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By G. M. Ross, I. M. Ross, J. A. Scott

"The otherwise waste heat in many water streams in the mining industry can be used to provide space heating of adjacent infrastructure including laboratories, workshops, and offices. This can be achieved by using heat pump systems, which can work as a replacement or in conjunction with existing space heating. In the example investigated—process cooling streams at an ore smelter—the analysis provided illustrates that annual heating costs can be 19% lower and a simultaneous 62% reduction in CO2 emissions can be achieved.RÉSUMÉ Dans l’industrie minière, la chaleur qui serait normalement perdue des circuits d’eau pourrait servir à chauffer des structures adjacentes incluant les laboratoires, les ateliers et les bureaux. Cela pourrait se faire en utilisant des systèmes de thermopompes, qui pourraient remplacer ou s’ajouter au chauffage existant. Dans l’exemple étudié, des circuits de refroidissement de procédé à une fonderie, l’analyse fournie illustre qu’il est possible de réduire les coûts annuels de chauffage de 19 % et d’obtenir une réduction simultanée de 62 % des émissions de CO2."

Jan 1, 2016

By J. P. Harrison, K. Gao

It is well known that in situ stress measurements at a given site will generally display significant variability. However, it appears that a robust analysis of such measurements – i.e., one that is faithful to the tensorial nature of the data – is not available. Despite the fact that stress is a tensor, stress magnitude and orientation have long been analyzed separately using classical statistics. In earlier work we demonstrated the applicability of tensor statistics to the analysis of stress variability. Here, we investigate further the difference between tensor and classical statistics with respect to the stress tensor correlation matrix. Our analysis commences with the selection of a series of valid correlation matrices. Then, assuming that standardized tensor components follow the multivariate standard normal distribution, these correlation matrices are used to generate marginal probability distributions of the eigen-parameters (i.e., principal stress magnitude and rotation angle). From these, random stress tensors are generated, their eigenparameters determined, and the probability density distributions of these obtained using both classical and tensor statistics. Our results indicate that, for all correlation matrices, both methods give practically identical distributions for principal stress magnitude. However, the discrepancy between the two methods with regard to probability density distribution of rotation angle is highly dependent on stress component correlation. This discrepancy is usefully quantified in terms of the integral, with respect to orientation, of the difference between the two probability density distributions. This parameter, which we term Area Difference, is closely linked to the magnitude of the correlation matrix determinant, which itself is related to the normal stress correlation coefficient (i.e., ?x ,?y ??). Assuming that Area Difference should not exceed 0.1, we identify the critical determinant for any particular value of normal stress component correlation coefficient. Thus, using published in situ stress data and the obtained critical determinants, we show that for a specific normal stress component coefficient, when the correlation matrix determinant is less than its critical determinant, the more precise tensor statistics should be used to calculate the distribution of rotation angle. These results demonstrate that the customary analysis of stress measurement data may lead to erroneous results, and that tensor statistics appears to be preferred approach.

Jan 1, 2015

By G. R. Haiden, E. Henderson

"An LHD teleoperation and guidance system, developed at the Ontario Division of Inco Limited, has been demonstrated in operation at Copper Cliff North Mine (CCNM) since late September, 1993. The tests performed to date have evaluated the feasibility and production viability of multiple LHD operation, from surface by one operator.The systems technology required to accomplish this consists of an electronic monitoring and control package mounted on the LHD; a high bandwidth mining computer network capable of providing radio frequency coverage; and an operator control console which provides an operator workstation for multiple LHD operation.This paper discusses the systems required to accomplish the task of LHD teleoperation and guidance, the benefits of multiple machine operation and future research and development directions. IntroductionSince underground mining began, persolU1el have entered the mine workings to mine ore. Today, however, the rapid advancement of modem telecommunications, computer hardware and software technology has opened the door to remote mining technology that was considered unfeasible a few years ago. This paper discusses the ingredients of remote mining technology that have been developed at Inco Limited.Figure I represents an historical view of the application of electronics to LHD operation at Inco Limited. In 1980, the first radio remote controls for the operation of LI-IDs in large open stopes were tested. The successful application of this technology at Inco went hand-in-hand with the development and application of the Vertical Crater Retreat mining method. The combination of these two advances had a very positive effect on the productivity in the mid-eighties at Inco. In 1991, the Mines Research Department of the Ontario Division advanced remote control technology by developing a high capacity underground mining telecommunications system. This system is capable of moving voice, data and video information throughout the mine workings. The system is based on broadband communication technology found in most automated factories, with the added benefit of providing the information to and from mobile equipment through radio interfaces. The first test of the system consisted of an operator teleoperating a single LHD (on the 3000 ft level) from the surface. The next test on September 13, 1993, demonstrated the first production application of multiple LHDs being run from surface with a single operator."

