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By T. T. Chen, W. Petruk

The mineralogy of the feed, concentrates and tailings from the Heath Steele mill in New Brunswick was studied in detail to determine the liberation and recoveries of the major ore minerals, and to characterize the occurrence and distribution of the trace elements. The ore milled during August 1977 contained an average of 4.34 wt % Zn, 1.25 wt % Cu, 1.64 wt % Pb and 90 gr/ton Ag. The main trace elements in the ore are silver, cadmium, indium, cobalt, antimony, bismuth, arsenic, mercury, tin and gold. Silver is carried in solid solution in tetrahedrite-tennantlte, galena, Ag-Sb sulfosalts and Pb-Bi-Sb sulfosalts. Approximately half of the silver is recovered in the lead and copper concentrates and the remainder is lost in the tailings and Zn concentrate. As the major silver-bearing minerals also contain Sb and Bi, recovering silver by ore dressing would involve recovering elements that are troublesome in extraction metallurgy. Cadmium and most of the indium and mercury occur in solid solution in sphalerite and consequently are recovered in the zinc concentrate. Some indium is also recovered in the copper concentrate in a second unidentified indium-bearing mineral. Cobalt and arsenic occur principally in arsenopyrite, cobaltite, a Co-Fe sulfarsenide, pyrite and pyrrhotite, and follow these minerals into the tailings. Recovery of the valuable element cobalt, therefore, would involve recovering the environmentally hazardous element arsenic. Most of the tin and gold report to tailings. The ore was ground to about 80% minus 270 mesh. At this grind, 71 wt % of the sphalerite, 66 wt % of the chalcopyrite and 59 wt % of the galena were liberated. Recoveries of free sphalerite, free chalcopyrite and free galena in the Zn, Cu and Pb concentrates were 85 wt %, 76 wt % and 80 wt %, respectively; recoveries of unliberated sphalerite, unliberated chalcopyrite and unliberated galena in the respective Zn, Cu and Pb concentrates were 48 wt %, 5 wt % and 7 wt %. Some of the unliberated sphalerite and chalcopyrite grains in the tailings are large and would have been liberated at a finer grind.

Jan 1, 1980

By Y. Sasseville

"Niobec has been using vibrating screens and screw classifiers as a double stage classification in its grinding circuit since the very beginning of its operation in St-Honoré. Most of the other mineral processing plants around the world uses cyclones as the classification device in their grinding circuit. The difference between these two methods are well known in terms of capital cost and grinding efficiency but the differences in terms of the impact on the downstream processing stages are a lot harder to predict and are case specific. In the interest of lowering the capital cost of a future expansion project, Niobec decided to test the cyclones in its actual grinding circuit and evaluate their impact on the recovery of the downstream processing stages as well as the operating cost of the mill. We switched between cyclones and screens for 8 month in 2013 and early 2014 and we are now operating only with cyclones since march 2014.INTRODUCTIONThe Niobec mine and concentrator were built in the mid 70’s and at that time, the mill was processing 1 500 tons per day. Over the years, many expansion projects have brought the plant to 7 000 tons per day. Throughout the initial concentrator design and commissioning, screens have been chosen over cyclones because of their higher classification efficiency which is known to reduce variability and limit the fine generation especially due to a high undersize classification efficiency. Just like many other plants, fine particle generation is a major problem at Niobec because of its negative effect on downstream processing stages. In the interest of lowering the capital cost of a future expansion project, Niobec’s engineering team decided, 35 years later, to test the cyclones in its actual grinding circuit and evaluate their actual impact on the final recovery and the operating cost of the mill.The grinding circuit is separated in two lines which will be called Circuit #1 and Circuit #2 along this paper. Circuit #1 is, as you can see in Figure 1, composed of a rod mill and two parallel ball mills in closed circuit with screens and screw classifiers. The screens oversize are sent to the screw classifiers while the undersize are sent to the next processing stage. The screw classifiers overflow are both sent back to the pump box while their oversize streams return in their corresponding ball mills for further grinding. Circuit #2 is, as you can see in Figure 1, quite the same as Circuit #1 except it has only one set of screw classifier and ball mill. Figure 1 also shows the modification in arrangement each circuits went through to integrate the new cyclones. One of the ball mills in Circuit #1 now appears dotted because it can still be used but is not now"

