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By Ron Davidson

"The Utility Mine in southeast Saskatchewan is owned by Saskatchewan Power Corporation and operated by Mana/ta Coal Ltd. Up to 3.3 million tonnes of lignite is supplied annually to Saskatchewan Power's Boundary Dam Generating Station. The coal occurs in two predominant seams which are covered by up to 37 metres of saturated fine-grained overburden. Overburden is removed by two draglines working in two pits. Coal is hauled to the mine mouth power station. Comprehensive drainage and reclamation programs are integral parts of the operation. IntroductionThe Utility Mine is owned by Saskatchewan Power Corporation and operated by Manalta Coal Ltd. It is located in southeastern Saskatchewan, approximately 200 km southeast of Regina and 8.5 km southwest of Estevan (Fig. 1). The climate of the Estevan area is semi-arid with long, cool winters and short, hot summers. The mean annual precipitation is 42 cm and the mean summer temperature is 20°C; mean winter temperature is -10°C. The Utility Mine supplies coal to the adjacent Boundary Dam Generating Station. Increases in the station's generating capacity during the past decade have resulted in an extensive expansion program for the Utility Mine. This expansion program, the geological conditions present in the area, and the mining/reclamation operations will be highlighted in the following sections<1.2). History The Estevan area has a long history of coal mining. In the early years, coal was mined via entries into coal seam outcrops along the slopes of the Souris River valley. Surface strip mining was introduced in the late 1920s and progressed to the point where it totally replaced underground mining by the 1950s. Surface mining methods are currently used exclusively by all of the Estevan area operators."

Jan 1, 1985

By A. J. Antony Chettupuzha

During a construction project, it is important to ensure that accurate and pertinent knowledge is delivered on time to appropriate personnel. The criticality of documents exchanged or referred to by various parties, evolves over the course of the project lifecycle. Determining the criticality of documents at different stages of the project can aid companies with managing the flow of information in an organized manner, while providing for the detection of potentially disruptive, erroneous material that could result in delays and costs. Therefore, it is crucial to determine documents which have the potential to disrupt a process (by virtue of being incorrect versions etc.) so that they may be isolated or prevented from entering or interfering with the active flow of information in a project, while also ensuring standard revisions of documents are recognized and accessed accordingly. Electronic Product and Process Management [EPPM] systems provide the capability to establish and map information flow between different parties in a construction project. Analyzing an EPPM system may yield information about the criticality of certain documents within an activity, as well as isolate characteristics peculiar to documents which can assist in risk mitigation. We propose methodology that identifies such critical documents.

Aug 1, 2013

By G. Molloy

The purpose of this paper is to demonstrate the value of applying continuous improvement, in particular 5S and standard work, in an underground environment. 5S and standard work are two aspects of Lean manufacturing that have been applied in many industries. At Vale Canada Limited, the focus is to first stabilize the process, commonly through the use of 5S, standard work and other continuous improvement techniques. In parallel with building an engaged workforce, these approaches aim to incrementally stabilize and improve a process. 5S is an employee-driven, systematic methodology to reduce waste in all its forms through attaining, maintaining, and improving workplace organization. Identified as a foundational part of any improvement process, 5S aims to remove wastes that impact on the overall efficiency of the area. Standard work is used to formulate a common approach to how tasks are carried out to ensure consistency. Standardization involves identifying, establishing, and following the best method. The aim is to eliminate the variation that can occur when there is not a pre-defined established standard. Demonstrating the value of 5S and standard work in an underground environment will be achieved by first understanding the overall concept of Operational Excellence and continuous improvement as practiced within our operations. The paper will then cover a real application of 5S and standard work within the underground environment at Thompson, Manitoba.

