Search Documents

By Burcu Ertug, Necip Ünlü

"On average, one out of two glass bottles coming on to the market is provided by recycling processes in Europe. Glass recycling has been started by the early of 1970s in Turkey, and the recycling amount has been reached to 70 thousand tons recently, while 4.2 million tons which represents only 25 percent of total glass manufactured, is the amount of glass collected annually for recycling in the world. The glass recycle process basically involves collecting, sorting, then crushing and grinding after which glass cullet is produced as the secondary raw material. Removing of the contaminants from the glass cullet, and then melting are the next steps. In this study, recent developments of 100% recyclable without any deterioration in quality, and never decomposable glass, are discussed detailed in terms of glass production processes.1.IntroductionIn many countries, waste glass constitutes a large proportion of solid wastes, and recycling the glass is a major environmental problem all over the world [1]. Among the diverse types of waste, glass is one of the most valuable recycling materials because it can be revived and recycled completely and hardly decomposes [2]. Between 80% and 85% of the mass output from the worldwide glass industry is either in the form of containers for the food, beverage, and pharmaceutical industries, or flat glass for building construction or for motor vehicle manufacture. Other product segments, whilst only constituting about 15% of the mass output, produce high value technical and consumer products by comparison with container and flat glass [3].In the present study, the recycling of Liquid Crystal Display (LCD), Cathode Ray Tubes (CRT) and Printed Circuit Boards (PCB) were examined. The production of glasses and glass-ceramics from glass cullet, synthesis of different compounds from recycled glass were other subjects of interest. The use of recycled glass for construction industry and using glass as aggregate were emphasized. Finally the recovery of glass fibers were investigated."

Jan 1, 2012

By C. P. Patel

"The Sturgeon Lake Joint Venture volcanic massive sulpide deposit was discovered in 1970. Milling was started by Falconbridge Copper Ltd. at Sturgeon Lake in September 1974. The Sturgeon Lake pit and mill are located 88 kilometers by road northeast of Ignace, Ontario. IgnE1ce is a town of some 2800 people located on the Trans-Canada Highway, 241 kilometers west-northwest of Thunder Bay. The mill is treating an average of 1100 TPD producing separate concentrates of copper, lead and zinc. Initially, difficulties were experienced in achieving accept-able concentrate grades and recoveries but these were eventually overcome. This presentation describes current metallurgical strategy as practiced at the Sturgeon Lake mill.But first, a few words about the type of ore being treated. In geological terms the ore is classified into two main categories. They are the massive sulphides with underlying zones of stringer sulphides as illustrated in Fig. 1. The plan view is shown in Fig. 2. The areas of East-limb and North-limb are as shown. These last two ores have suffered enough alteration to cause problems during treatment. The massive sulphides consist of chalcopyrite, sphalerite, galena, tetrahedrite and small amounts of pyrrhotite among other gangue materials. The stringer ore is comprised of predominantly chalcopyrite intrusions into rhyolite and has lesser amounts of sphalerite and tetrahedrite. At present we are treating a predetermined blend of massive and stringer ores from zones that have been metallurgically tested to ensure compatibility with current treatment procedure in the plant. Ore responding to this treatment is classified as normal ore while the ore proving incompatible is classified as north-limb ore or east-limb ore."

Jan 1, 1980

By W. R. K. Wu

Results of linear correlations of two to four variables by the least-squares method are presented. The variables include 63 parameters representing coal composition, coal plasticity, and coke strength. The composition parameters are on chemical analyses; the plasticity parameters, on three plastometer and dilatometer tests and four miscellaneous tests; and the coke-strength parameters, on three ASTM indices. Seventy-two to eighty-four plastic coals were used in the plasticity and carbonization tests, which together form the basis of this report; 43 nonplastic or weakly plastic coals were used in the coal-band studies. Plots of relations between volatile matter, carbon, and oxygen contents of 1,860 U.S. coals and the 84 coals used are shown. Similar plots between volatile matter and hydrogen or atomic H/C of the 84 coals are also included. Significances of regression coefficient signs for coal composition parameters in the significant correlations found are discussed. Based on these significances, the following relations are shown: (a) coke strength versus average aromaticity, or mineral matter content, of the parent coal; (b) characteristic temperatures of the plastometer and dilatometers, the free-swelling index, or the Gray-King type versus average hydroaromaticity of the coal; and (c) nontemperature parameters of the plastometer and dilatometers versus the physical properties of a certain group of compounds from thermal decomposition of coal. Similarly, significances between the positions of coals in the coal band and the aforementioned relations are also discussed. A structural theory of coal plasticity is proposed. Applications of the correlation results are discussed. Composition parameters, such as carbon, atomic H/C, and calorific value may be used as a basis for selecting coking coals for stronger coke. Plasticity parameters, such as the end temperatures of the plastometer and dilatometers and the free-swelling index, may be used for the same purpose. Based on the best correlations found, coke-strength indices may be estimated to within 4 to 8 units of the observed values; the end temperatures of the plastometer and dilatometer tests, 5° to 10° C.; and the free-swelling index, within 1 unit. Accuracies of all these estimated values are examined, based on the experimental errors of the data involved. Finally, estimations of plasticity parameters from one test with those from others are shown.

