northeast of Vancouver. The nearest towns are Logan Lake, located IS km to the east and Ashcroft, located about 50 km to the northwest.Preproduction stripping of rock and overburden at the Valley Mine's Lake Zone Pit began in mid-1982 following a decision to discontinue mining in the adjacent Jersey Pit. Equipment and mining methods were carried over from the Bethlehem Copper operations which, with Valley Copper Mines, were merged into Cominco in December 1982.Blasting practices, as carried over from the Bethlehem pits, were designed to provide the fine fragmentation required to meet production requirements using the Bethlehem crusher. However, after mining the first few benches of the Lake Zone Pit, it became apparent that overblasting at the pit limits was causing a number of bench failures, as well as contributing to an over-all reduction of the material strength of the rock mass forming the southwest wall of the pit.With present ultimate pit plans calling for the southwest wall to be as high as 300 m, Valley staff realized that potential slope stability problems should be dealt with as early as possible. This philosophy would enable experimentation on phase pit walls in order to attain the optimum slope angle on the ultimate pit wall.As part of an over-a ll slope stability program, a controlled blasting program was initiated at the Lake Zone Pit in March 1983. In this program, Valley engineering and production staff worked together with Golder Associates in establishing design criteria and evaluating the results. This program resulted in a marked improvement in the soundness of pit walls while maintaining the required degree of fragmentation."

Jan 1, 1985

By Blaycock. S. C.

WE should indeed feel proud and satisfied with the accomplishments of our great mining and metallurgical. industries during the past quarter of a century, for they have vastly exceeded those of any previous period of like duration. 1 feel that Canadians, and particularly those in the mining industry, should know more concerning the important role our industry will be called upon to play in the present war. Our Empire metals will be an outstanding factor in this conflict. Every man connected with the industry, from the lowest paid labourer to the highest official, can feel proud that his every effort results in more and more production of those metals which will help to give the Empire supremacy. He can feel assured that, by sticking to his job and by putting his whole heart into his work, he is making a contribution towards winning the terrible struggle in which our Empire and our gallant French allies are engaged. These two great peoples will have ro bear the brunt of the task of ridding the world of the menace of those who would set up force. and might in the place of right and justice in the settlement of international affairs. As the present European crisis developed, it became evident that they, alone, would have to accept the challenge and fight the enemies of Democracy to ensure the survival of the small nations of Europe and, indeed, of the great democratic powers themselves. The acquisitive eye of the German leaders had looked far ahead and they had realized that the eastern European states, already reeming with population, were no solution to Germany's space problem; but they thought that these states could be gobbled up one by one, each in turn strengthening Germany's might until it could successfully challenge France and England. No glimmer of doubt dimmed their vision. The two great democracies once subdued, they could proceed to seize Canada and the United States. This clone, they would have an abundance of room to expand, as well as those resources-grain, timber, cotton, nickel, iron, lead, zinc, copper, gold, silver, sulphur, oil-which German statesmen have always coveted. Von Ribbentrop, von Alvensleben, Bernstorff, and many others have made exhaustive studies of our resources. German rulers had been told that the French would not fight and that the British could not. They knew of the rust on the British war machine. There was no cloud in the sky; their fond dream was at last robe fulfilled.