Aug 1, 2013

By Don Lemmen

Impacts, Adaptation and Vulnerability ? regional climate changes (temperature and extreme events) have already affected many physical and biological systems ? natural systems are vulnerable to climate change, some will be irreversibly damaged ? many human systems are sensitive to climate change ? Projected changes in climate extremes could have major consequences

Nov 1, 2002

Overview of Presentation Why Enter Agreements with First Nations Making it Win-Win ?The Principles The Process Making the Process Work Resource Agmts Defined Resource Agreements are legally binding agreements between a resource company and the First Nation(s) whose Aboriginal or Treaty rights may be impacted by the activities of the proposed project

May 1, 2009

By Junto Nishiwaki, Shinji Kumai

"Mechanical and physical properties of the impact welded dissimilar metal joints are controlled by joint interface morphology. An intermediate layer (IML) is often formed at the joint interface and this deteriorates the interface quality in some metal combinations. Numerical and experimental studies were performed in order to examine the formation mechanism of the wavy interface and intermediate layer for explosive welded Al/Cu dissimilar metal joints. The impact welding process consists of (1) high-speed oblique collision of metal plates, (2) metal jet emission and large deformation and temperature increase at collision point and (3) rapid cooling at the joint interface. Euler-Lagrange coupling method, smooth particle hydrodynamic (SPH) method and modified laplacianFoam (LF) method were linked together to simulate a series of processes from (1) to (3), and the final interface morphology including the formation of IML was reproduced. The wavy morphology (wave-height, wavelength) and the position and composition of IML formed at the joint interface of Al/Cu joints were quantitatively in good agreement with those reproduced by numerical analysis. Our simulation results are useful for the control of the interface morphology, reduction of the amount of IML, and improvement of the mechanical properties of the impact welded dissimilar metal joints.INTRODUCTIONImpact welding is a kind of solid state joining method providing extremely high joint strength for both similar-and dissimilar metal combinations. Explosive welding and magnetic pulse welding are representative methods to achieve the impact welding. By a high-speed oblique collision between two metal plates, a metal jet is emitted from the collision point. The metal jet can remove any oxide films and contaminations on the plates and produce an active refreshed surface. Consequently, good metallurgical bonding can be achieved even for dissimilar metals (Crossland, 1982). Solid metals deform like fluids under the high pressure condition at the collision point and characteristic wavy interface is formed. In addition to the wavy interface, an intermediate layer (IML) is often formed at the joint interface in some metal combinations. Elimination or reduction of the amount of IML at the joint interface is desired since the excessive IML formation along the joint interface causes a large reduction in physical and mechanical properties. Formation of IML is considered to result from characteristic thermal history at the joint interface including partial melting due to the local temperature increase and successive rapid cooling behavior at the joint interface. In order to control the IML formation at the joint interface, it is necessary to reveal both heating and cooling processes at the joint interface. However, it is impossible to observe the phenomenon occurring at the joint interface and also difficult to investigate the temperature change at the joint interface directly during the impact welding. Therefore, simulation or numerical analysis is indispensable to overcome this problem. In the present study, the explosive welded Al/Cu joint, which is prone to form IML at the joint interface, was selected for the research. By using a newly developed numerical analysis method, not only the formation process of wavy interface, but also the local temperature increase and successive temperature decrease at the joint interface were reproduced. The formation process of IML was investigated by using both numerical analytic and experimental results."

Jan 1, 2018

By J. H. . MORGAN

Talc-soapstone deposits exist in Patton Township of Quebec and have been mined by Bakertalc Inc. or its predecessors since 1938. The company produces products ranging from purified and micronized talc through to soapstone lumps. The deposits are found within serpentinite dykes and are zoned. Zoning grades from a serpentine core through zones of talcmagnesite, schistose talc and talc-chlorite schist be/ ore reaching the wall rock of quartz-sericite-chlorite schist. Talcmagnesite zones generally comprise 80 to 90% of the mined rock. The serpentinite dykes containing the talc probably were originally post-Ordovician peridotite of the same series that hosts the Eastern Townships asbestos deposits. Alteration of serpentine to talc-soapstone and magnesite apparently resulted through addition of silica and carbon dioxide along shears and fractures. Talc concentrations occur also at the intrusive contact between dykes and wall rock. The present Bakertalc Inc. operation at the Van Reel Mine is being worked from an inclined shaft 200 m below surface. The talc rock undergoes a variety of milling processes, depending on its particular market, be/ ore being bagged and shipped.