Jan 1, 2015

By Stephen L. Chryssoulis, Stamen Dimov

"Preg-robbing has been known for many years, where increased losses are suffered because dissolved gold is removed from solution by adsorption onto carbonaceous matter. In direct cyanidation circuits it is reasonable to conclude that the preg-robbed gold is either in a gold cyanide [Au(CN) - 2, AuCN] or metallic [Au°] form. However, in circuits with a pre-oxidation step possibilities increase and multiply even further because of water recycle streams containing apparent and not-so-apparent gold ligands. It is in these circuits where speciation of sorbed gold, i.e. the identification of the gold compound, is useful. The importance arises from the fact that proper identification of the sorbed gold species can be used to determine how, when, where and why gold was removed from solution, thereby identifying the exact cause of the problem and providing clues as to how it may be rectified.INTRODUCTIONTo the best of our knowledge, this is the first attempt ever to speciate gold preg-robbed by carbonaceous matter using a surface sensitive microbeam technique. This approach enables the direct determination of gold species sorbed on carbonaceous particulates, opening an entirely new field in the understanding of the chemistry of gold sorption on carbon. The reasoning behind this effort was to add to the current knowledge of the detrimental effect chloride ions have on gold recovery by the pressure oxidation and in particular why in the ensuing CIL step, gold is not being desorbed from the surface of the carbonaceous particles (Table 1)."

Jan 1, 2004

Improved Process & Practices Result In: ? Reduction of undesirable downtime, & expensive secondary damage ? Improved equipment performance & health ? Extension of equipment life, & reduction of operating costs ? Safety and environmental performance improvement Equipment knowledge capture and consistently applied

May 1, 2010

By Stephen A. Gasiorowski, Frank J. Hrach, James D. Bittner

Separation Technologies, LLC (ST) has developed a processing system based on triboelectric charging and electrostatic separation that provides the mineral processing industry a means to beneficiate fine materials with an entirely dry technology. The environmentally friendly process can eliminate wet processing and required drying of the final material. The process requires little if any pre-treatment of the material other than grinding and operates at high capacity - up to 40 tonnes per hour by a compact machine. Energy consumption is low, approximately 1 kWh/tonne of material processed. Since the only potential emission of the process is dust, permitting is typically relatively easy. In contrast to the other available electrostatic separation processes that are typically limited to particles greater than 75 µm in size, the ST belt separator is ideally suited for separation of very fine (<1 µm) to moderately coarse (500 µm) materials with very high throughputs. The triboelectric particle charging is effective for a wide range of materials and only requires particle-particle contact. The small gap, high electric field, counter-current flow, vigorous particle-particle agitation and self-cleaning action of the belt on the electrodes are the critical features of the ST separator. The high efficiency multi-stage separation through charging / recharging and internal recycle results in far superior separations and is effective on fine materials that cannot be separated at all by the conventional electrostatic techniques. Since 1995, this triboelectric process has been extensively used for the beneficiation of coal fly ash with eighteen separators in place and over 100 machine-years of operation at locations in North America and Europe. The technology has been also successfully applied to the beneficiation of a variety of minerals including calcium carbonates, talc, and potash.

Jan 1, 2012

By Linda C. M. Elliot, Liangxue Liu

"The deposition of tailings under water is considered to be one of the most environmentally promising and potentially cost effective methods to reduce or eliminate acid mine drainage from tailings. One of the concerns of subaqueous deposition has been that metals may leach into the cover waters, thereby increasing aqueous metal concentrations to higher than acceptable limits. This potential was seen to have an even greater possibility for impact when the tailings are deposited under acidic lake water.The following paper summarizes the results of subaqueous tailings pilot column test work conducted to determine the effects of subaqueously deposited tailings on lake water and tailings pore water. Two types of tailings were tested: high sulphide tailings (pyrrhotite concentrate), and low sulphide tailings (end of pipe slime tailings).Data was collected from five columns over a 13 month test period. The results indicated that a stagnant I 000 mm water cover was capable of maintaining the underlying tailings in a reducing condition. The upwards diffusion of pore water resulted in a pH increase in the waters overlying the thickened pyrrhotite tailings and the pyrrhotite tailings with a shallow cover of substrate. A conductivity gradient between the tailings and the water cover caused a diffusion of salts upwards into the overlying water column. Precipitation noted at the tailings water interface may be related to the precipitation of ferric oxyhydroxides, which resulted in a decrease in Fe concentrations noted in the water cover. Other metal concentrations did not exhibit significant increases in the water cover. A sulphate concentration gradient between the tailings and the water cover may have caused the diffusion of SQ4 from the tailings into the water cover."