Jan 1, 1994

By L. Nastac, Y. Xuan

"The metal-matrix-nano-composite (MMNCs) in this research work consists of an A356 alloy matrix reinforced with 1.0 wt. % SiC 50 nm diameter nanoparticles that can be dispersed within the molten alloy matrix via ultrasonic stirring technology (UST) and induction melting and stirring processing. The necessary ultrasonic parameters to achieve the essential cavitation for adequate degassing and refining of the A356 alloy as well as the optimum fluid flow characteristics for uniform dispersion of the nanoparticles into the A356 alloy matrix have been investigated in this study by using computational fluid dynamics (CFD) modeling with a magneto-hydro-dynamics (MHD) model and an UST cavitation model.The MHD model accounts for turbulent fluid flow, heat transfer and solidification, electromagnetic field as well as the complex interactions between the solidifying alloy and nanoparticles by using ANSYS Maxwell and ANSYS Fluent Dense Discrete Phase Model (DDPM) and a particle engulfment and pushing (PEP) model.INTRODUCTIONAluminum matrix nanocomposites can offer outstanding properties, including low density, high specific strength, high specific stiffness, excellent wear resistance and controllable expansion coefficient, which make them attractive for numerous applications in aerospace, automobile, and military industries field (Bozic, 2010, De Cicco, 2009, Elshalakany, 2014, Goh, 2006, Jia, 2013 and 2015, Liu, 2014, Reihani, 2006, and Su, 2010).As shown in literatures (Aki, 1999 and Mussert, 2002), it is highly advantageous to use nano-sized ceramic particles to produce metal matrix nano-composites (MMNCs) since similar ductility and higher strength with the metal matrix can be achieved. Currently, there are several fabrication methods of MMNCs, including mechanical alloying with high energy milling (Chen, 1997) , ball milling (Filho, 2003), nano-sintering (Groza, 1999), spray deposition, electrical plating, sol-gel synthesis, laser deposition, etc. The mixing of nano-sized ceramic particles is normally lengthy, expensive, and energy consuming.Ultrasonic Stirring Technology (UST) has been extensively used in purifying, degassing, and refinement of metallic melt (Jian, 2005, Khalifa, 2008, Eskin, 2002, Xu, 2004, and Meek, 2006) mainly because introducing the ultrasonic energy into a liquid will induce nonlinear effects such as cavitation and acoustic streaming. SiC nanoparticles are widely used as reinforcement particles due to their relatively good thermal and chemical stability. Ultrasonic vibration can improve the wettability between the reinforced nanoparticles and the metal matrix (Lan, 2004, Cao, 2008, and Yan, 2011), which will assist to distribute the nanoparticles more uniformly into the metal matrix. Ultrasonic cavitation in liquids causes high speed liquid jets of up to 1000 km/h. Such jets press liquid at high pressure between the particles and separate them from each other (Hielscher, 2005)."