Jan 1, 1984

By Alain Tshilombo, Vijay Reddy, Chowdary Meenavilli, Kelvin Buban, Cory Kosinski, Sriraj Meenavilli, Siddhartha Tirumalaraju

The use of artificial intelligence (AI) for process optimization is expected to play an increasingly important role in the future of the mining industry. The objective of AI is to develop a data driven soft (virtual) sensor using historical data that can estimate unmeasurable characteristics of the process and provide appropriate recommendations during operation to optimize the process through continuous learning. The application of AI to a hydrometallurgical process was evaluated by Sherritt Technologies in coordination with NTWIST. Historical operating data obtained from the Ambatovy facility’s High Pressure Acid Leach (HPAL) circuit was used to develop models to predict autoclave discharge parameters based on operating conditions and ore mineralogy. The prediction models were developed in such a way to also allow the user to simulate and test different operating conditions. A second set of models (AI model) were developed based on the prediction models, economic data and operating constraints for a given process unit to identify optimal reagent and steam dosages across the HPAL circuit. The development of these models was significantly complex due to the dynamic and interactive nature of the HPAL process. Despite the complexity of the models, the models were able to predict, with accuracy, the relationship between ore composition, leach autoclaves retention time, acid addition and steam addition with metal extractions as well as levels of impurities in the autoclave discharge slurry. The study showed that AI has the potential to improve the overall operation of a facility through providing tools to assist with training, troubleshooting and process optimization. INTRODUCTION The Ambatovy project, located in Madagascar, is one of the world’s largest nickel and cobalt mining and processing operation, with a design capacity of 60.000 tonnes of nickel and 5,600 tonnes of cobalt per year (Collins et al., 2016). Commissioning and start-up of the Ambatovy mine and plant facilities were completed in 2012, with acid first introduced to the ore leach in March 2012. Commercial production (defined as 70% of design capacity) was achieved in January 2014 and the production level required to achieve financial completion (90% of design capacity for 90 days) was achieved in March 2015 (Valle et al., 2016). Figure 1 shows a simplified flowsheet of the hydrometallurgical pressure acid leach (PAL) process employed by Ambatovy.

Jan 1, 2019

By L. S. Trenholme

"Belleterre Quebec Mines, Limited, is a subsidiary of Mcintyre Porcupine Mines, Limited. The property is in Guillet township, Quebec, 45 miles due east of Haileybury, Ontario. It is accessible by 72 miles of gravelled road from New Liskeard, Ontario (Fig. 1).Gold production at the property commenced in 1936 and to March 31st, 1945, had exceeded $9,000,000. For the past 3 years the milling rate has averaged 325 tons a day and the gold recovery about $14 a ton.GENERAL GEOLOGYThe rocks of the district consist of Keewatin-like volcanics conformably overlain by Timiskaming-like sediments. Together they form the remnant of an easterly plunging anticline engulfed by granite (Fig. 2). The pregranite intrusives consist of diorite, gabbro, and ultrabasic rocks, occurring as dykes, sills, and irregular stocks. Dykes of porphyry and lamprophyre presumably related to the batholithic intrusive are common in this area. The veins of quartz are also probably derived from the batholithic intrusives. A few dykes of Keweenawan-type diabase have been observed."

Jan 1, 1954

By Brian Putland

Single stage semi-autogenous / autogenous (S/AG) milling has become a common design for a variety of ore types with the advantages of being comparatively low capital cost and flexible for future expansion. The single stage SAG/AG milling option is ideal for starter projects with significant exploration and expansion potential. Currently a number of the largest SAG mills designed are installed in single stage configuration. This paper discusses the challenges associated with the process design of single stage SAG/AG milling circuits, the design flexibility required to ensure a robust circuit and the operating techniques adopted at successful installations.

