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By Peter Chmara

The measurement of dust concentration in Ontario mines since 1926 has been accomplished by konimetry, based on South African experience and methods. The introduction of a voluntary program of semi-annual surveys of air conditions at all operations throughout Ontario mines created a need for an instrument that would assess konimeter spots rapidly and accurately. The development of the Electronic Scanner, it is felt, answers this need. A program whereby all konimeter spot samples taken at Ontario mines will be counted at the MAP AO field offices in North Bay is described.

Jan 1, 1969

By T. R. Skerry, H. P. Hudson, T. E. Warren

"ALTHOUGH coal is generally the cheapest fuel on the basis of heating value it has been at a disadvantage in competition with other fuels because means have not been available for efficient •Conversion of its thermal energy to mechanical work. Taking the •railway application •as an example, the cost of Diesel oil is about three times that of its thermal equivalent in coal, but the overall efficiency of a Diesel locomotive is about five times that of a coal-fired steam locomotive. Accordingly, the Canadian railways are replacing all coal-fired steam Locomotives, as they are retired from service, with Diesel units. This conversion in itself represents a major loss to the coal industry because the value of railway fuel is approximately 130 million dollars per year, and there are other applications in the medium power range where oil is displacing coal. There is, therefore, a strong incentive to attempt development of an efficient coal-burning engine.Coal has never been a promising fuel for reciprocating internal combustion engines because of the time required for its combustion in pulverized form . This is not less than one-tenth of a second so that the speed of such an engine would have to be very slow. There are also serious difficulties of a mechanical nature arising from the necessity for intermittent combustion and the use of close-fitting pistons."

Jan 1, 1952

By S. Kapusniak

Specialist Machine Developments (SMD) is a design and manufacturing company involved in the design of Remotely Operated Vehicles (ROV?s), ploughs, trenchers and mining machines for use in submerged environments. Established in 1971, the company has made over 500 vehicles for subsea use. These range in size from small remotely operated swimming vehicles with a weight of less than a tonne to heavy duty seabed crawling machines with a weight of up to 310 tonnes (in air). Primarily, these machines have been designed for offshore vessel-based applications, but the machines are equally suited to other submerged mining applications onshore. Many onshore deposits can technically and theoretically be mined using currently available submerged mining ROV technology. Similar equipment to that in use subsea could easily be fast-tracked into use to extend the life of opencast mines facing severe hydrological problems. It could also easily be used to mine vertical ore-bodies where the stripping ratio has become uneconomical due to increasing depth. In some cases mining ROVs could even be suitable for use as the primary extraction method for a new mine. Exploration and extraction techniques used in oil and gas gradually developed and moved from land to offshore in the middle of the last century. Are we about to witness a similar shift with other minerals? This paper describes the design concepts of submerged mining equipment, targetted subsea mineral deposits, the suitability of submerged mining ROVs for onshore deposits, limits to their application and parallel research and development activities which will help to accelerate the use of such equipment in the emerging submerged mining sector.

Aug 1, 2013

By D. J. MacKinnon

Zinc metal was first produced in India around 1100 A.O. and a zinc industry based on retorting gradually developed in both India and China(1) . The vertical retort method for smelting zinc ores was developed in England in the 1730s; this was followed by the more fuel efficient horizontal retort process developed by the Belgians in the 19th century(2) . The horizontal retort process was the standard method of zinc manufacture until the 1950s when it became obvious that it could not compete with electrolytic zinc technology(2). The present day extractive metallurgy of zinc is dominated by the electrolytic process which now accounts for almost 80% of the world's primary zinc production. In recent years the electrolytic zinc process has seen significant improvements: the fluid-bed roasting of zinc concentrates, improved leaching and residue treatment techniques such as the jarosite and goethite processes, improved solution purification procedures, mechanization of the zinc electrolysis step and of the zinc melting and casting operation. In addition, new leaching processes have been implemented for the treatment of oxidized ores, particularly silicates, and the pressure leaching of zinc sulphide concentrates is now a commercial reality. Although the electrolytic zinc process was first used on a commercial scale in 1916, its history can be traced back to the 1860s. The purpose of the present paper is to outline the early history of the electrolytic zinc process and to trace the significant developments which led to the first successful commercial electrolytic zinc plants.