Jan 1, 2016

By Pura Alfonso, Sarbast Hamid, Hernan Anticoi, Eduard Guasch, Josep Oliva

"Av. Bases de Manresa 61-63, Manresa (08242) Barcelona, SpainTantalum is a strategic metal and an improvement of the mineral processing is an important issue. The main objective of this work is to optimize the grinding technologies for tantalum ores with high pressure grinding rolls. The selected ore for this study was an altered leucogranite from the Penouta Open Pit Mine (NW Spain). In the present work mono-size experiments have been carried out using grinding rolls with controlled pressure. The particle size distribution has been monitored in the input and output of the high pressure grinding rolls for each experiment. The cylinder pressure that is transmitted to the particles has been determined. New population balance models are presented for high pressure grinding rolls with parameter adjust for tantalum ore. The obtained model uses the physical description of particles under the comminution action of the grinding rolls. The obtained results are in agreement with other models and the errors in the adjustment are low. The selection function proposed for this model describes adequately the breakage probability of the particles inside the high pressure grinding rolls. The presented model can be a good alternative for simulating a high pressure grinding roll process. INTRODUCTIONTechnology for grinding have been improved for many years, introducing new variables and parameters involving energy consumption, mechanical stress analysis of the compression particles or pressure application for optimizing the comminution (Morrell et al, 1997). High pressure grinding rolls is a modern technology that is proven to reduce the operating costs in full scale plants when compared with other milling technologies. Its benefits on energy saving and simplicity in the process have been studied and applied, first in the cement clinker industry (Abouzeid & Fuerstenau, 2009) and after in mining activities, especially in metallic ore deposits (Austin et al, 1991; Guevara & Menacho, 1992; Morrel et al, 1997; Torres & Casali 2009; Numbi & Xia, 2015). Many author structures of the High Pressure Grinding Rolls modelling in three main branches; (a) throughput modelling, (b) Power and energy model and (c) particle size distribution modelling (Austin et al, 1991; Guevara & Menacho, 1992; Austin & Trubelja, 1994; Morrel et al, 1997; Torres & Casali, 2009)."

Jan 1, 2016

By Audrey Wagenaar

Introduction ?? Rising public pressures are being placed on companies worldwide to protect the environment and the health and safety of their workers and local communities. ?? International bodies and shareholders want to make sure developments and companies can meet internationally acceptable standards for EHS. In 2005, Golder Associates was asked by the IFC to conduct a comprehensive review and update for their Environmental Health & Safety Guidelines including the mining sector.

May 1, 2008

By P. I. Laforest, M. S. Moats

"Antimony in smelted copper anodes has been shown to cause problems in electrorefining including brittleness of starter sheets. In order to improve deposit properties, a study was conducted examining the effect of anode chemistry on cathode ductility and electrolyte chemistry. Two industrial anodes with different molar ratios of As/(Sb+Bi) were used in laboratory electrorefining experiments with commercial electrolyte, and the addition of commercial glue and Avitone. The ductility of 21-hr copper deposits was evaluated by a 180° bend test. X-ray diffraction (XRD) and metallography were performed on unbent specimens to characterize the deposit structure. Increasing the anode As/(Sb+Bi) molar ratio from 0.54 to 3.8 resulted in an increase, on average, from four to eight bends to failure in cathode material produced. Significantly lower concentration of antimony (V) in the electrolyte was detected when operating with the higher molar ratio anode. The presence of (111) and (200) planes was noted in cathode material produced from the higher molar ratio anode suggesting that mixed growth character could be responsible for the observed increase in bend test results. The ductility of the starter sheet materials was improved by a higher anode molar ratio.INTRODUCTIONThe presence of antimony in copper electrorefining electrolyte has been reported to cause problems in cathode production (Hiskey, 2012; Peng, Zheng & Chen, 2012; Wang, Chen, Zhou-Lan & Lian-Sheng, 2006; Wang, Chen, Zhou-Lan, Wang, Xiao & Zhang, 2010; Wang, Chen, Zhou-Lan, Wang, Xiao & Tang, 2011; Wesstrom, 2014). To better understand the impact of antimony, laboratory scale electrorefining experiments were conducted using industrial inputs (anodes, cathodes and electrolyte). The influences of anode chemistry on the valences of antimony and arsenic in the electrolyte were monitored and correlated to physical cathode characteristics, such as a bend test to failure and crystallographic orientation.Commercially, starter sheets are produced by electrorefining impure cast copper anodes onto titanium blanks. The starter sheets are then hung in an electrorefining or electrowinning cell using loops of bent starter sheet material. These loops, in the absence of sufficient ductility, fail resulting in cathodes falling into the electrolysis cells. It is thought that the reduction in ductility can be related to anode composition; in particular, the molar ratio of arsenic to antimony plus bismuth As/(Sb+Bi). It has been stated that maintaining this ratio above 2:1 results in numerous improvements to electrorefining operations (Baltazar, Claessens & Thiriar, 1987; Kamath, Mitra, Radhakrishnan & Shetty, 2003; Krusmark, Young & Faro, 1995; Noguchi, Itoh & Nakamura, 1995; Wenzl, 2008)."