Jan 1, 2012

By B. Adams, T. Angelov, G. Sasov, D. Steinhilber, A. L. Tsekov, S. Neufeind

A complementary ion exchange/solvent extraction process for the recovery of copper from low- grade ores is described. It has successfully been implemented on a full-scale plant level at the Buchim Copper Mine in Macedonia, yielding a maximum copper cathode production of 2400 tons per year. Compared with conventional SX/EW operations, this technology makes the exploitation of low-grade copper ores economically attractive, due to reduced operational and capital expenditures. Furthermore, the additional Lewatit® ion-exchange installations diminish the volumes of harmful organic substances in the following SX step and minimise the risks associated with the handling and usage of these chemicals, such as environmental pollution or fires. Finally, the significantly diminished quantities of liquids for the SX operation have a tremendous effect on the footprint of the plant (ca. 50% less) thereby leading to a reduction of capital expenditures. This paper reviews the main stages of the combined IX/SX process, the applications for metal recovery and introduces projects where the process is applied. Key findings of the process are also presented. A comprehensive technical comparison between processes has been carried out. This paper also evaluates the advantages of using combined IX/SX technology as a purification and separation step in copper production process, with the aim of further increasing the overall copper recovery and to ensure that a suitable copper concentration in the advanced electrolyte is achieved. The implementation of a Ion Exchange (IX) process in the classic Solvent Extraction-Electrowinning process(SX/EW) is found to be beneficial for processing of pregnant leach solutions both from spent and new copper heaps and dumps, acid mine drainage and other industrial streams without any preconditioning as well as in terms of achieving improved recoveries and copper cathode quality. INTRODUCTION The concentration and separation of copper from primary leachates is one of the key operations in the hydrometallurgical processing of oxide ores (Langner, 2011). Conventionally, this basic operation is conducted by submitting the pregnant leach solution (PLS), with a 1–5 g/L Cu content, from the initial sulfuric acid leach to a solvent-extraction (SX) process in which copper reports to the organic phase. After phase separation, the metal is stripped from the extractant/diluent mixture employing sulfuric acid to furnish a concentrated metal solution, usually containing 40–50 g Cu/L. The final products of the overall process are copper cathodes, which are obtained from a terminal electrowinning step.

Jan 1, 2019

By Chunlin Chen

Published data on thermodynamics of tin in liquid copper, matte and slag have been reviewed, assessed and used in development of thermodynamic solution models of melts. The developed model/database was applied in modelling the Sn deportment in primary copper smelting and e-waste melting processes. The results show that Sn can be removed from the matte through evaporation of various volatile Sn species (with SnS the most volatile) and slagging during copper smelting. The Sn removal increased with increasing matte grade due to the increased gas and slag volume. In the e-waste smelting process, fluxing strategy was developed for smelting e waste to produce a slag with reasonable liquidus and viscosity. Modelling results show that very low amounts of Sn reported to the gas phase due to low S, hence low SnS partial pressure in the system. The black copper produced could contain a few percent of Sn depending on the oxygen potential. The Sn in the black copper could be removed to the slag phase during anode refining. INTRODUCTION Tin is an impurity element commonly found in copper ores, which will be dispersed into various solid, liquid, and gaseous streams during the pyrometallurgical processing of copper. Tin alloy is widely used in electronic soldering due to its low melting point. The growth in treatment of recycled e-waste through primary and secondary copper smelting has led to an increased tin input to the smelting system. Therefore, the deportment of tin between phases is of great interest to the operators of modern smelters. Multi-Phase Equilibrium (MPE) is a thermodynamic package developed by CSIRO for simulating reactions between phases in multi-component and multi-phase systems (Zhang et al., 2002). Over the years the capability of the MPE model has been extended to cover the behavior of a large number of elements in high temperature system (Chen, Zhang, Wright, & Jahanshahi, 2006). In the present paper, the thermodynamic data on tin in liquid copper, matte and slag have been reviewed, assessed and used in the development of a database for Sn slag, alloy and matte phases. The model/database was applied in modelling the tin deportment in primary copper smelting and e-waste smelting processes. The aim of this study is to provide a better understanding of the chemical behaviours of tin in high-temperature copper processing and e-waste smelting.