Jan 1, 1997

By S. Bellec, A. Berton

"Usually, steady state mass balances are used for the design of mineral processing plants. However, this tool does not take into account the impact of process inputs variability nor does it evaluate process transient behaviours between stationary states, such as mill start-up and shutdown. The use of advanced simulations enables the integration of dynamic behaviours in process design decision-making by highlighting situations that are undetectable by using only steady state mass balances. Applying these simulation tools to brown field projects allows the simulator performances to be calibrated and validated on actual plant data before it is used as a prediction tool for the modified plant.Three (3) simulators were implemented at the design stage of a major upgrade project for an ore processing plant in order to assess process behaviours under different production scenarios. These simulators were built to evaluate the impacts on major elements such as mine production, ore stockpile, concentrator production as well as water demand. A validation of individual equipment models was performed whenever sufficient measured data was available. The simulators were then used to study the impact of ore variability (grade, hardness, throughput), to assess day-to-day production special events, and to evaluate the true stockpiles live capacity.The use of a stochastic simulator for equipment sizing allowed a more precise sizing of many pieces of equipment and avoided important expenses in the fresh water pumping system. The dynamic simulator also confirmed that the water in place system would suffice, even in the most demanding production scenario. Finally, the stockpile simulator allowed an important production bottleneck to be quantified and then made possible the assessment of various practical solutions for the stockpiling-reclaiming issues.Post start-up, process data underlines the fact that using advanced simulation tools was useful to mitigate process-related risks associated to the plant expansion, showing generally accurate prediction and adequate equipment sizing, leading to smooth process commissioning. The presented methods are part of what is now routine in Soutex’s participation in both greenfield and brownfield projects."

Jan 1, 2015

By H. Sahay

This paper summarizes the history and ore-grade statistics of mining the Ming orebody, and then details the mining methods. Included are raising, stoping, drilling and blasting techniques. Particular attention is paid to ground support, ventilation and pumping requirements.

Jan 1, 1979

By Jason J. Crowder

Presentation Outline ? Introduction ? Costs of ground support and rehabilitation ? Why post-failure rock mass properties are necessary ? The Rock Mechanics Problem ? Present State of Modelling and Instrumentation in Mining ? Case Study Background ??Williams Mine ? Deriving Parameters for Modelling from Instrumentation ? Results from Case Study ??Back Analyses ? Discussion of Research Impact t Summary

May 1, 2006

By T. J. Yeomans

"The Kidd Creek metallurgical site is situated twenty-six kilometres east of Timmins, Ontario. The site consists of a 4.5 niillion tonne per year concentrator, a 127,000 tonne per year electrolytic zinc plant and a 79,000 tonne per year copper smelter/refinery complex.The concentrator commenced operations in 1966 and was expanded to its present capacity in 1978. The zinc plant commenced operations in 1972, and the copper smelter/refinery in 1983.The concentrator tailings, and both liquid and solid waste products from the other plants are disposed of within a 1215 hectare tailings disposal area. Here, a method known as centraljzecl thickened discharge is used to form a stable cone-shaped hill. A low permanent perimeter dyke structure encloses the cone and directs cone run-off and thickener overflow to a treatment pond. After treatment with lime slurry, this neutralized effluent is recycled to the metsite and also discharged into the Porcupine River system.The tailings system has been in operation in its present form since 1972, upon completion of dykes and a 110 metre thickener unit. Underflow densities were continuously increased until thickener overloading became a serious problem. This necessitated the construction of a second 110 metre thickener, which was completed in 1983. Target densities have been achieved without difficulty since then.This paper discusses the operation of the tailings system, reviews past performance, and outlines future operations."

Jan 1, 1986

By R. Vracar, D. Sinadinovic, Ž. Kamberovic

The paper presents a study on the oxidation of polymetallic gold ore by oxygen in an autoclave. It presents optimum parameters of autoclave leaching of sulphide refractory ore in self-generated sulphuric acid solutions aiming to get products with favourable technological characteristics from which precious and other useful metals can be recovered. A high partial oxygen pressure (1.5 MPa to 2 MPa), high leaching temperature (190°C to 200°C), pulp density 80 g/L to 240 g/L, ore fraction size 76 µm and leaching time up to 4 hours yield good results in rich ores. The full extent of copper and zinc conversion as well as a high extent of iron conversion has been achieved, while lead, gold and silver and a minor part of iron remain as a solid residue among gangue minerals.