Jan 1, 2016

By C. Kim

The integration of three-dimensional (3D) data with infrared thermography has received much attention for its potential use as input data for building energy simulations. Therefore, researchers have proposed methods to integrate 3D data with infrared thermography obtained by different sensors. These studies show the potential of the integration of 3D data and infrared thermography using various systems. However, these studies have ignored property aspects of infrared thermography, such as the low resolution of infrared thermography and external environmental influences. Thus, their proposed methods to integrate 3D data and infrared thermography are inadequate because these problems can affect the resulting building energy simulation. This research proposes a framework that integrates infrared thermography and 3D data while accounting for the resolution and shadow effect of infrared thermography. The proposed framework consists of three steps. In the resolution enhancement step, bi-cubic interpolation is proposed. In thermal data correction from the shadow effect, the shadow area is detected from the visible image, and then the shadow effect is removed from the registered infrared thermography. Finally, enhanced infrared thermography is mapped to the 3D data obtained by a laser scanner. The performance of the proposed framework was evaluated using test images obtained from a building in operation. The experimental results show that the proposed framework provides a 3D thermal model that is useful and accurate in simulating building energy. It is expected that the 3D thermal model can be used for accurate energy simulation of existing buildings. In addition, the proposed framework can be applied in defect detection for buildings. Furthermore, this novel approach enhances infrared thermography using visible images.

Aug 1, 2013

By Charles W. Villiers

AS is well known, there are large and valuable deposits of coal in British Columbia, both on the mainland and on Vancouver island. These deposits are widely distributed over the Province. The chief sources of supply on the mainland are found in the Fernie and Princeton-Nicola districts and on Vancouver island in the Comox and Nanaimo districts. The coals range from a very high quality bituminous coal to lignite. On the Upper Skeena river there is said to be a very large deposit of anthracite or semi-anthracite, but this field has not been developed. Coal was first discovered in British Columbia on the north end of Vancouver island in the year 1835, but it was not until 1852 that coal mining was seriously undertaken by the Hudson's Bay Company at Nanaimo, where mining has been carried on continuously ever since that date. The production of coal in the Province continued to increase until the year 1910, when the annual output reached its peak at 3,100,000 tons and a total of 7,800 men were employed in the industry. Since 1910, the production has dropped steadily until, in 1934, only 1,347,000 tons of coal were produced and less than 3,000 men were employed. This continued decrease in production has in no way been caused by lack of coal reserves. It has been due entirely to curtailment of markets. I do not propose to discuss coal mining practice in British Columbia, where we have all sorts of mining conditions, including submarine mining. There is no lack of coal supplies for either industrial or domestic purposes, nor is there likely to be any shortage of coal in the Province for many generations. We have our mining troubles, which increase the cost of production, but there are no insuperable difficulties to prevent the extraction of a large and increasing supply of coal. Our main difficulty-in fact our only serious difficulty-is to find a market for our output, and we must consider means which can be evolved not only to conserve our existing markets but also to expand them, at any rate within the boundaries of Canada. I will therefore confine my remarks chiefly to the all-important factor of Markets for our coal.