Jan 1, 1940

By Erwin L. Zodrow

"For 25 chemical elements in electrostatically precipitated fly ash (Lingan coal-fired power station), concentration changes are studied as a function of increasing proportions of fines (ash particle diameter less than 45 micrometres). Elements that are involved when concentrations increase as the proportions of fines increase are likely to escape into the atmosphere. These are Th, U, As, S, P, Sb, Na, Ag, Zn, Pb, Ni, Ba, Sc, AI, Mo (and Bi, Ge, Ga, F and Li), i.e., more or less highly volatilized elements. Of the less volatilized metals such as Fe, Ca, Cu, Ti, K, Co, Mn (and lanthanides), certain portions presumably also escape as stack emissions. Diadochy and spinel formation in bottom slag is presented as an emission-reducing agent for certain metals.IntroductionThe Lingan coal-fired power generation plant, owned and operated by the Nova Scotia Power Corporation, produces annually about 140,000 metric tons of ash (the residual mineral content after burning coal). The tonnage is based on a 15 per cent average ash content of Cape Breton coal.For purposes of this report, samples of the hard, fused slag (bottom slag) that is accumulated at bottoms of boilers, and electrostatically precipitated fly ash (ep ash), were collected and investigated. Bottom slag is a minor component of the produced ashes.The ashes were surveyed and the presence of over 75 major, minor and trace elements is reported. From this survey, 25 elements were selected to establish elemental enrichment/depletion trends when the proportions of the less than 45 micrometre <45µm) fractions in ep ashes increase. The results are significant in that, taking the case of elemental enrichment, the elements involved are likely to escape into the atmosphere, i.e, highly volatilized elements. Depletion trends for elements are presumably associated with less volatilized elements during coal-firing. Quantification of the emission of atmospheric pollutants is not considered part of this work. ""Igneous"" minerals generated during coal combustion include spinels (found mainly in the bottom slag), quartz, glass and mullite."

Jan 1, 1982

By M. Bourassa, P. Roy

"This paper describes the automation of Kiena's grinding circuit which comprises an open SAG mill circuit and a closed ball mill circuit with two stages of hydrocyclones. The circuit has been instrumented according to a two level control strategy.The regulatory control strategy is implemented in an industrial controller. This controller does data filtering and calculation (flowrate and solid content) and regulates the pump box levels (2), the water additions: or the pulp percent solids (4) and the fresh ore feed rate.The supervisory control calculates for the industrial controller, the fresh ore feed rate setpoint and the pulp percent solids setpoints in order to optimize the grinding circuit operation. It is made of two modules, one for data filtering and one for control optimization. The filtering program uses modern tools to adjust the measured value and estimate missing data (dynamic material balance, on line estimation of model parameter, etc.). The control program acts as an expert system which combines the benefits of model-based control and rule-based control. A multivariable predictive controller (DMC) is used to maintain the circulating load and the hydrocyclones feed percent solids (which is correlated to particle size) while the rule-based control validates the previous output, detects and avoids the SAG overloads and sump pumps overflows.The system has been operating since MAY 1992 and the benefits obtained are discussed.INTRODUCTIONIn 1990, Les Mines d'Or Kiena decided to go ahead with a project for automating its grinding circuit as proposed by the Centre de recherché minerals (CRM). Its objectives in doing so were to marginally increase production capacity (1 % ) and to create a new challenge for plant staff. The main stages of the project, which involved CRM, Kiena Mines and a consultant, are shown in Table 1. The project was completed in May 1992 with the implementation of a supervisory control system. This text describes the main features of the system with a special focus on its most innovative aspects."

Jan 1, 1993

By Michel Garon

"Several years ago computer control of the flotation process was successfully implemented at the Matagami concentrator of Noranda Mines Inc. At that time this was the first computer application being installed at this operation. The last few years have seen an extensive use of programmable controllers in areas such as the copper and zinc dewatering circuits and the lime preparation system. With the aid of such instruments, these areas have attained a high level of automation and as a result, a high degree of efficiency. The controllers have proven to be very dependable and easy to use.IntroductionThe Matagarni Division of Noranda Mines Inc. operates two mines in the Matagami District of northwestern Quebec which is located about 650 km northwest of Montreal. The mines ship ores to a central concentrator whose throughput averages 95,000 tonnes of ore per month. Metal contents of the mill feed average 0.9 per cent copper and 5.0 per cent zinc. Concentrate outputs are approximately 3,200 tonnes of copper and 8,200 tonnes of zinc per month.The concentrator commenced operation in 1963. An on-stream X-ray analyzer was installed in 1968, providing analyses of several samples in the flotation circuit without the aid of a computer. In 1974, control of the circuit by computer was added to the system. As a result, zinc flotation efficiency improved considerably and reagent costs decreased through the reduction of copper sulphate consumption.In the past few years it was realized that significant improvements could also be made in other parts of the operation . Copper and zinc dewatering circuits and the lime preparation system were identified as major areas that could drastically benefit from automation. In 1982, programmable controllers were seriously considered as an attractive alternative for achieving the company &apos;s goal. Because of their relative lowcost and their high degree of flexibility, they were selected for implementing automation and, for improving the efficiency in each of these areas."