Jan 1, 1999

By Susumu Tsubota

Three types of reference gold catalysts, i.e., 3wt%Au/TiO2 (Au-Ti: Type A), and 0.3wt%Au/Fe2O3 on alumina beads (AUS: Type B), and 5wt%Au/Fe2O3 (Au-Fe: Type C), were produced in a test plant scale by Sud-Chemie Catalysts Japan, INC. under the licensing of AIST. To evaluate the validity of the preparation methods and conditions used for the reference samples, elemental analyses by ICP, particle size measurements by TEM, and catalytic activity measurements for the oxidation of CO and H2 over these catalysts were made. Gold catalysts can be prepared in a large scale of ca 400g for the Au-Ti and Au-Fe catalysts, 5 kg for the AUS catalyst with good reproducibility. It was confirmed that they were available for useful as the reference gold catalysts of World Gold Council.

Oct 1, 2003

By Yan Jie

A series of production technologies are described for gold recovery from complex gold concentrate blended with copper concentrate treated in the SKS smelting process comprising: 1) Feed preparation and proportionate feeding of complex gold concentrate and copper concentrate; 2) SKS smelting gold recovery operation and process control technology developed based on reaction mechanism, process simulation and slag formation optimization study; 3) a dry-process quenching arsenic collection technology developed during de-bottlenecking severe restriction of SO3 in the off-gas on As collection system by suppressing and eliminating SO3 in off-gas as a result of optimizing SKS smelting process conditions and spraying caustic soda absorbent so as to reduce off-gas dew point temperature; 4) electrorefining of impure anodes; 5) technology for recovering such precious metals as Au, Ag, Pt, Pd, etc. from high-Sb copper anode slime produced as a result of gold recovery from complex gold concentrate by using SKS smelting process. INTRODUCTION Gold concentrate resources in China are mainly found in Shandong province, Henan province and the Inner Mongolia Autonomous Region, etc. Currently, recovery of gold is based on pre-oxidation (roasting) cyanide leaching process. This process produces a large amount of cyanide-containing wastewater, cyanide leaching residue and relatively high SO2-bearing flue gas during production, which can cause increasingly more serious environmental pollution issues. Besides, this process route suffers from a relatively low precious metals recovery (70–80%) found when treating refractory gold concentrate and carbon-bearing gold concentrate. These issues have severely restricted the development of the precious metals processing industry in China.

Jan 1, 2019

By B. R. Conard

Occupational epidemiology of the nickel-producing industry has found that inhalation exposures to certain nickel-containing substances are linked to respiratory cancers and to nonmalignant respiratory endpoints. Establishing such a linkage, however, is complicated by the fact that some diseases occur long after exposure to a causal agent (i.e., some diseases have long latencies). Furthermore, most chemical agents (especially nickel substances) vary significantly in their toxicological properties and their concentrations in workplace air have varied over processing history. Because of these complications, it is critical to understand historical exposures to specific nickel substances. To assist in this effort, the author focuses on the history of smelting and its related processes at Vale Canada’s (Inco’s) Ontario operations in the first half of the 20th century.

Jan 1, 2012

By G. Barrasso

REACH was proposed by the EU Commission in October 2003 and stands for the Registration Evaluation, Authorisation and Restriction of Chemicals. It requires that all substances identified as persistent, bio-accumulative and toxic, whether the risk of those chemicals being released is real or perceived, require registration prior to them being allowed to be imported into the European Union. An internal investigation by the metals industry indicates that almost all primary raw materials streams would be classified as hazardous due to the potential health or environmental hazard properties of one or more of their ingredients. REACH uses a wide definition for chemicals and metals and as such its implications greatly impact the entire supply chain of the metals industry. The process of registration would require the producer/ importer to produce a dossier. Initiatives along the same lines as the EU REACH are also coming up in other parts of the world. REACH requires registration of at least four substances manufactured by the aluminium industry: aluminium metal, including powder, aluminium oxide, and aluminium hydroxide. The proposed legislation permits the affected companies to band together to form a consortium to develop certain aspects of the registration application. The aluminium industry has established a consortium and testing is currently underway.