Jan 1, 1936

By Kati Tschöpe

Cathode wear has become an increasing challenge in the aluminum industry due to the use of more graphitized materials. Today, there exist no standard laboratory methods for measuring cathode wear where different commercial materials can be ranked. The typical average wear rate in an electrolysis cell is quite small. The aim of this work was to design a test method where the wear could be accelerated compared to industrial cells. It was focused on polarized tests where the cathode is exposed to electrolyte, which gives higher aluminium carbide solubility. The cathode materials were characterized by microscopy and image analysis.

Jan 1, 2011

By K. E. Waters, J. E. Nesset, F. Rosenblum, J. A. Finch, S. Moon

"Some materials when exposed to various conditions can exhibit a rise in temperature without requiring an external heat source. Generally referred to as pyrophoric or self-heating substances, they challenge the safety of materials handling, storage and transportation. Reliably assessing the self-heating potential of materials is thus essential. Over the years a number of test protocols have been developed. A widely accepted method is that recommended by the United Nations to certify the safety of shipping pyrophoric goods. Our test work on sulphide materials has shown that the U.N. test can give false negatives if the sample oxidation history is not considered. Depending on the degree of oxidation (“weathering”), the same sulphide material can exhibit self-heating ranging from safe to hazardous. For concentrates, oxidation can occur during storage and transport making the sample weathering history an important consideration in the test work. To make the U.N. test, and other single-stage self-heating procedures, more reliable in assessing self-heating potential when testing sulphide materials, it is suggested that a weathering step be incorporated in the test protocol. This test work for two sulphide samples, an ore and a concentrate, demonstrates the impact of incorporating a weathering stage in the test protocol. INTRODUCTIONSelf-heating occurs when exothermic reactions produce heat faster than can be dissipated to the surroundings. Numerous substances self-heat, ranging from wood chips and powdered milk to coal and sulphide minerals (Beever & Crowhurst, 1989; Hudak, 2002). Mixtures of sulphide minerals, most notably those containing the iron sulphide pyrrhotite (Fe(1-x)S), commonly encountered in the extraction of base metals (e.g., copper, zinc, lead, and nickel), are particularly prone to self-heating (Rosenblum, Nesset, & Spira, 2001; Payant, Rosenblum, Nesset, & Finch, 2012). In the mining and subsequent processing stages, the minerals are progressively liberated and finely ground, then separated, usually by flotation, with the resulting concentrates stored and transported to smelters for metal extraction. At most of these stages the sulphides are exposed to both moisture and oxygen, conditions that promote partial sulphide oxidation and the formation of elemental sulphur. Studies have shown that pyrrhotite, in particular, readily oxidizes to form elemental sulphur (Bernier & Li, 2003; Belzile, Chen, Cai, & Li, 2004; Somot & Finch, 2010). The elemental sulphur becomes fuel for further self-heating as the temperature of the mineral mixture increases above 100 oC (Rosenblum & Spira, 1995; Somot & Finch, 2010). It is believed the propensity of pyrrhotite to self-heat is a result of its iron-deficient, and hence somewhat unstable structure. It is worth noting that pure metal sulphides (with the exception of pyrrhotite) do not exhibit appreciable self-heating. A mixture of minerals sufficiently different in their electrochemical rest potential is required to initiate self-heating at ambient temperatures (Payant et al., 2012)."

Jan 1, 2016

By I. J. Burgess, B. C. Barlow

"The electrodissolution of nickel pellets with different controlled electrical variables was investigated in an effort to mitigate plating residue in Watts bath based electroplating cells. During galvanostatic dissolution at 0.4 A dm-2, the anode potential was seen to oscillate between passive and pitting potentials. In-situ microscopy and ex-situ characterization has shown that lacy-pit formation and large, partially perforated, pit covers form during the potential decay from pitting potentials. In general, covered pitting at low current density shows increased plating residue. Using potential pulses is one way to maintain greater control over surface pitting by creating a higher density of pit nuclei while at the same time controlling their growth. Pits generated from a series potential pulses were examined ex situ for a range of pulse times and stages of pit growth were identified. An alternative method of anode dissolution was devised using potential pulses and duty cycles that allowed average current densities comparable to industrial plating conditions to be achieved. By restricting the time at pitting potentials to 0.05 s, plating residue was reduced more than six-fold in comparison to an equivalent galvanostatic experiment run at a comparable current density.INTRODUCTIONIn typical galvanostatic (direct current) nickel electroplating cells employing soluble anodes, some amount of plating residue is produced which consists of metallic nickel and impurities that detach from the bulk in the form of small fines. Significant buildup of residue requires plating operations be halted and the anode assembly cleaned of residue before operation can resume. While variables in the refining process have been shown to affect plating residue, more precise control of electrochemical variables may provide an attractive route to mitigation of residue."