Jan 1, 2019

By CRO CRO

Elk Valley Coal?s Cheviot Project is located in the Alberta foothills south of the town of Hinton. The mine has been in operation now for the 3 years. The start up and subsequent operation of the Cheviot project has been directly influenced by the Cardinal River Mine. As the Cardinal River Mine was winding down due to reserve depletion in 2004, the price of seaborne traded metallurgical coal jumped to record levels and customers began aggressively seeking new sources of supply. Several months later, the owners of Elk Valley Coal decided to begin mining at the Cheviot mining area, extending the life of the area?s operations by over 25 years. The Cheviot Project had been delayed by low coal prices, ownership changes and a complicated and lengthy regulatory process fueled in large measure by stiff opposition from a number of major environmental organizations. Chief to the startup of the project was the construction of a 23-kilometer-long haul road that would connect the new coal measures to the existing Cardinal River processing and rail facilities. Construction of this road was completed with the first coal truck making its first trip in October 2004. This paper will look at some of original assumptions, the actual mining experiences and the lessons that were learned while moving from the drawing board to the current development as it exists today.

May 1, 2007

By Nordau R. Goodman

T-he Ojibway Salt Mine near Windsor, Ontario, produces almost two million tonnes of97% pure rock salt annually. The salt is mined from the middle F horizon of the Silurian Salina Formation. The salt beds have a gentle dip into the Michigan depositional basin. There is no evidence of deformation. The rock salt is buff coloured and has a number of thin carbonateanhydrire bands. Secondary salt crysrallization occurs throughout the mine.

Jan 1, 1984

By F. R. Archibald

MR. A. F. B. Norwood: Having been associated in the past few years with nine different plants roasting aurif erous concentrates in Australia, two of which were new installations for which design and construction were undertaken by the writer, I read Mr. Archibald&apos;s paper with very great interest, and I deem it a great privilege, as a member of a sister Institution, to be invited to contribute to the discussion on the paper. I wish to congratulate the author on a very informative and interesting paper, and, although situated many thousands of miles away, I feel I have gathered from it a very close idea of the operating conditions and of the work that has been carried on at the Beattie gold mine. Working along somewhat different lines, it is interesting to note that the conclusions drawn by the author run closely parallel to those accepted in Western Australia, viz., that the object of roasting is to obtain a porous calcine, and that this can best be achieved by roasting first at a temperature below 900 deg. F. to 1,000 deg. F., and then raising the temperature at the finish of the roast. Turning first to the laboratory work, the materials I have studied in Western Australia cover a range from those with little or no arsenic to concentrates carrying as high ?as 20 per cent, i.e., even higher than in the analysis quoted for the eoncentrates from Nepheline Products, Limited. In the ease of arsenic-free pyrite concentrates, the roast is ideally carried out at a temperature ranging from 900 deg. F. to 1,000 ferric oxide is one cause of the refractory gold remaining In deg. F. No improvement in extraction is obtained when the calcines are cyanided by raising the final temperature above this point; nevertheless, in technical practice it is desirable to finish the roast at 1,200 deg. F. in order to decompose basic ferric sulphate and thereby reduce the consumption of chemicals in the subsequent cyanidation step. However, if at any stage of the roast the temperature is raised above 1,200 deg. F., the extraction by cyanidation falls, and continues to do so the higher the maximum temperature that is reached. Line A in the accompanying graph typifies this effect.