Jan 1, 1971

By H. R. Bullis

"A 2003 paper discussed the idea that as gold mining companies grow larger it becomes more difficult for them to discover or acquire new gold deposits large enough to replace extracted reserves on an annual basis. Deposits of the size required to replace annual production of very large gold producers (VLGPs) are statistically few. An update in 2005 reviewed VLGPs with respect to production, reserves, and reserve life and observed recent changes in the gold mining industry. Now, more than 12 years later, this paper explores how those VLGPs have fared and how the gold mining industry has changed. KEYWORDS Gold, Gold price, Production, Reserves, Very large gold producer (VLGP) RÉSUMÉ Un article de 2003 examinait le concept selon lequel, à mesure que les sociétés d’exploitation aurifère se développent, il leur devient de plus en plus difficile de découvrir ou d’acquérir de nouveaux gisements aurifères suffisamment grands pour remplacer les réserves qu’elles extraient annuellement. Statistiquement, il existe très peu de gisements de la taille requise pour remplacer la production annuelle des très gros producteurs d’or. Une mise à jour de l’article en 2005 se penchait sur la production, les réserves et la durée de vie des réserves des très gros producteurs d’or ; elle portait sur les récents chan¬gements au sein de l’industrie de l’exploitation aurifère. Aujourd’hui, plus de 12 années plus tard, cet article explore l’évolution et les résultats de ces très gros producteurs d’or, ainsi que les changements qu’a connu l’industrie de l’exploitation aurifère. MOTS CLÉS or, prix de l’or, production, réserves, très gros producteurs d’orINTRODUCTION In 2005, the world’s top five gold producing companies were Barrick (after purchasing Placer Dome; 9.1 million ounces; Barrick Gold Corporation, 2005; Placer Dome, 2005), Newmont (8.2 million ounces; Newmont Mining Corporation, 2005), AngloGold Ashanti (6.2 million ounces; AngloGold Ashanti Limited, 2005), Gold Fields (4.2 million ounces; Gold Fields Limited, 2005), and Harmony Gold (3.0 million ounces; Harmony Gold Mining Company Limited, 2005). During the years leading up to that point, there had been a flurry of activity in the gold sector directed at consolidating production and reserves to create very large gold producers (VLGPs). As defined in Bullis (2005), a VLGP is a mining company whose primary busi¬ness is gold production and that has annual gold production more than 5 million ounces. A stated corporate goal of several of the VLGPs at the time was to become the largest gold producing company in the world."

Jan 1, 2019

By M. Muinonen, R. Pandher

Royal Nickel Corporation is developing the Dumont Nickel Project, a large nickel sulphide deposit located near the town of Amos, Québec. The nickel occurs as pentlandite, heazlewoodite, and awaruite. The relatively low grade ore can be processed to a very high grade nickel concentrate, containing 29% Ni. The absence of copper and precious metals in the ore renders this concentrate amenable to processing by dead roasting in a fluid-bed roaster and smelting in an electric furnace to produce ferronickel for sale to stainless steel producers. Laboratory test work and conceptual engineering design was completed to demonstrate the amenability of Dumont concentrate to produce ferro-nickel.