Jan 1, 2016

By A. Mellek, M. Pischtschan, M. Perrucci

ABB has received an order for one of the most challenging mill drive projects in its history. With one SAG mill and one ball mill to be added at an iron ore mine in Sweden, the customer’s plant managers wanted to have the most efficient solution for driving their mills but had the budget limitations typically faced by the majority of mining companies during periods of market downturn. To find the best balance between cost of acquisition and highest performance throughout the lifetime of the plant, ABB was selected to deploy a synchronized bypass solution, in which only one drive system is used for two different mills in series. However, being one of the first grinding mills in the world with such a solution was not the only challenge the ABB team faced: The inclusion of some mill application functions - e.g., frozen charge protection, automatic positioning and creeping mode - brought the demands on the engineers to another level. With only one frequency converter and one mill application controller available, the configuration logic and interlocks had to be meticulously designed and thoroughly tested to ensure a smooth and safe startup. The solution offers a footprint reduction and more operator flexibility at a reduced investment as each mill can be run in both directions, and wear on the mechanical components can be greatly reduced due to ABB’s premium ring-geared mill drive (RMD). This paper will describe the details of the project, the configuration developed and the tests performed to guarantee correct software functionality. Mill startup is scheduled for January 2016.

Jan 1, 2016

By H. Langlois

"Included in the Mines Gaspe mining complex located at Murdochville, Quebec, is a copper smelter which comprises a reverberator furnace, two Peirce-Smith converters, an anode furance, and a sulphuric acid plant.The 50% smelter capacity available is supple mentedby custom concentrates for treatment. As these concentrates can be varied and extremely complex many modifications and improvements have been brought about to optimize and make the process more flexible since its inauguration in 1955.IntroductionThe copper smelter of the Mines Gaspe mining complex is located in Murdochville, a small municipality in the heart of the Gaspe peninsula, 90 km northwest of the town of Gaspe .This metallurgical installation has a daily smelting capacity of 650 tonnes of concentrate and an output of 250 tonnes of copper and 900 tonnes of sulphuric acid. Its main components are: a reverberatory furnace, two Peirce-Smith converters, one rotary anode furnace and one acid plant. The gases, which are produced by the converters, are treated at the acid plant then combined with gases from the reverberatory furnace before being vented through a 152 metre high stack .From the beginning of its operation until the present day (1991), the smelter has treated 7 million tonnes of concentrate and 100 thousand tonnes of scrap for a production of 1.8 million tonnes of copper and 2.2 million tonnes of sulphuric acid."

Jan 1, 1993

By D. Bernard

Over the last decades, the wrought aluminum casting industry has made significant progress with regards to process consistency by the introduction of new technologies in the field of liquid metal processing and casting. These technologies, combined with the application of best practices, have led to increases in productivity as well as better process performances and product quality. The competition in the addedvalue aluminum products (by opposition to P1020 production) is, however, very strong and involves players that did not hold a major role five years ago but who are now exerting a strong competitive pressure on our industry even sometimes from far abroad. There are still technical and technological challenges remaining in the different areas of aluminum casting production, amongst which metal pre-treatment, furnace operations, in-line treatment and casting hold a predominant influence. The comprehension of the contribution of each individual process step to the entire process chain is a key element and must be considered in future process optimisations. This paper presents the technological position of the casting industry and tries to highlight areas where further progress can be made.

