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By N. Ahern, M. Barbanell

Mercury is often present in gold ores and can be released during processing. In view of health and environmental concerns related to mercury, the mining industry takes leadership in the responsible management of mercury. This paper reviews various aspects of mercury management, including an overview of mercury deportment in typical gold processing flowsheets; trends in mercury legislation impacting the international flow and management of mercury in the gold mining industry; and treatment, storage and disposal options for mercury and mercury containing materials.

Jan 1, 2014

By Stephen Hardcastle

Personnel Heat Exposure Issues In Canada?s Deep Mechanized Mines ?Project developed in 2004 ?Base/precious metal industry identified heat stress/management as a major challenge affecting productivity and operating costs ?Project started in 2005 ?Current research nearing completion ?Guidelines, further data analysis and ?Communicating the Science? will continue into 2011 Managing Heat Exposure Control?. The cost implications ?Controlling the environment ?Ventilation already a major expenses/energy user ?Large Canadian mines are currently delivering massive volumes of air 15-20 tons of air/ton ore ?Large investments in ventilation upgrades, mechanical cooling

May 1, 2010

By T. Shariff

Titanium alloys have found increasingly wide range of applications in aerospace, chemical, medical, sporting, power generation, oil and gas extraction industries mainly due to the low density, high mechanical property characteristics, biocompatibility, and excellent corrosion resistance. In the manufacturing routes of their finished products, welding has been a key technique used and always been a main concern requiring the stringent compliance to the well defined process. Conventionally, gas tungstenarc (TIG), gas metal-arc (MG), plasma arc, and electron beam welding processes have been used to weld titanium alloys. Nowadays, laser beam welding has provided great challenging applications for titanium alloys due to the low and precise heat input, deep and narrow fusion zone, small heataffected zone, low thermal distortion and high productivity. At the NRC Institute for Aerospace Research, some R&D work has been undertaken for titanium alloys using laser beam welding process. These investigations have mainly concentrated on optimizing the welding process as well as understanding the fundamental process-structure-property relationships. In this invited keynote presentation, the research progresses obtained and the main issues encountered in laser welding of titanium alloys will be briefly summarized.

Jan 1, 2011

By Weldon Li

Outline ?Introduction and Motivation ?Previous Research ?Details ?Findings ?Current Multi-Piece Mining Wheel Research ?Methodology ?Preliminary findings ?Current and Future Activities ?Summary and Closing Remarks

Oct 1, 2010

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 M. Mahdi, L. So, A. MacMillan, D. Metcalfe, J. Woloshyn, D. Sauter, N. Uys, JP. Janse van Rensburg

For city smelters, with limited real estate, efficient slag cleaning furnaces followed by water granulation to produce an iron silicate product is the preferred process approach. Water granulation, however, consumes large volumes of water and requires high maintenance due to abrasive slag/water slurries. Air granulation offers an alternative to water granulation, which eliminates water use and has low maintenance requirements. Although full-scale operation has not been implemented for copper slags, full-scale operation for platinum group metal (PGM) converter slag has been implemented. A review of full-scale air granulation performance for PGM converter slag is provided. Based on PGM converter slag granulation performance, parallels to copper slag granulation are drawn and full-scale operation for copper slag is modelled using computational fluid dynamics (CFD). INTRODUCTION Typical slag management practices in the copper industry include dumping, slow air cooling, and water granulation, as shown in Figure 1. Dumping is the most commonly used slag handling method for most metal production plants, but presents challenges including the requirement for a large slag pit, requirement for expensive/high-maintenance “hot” mobile equipment, risks associated with transportation of molten slag, and no value recovery from slag as a sellable by-product or from slag as a source of heat.