Jan 1, 2001

Project Located in northwestern British Columbia 70km West of Cassiar Highway Galore Creek Project and Road Access Corridors Designated For Mineral Development in Stikine-Cassiar Land Resource Management Plan (LRMP)Approved in 2000Strong BC Government, local community and Tahltan First Nation Support for Project

May 1, 2006

By Neil H. Brown

Outline ? Cameco - Cigar Lake ? Cigar Lake Mine Development ? MDS #1 ? MDS #1 Improvements ? MDS #2 ? MDS #2 Improvements Pending ? Acknowledgements Mine Development System ? Mining methods tested and developed over the years ? Construction began officially in 2005 ? Water inflow events in 2006 and 2008 ? Successful dewatering and re-entry in 2010 ? Remediation continues ? Production target is mid-2013

Oct 1, 2010

By G. Couture

"The Glencore Raglan mine Concentrator, located in Quebec’s Nunavik region, has been in operation since 1997. The nickel metallurgical plant was originally designed to process 100 tonnes per hour of ore to produce 130 000 tonnes of nickel concentrate per year at 16% Ni. The increased grinding capacity and the discovery of rich ore bodies have increased the annual production to more than 190 000 tonnes of concentrate at 19% Ni. In 2014, the Metallurgical group, with support from BBA, implemented an expert control system on the flotation circuit. This project was initiated to cope with the high variability of the concentrator’s feed. Increasing the plant recovery and final concentrate grade were also important project objectives. The implementation of the expert system ensures better control of concentrate inventory while maintaining maximum plant throughput. This paper describes the successful implementation of the new control system, the control technology selection and the flotation circuit optimization. It will also discuss the performances obtained with this new approach and the improved process stability.IntroductionThe Raglan Mine is located in Northern Quebec along the 62th parallel. It has been in operation since 1997 and was originally designed to produce 130 000 tonnes of concentrate annually at 16% Ni. The increasing of the grinding capacity and the discovery of rich ore bodies have increased the annual production to more than 190 000 tonnes of concentrate between 18 and 20% Ni."

Jan 1, 2015

By Patrick Pelletier Jr., Pierre-Alexandre Bossé, Gianni Bartolacci, Ian Orford, Steve Parent

"Over the last decades, many authors have shown the importance of froth in the flotation process. Mineral recovery is related to froth recovery and flotation. Selectivity is affected by froth characteristics, especially structure and loading. The characteristics of froth textures could therefore be used for diagnosing flotation.Machine imaging, especially image texture analysis, allows on-line measurement of important froth characteristics and process state classification. The measured characteristics include froth texture, loading and stability indicators. To extract information from images, texture analysis tools are used as well as a block-matching algorithm (BMA). For process state classification, images are analyzed with the same tools and clustering is done with multivariate data analysis algorithms.Two case studies, Brunswick Mine Concentrator Cu/Pb circuit and LaRonde Mine Zn circuit, are presented to show that these indicators may be used for diagnosis and control. The influence of manipulated variables on measured froth features is shown as well as the relationship between froth characteristics, mineral recovery and flotation selectivity.INTRODUCTIONImaging is a way to depict abstract characteristics of a scene or an object; it is often related to other types of scientific observations, chemical component concentrations, for example (Geladi and Grahn, 1996). In this paper, the scene is flotation froth. Imaging can be especially useful in applications where it is difficult to obtain the measurements needed for process analysis – froth flotation, for example."

Jan 1, 2006

By E. V. Manlapig, K. R. Rahal, J-P Franzidis

"The Floatability Characterisation Test Rig or FCTR is a highly instrumented, mobile flotation pilot plant built by Baker Process (now EIMCO) for the AMIRA P9 Project for use in flotation plant modelling and simulation studies. With the Mintek Floatstar system controlling the level in every cell, and the facility for full stream sampling on all streams, the FCTR is a unique tool for producing data of sufficient quality for flotation plant modelling. The plant was commissioned at Lonmin's Karee and Eastern Platinum concentrators in 1999/2000, and completed a number of test work programs to investigate the effect of power input and regrinding on metallurgical performance. Lonmin's experience with the FCTR has caused it to build two of its own to undertake further projects on its various mines. This paper describes the design of the FCTR and the features that make it a unique research tool, and the benefits derived by Lonmin through their experience with the unit.INTRODUCTIONAs part of the Australian Mineral Industries Research Association (AMIRA) P9 project, a new model for flotation has been developed, in which the overall recovery, R, of the jth floatability class of the ith size class of a particular mineral, is given as (Savassi, 1998):"