Jan 1, 2006

By Randy Billing, J. Fraser Wilson

"IntroductionThe job of designing and implementing effective environmental management sounds like what one executive, assuming responsibility for a very sick organization with lots of potential described as, ""an insurmountable opportunity"".Effective environmental management is an opportunity, no doubt. Its an unusual, if not unique opportunity. Insurmountable? Maybe not! Indeed, in the authors' experience, the keys to unlocking this opportunity are not in new or complicated technicalities; they are in the existing strengths and successful experience that one has in managing other complex and exacting management issues.To begin, it is necessary to understand what these issues of sustainable development mean to business. What is the nature of this opportunity? What makes it look unsurmountable?New Games: New RulesLawyers have described some of the new rules companies are facing and there is a new game being played; a game characterized by unique challenges.Take two, for example: • The ecological problems to be faced are Mother Nature's business, the political solutions required are our business. This combination of natural problems and political solutions requires the development of new management mechanisms, to bridge the gaps among us, as individuals, as professions, as interest groups and so on; indeed, even as countries;• and gaps there are : about as many gaps as the people involved : many of them with new and changing expectations, often mutually exclusive and not negotiable.The challenge of these relationships and communications among so many different interests is one of the keys to effective environmental management.Like any game, this one has rules and they are new, too. These rules are evident not just in new legislation - tough legislation with draconian penalties; they are also evident in new and exacting business policies, value driven and just as unforgiving of poor performance. Senior management of many companies are speaking about the role of enlightened corporate policies and how important it is for everyone involved that these policies drive and reflect business practices. Absence of day to- day behaviour which evidences the words in action, the policy on the wall of a corporate office or published in an Annual Report is first evidence for the prosecution , not the defence.The challenge of practical policies is another key to effective environmental management.This is a new game, with new rules: the challenge of change."

Jan 1, 1991

By Janice Zinck, Ian London

In recent years, the secure supply of critical and technology metals has become increasingly important tomajor industrialized economies that seek to sustain their industrial base and develop advanced technologies, such as clean energy. Canada, with its significant reserves of rare earth element (REE) and other metals, has an opportunity to supply some of the global demand for these materials. However, to transition from promising mineral deposits to marketable products, investment in strategic research and development (R&D) and expertise is needed to address the complex technological challenges around the production, separation and processing of these metals, and to better understand the global market for these key commodities. To this end, in its April 2015 budget, the Government of Canada committed to invest $23M over 5 years to accelerate production of REE and chromite/ferrochrome. The goal of this program, developed in close association with industry, is that Canada contributes a sustainable supply of REE to the global market. The research and development program will provide the technological capacity to establish a Canadian REE industry. This paper will discuss REE R&D advances achieved in the first year of the program in areas of mineral characterization, beneficiation, leaching, separation and environmental management and will highlight the Canadian model of collaboration where industry (e.g. prospective producers, technology companies), government, academia and other stakeholders work closely to ensure that the R&D is targeted, innovative and effectively deployed and commercialized.

Jan 1, 2016

By G. Dodbiba, A. Otsuki, T. Fujita, J. Ponou, A. Shibayama

"The different types of nano to submicron particles, which are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The information is very useful for mineral processing treatment. The IFA can measure the particle size distribution in low to high concentration of particles in liquids and non-light transparent liquids. Here, mainly the emulsion and bubble size measurements are described.Emulsion (w/o type) is prepared with oil and water mixture. The nano to micro emulsion particle size is usually measured by light scattering method. The particle size distribution of emulsion of light oil measured by IFA agreed well with the one by the dynamic light scattering (DLS) method. The water size distribution in emulsions of gasoline is difficult for the small reflection index and C heavy oil is difficult for the black color by DLS method. The IFA can measure both emulsions.There are many methods to measure fine air bubbles, however, the finer nano size measurement apparatuses are DLS method and IFA. A “ghost” peak appeared in the large particle micron meter size in DLS method. The mean diameter in IFA is similar with DLS for the nano meter size. INTRODUCTIONParticle size distribution measurement of nano to submicron particle, emulsion and bubble size distribution are very useful for ultrafine particle separation and characterization of fine particles by the necessity of recent fine minerals separation (For example, Li et al.2016, Mikhlin et al.2016, Wang et al.2013). As for the size measurement of solid particles in liquids, three different types of nano to submicron particles, that are well-dispersed nano particles, coagulated nano particles or settled submicron particles, have been measured by the interactive force apparatus (IFA). The particle size distributions are compared with the one of dried particles measured by TEM or SEM. The well-dispersed nano particle size distribution by IFA is influenced by the nano size surfactant micelles and becomes smaller, when compared with the TEM result. The size distribution of nano size of magnetite particles in water is influenced by the isoelectric point and the mean diameter of coagulation becomes larger. The particle coagulation in diluted suspension is about 2nm smaller when compared with the higher concentration. The submicron nickel particle size distribution is well agreed the result by SEM. The coagulation effect is small in the submicron size of nickel powder in water (Fujita et al., 2013). In this paper, the emulsion and bubble size measurements are mainly described."