Jan 1, 2019

By J. W. Scott, G. G. R. Falkenberg

"The Syncrude project is an integrated complex designed to mine, extract and upgrade bitumen from the Athabasca tar sands to produce 129,000 barrels per day of synthetic crude oil. This paper provides a brief general description of the location, history and geology of the tar sands and the overall organization and structure of the project. The major emphasis and the bulk of the detail presented deals with the extraction plant; a material handling and mineral processing installation designed to treat 312,000 tons per day of tar sand feed.History of the Tar SandsThe Athabasca tar sand deposit was recorded in 1788 by Peter Pond, however the first serious geological mapping and exploration did not begin until 1915. Little interest was taken in the deposits until the Second World War, when the governments of Canada and Alberta conducted an extensive exploration program. In addition a number of pilot plants were sponsored during the 1940 -1950 decade. The hot water separation process was successfully demonstrated on the pilot plant scale during 1948 -49, and was established commercially in 1967 in the G.C.O.S. plant. The Syncrude plant, due to come on stream in April 1978, also employs the hot water separation process."

Jan 1, 1978

By J. Locat, G. Parker, D. Turmel

ABSTRACT Since 1964, the Iron Ore Company of Canada has deposited iron ore tailings into Wabush Lake in western Labrador, Canada. From 1999 to 2008, the authors completed multibeam bathymetric and sampling surveys and an airborne LiDAR survey. These data were integrated to study the evolution of the tailings delta shoreline and lakebed elevation. Subaqueous channels evolved between surveys, influencing the tailings depositional pattern. With this analysis it is possible to evaluate the effect of disposal strategies on the delta topset and tailings accumulation. This project uniquely couples marine and terrestrial techniques to follow the fate of tailings in a dispersal system.

Jan 1, 2014

By F. Rosenblum, P. Spira

"A correlation has been established between the oxygen demand of Brunswick Mining and Smelting ore and flotation results at the bench, pilot plant and operating plant scale. A method of dete""1llining the aeration requirement of sulphide ores on the basis of this correlation is presented. It is shown that abraded iron from grinding media plays an important role in aeration and flotation. Laboratory grinding must therefore be conducted under controlled conditions with suitable grinding media in order to obtain the true aeration requirement of the ore.A method of evaluating aerator efficiency, also based on oxygen demand measurements, has been used successfully at Brunswick Mining to design pilot plant and full-scale aeration systems.1. IntroductionPre-flotation aeration of sulphide pulps has been practiced in the Noranda Group for many years to help in the depression of pyrite and pyrrhotite and to promote chalcopyrite and/or galena. Recently, two out of three parallel circuits at the Brunswick Mining and Smelting Corp. Ltd. concentrator have been converted on a test basis to a new flowsheet incorporating aeration as a basic step. Among other benefits, a substantial decrease in the middlings load has been achieved as a result of improved pyrite rejection. There has been increasing interest in other organizations in the potential advantages to be derived from' aeration in terms of improved metallurgy and/or decreased reagent consumption."

Jan 1, 1978

By Franz Simon

Conventional fine gold electrolytes for barrel applications working electrolytically actually permit significant precious metal savings by corresponding optimizations but the most gold is still deposited on areas of the components where it is not absolutely essential for the desired bonding and soldering applications, i.e. in high current density areas. Therefore an electrolyte working electrolessly has been developed which inevitably leads to a much more uniform thickness distribution since in an electroless process there are no areas favoured by metal deposition and current distribution. The new electrolyte will be presented and its performance will be compared with conventional electrolytes as regards thickness distribution. The potential gold savings will be discussed.

Oct 1, 2003

By Franco Chiesa, David Levasseur, Bernard Duchesne

A 500kg aluminium AlSi7Mg03 casting has been poured and the metallurgical quality at different locations inside the casting has been thoroughly investigated. It included measuring the local tensile properties (YS, UTS, El) in the T6 condition, the dendrite fineness (DAS) and the level of microporosity. A correlation was found between the microporosity level, the local solidification time and solidus front velocity; this correlation allows to predict the porosity level in large aluminium castings (solidification times between 20 and 200 minutes). Quite expectedly, properties varied widely within the casting and the actual mechanical properties were much less than the "textbook values" based on measurements carried out on separately cast standard specimens. A correlation between the secondary dendrite arm spacing (DAS) and the local solidification time was in keeping with previously published data. Finally the conditions to obtain an acceptable finish on machined surface were determined.