Jan 1, 1985

"The Cordillera contains numerous porphyry deposits and prospects, many containing economic quantities of copper, molybdenum, gold and tungsten. Over the lost twenty years, different phases of exploration have been driven by individual commodity prices and new discoveries. Exploration methods have remained largely unchanged since the 1960s and 1970s with the range of techniques chosen for each situation depending on the stage of the program, the type of porphyry target and the local environment. Improvements or changes to techniques have resulted from awareness of specific features in new deposits or regional problems. During the last ten years much of the emphasis has been on the re-evaluation of known porphyry deposits with more exploration in areas previously recognized as prospective. Re-evaluation of known deposits has resulted in increased reserves, often with improved gold grade, and the discovery of new zones. Several new deposits have been discovered including gold-only deposits of probable porphyry affinity.Research related to porphyry deposits has followed trends in exploration and has been directed toward the type of deposits that have been of current interest. In addition to research on specific deposits and areas, general research related to porphyry deposits has addressed three broad themes. The first theme involves the role of tectonic processes and the nature of source regions. Although different in detail, recent tectonic models suggest that a tectonic change or hiatus may be important for the generation of metal-rich magmas from various source regions and subsequent fractionation that permits volatile saturation. The second theme is based on magmatic processes, particularly the generation of a volatile phase enriched in metals. This research supports the general orthomagmatic model for porphyry deposits and has helped to define the influence of specific variables in the generation of different types of porphyry deposits. Finally, research on alteration and mineralization has provided evidence for different types of fluids and fluid processes involved in the formation of porphyry deposits. These data also support the orthomagmatic model but indicate additional complexity in magmatic-hydrothermal systems including the role of external fluids. Although important advances have been made, research has had a limited impact on exploration.Exploration and research on deposits that occur in the peripheral and upper parts of porphyry systems have been important over the last ten years. Although considerable advances have been made, the relationship of different styles of peripheral mineralization to magmatic processes in the core of the system remains ambiguous. An improved understanding of the processes that generate zoning, peripheral mineralization, and the surrounding alteration envelopes would be beneficial to exploration."

Jan 1, 1995

By H. J. McQueen

The modeling of the extrusion of 6061 alloy and its composites with 10 to 20 vol% Al203 or SiC by two techniques. The uniaxial finite element method FEM (DEFORM" ) provided force-stroke curves and temperature rise over the range 450-500 °C, 2.6-5mm/s and extrusion ratios of 31 and 64. The traditional technique considers ideal work and redundant work as well as friction and uses average temperatures and strain rates. The two techniques are used to clarify each other and to extend the analysis to 400 and 350 °C. The calculated efficiencies are compared to measured values in extrusion trials and to values derived for 7075 extrusion analyses. The analyses are based on constitutive equations determined by torsion testing tests.

Jan 1, 2004

By J. Chao, C. Tan, N. Stubina

"Since J978, Falconbridge Limited has operated two electric furnaces at its nickel-copper smelter in Sudbury. As part of its S02 Abatement Program, the smelter has undergone many changes over the last seven years.This paper describes the impact of these changes on the operation of the furnaces. Some of the topics to be covered include: the installation of sidewall copper coolers; current operating conditions; and furnace heat and mass balances. HistoricalFalconbridge began smelting ores in the Sudbury area in 1930. The original smelter consisted of a 1.3 m by 3 m blast furnace and two 4 m by 6 m converters. The blast furnace was supplied with untreated mine are and molten slag/matte was discharged into a round settler.In 1933 the smelter began treating flotation concentrates. The concentrates were mixed with fine magnetic ore and flue dust, then sintered on down-draught Dwight Lloyd machines. This provided an agglomerate suitable for furnace burden which was charged to the blast furnace while still hot.Between 1930 and 1954 nickel production was increased by lengthening the 3 m furnace to 4.6 m, then to 6 m, and later by constructing additional furnaces. By 1958, the plant consisted of one 7.5 m blast furnace, a settler, and three 4 m by 9 m converters."