Jan 1, 2015

By J Seppelt, G S. Lane, E Wang

Newcrest’s Cadia concentrator operated from 1998 to 2012 with a traditional SABC grinding circuit treating Cadia open pit ore. The Cadia comminution circuit was well characterised through surveys and data that are available in the public domain, and became a benchmark standard for the industry and practitioners modelling large SAG mill based circuits. In 2012, the HPGR-based crushing circuit was introduced in front of the SAG mill to increase throughput when treating the Cadia East ore that was derived from an underground block cave. This ore was expected to be more competent and have a coarser run-of-mine size distribution.Numerous previous papers have described the design and commissioning of the Cadia HPGR-based circuit.This paper describes the improvement in comminution energy consumption resulting from the introduction of the HPGR, including identifying the impact of process complexity and an increase in ancillary energy consumption for conveyors, screening, and crushing.CITATION:Lane, G S, Seppelt, J and Wang, E, 2018. Quantifying the energy efficiency transformation at Cadia due to HPGR crushing, in Proceedings 14th AusIMM Mill Operators' Conference 2018, pp 141–152 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Aug 29, 2018

By J. F. Burr, D. P. Snyder, G. W. Luxbacher

"The Mine Improvement and New Emergency Response Act (MINER Act) of 2006 established the Office of Mine Safety and Health (OMSH) within NIOSH and provided authority for awarding contracts related to the development and implementation of new mine technology and equipment. Subsequently, Congress provided additional funding to NIOSH to initiate and continue the program. OMSHR has fulfilled this Congressional mandate through annual Broad Agency Announcement (BAA) solicitations, directed Requests for Proposals (RFP) and Inter-Agency Agreements (IAA), and has further expanded the program through capacity building BAA contracts with U.S. university mining departments in the areas of mine ventilation and ground control. This paper describes the extramural funding program and broadly examines the results of the 150+ contracts issued to date, grouped into key focus areas. INTRODUCTION The Mine Improvement and New Emergency Response Act (MINER Act) of 20061 established the Office of Mine Safety and Health Research (functioning as the Office of Mine Safety and Health Research or OMSHR) within the National Institute for Occupational Safety and Health (NIOSH), and provided authority for awarding contracts related to the development and implementation of new mine technology and equipment. The OMSHR external contracts program was formed in accordance with the MINER Act and has since issued over 150 contracts focused on worker health and safety. Initial funding for this program was provided by Congress through two Emergency Supplemental Appropriations (ESA) and was focused on emergency oxygen supply, communications and tracking, and refuge chambers (also referred to as refuge alternatives). Since the MINER Act, Congress has continued to fund the program through the annual NIOSH mining appropriation. The program was supplemented starting in 2009 with an academic capacity building program directed toward developing university tenure-track faculty and facilities and supporting graduate students in the area of mine ventilation; ground control was added as an additional focus area in 2011. A short synopsis of each contract is published on the NIOSH Mining website2 and final reports are available in digital form on request. A summary of the progress OMSHR has made over the 10-year period since the Act was published previously.3"

Jan 1, 2018

By C Bellia, A Maldonado, S Strong, H Baxter

This paper discusses the technical and cost benefits of alternative data collection techniques used to collect lithological information, obtain laboratory testing samples and perform in situ testing. A comparison between diamond coring and sonic coring techniques is made using data from a recent geotechnical investigation for a final pit slope cut-back. The impacts of the coring method on laboratory strength testing results, material character testing and, ultimately, the mass strength parameters and subsequent slope design adopted are compared. The sonic coring method was chosen out of necessity and enabled the collection of tube samples of a clay unit of interest as well as bulk samples for material character and geochemical testing. The sonic coring generated unexpected degradation of clastic units, while cohesive clay-dominated units were recovered well. The likelihood that disturbance due to the coring method would result in lower than expected triaxial strength results was recognised ahead of time, with surplus samples collected and single-stage triaxial strength testing undertaken. This testing compared favourably with historic three-stage testing, where sample degradation occurred during the later stages. Material character testing of fine-grained, clay-dominated units was comparable with historic diamond core testing, while grain size estimates for more clastic units tended to be finer than previous results. The use of sonic coring over non-cored methods enabled the collection of material texture data, geotechnical properties and a full suite of geochemical analyses. This provided a comprehensive understanding of the lithological and geotechnical character of the rock and soil mass. A high-confidence geotechnical model was developed. The end result was the development of a slope design that was more aggressive than was previously designed (5° steeper inter-ramp angle), which has proven to be appropriate to the conditions following excavation. Overall, sonic coring was a cost-effective means of obtaining additional geotechnical data for the site.CITATION:Baxter, H, Bellia, C, Maldonado, A and Strong, S, 2015. Case study assessing alternative data collection techniques and analysis methods to assist with geotechnical slope design, in Proceedings Iron Ore 2015, pp 419–428 (The Australasian Institute of Mining and Metallurgy: Melbourne).