Jan 1, 2014

By William DeWit

When rivers are contaminated from industrial operations, as often occurs near repositories of spent mine tailings, decision-support tools can be critically important in evaluating the effectiveness of various engineering impact-management measures. Even where data describing river flows and quality are sparse, simple mixing-zone models can be constructed that can contribute greatly to understanding how impact-management measures can differentially affect existing river-chemistry regimes. There can be circumstances where accumulated surface waters near contaminated land can bear contaminant loadings that could be acceptable to river regimes if there were methods available to evaluate optional discharge rates and to predict post-mixing consequences on river chemistry. Nomographs can be constructed to evaluate discharge regimes that appear capable of releasing contaminated accumulated pond water without compromising water quality in a nearby river. River-mixing zone models also contribute to predicting rates of acceptable discharge and release to the receiving environment.

May 1, 2011

By M. Hall

"SomarioEl circuito de molienda a Selbaie consta de molino semiaut6geno en un circuito cerrado y molino de balas en un circuito cerrado. El amperaje del motor de se usa controlar el tonelaje el molino. Este sistema estabiliza el circuito pero no mejora activamente el rendirniento del circuito. Se desarroll6 auxiliar el rendimiento del circuito un sistema experto en manipular las objetivos de existir control proporcional-integral. Se ejecut6 el sistema con el Comdale /C conjunto del sistema experto y ha side funcional hace tiempo el mayo de 1992. El sistema experto ha resultado en un aumento en tonelaje de 7tph y una disminuci6n de $210,000 en el caste anual de media de molienda. Se describe el desarrollo del sistema y los provechos derivar se presenta.AbstractThe grinding circuit at Selbaie consists of SAG mill and ball mill closed circuit grinding. The SAG mill motor current is used to control throughput. This system stabilizes the circuit but does not actively optimize circuit performance. An expert system was developed to aid the optimization of the circuit by manipulating the set-points of existing PI control loops. The system was implemented with the Comdale /C expert system package and has been on line since May 1992. The expert system has resulted in a net increase in tonnage of 7tph and a decrease in annual grinding media costs of $210,000. The system development is described and the benefits derived are presented."

Jan 1, 1994

By R. J. Grant, D. W. Scott, M. A. Cooper, E. R. Shannon

"The Brunswick No.12 site concentrator processes 10,500 tonnes per day of a complex lead, zinc, copper and silver ore producing four concentrates by differential flotation. Research over the years has led to increased understanding about the mineralogical and flotation characteristics of the ore. A pilot plant study conducted at Lakefield Research, primarily designed to investigate the technical feasibility of semi-autogenous grinding, provided an opportunity to test recent theories about grind size,, reagent schedule and flowsheet configuration.A fundamental approach was taken with each of the unit processes involved in grinding and flotation. Basic operating and metallurgical criteria were established in each area and a step-by-step implementation program initiated in the plant.Significant improvements in metallurgical and financial performance have been realized through the application of basic grinding and flotation principles using conventional milling equipment and without major capital expenditure. Current operating practice is detailed and metallurgical advancements cited.INTRODUCTIONBrunswick Mining and Smelting operates one of the world's largest lead and zinc mines near Bathurst, New Brunswick. Brunswick is a publicly traded company with majority ownership held by Noranda Minerals (63%). In addition to the No. 12 underground mine, the company operates a lead smelter and phosphate fertilizer plant in Belledune, N.B. and maintains a 25% interest in a joint venture with Noranda Minerals' Heath Steele mine near Newcastle, N.B. Through the four operations, a total of 2000 people are directly employed with fixed assets totalling Cdn$187 million (BM&S, 1991)."

Jan 1, 1993

By G. Dubé, A. Leclerc, P. Quinn, G. E. Agar, J. Y. Clouthiér, J. D. McLaughlin

"Gold dissolution by cyanide requires the presence of oxygen which is usually supplied by sparging compressed air into the gold containing slurry. For those ores that contain certain obnoxious substances that consume oxygen, maintaining the required minimum level of dissolved oxygen can be troublesome. One of the most economical solutions to the problem of low dissolved oxygen, especially in plants that have air compressors installed, is to enhance the rate of oxygen mass transfer.The oxygen mass transfer rate was measured in a two phase system using two different sparger arrangements, and with addition of a frother that is known to reduce the bubble size produced by the sparger. The common sparger system was shown to be inefficient compared to a readily available but under utilized method of gas dispersion which introduces air directly below the reactor turbine. Transfer of this technology to an operating plant confirmed the beneficial effect of the improved sparger system. The addition of the frother did decrease the bubble size, but it also reduced the oxygen mass transfer rate."