Jan 1, 1949

By T. A. Postolski, A. J. Sinclair

"Abstract - Where block (selective mining unit) grade distributions can be determined, the effect of average random errors of block grade estimates on metal recovery can be evaluated quantitatively. That is, for a given estimation error and cutoff grade, it is possible to calculate the quantity of metal that is lost as a result of misclassifying ore blocks as waste, as well as the dilution that ensues from misclassifying waste blocks as ore. Example calculations using a computer program GAINLOSS and realistic block grade distribution parameters for both a porphyry-type deposit and an epithermal gold deposit illustrate some fundamental relations that are important in quality control of estimation and in reconciliations concerning a comparison of ore estimates with production.Where the cutoff grade is on the lower tail of the grade distribution, metal arising from dilution can be much less than metal lost through misclassifying ore as waste. Hence, average grade of milled material could possibly be higher than expected (estimated) and tonnes milled will be smaller than estimated.Where the cutoff grade is on the higher tail of the grade distribution, tonnes arising from dilution will be greater than tonnes lost by misclassifying ore as waste. Thus, tonnage mined will be greater than estimated and the average grade milled will be less than estimated.The software GAINLOSS permits rapid comparison of the tonnes and average grade for all blocks selected as ore for a variety of levels of block estimation errors. These comparisons can be incorporated in a financial analysis to evaluate whether or not it is worthwhile to improve a high, average block estimation error to some lower value."

Jan 1, 1998

By Edward Rybinski, Serkan Dikmen, Walter Valery, Jorge Ghersi, Roberto Valle, Alex Jankovic, Javier Linares, Frank Davila

Compañía Minera Antamina is a polymetallic mining complex that produces copper and zinc concentrates as primary products and molybdenum and lead/bismuth/silver concentrates as by-products. In 2007, Metso Process Technology and Innovation (PTI) was contracted to increase SAG mill throughput by integrating and optimising blast fragmentation, crushing and grinding for the harder M4/M4A (CuZn) ores. Following the implementation of recommendations provided by Metso PTI, the SAG mill throughput increased from 2750tph to reach an average of 3600tph for the remainder of 2007. Due to continued application of mine to mill integration and optimisation philosophy, by 2010, the concentrator consistently exceeded the target of 4400tph while processing harder CuZn ores.

Jan 1, 2012

By Akira Miura, Katsuyuki Sato, Yuken Fukano

JX Nippon Mining and Metals Corporation has developed the JX Iodine Process, which is an innovative and patented copper-leaching process for low-grade primary sulfide ores. This process consists of the irrigation of ferric iron and a low concentration of iodide solutions. One-meter column leaching tests were conducted on ore samples from two different mines. At the end of experiments, the total copper recovery exceeded 70% for Sample A and 50% for Sample B with the iodine method, which was significantly higher than that with conventional ferric leaching of 14% for Sample A and 20% for Sample B. To elucidate the reason for the JX Iodine Process effectiveness, cross sections of leached residues were studied. Reaction products were confirmed around chalcopyrite even in the central area of particles in Sample A, however, reaction products were recognized at a depth of only 1 mm from the ore rim in Sample The resistance of Sample A to the leachate appeared to be lower than that of Sample B because Sample A had a high permeability and porosity, whereas Sample B had been affected strongly by a potassium alteration. No reaction products were visible on conventional leaching samples, even at the ore surfaces. INTRODUCTION Hydrometallurgical copper leaching (heap leaching or dump leaching) has been used extensively for copper recovery from oxide and secondary-sulfide ores, but not for primary copper sulfides, which contain mainly chalcopyrite as copper minerals. Although they are major resources of copper, primary copper sulfides are difficult to process because of their refractory nature. Extensive leaching studies have been carried out to leach primary copper sulfides (chalcopyrite), including biological and chemical, using a variety of oxidants and additives to enhance copper recovery. Watling (2013) reviewed acid-chloride-oxidizing agents with chalcopyrite. Abdollahi et al. (2015) tested silver as a catalyst for bioleaching with a chalcopyrite-bearing molybdenite concentrate. Hiroyoshi, Miki, Hirajima and Tsunekawa (2000) found a specific redox-potential zone for high-speed chalcopyrite leaching by controlling the ratio of ferric and ferrous iron. However, no ambient-temperature economic process has been developed for leaching primary copper sulfide, which usually has a low copper grade.