Jul 13, 2015

By Phil Shelton

What exactly does clean coal mean? Mining coal creates dust and releases methane gas. And burning coal liberates CO2 and emits particulates, including SO2 and NOx. Coal creates wastes that are often stored in unsightly and potentially dangerous slag heaps and lagoons. When clean coal technology is discussed, it sometimes seems that creating modern or ?ultra super critical? coal-fired power stations is presented as the main or even the only answer. However, there may be a more holistic approach. Using the energy potential of coal is always going to have environmental impacts. Some of these will be negative. But the need to secure future energy resources demands that society tackle these negative issues and find ways to minimize and offset them.

Jan 1, 2010

"1 INTRODUCTIONThe use of nondestructive testing (NDT) methods to evaluate the integrity of Augered Cast-in-Place (ACIP) and Drilled Displacement (DD) piles has been a subject of significant debate among engineers, contractors and NDT practitioners. This guideline document will illustrate the importance of reviewing all available information in conjunction with the NDT records. ACIP and DD piles have unique properties that must be considered when using a specific NDT method. Any evaluation of the integrity of an ACIP or DD pile must also include a thorough review of the detailed pile installation records and the site specific soil conditions. Long or theoretical descriptions of the methods have not been included in this publication. More detailed information about these NDT methods including their theoretical and historical backgrounds can be found in DFI’s Manual for Non Destructive Testing and Evaluation of Drilled Shafts (2004). Additional information can also be found in the more comprehensive textbook Nondestructive Testing of Deep Foundations by Hertlein and Davis (2006).1.1 PurposeThe intent of this guideline is to provide practical guidance for the proper interpretation of NDT results on ACIP and DD piles. Short descriptions of the main integrity methods available are provided along with several examples of how to use all of the information available to make sound engineering judgments about the results. This publication is a state-of-the-practice guideline to promote accurate engineering evaluations.For engineers inexperienced with NDT, these guidelines provide sufficient background information on NDT methods to help understand the limitations of the testing, assess the results presented to them, and formulate appropriate questions. This is particularly important for engineers charged with the responsibility to determine from those results what, if any, consequences there may be on the performance of the structure under construction."

Jan 1, 2016

By João Paulo Ferreira Santos

Neste trabalho foram obtidos nanocompósitos híbridos constituídos por nanotubos de carbono de paredes múltiplas (MWCNT) e por nanofibras eletrofiadas de nylon 6 em uma matriz epoxídica. Os MWCNT foram funcionalizados com grupamentos carboxílicos e dispersos através de ultrassom na resina epoxídica. A composição resultante foi disposta de maneira alternada com mantas de nanofibras de nylon 6 para formar estruturas compósitas na forma de sanduiches, as quais foram termicamente curadas. Medidas de resistividade elétrica das estruturas obtidas mostraram que uma percolação elétrica entre 0,05% e 0,5% (v/v) de MWCNT foi alcançada. Do ponto de vista mecânico, a incorporação de MWCNT na matriz epoxídica resultou em aumentos de módulo de elasticidade (26%) e na resistência a ruptura (19%), porém, devido a presença de aglomerados de nanocargas, a deformação na ruptura e a resistência ao impacto foram severamente reduzidas para 71% e 33%, respectivamente. Por outro lado, a adição de nanofibras de nylon 6 para formar um híbrido, mostrou-se, bastante promissora ao levar a aumentos de 8% na resistência ao impacto sem ocasionar perdas de módulo elástico, na resistência à ruptura e na deformação na ruptura.

Aug 8, 2018

By M. N. Shetty, A. C. D. Chaklader

RECENTLY, it has been demonstrated that a considerable densification and interparticle bonding can be achieved if a pressure is applied to a powder compact while the material of the compact is undergoing either a decomposition reaction' or a polymorphic transformation.' The term "reactive hot pressing" has been coined to identify this process in which a phase change is combined with pressure to achieve interparticle bonding. This process is based on a principle which postulates that there is an enhanced reactivity and mobility of the molecular species at the phase-transformation temperature and this effect is utilized for interparticle bonding in powder compacts. This note summarizes the results obtained in an attempt to utilize this technique to produce ceramic-metal composites. In this case, a decomposition reaction of a compound (which after decomposition yielded an oxide) was used to achieve interparticle bonding in ceramic-metal composites. The reactive hot pressing was carried out in a Phillips induction heating unit, using either a graphite or a high-temperature steel die which functioned as both the susceptor and the hot-pressing component. The die was heated to the desired temperature in a helium atmosphere. All cermets produced by this technique were based on alumina as the ceramic phase. Different metal phases such as iron, copper, and chromium were used to study the effect of varying the metal phase on the properties of the composite. a Mono-hydrate (Boehmite) was mixed with different proportions of metal powders (-325 mesh) in dry condition in a mortar and pestle. No special precautions were taken for proper mixing. The mixtures were then compacted into a cylindrical form having an approximate dimension of 1 cm in diameter and 1 cm in height. For this compaction an ordinary