Jan 1, 1993

By Yuki Soma, Tsutomu Ogawa, Jae Hyung Hong, Toshihiro Nagato

The Saganoseki flash furnace was built in 1973. The steel frames of the flash furnace were designed to absorb the expansion of refractories and contain expansion-absorbing materials between their frames and the skin plate. Expansion and deformation resulted in the furnace settler because of the repeated increase and decrease in temperature from more than 30 maintenance shutdowns. Preliminary investigations were conducted to confirm the condition of the settler, and it was found that partial cracks accompanied the expansion in the lower layer of the refractories. As a result, the risk of molten-matte leakage increased. Based on the above investigation, it was decided that the entire settler should be replaced by introducing a spring-displacement structure that was capable of maintaining the furnace integrity over an extended period. The difficult redesign and rebuilding of the Saganoseki flash furnace was accomplished successfully and safely in 76 days from September to December 2017, as planned. Because of various redesigns, the furnace was changed to a flash-smelting furnace that can withstand higher thermal loads based on recent trends of copper concentrate with increased sulfur and reduced copper. The new furnace is operating smoothly at present. INTRODUCTION The flash-smelting furnace of Pan Pacific Copper Co., Ltd. Saganoseki Smelting & Refinary commenced operation in 1973, with an original designed feeding rate of 71 t/h. As a result of facility remodeling and operational improvements, shown in Figure 1, the feeding rate was increased to 215 t/h in recent years. After more than 40 years of operation, the original settler in the melt holding section of the flash furnace underwent significant expansion and deformation.

Jan 1, 2019

By J. P. Harrison, G. F. Gambino

"This paper examines unpredictability in the parameters governing hydraulic fracturing (HF) as used in stress amelioration for underground excavations, with the aim of showing how this unpredictability may affect design decisions. Using uncertainty models that are appropriate to particular levels of information and degrees of uncertainty, this paper demonstrates how these can aid in decision-making related to feasibility assessments of HF arrays for stress amelioration.Cave mining operations produce large underground voids and high stress concentrations around critical mine locations. These stress concentrations increase the potential for rock burst events. Although de-stress blasting has a long history for redistributing high stress concentrations, to improve safety and reliability HF is now being trialled as an alternative.Unfortunately the HF process is extremely uncertain, and so predicting fracture propagation geometry is difficult. Although the major parameters governing HF propagation have been previously identified, no indication has been given regarding the contribution that uncertainty in these makes to unpredictability in the overall HF system. Using simplified models of HF and referencing a recently proposed characterization of unpredictability, we relate unpredictability in the various governing parameters to the effect it has on strain energy density (SED) in the surrounding rock. Within these models we analyse SED as well as the stress intensity factor (KIc) when investigating the effect of parameter uncertainty and its influence on various crack propagation criteria (Sih & Macdonald, 1974). These models are applicable to unpredictability associated with the development of new fractures; the case of pre-existing fractures is the subject of on-going work.The paper will assess in greater detail the various governing parameters, and investigate the appropriate use of other uncertainty models. As a result, we will show how assessment of uncertainty in HF parameters can be used to both guide feasibility studies and determine the optimal allocation of resources to improve the final design."

Jan 1, 2015

By Joanne G. Petrini

ISO 26000 Unique Process Unique Personality ?Almost 10 years in the making ?What type of standard is this? Different type of ISO Standard ISO 26000 Structure and Substance ?Principles ?Core Subjects ?Implementation Guidance ISO 26000 Impact ?Same old, same old? ?So Is there really anything NEW? ?Should I care??