Jan 1, 1994

By R. D. Brown

Manitoba has now joined Ontario and Quebec in providing for new incentives and lower tax rates for the mining industry. A single rate of tax (to replace the former two-tier royalty), an investment tax credit and a relatively straightforward set of rules for calculating taxable mining profits are the main features of new mining tax legislation announced by Manitoba&apos;s Finance Minister Donald W. Craik in his May 15, 1979 budget address. On introducing amendments to reform The Metallic Minerals Royalty Act, the Finance Minister indicated that the new tax regime is intended to restore the Manitoba mining tax system to a competitive position in Canada, and should result in renewed investment in the province&apos;s mining industry. 1n this regard, the government could be right-there is little question that the new tax regime will produce greater incentives for the mining industry than the two-tier royalty system introduced by the New Democratic government in 1975. The proposed changes, contained in Bill 57, would largely be effective January I. 1979.

Jan 1, 1979

By A. S. H. Kabir

Due to the high specific strength and excellent corrosion resistance, Ti-6A1-4V has been widely applied in aerospace industries. In this study, the welding performance of 3.2-mm and 5.1-mm thick Ti¬6A1-4V sheets was studied using a 4 kW continuous wave Nd: YAG laser. It is found that the use of filler wire, matching the parent metal composition, can bridge the joint gap and produce full penetrated welds up to a width of 0.6 mm without cracking. The laser welds were characterized in terms of the bead geometry, defects, microstructures, and hardness. With increasing joint gap, the percent porosity area increased, reaching just over 1% of the fusion zone area at a gap width of 0.6 mm for the 3.2 mm and 5.1 mm thick sheets. The maximum underfill depth in the Ti-6A1-4V laser welds was about 5% or 7% of the sheet thickness for the 3.2-mm and 5.2-mm thick materials, respectively, meeting the AWS D17-1 specification. The microindentation hardness was maximum in the fusion zone and sharply decreased through the heat affected zone until reaching the base metal value.

Jan 1, 2011

By I. Haskett

ABSTRACT The Redwater pool, in north-central Alberta, was discovered in October, 1948, and at the end of 1950 was about 85 per cent developed. Production is from a Devonian coral limestone reef and is found at an average depth of 3,150 feet. The pool has an estimated .productive area of 37,000 acres, and a maximum oil zone thickness of slightly over 200 feet. Wide variations exist in both type and values of porosity, with the average value determined for the reservoir being 6.16 per cent. The total stock tank oil in place is about 1.24 billion barrels. The crude has a saturation pressure of 485 psig, com-pared to the original value of 1,050 psig for the reservoir, and the principal recovery mechanism so far has been the natural water drive. Cumulative production to January 1st, 1951, has been about 15.5 million barrels. These withdrawals resulted in a reservoir pressure decline of slightly over 100 psi. Predictions of future behaviour indicate that the water drive will not be of sufficient magnitude to maintain the reservoir above saturation pressure past 1953, and that, with natural depletion, the pool will be produced largely by a solution gas drive. Pressure maintenance by water injection has been considered and the possibility of raising the pressure to the original value of 1,050 psig is also discussed. INTRODUCTION WITH the discovery of the Lewduc pool, early in 1947, the Devonian limestone became the major geological formation contributing to Western Canada&apos;s rapidly growing petroleum reserves. Redwater, discovered in October, 1948, is now the largest known Devonian pool in Canada, with a recoverable reserve estimated at approximately 500 million barrels. Until recent years, the knowledge of the nature and characteristics of this type of limestone reservoir has been comparatively limited.

Jan 1, 1951

By Tom Dettweiler

Who We Are A global pioneer in discovery, development and recovery of deep-ocean assets Shipwrecks Deep-sea Minerals Company Overview Founded 1994 HQ ?Tampa, Florida USA Employees 45 Tampa + 150 Abroad Publicly Traded: NASDAQ:OMEX Requires Specific Financial Controls and Reporting

May 1, 2013

By Jarret Thomson

An understanding of groundwater flow is essential for many aspects of mining. This is especially true for the process of shaft sinking through the sandstones of the Manitou Falls Group in the Athabasca Basin of northern Saskatchewan. Experience has shown that the hydraulic conductivities of these sandstones can be relatively high, especially in zones containing natural fractures. To develop a better understanding of the inflow potential into a shaft, a laboratory testing program was undertaken to investigate the hydraulic conductivity of fracture core samples from the Manitou Falls Group. This program involved the measurement of hydraulic conductivities under steady-state flow conditions, while cycling the effective confining pressure across a span that is representative of in-situ conditions. The change in fracture aperture was simultaneously recorded at each confining stress level. It was found that existing relationships relating aperture and flow did not accurately capture the behavior of the samples tested. The effects of fracture staining and infilling were also investigated, and were found to have a notable impact on the hydraulic conductivity.