Jan 1, 2006

By Garry Biles, Ken Major, Raj Anand

"Prime Resources Group Inc. (Prime) commenced the Eskay Creek Mine operations in 1994 in northern British Columbia. The ore from the underground mine is crushed and shipped to smelters in Japan and Canada. The nominal production rate is 300 tonnes per day.Before commencing the above operations, preliminary evaluations for the high grade gold mine had indicated that an extremely complex metallurgical and chemical process flowsheet would be required to recover the economic metals. Subsequent to the metallurgical testing program, Prime identified markets for the untreated ore and initiated underground mining and ore transportation operations.Prime recently identified lower grade ore zones, which are less economic or uneconomic to mine and ship directly to the smelters. Test programs were initiated to evaluate processes for upgrading the ore to a marketable product. In 1997, Prime will complete the engineering and construction of a 150 tonne per day flotation plant to concentrate the gold and silver values for the NEX and 109 zones. The mine will then, in addition to the direct shipping of the shippable ore, ship concentrate from the millable ore. This paper discusses the development and design of the flotation plant.IntroductionThe Eskay Creek Mine is located in north-western British Columbia approximately 83 km north-west of Stewart, B.C. as shown in the location map Figure 1. Access to the site is provided by a restricted access gravel road from Bob Quinn Lake junction of highway 37, a distance of about 59 km. The work force at the mine is based on a two-week rotation schedule. Employees are flown from as far away as Vancouver to Smithers by commercial airlines and then from Smithers to the Bob Quinn airstrip by local charter. During poor weather conditions, transportation to site is by vans that take about six hours to travel the 450 km road distance."

Jan 1, 1998

By Unkown

The Province-wide road ban on movement of heavy loads has had the effect of curtailing or stopping development in several areas. In the Leduc area, the discovery well has been restricted in flow to only a fraction of normal due to limited storage space, but drilling at Imperial Leduc Nos. 2, 3, and 4 has been continued for the past few weeks. The No. 2 well is within 100 feet of the producing horizon and should be completed within the next few days. According to reports, it has been logging slightly lower, structurally, than the discovery well, but, regardless of the outcome, it has been an important test to determine westerly cross-section of the Leduc structure. No official reports have been made available of any tests made during the drilling of the well, but it is understood that promising oil and gas shows have been indicated in higher formations. Actual drilling operations have not been commenced by any of the other companies holding leases in the immediate area but it is expected that, when road bans are removed and equipment is assured, several wells will be commenced. Announcement has been made that Imperial Oil, Limited, will drill a well near Battle lake, about thirty-five miles southwest of the Leduc field. Location of the well has been made following an extensive seismograph survey of the area, with total depth of the test well expected to be in the 8,000- to 8,500-foot range. Drilling will be done with the heavy-duty rig last used at the De Winton test. Imperial Oil have abandoned hope of oil production in the Provost area after drilling nine wells, but will retain their interest in the gas field that has been developed. Of the wells drilled, four indicated gas flows ranging from 1,060 to 13,200 M.c.f. per day.