Jan 1, 2016

By G. W. Zhang, Changsha Research Institute of Mining and Metallurgy, X. Xiao, Y. Long, L. L. Huang

"The paper presents a scale-up and design method of vertical screw stirred mill, in which the closed circuit of mill and hydrocyclone was assumed as one factor, theoretically regardless the affects inside system of the mill and hydrocylone. The specific energy is chosen as a scale-up criterion, based on the premise that when fed the same feed material, mills of different sizes delivering the same specific energy will yield products.Batch grinding tests are conducted to determine the specific energy, and combined with industrial production data, scale-up and design of vertical screw stirred mill for industrial production are accomplished. Having developed this method for the vertical screw stirred mill used in regrinding duty of iron ore in Ma Steel, it has now been successfully applied in other installations.INTRODUCTIONThe Towermill was developed in Japan in the 1950s, by the Tower Mill Kubota Corporation, it was fine and ultra-fine grinding mill of the metallic ores and concentrates. Due to the rapid development of metal mining and useful minerals disseminated fine, fine grinding and ultrafine grinding equipment has also been more wide used in minerals processing industry. Typical fine and ultra-fine grinding mil are the Vertimill and Stirred Media Detritor (SMD) Mill of Metso, Eirich Towemill, Outotec HIGmill, FLSmidth VXPmill, Xstrata Isamill and the vertical screw stirred mill (JM) of CRIMM, etc.JM series of vertical screw stirred mill were invented by Changsha Research Institute of Mining and Metallurgy in the 1980s. Energy saving and consumption reducing have been achieved through the optimization and engineering practice. More than 500 units JM series of vertical screw stirred mill are used in the iron ore, copper ore, copper-molybdenum ore, molybdenum ore, Pb-Zn ore and Au ore."

Jan 1, 2016

By David Rahal, Saul Ortiz, Maria Escobedo

The general trend in the minerals industry is towards the processing of fine grained, disseminated mineral deposits. This has led to an increase in the number of fine/ultra-fine grinding installations using stirred media mills. The challenge is that both the equipment type and the mineralogy of the deposit have an effect on specific energy consumption. Fresnillo PLC recognized this issue and addressed it by providing samples for testing in a laboratory regrind system. The objective of the test program was to determine the specific energy required to achieve a product size of 10 µm (P80). A specific energy plot was generated for both a lead and zinc flotation concentrate. It indicated that 34 kWh/t and 51 kWh/t were required for the two samples (Pb and Zn respectively). This difference highlights the effect of mineralogy on the energy required for fine grinding. The regrind feed and products were submitted to a range of basic mineralogy tests to quantify the mineral differences that could have changed the specific energy requirements. These tests provided general mineralogy, documented optical textures, and provided particle size microscopy. The lead concentrate was found to contain significant amounts of silicates in addition to the dominant sulphide, pyrite. The zinc concentrate was determined to be mostly sphalerite with minor amounts of quartz, chalcopyrite, pyrite and galena. The material testing results illustrate the importance of basic mineralogy studies in conjunction with comminution testing to determine specific energy consumption.

Jan 1, 2016