Jan 1, 2002

By A. McLean, M. Barati

In this paper, examples are presented of pyrometallurgical research and associated teaching activities during the past century within the Department of Metallurgical Engineering, now the Department of Materials Science and Engineering, at the University of Toronto. Throughout these years, pyrometallurgical research has been characterized by recognition of the importance of the interdependence of measurements and models as well as the development and application of sensors, for the generation, validation and practical implementation of new knowledge. The important role played in the delivery of lectures and participation in joint research by Adjunct Professors with strong backgrounds in the pyrometallurgical industry is described. Projects conducted in close collaboration with the industrial sector and opportunities for students to obtain practical experience working as teams on a "round-the clock" shift basis within an industrial pilot plant environment are outlined. These activities, together with the involvement of students in poster competitions and the presentation of papers at society conferences and technical meetings, are still vital elements in the development of pyrometallurgists equipped with the appropriate professional skills for subsequent employment within academia, government laboratories or the industrial sector.

Jan 1, 2015

By Shawn Healey, Ray Norcross

"Site IdentificationNew Britannia MineA 50/50 WX Gold Inc. - High River Gold Mines Ltd. Joint VentureTVX Gold Inc. is the OperatorLocationThe New Britannia Mine is located in the town of Snow Lake, Manitoba, which is situated between Flin Flon and Thompson, 420 miles north of Winnipeg.Brief Description of OperationNew Britannia Mine processes 2000 tonnes per day at an average grade of 4.5 g/t. Mill recoveries are currently 91 YO, accounting for forecast of 98,000 ounces for 1998.New Britannia Mine's mill complex incorporates conventional crushing, grinding and carbon-in-pulp technology. The design capacity of the New Britannia Mine mill is 1850 tonnes per day. The mill has processed upwards of 2300 tonnes per day, with no required upgrades.Gold recovery averaged 89.8% for 1997 compared to the planned 87% recovery expected from projected metallurgical test work. Year to date recovery mid December 1998 stands at 91.1 %Cash costs for the 1998 year to date were down to U.S. $221.49 per ounce, down 12% from the 3rd quarter of 1997. Milling costs for 1998 YTD were at Cdn. $9.38 per tonne and Cdn. $73.50 per ounce.Geology - (Orebody Description)The Snow Lake gold deposit is located within the Aphebian Flin Flon / Snow Lake Greenstone belt. This belt is composed of an assemblage of poly-deformed volcanosedimentary supercrustal sequences intruded by pre and sin tectonic ultra mafic and mafic intrusions and sin to post tectonic granitoid.The principal gold bearing rock at the New Britannia Mine is made up of quartzcarbonate material in sequence of basic and acidic volcanic rocks contained within a shear zone. The ore itself is gold associated with the sulphide mineral arsenopyrite and contains some pyrite, pyrotite, plus chalcopyrite. Proven and probable reserves at December 31, 1997 were at 4.04 million tonnes at 4.6 g/t and underground exploration continues to confirm the extension of the ore zones to depth."

Jan 1, 1999

By Don Thompson

It isn?t a lie if you don?t tell the whole truth The pictures National Geographic didn?t print Other photos National Geographic didn?t print?

May 1, 2009

By Brian Hart, Stamen Dimov

"The Time of Flight Secondary Ion Mass Spectrometer (ToF-SIMS) is unique in that it measures the outermost atomic layers of any material. The technique is particularly suited for determining surface chemical composition of mineral particles. It is most commonly used as a diagnostic tool to measure mineral surface chemical variability in plant and bench top flotation separation processes. Recently, research towards understanding the full capability of the instrument has resulted in the development of new diagnostic applications related to various Au extraction technologies and the development of the ToF-SIMS as a predictive tool for assessing the chemical reactivity of the ore.In this paper we will present a brief review of the ToF-SIMS technique with recent advances in instrumentation and methodologies including:•,?recent developments and advances towards a semi-quantitative approach to the evaluation of mineral surface modifiers (ex. Cu),•,?flotation case studies investigating activator, depressant and collector loading variability within a flotation process,•,?the recently developed chemical reactivity test which we believe has the potential to predict the behaviour of minerals in a flotation test in response to chemical transfer during grinding,•,recent applications for determination of surface Au preg-robbed in carbonaceous materials.A portion of this material has been recently presented at the COM 2009 meeting and at SIMS XVII (see Dimov et al 2009 and Hart et al, 2009).INTRODUCTIONIn flotation seperation surface chemistry is the principal determinant for selective separation of the various mineral phases (Ralston, 1994, Smart et al, 2003). Determination of this hydrophobic/hydrophilic balance by particle therefore requires correct identification and selection of the particular mineral phase(s) followed by a statistical analysis of the surface chemical characteristics of the particles with an estimation of the spread of values (Smart et al, 2003)."

Jan 1, 2010