Jan 1, 1965

By J Hudson

Autogenous (AG) and Semi Autogenous (SAG) grinding mills are the conventional selection for large-scale grinding circuits. It is accepted that these forms of comminution are not the most energy efficient available. This efficiency combined with escalating energy prices, steel prices and the requirement to process larger, lower grade deposits has necessitated that better comminution techniques are found to challenge the dominant position of AG/SAG mills in the grinding circuit. Recent advances in high pressure grinding rolls (HPGR), particularly in terms of roll surface protection have meant that, depending on the application, an economic alternative is available to the large diameter AG/SAG mills. Mining companies now recognise the potential benefits of HPGR and so they need proper assessment in the design of new or upgrade of existing grinding processes. Of course, the answer to the question AG/SAG or HPGR is not straightforward and the impact of the grinding process on the whole metallurgical process needs to be evaluated. Clearly this is a complex decision to make and requires substantial metallurgical knowledge, test work, and objective analysis. The perceived downstream processing benefits will differ between different plants depending on the ore type and processing conditions. The optimal design of the comminution circuit requires that a robust methodology is followed to objectively characterise the ore, size the equipment and determine the downstream processing benefits. The paper gives a brief comparison of the capital and operating costs for both grinding systems, and then outlines the appropriate test work that is required to make an informed decision.

Jan 1, 2006

By SANDEEP KUMAR JENA

This paper reviews the recovery of potassium from different rocks and mineral sources. Global demand for potassium is rising steadily due to the growth of agricultural production. Fertilizer manufacture consumes the majority of the world’s potassium production, with other uses including those in the pharmaceutical, glass, ceramic, food and detergent industries. The availability of soluble potash (K2O) minerals, such as sylvite, kainite and carnalite, in countries like Canada, the United States, Israel and Russia makes them major potash producers, whereas agriculture-based countries like Liberia, Somalia, Central African Republic, Thailand, Indonesia, Malaysia and India meet their potassium requirements through imports only. In these countries, the huge availability of potassium-bearing rocks/minerals like nepheline syenite, feldspar, mica and glauconitic sandstone, containing around 4 to 17 percent K2O, brings up the prospect of commercial production of potassium. Potassium recovery from minerals/rocks is complicated due to the uniform distribution of potassium throughout the crystal structure. Different physico-chemical separation methods like bioleaching, chemical leaching, flotation and roast-leaching have been discussed for the successful recovery of potash values from these rocks/minerals. Although seawater is vastly available, the recovery of potassium from seawater using chemical precipitation, solvent extraction, membrane separation and ion-exchange methods is not cost-effective due to low concentration of potassium.

By Jason Rrno

The emergence of Impact and Benefit Agreements (IBAs) in the Canadian mining sector has been read by many as a positive governance innovation. Negotiated directly between mineral resource developers and Aboriginal communities with limited government interference, IBAs serve to manage impacts associated with a mining project and deliver tangible benefits to local communities. Notwithstanding their increasing use and significance, limited systematic analysis has been undertaken to determine whether they are, in fact, working. This paper reports on the effectiveness of a number of IBAs negotiated in support of three northern Canadian diamond mines, drawing on evidence from time-series data, key informant interviews, and focus group meetings in Yellowknife and Dettah, NWT, and Kugluktuk, NU. While some deficiencies were apparent and perceptions of effectiveness varied somewhat by Aboriginal community, the IBAs were generally found to be meeting their objectives, especially with respect to the delivery of benefits. For Aboriginal communities affected by mineral development in the Canadian North, this represents a significant change to typical outcomes of the past. Moving forward, research on IBA effectiveness needs to adopt a longer timeframe and begin to gauge the degree to which IBAs are able to address long-standing concerns associated with hinterland resource extraction beyond their agreement-specific objectives.

May 1, 2010

Chromium, a critical mineral for which the United States is largely dependent on foreign sources, is the subject of a new report just issued by the Interior Department's Bureau of Mines. The report is the first in a new series called "Mineral Commodity Profiles" (MCP's). Designed to give an updated review of important events affecting critical minerals, it also presents a comprehensive description of industry structure, supply-demand relationships, technology, and outlook for the future.