Jun 1, 2012

By Alyson Morley

The mining sector in Canada is facing significant challenges to develop a competent workforce, including increased technical and logistical operational demands, and the imperative to promote local content. There is an increasingly unpredictable labour pool which can be aging, or have skill shortages, or non-aligned skills. As globalisation continues, companies also require efficiencies during operation across various locations. AMEC has met these challenges in the global oil and gas sector by developing our Capability Development and Competence Assurance (CDCA) program. CDCA is applicable across all process industries, including mining. CDCA supports simultaneous consistency and flexibility by defining competence at task level, with corresponding best practice blended training programs, and evaluation criteria and processes. CDCA then defines role profiles mapped to local task definition. When combined with web-based technology, this granularity allows us to manage high volume workforces, while retaining individual learning plans and progression, aiding job satisfaction, and employee retention.

May 1, 2007

By F. Vahdatikhaki

Simulation techniques have offered significant boosts toward a cost-and-time-optimized planning of construction projects by enabling project managers to effectively comprehend the behavior of projects. Using historic data from projects of like nature, simulation considers uncertainties involved in a project through accommodating the stochastic modeling parameters. However, the heavy reliance on the statistical data and not taking into account the context-specific features of the project cause the degradation in the realism and accuracy of the simulation models. Similarly, the extent to which a historic pattern could be retrofitted to new projects will decrease in line with the growing uniqueness of the projects and the novelty of construction methods. Furthermore, the existing real-time simulation frameworks are not capable of distinguishing the transient environmental changes, with minimal long-term impacts on the productivity, from the influential changes that will greatly impact an operation. In addition, existing simulation tools are devoid of location awareness, resulting in the inability to consider safety threats in their representation of the project. To address these issues, this research proposes a framework based on the integration of new tracking technologies used in Automated Machine Guidance (AMG) with simulation-driven 4D modeling methods. The proposed framework automates the adjustment of the simulation model based on the updated data from the site, and thus transforms simulation from a predictive tool used at the planning phase to a proactive monitoring platform usable throughout the planning and construction phases. A prototype is developed to test and demonstrate the effectiveness of the proposed approach.

Aug 1, 2013

By John H. Schloen

"The object of this paper is to review electrolytic copper refining as it was in 1954(1), as it is now in 1984, and to comment on the many improvements which have been made in the last thirty years.In 1954, and even in 1984, the ASTM specification B 115 for cathode copper was 99.90% minimum copper plus silver content and 100% minimum electrical conductivity, IACS standard. However, to meet competition and to satisfy the requirements of the fabricators and the electrical industry, the electrolytic refinery must supply a product of 99.95% to 99.96% minimum copper content, and 101fJlo minimum electrical conductivity.The range of cathode impurities reported by 20 major copper refineries in 1954 are given in Table I.The much more rigid British Specification, DD 78, for high-purity cathode copper, specifies individual elements, as well as groups of elements, as shown in Table 2.The Svenska test has been replaced by a similar procedure which uses 2.r mm diameter wire. The ISO test is the one listed in the DD 78 specification. In Table 3, corresponding values for the Svenska and ISO test s are given for various wire bar coppers."