May 1, 2011

By M. J. Dry, G. B. Harris

"This paper presents basic chemistry and operating conditions for the hydrolysis of ferric chloride into solid hematite and gaseous hydrogen chloride, and shows how this unit operation can be applied in chloride hydrometallurgy to regenerate strong hydrochloric acid and reject iron without also rejecting valuable metals such as nickel, copper and cobalt. Two examples are used to illustrate the hydrolysis technology and compare it to existing technology. The first is the regeneration of spent steel pickling acid, comparing hydrolysis to conventional pyrohydrolysis. The second example is the processing of a hypothetical low grade nickel laterite, comparing the novel chloride hydrolysis route to conventional sulphate HPAL technology.INTRODUCTION Whilst, in many respects, the control and removal of dissolved iron from chloride leach solutions can resemble the manner in which it is done in sulphate systems, chloride chemistry additionally offers the ability to achieve the same objectives in different ways (Harris, 2014). Conventionally, iron is oxidised to its ferric state (if necessary) and then precipitated with a base, usually magnesia where the feed is a laterite and lime where it is a sulphide, since calcium will precipitate sulphate formed during leaching. One method for controlling iron is to form FeOOH, either ß-FeOOH (akaganéite), a-FeOOH (goethite), or a mixture thereof (Fillipou and Choi, 2002). However, if akaganéite is formed, the precipitate will contain a significant chloride component (as high as 7% Cl), leading to chloride losses and difficulty in satisfactorily disposing of the residue. Washing chloride from akaganéite is almost impossible due to the propensity of the solids to undergo peptization. The conventional approach requires the addition of a base, but it is based to some extent on controlled supersaturation precipitation (Demopoulos, 2009), which produces a more uniform and crystalline material and is far more attractive than, for example, the turboaeration process proposed by Great Central Mines in their chloride copper process (Raudsepp & Beattie, 1986)."

Jan 1, 2016

By G. Chung, W. Petruk, D. Doyle

"A series of tests was conducted on Carol Lake iron ore, which contains about 38 wt % hematite and 19 wt % magnetite, to establish a flowsheet for high weight yield by spirals. A pilot plant was run in parallel with the IOC concentrator to simultaneously test two flowsheets on the same feed material. The IOC concentrator processes the ore by treating it directly in a spiral circuit, whereas the pilot plant used a laconite flowsheet which had a low intensity magnetic separator (LIMS) at the front of the circuit. The LIMS produced a non-magnetic (hematite-rich) product and a magnetic (magnetite-rich) product prior to treating the ore in two separate spiral circuits. The results from about 150 tests were evaluated by chemical assays and materials balancing techniques, and a selected test was evaluated by the image analysis and materials balancing technique.The image analysis and materials balancing evaluation showed that a higher hematite recovery was obtained by the hematite spiral circuit than by the IOC concentrator spiral circuit, and a slightly lower magnetite recovery by the magnetite spiral circuit than by the IOC concentrator spiral circuit. Furthermore the hematite recovery by hematite spirals was higher than the magnetite recovery by magnetite spirals. The better hematite recovery was achieved because a higher liberation is obtained for hematite than for magnetite, and the hematite in the Carol Lake ore has a narrower grain size range than magnetite. Consequently, better spiral control can be maintained when processing a hematite-rich spiral feed, than when processing a magnetite-rich spiral feed. Since the feed to the IOC concentrator spiral is a mixture of hematite and magnetite, an intermediate hematite recovery is obtained by the IOC concentrator. INTRODUCTIONA study of characteristics that affect recoveries of hematite and magnetite from the Carol Lake ores of the Iron Ore Company of Canada (IOC), was carried out in connection with a project on designing a flowsheet for maximum weight yields. A pilot plant using a taconite flowsheet was run in parallel with the existing IOC concentrator which uses a classical iron ore flowsheet. About 150 tests were run to compare iron recoveries and weight yields by the spirals in the two flowsheets. Better iron recoveries were indicated for the taconite flowsheet, but the results were not consistent and the reasons for the observed differences were not apparent. The material from one test (Test 61), which gave better iron recoveries for the taconite flowsheet, was evaluated by the image analysis and materials balancing technique. A suite of samples was taken from 5 points in the IOC concentrator and from 8 points in a pilot plant (taconite flowsheet). The samples were analyzed to compare the behaviours of the Carol Lake hematite and magnetite in the spirals of the two flowsheets. The results provided a sound basis for further tests in designing a high weight yield flow sheet."

Jan 1, 1993