Jan 1, 1947

By Xuanxue Mo, Kaihui Yang

"The Laochang mine, located in the Sanjiang area of southwestern Yunnan Province of China, is a volcanogenic massive Pb-Zn-Cu sulfide deposit. It is hosted by a pyroclastic sequence of Early Carboniferous age, namely the lower member of the Yiliu Group, which was intruded by syenite and rhyolite porphyry. The volcanic suite is basaltic or basaltic-andesitic in composition, has alkaline affInities, and is associated with the initial rifting along the margin of the Baoshan-Shanstate continental microplate (Yang, 1989). The ores are typically Pb>Zn>Cu in composition, averaging 3.820/0 Pb, 3.51% Zn, from 0.01% to 1.85% Cu (0.107% av.), a high average content of Ag (113 glt) and recoverable amounts of Au, n, Gd, Ga, Ge, In. A massive sulfide zone, in which lenticular and stratiform orebodies are localized in a sulfide-<:arbonate-silica shale unit or sulfidic tuffIte horizon that usually overlies coarse-grained pyroclastic rocks, is underlain by a stringer sulfide zone developed in a subvolcanic intrusion or volcanic sequence. The sulfIde mineral assemblages, from the top to the bottom of the deposit, are: realgar + orpiment - galena + sphalerite + pyrite - chalcopyrite + pyrite + pyrrhotite + arsenopyrite. Oxide and sulfate minerals occur rarely in the massive ores. The massive ores are generally fme-grained and banded, but coarse-grained ore, colloform and framboidal texture, and growth-zoned pyrite and sphalerite are common. Sedimentary features such as graded bedding, brecciated and deformed ore clasts, and chaotically emplaced blocks, are well preserved, indicating that the massive orebodies have undergone slumping and displacement. Alteration is weak in the hanging-wall rocks, but strong in the stringer zone. Two distinctive alteration zones have been identifIed: the upper zone, characterized by an assemblage of quartz, carbonates, chlorite, albite, zeolite and sericite, and the lower zone containing diopside, tremolite, actinolite, gamet, clinozoisite, and epidote.The general features of the Laochang deposit are in accord with the descriptive model of VMS deposits (Lydon, 1984). However, it falls into neither the Zn-Cu group nor the Zn-Pb-Cu group chemically (Franklin et al., 1981). The depositional setting of the Laochang deposit is quite different from Cyprus or Besshi-type massive sulfide deposits. Laochang is hosted by alkaline lavas that were erupted in a submarine continental rift. Although some features of the Laochang deposit are similar to those of Kuroko-type deposits, there are remarkable differences in the alteration mineral assemblage, the proportion of ore-forming elements (lead enriched) and the amounts of oxides and sulfates. These suggest corresponding differences in ore fluid composition and the associated ore-forming environment. Thus, the authors suggest that the Laochang deposit may be a distinct type of VMS deposit."

Jan 1, 1993

"2.1. General Considerations and Properties2.1.1. IntroductionOur present knowledge of the platinum-group elements (POE) is extensive, the reason being two-fold. The elements have many uses and, moreover, they exhibit extremely varied chemical behaviour, depending on their state of oxidation and chemical environment. The present chapter reviews a selected body of material which is of particular relevance to mineralogy and geochemistry.Comprehensive treatises on the POE include those by Mellor (1956-1957), Gmelin (1938-1957) and Pascal (1958). The inorganic chemistry, particularly coordination chemistry, has been dealt with in works by Griffith (1967), Hartley (1973) and Livingstone (1975), and the analytical chemistry by Walsh and Hausman (1963), Beamish (1966) and Beamish and Van Loon (1972, 1977). Darling (1973) and Savitsky (1978) have reviewed the metallurgical properties and applications of the metals. Goldberg and Helper (1968) have reviewed the thermochemistry and oxidation potentials of POE systems, and Wagman et at. (1969) have also provided selected values of their thermodynamic properties. The geochemistry of the POE has been reviewed by Yushko-Zakharova et at. (1967), Cousins (1973), Cabri (1974), and Naldrett and Duke (1980).Platinum was used briefly as a coinage metal in ImperialRussia. Otherwise, the principal early use for platinum and its alloys was in the fabrication of chemically resistant apparatus. Subsequently, a large part of platinum production was utilized for catalysts in the sulphuric acid and ammonia industries. Platinum has been replaced by vanadium pentoxide in the manufacture of sulphuric acid, but, in recent times, catalytic upgrading of petroleum and emission control systems for automobiles have opened further huge markets for the metal. All of the POE find uses either as reagents or catalysts in the synthesis of organic compounds, e.g., in the Wacker process, which uses palladium chloride to catalyze the production of acetaldehyde from ethylene. There are, of course, a large number of specialized uses for the elements, particularly in alloys, temperature measurement devices, cancer therapy and so on."

Jan 1, 1979

By RAYMOND C. HARTVIKSEN

The Drumbo Mine is located near Highway 401 between Woodstock and Kitchener in southwest Ontario. The tabular flat-lying gypsum bed is between 1.5 to 2.4 m thick and is situated near the base of the Salina Formation, about 116 m below surface. The mine is owned and operated by Westroc Industries Limited. The 3.8 m diameter shaft was drilled using a Hughes CSD 820 drilling rig and a liner sinking technique new to the North American continent. The shaft was completed in the fall of 1977, and remaining facilities were finished in the fall of 1978. Gypsum production started in December 1978, employing the conventional room-and-pillar method of mining.