Jan 1, 1986

By Hajime Miki, Gde Pandhe Wisnu Suyantara, Ahmed Mohamed Elmahdy, Hidekazu Matsuoka, Kyushu University, Tsuyoshi Hirajima

"Selective flotation of chalcopyrite and molybdenite was studied using various surface treatment methods such as electrolysis, ozone treatment, and plasma. Oxidation via electrolysis method indicated that only chalcopyrite surface is affected by electrolysis due to conductivity difference with molybdenite. Oxidation treatments and XPS analyses indicated that chalcopyrite became hydrophilic due to deposition of oxidized iron on its surface. Various oxidizing methods also showed that chalcopyrite was selectively oxidized and this can apply selective flotation of chalcopyrite and molybdenite. The possible mechanisms are proposed in this work based on surface analyses and thermodynamic calculations.INTRODUCTIONCopper sulphide minerals often associate molybdenite (MoS2) which is one of the most important by-products (Wills, 2006). It is important to recover molybdenite perfectly not only since molybdenite is valuable mineral, but also contamination of molybdenite into copper concentrate or contamination of copper mineral into molybdenite concentrate indicates penalty for both concentrate values (Wills, 2006). Conventional separation of copper sulphide and molybdenite has been achieved with sulphide bulk flotation followed by selective molybdenite flotation with NaHS addition since NaHS works as a depressant for copper sulphide. However, this current process shows imperfect molybdenite recovery and depressant such as NaHS needs to be used under specific flotation plant since it might be environmental contaminant. Hirajima et al., (2014) have been studied selective flotation of molybdenite and chalcopyrite (CuFeS2), which is the most important copper mineral, with plasma pre-treatment. They reported that plasma pre-treatment process followed by washing treatment can improve molybdenite floatability and depress chalcopyrite. This result is attributed to surface oxidation and selective conversion of chalcopyrite and molybdenite wettability. It may be hypothesized that another surface oxidation methods could give a similar result as plasma treatment process. To test this hypothesis, in this study, as comprehensive study of oxidation effect, various oxidation methods such as electrolysis, ozone, and plasma were investigated. Electrochemical measurements, thermodynamic calculations to predict the chemical reactions happened during the process, various surface analyses, and flotation experiments were carried out."

Jan 1, 2016

By R. A. L. Drew, J. P. Immarigeon, F. Jalilian, M. Jahazi

In the present work TLP bonding of Inconel 617 is investigated. The influence of the main processing parameters i.e. time and thickness of the interlayer were studied with optical and scanning electron microscopy. Boron containing interlayers with two different thicknesses were used and the influence of various holding times from 5 min to 24 hours on the microstructure of the bond region was investigated. The results indicated that, for the testing temperature of 1065°C and holding times above 2 hours with an interlayer of 25.4 microns thick no liquid phase was observed. The same phenomenon occurred only after 6 hours for a 76.2 microns thick interlayer. Precipitate growth started at grain boundaries and continued inside the grains. The composition, size and morphology of the precipitates were studied using electron microprobe analysis. No noticeable changes were observed in the grain size of the base metal with increasing holding times.

Jan 1, 2004

By Imane Benhamed, Jaouher Diouani, Laurent Cassayre, Florent Bourgeois, Carine Julcour-Lebigue, Université de Carthage

The attrition-leaching process aims at improving leaching performance when formation of passivation layers at the surface of leached particles is a severe limiting factor, as discussed recently by Julcour and coworkers (Julcour et al., 2015). This paper proposes a geochemistry-based modelling scheme for deriving the window of possible operating conditions for the attrition-leaching process to match the properties of the processed ore. The rationale is that the attrition-leaching process maintains the surface of reacting particles in an unpassivated state by continuous mechanical removal of surface leach layers, so that the process reactions can be modelled from thermodynamic equilibria throughout the duration of the process. The strength of the proposed modelling approach is that it bridges the gap between the properties of the ore and the process operating conditions. The present paper exemplifies the proposed process modelling route for derivation of the attrition-leaching process operating conditions in the context of the leaching of silicate ores, matching model predictions against controlled laboratory experiments. It is shown how thermodynamic modelling, when used in conjunction with a solid knowledge of the phases present in the system, can assist with deciding upon suitable process operating conditions. As an example, this firstprinciple modelling approach predicted that steel grinding medium would be converted into siderite (FeCO3) under a wide range of operating conditions, which led to questioning this initial choice of grinding medium for the attrition-leaching process under mineral carbonation conditions. It is emphasised that the same approach could be applied to ores of greater economic significance.

Jan 1, 2016