Jan 1, 2019

By S. Kodama, G. Sasaki, K. Matsugi, K. Sugio, Y. B. Choi

"Pure aluminum (Al) matrix composites with changing the volume fraction of TiB2 particle content from 10 to 30% was fabricated by spark plasma sintering (SPS) process. Then the microstructure, density, dispersibility and thermal conductivity of the composites was estimated. As increasing TiB2 content, the dispersibility of particles and the density of the composites degraded slightly. And, the effect of the dispersibility of TiB2 particles on the thermal conductivity was quite little. The thermal conductivity of the composites was less than the theoretical value calculated by Maxwell-Eucken equation considering the effect of the density. It is due the influence of the interface heat transfer rate, because these composites have many small sized particles and have high interface density.INTRODUCTION Recently, metal matrix composites (MMCs) have been used widely in electric / electronic components, architectural materials, transportation equipment, aerospace and a precision instruments, because it’s superior properties have been greatly watched. Demand of MMC for industrial use has been increasing gradually. Furthermore, multifunction properties are required for the composites strongly. By integrating the dissimilar materials, the composites have various properties that we cannot get from monolithic materials. On the other hand, the response to the thermal management is required for materials, recently, and the need for the structural material controlling the thermal conductivity has been increasing. Especially, superior thermal conductivity and good mechanical properties from room temperature to high temperature are required for heat sink and heat exchanger at the same time. In late years, a study on the composites combining carbon materials and aluminum and copper has been developing, and actually the composites with high thermal conductivity which is not provided in the conventional materials is developed. On the other hand, non-oxide ceramics particles such as SiC and AlN, TiB2 have good thermal conductivity. Particularly, as TiB2 has good electrical conductivity, TiB2 containing MMCs is expected as innovative materials used as electric/ electronic components. Furthermore, as TiB2 has low density, high melting point, low thermal expansion and good deformation resistance, the development of high performance composites with multi-functional properties is expected. As thermal conductivity of pure Al and TiB2 are 225 and 66.4 W/mK, respectively, it is expected that the degradation of thermal conductivity by adding dispersant in Al matrix is suppressed. The authors have carried out a thermal conductivity, electrical conductivity, mechanical properties of 20 vol.% TiB2 dispersed Al composites (Sugio, 2016, Sasaki, 2016). In this study, the influence of quantity of addition of TiB2 on microstructure, thermal conductivity was studied minutely."

Jan 1, 2018

By M. Hashemzadeh

The efficiency of water use is a top priority for the global minerals industry, especially in regions with limited freshwater supplies. In these areas, the freshwater shortage has prompted mining companies to search for alternatives to freshwater sources. Seawater has been proven to be a potential water source for mineral beneficiation and metal extraction processes. This study compares chalcocite leaching behavior with ferric chloride to that with cupric chloride. We carried out leaching tests with a highly pure chalcocite sample in jacketed reactors under fully controlled pH and solution potential. The effect of chloride concentration, oxidant concentration, and temperature on copper extraction was quantified in both cupric and ferric chloride systems. In the ferric chloride system, increasing ferric concentration showed a positive effect on the first stage of chalcocite leaching. In the second stage, increasing temperature markedly enhanced copper extraction. In the cupric chloride system, chloride concentration presented a considerable effect on both the first and second stages of leaching, while temperature had a remarkable effect only on the second stage. The findings of this study would be beneficial to mine operations aiming to replace fresh water with seawater for heap leaching of chalcocite. INTRODUCTION Mineral processing operations/plants are normally operated adjacent to mines which are often located in remote and arid area, such as northern Chile, southern Peru and Australia with limited access to fresh water (Liu, Moran, & Vink, 2011, 2013). Water scarcity in these areas has prompted mining companies to invest in sustainable technologies to reduce the water use and/or increase the water use efficiency. One of the current sustainable approaches in mineral processing operations is to replace fresh water with seawater. Seawater is now being increasingly used for mineral beneficiation and metal extraction processes (Hernández et al., 2015). Another application of seawater could be for heap leaching of copper secondary sulfides, mainly chalcocite. However, the high concentration of chloride ion in seawater may significantly affect leaching kinetics of copper sulfide concentrates and ores (Watling et al., 2014). Therefore, it is essential to develop a fundamental understanding of the leaching of chalcocite in chloride media.

Jan 1, 2019