Jan 1, 1977

By Alastair Torrance, Mitchell Nipperess, Andrew Olsson, Italo Onederra, Gary Cavanough

Components of bulk explosive products include ammonium nitrate, water, fuel, stabilizers, and calcium nitrate. The physical attributes include prill/emulsion ratio, density, and viscosity and in the case of prilled ammonium nitrate, hardness, size distribution and fuel oil absorption. These components and attributes in conjunction with ground conditions determine all aspects of explosive performance including the risk of fume. This paper presents a fume risk assessment matrix of explosives components and physical attributes as a function of a simple description of ground conditions. Instrumentation to provide a measure of the quality of the explosive product are also described and these include both “on bench” physical measurements and laboratory analysis. “On bench” methods include “in hole “density, velocity of detonation (VOD), detonation pressure and detonation temperature. Part of the quality control process involves a mobile laboratory unit which at this stage can provide measurements of water content, ammonium nitrate content, calcium nitrate content, fuel content, prill characteristics and prill/emulsion ratio. This unit can be taken to sites to enable the testing of bulk and sensitized products at site rather than after transportation.

Jan 1, 2015

By J. Lee

As the usage of BIM increased in the construction industry, some construction owners started exploring the use of BIM for maintaining their facilities. Construction Operations Building Information Exchange (COBIE), a spreadsheet data format suggested in 2007 to manipulate building information, is considered as one of the solutions that would facilitate the process of transferring information from BIM to applications for facilities management. Several BIM and Computer Aided Facilities Management (CAFM) applications offer functions to export or import the COBIE data. To facilitate the process of generating the COBIE data out of Building Information Model, some add-in applications, such as COBIE Toolkit for Revit, also were developed. However, most of these applications handle a limited amount of COBIE data. Professionals using these add-in applications therefore sometimes end up spending a significant amount of time to add additional data manually to the COBIE data file. To automatically get a data-rich COBIE file, we developed a prototype application that extracts information from Revit, which is one of the BIM authoring tools, stores them in an external database, and then produces the COBIE file using information stored in the database. We applied our application to a pilot project and produced 8 COBIE worksheets automatically, which demonstrated a significant amount of time saving. This paper presents how our prototype application produces 8 COBIE data sets automatically. It also addresses our attempt to handle more COBIE data sets.

Aug 1, 2013

By Elaynne Rohem Peçanha

Com o objetivo de estudar a interação da hematita com biorreagente de flotação (Bacillus subtilis), foram realizados experimentos de ângulo de contato. Após a interação com o biorreagente, a superfície da hematita apresentou uma hidrofobicidade apresentando um valor de 46,0º. Os experimentos de potencial zeta mostraram uma interação acentuada entre o reagente e o mineral na faixa de pH alcalina com deslocamento do ponto isoelétrico da hematita. Ensaios de microflotação foram conduzidos em tubo de Hallimond modificado, em pH 6, com uma recuperação de, aproximadamente, 80%. As teorias DLVO e X-DLVO foram aplicadas para avaliar as energias de interação entre o reagente e os minerais. As duas teorias foram capazes de prever a interação que ocorre entre o biorreagente e a hematita. Os resultados evidenciaram o uso promissor do reagente na flotação direta de hematita.

Aug 17, 2017

By Tassos Grammatikopoulos, Vladimiros Papangelakis, Douglass Duffy, Cheryl Washer, Srinath Garg

Flotation operations in Sudbury, Ontario, seeking to separate pentlandite and chalcopyrite from mixed sulphide deposits, produce pyrrhotite tailings that have been disposed of in tailings ponds for over 50 years. These reactive tailings are viewed as waste, despite containing ~0.8 wt% Ni, and represent an environmental liability because of their acid mine drainage (AMD) potential. Given the large quantities of pyrrhotite currently stored in Sudbury, and declining ore grades elsewhere, these tailings have shifted from being viewed as a waste to a potential resource. Recent advances in the bioleaching of low-grade sulphide ores have raised the prospect of bioleaching as a potential low-cost processing option. However optimization of this proposed process requires a thorough understanding of the mineralogy of the pyrrhotite tailings that would be leached. The work presented here addresses the characterization of two distinct Sudbury pyrrhotite tailings, namely from the Vale and Glencore operations, using electron microprobe, XRD and QEMSCAN analysis. Particular focus is given to how the mineralogy may affect bioleaching as a processing option, through the deportment of nickel and the various phases present

Jan 1, 2015