Jan 1, 1984

By Simon C. Dominy, Patrick R. Stephenson, Alwyn E. Annels

Abstract - The often complex, erratic, and localized nature of gold is a common feature of many vein-style gold deposits. This style of mineralization is often referred to as being nuggety or possessing a high-nugget effect. As a result of these complexities resource estimation is difficult and in general, only Exploration Results can be provided or an Inferred Mineral Resource estimated from surface drilling data alone. Underground development, further drilling, and probably bulk sampling will be required to delineate Indicated and Measured Resources. Tonnages can generally be estimated from diamond drill and development information with a reasonable degree of confidence. Grade is much more difficult to define with confidence because it is commonly highly erratic and discontinuous in nature. The dependency of higher confidence Resource categories on development information may create a Catch 22 situation, with funding for such development often depending on the prior definition of at least Indicated Resources. There are no easy solutions to these challenges posed by high-nugget effect deposits, and it is important when classifying and reporting not to downplay the uncertainties often associated with Mineral Resource and Ore Reserve estimates for such deposits. However, in common with all deposit types, if the principles that underpin the estimation, classification, and reporting procedures are borne in mind and common sense applied, most issues can be satisfactorily resolved. This paper discusses the classification and reporting of Mineral Resources for high-nugget effect gold vein deposits within the framework of the JORC Code (JORC, 1999).

Jan 1, 2001

By C. Chongo, L. Little, Q. Mclennan

Since commissioning in 2005, First Quantum Minerals’ Kansanshi Mine in Zambia has produced over three million tons of copper and 1.8 million ounces of gold from a deposit with highly varied copper mineralization. The processing plant is complex with three independent flotation circuits, gold gravity concentration, atmospheric and high pressure leaching, solvent extraction, and electro-winning. For the first ten years of operating the plant, copper mineralogy was inferred from total copper and acid soluble copper assays, and various misconceptions developed about the mineralogy which impacted operational strategy and project decisions. In 2015, an on-site mineralogy section was set up with an Automated Scanning Electron Microscope, the Zeiss MinScan. This instrument has provided detailed mineralogical data that have debunked some of the mineralogy myths that had developed, highlighting the key underlying issues affecting processing performance. This has enabled the development of projects targeting losses of specific copper minerals in defined size classes, unlocking significant value. This paper describes some of the early misconceptions around mineralogy at Kansanshi processing plant, outlining projects that have benefitted from understanding copper mineral distribution. Learnings from Kansanshi are to be applied at other FQM sites, with a similar mineralogy program being set up at the Cobre Panama project. INTRODUCTION The deposit Kansanshi Mine is located in the North Western Province of Zambia, and it has been the largest copper producer in Africa for over a decade. The deposit occurs within a broad northwest trending antiform that can be traced for 12 km, hosted in a zone of complicated faulting, abundant vein injection, breccia development and down-dropped rock units that lies within Kansanshi’s mining license. The copper mineralization within the deposit is predominantly vein-hosted, although some is strata-bound, occurring in thin bands and veinlets parallel to foliation, and some is disseminated associated with albite-carbonate alteration (Gray, 2015). Supergene enrichment has led to significant variety in the copper mineral speciation. This alteration is complex, and has not followed the text-book principles with a neat layer of supergene mineralization overlying fresh hypogene ore. Rather, the occurrence and extent of oxidation and supergene enrichment is highly irregular throughout the deposit, sometimes occurring at significant depth in localized pockets and along fault lines. Gold mineralization tends to follow the copper within the deposit, but it is dominated by coarse-grained, free-milling native gold. The extent of copper oxidation – measured as the fraction of total copper that assays as acid soluble – is used to classify ore into three main ore types, named Sulphide, Mixed, and Oxide, which are then fed to three different primary crushers for processing in independent circuits.

Jan 1, 2019

By M. W. Bates, A. L. Mular

This paper, based on work carried out at Queen's University, describes the development and use of mathematical models of the parallel cyclone classifiers being used in the Strathcona mill of Falconbridge Nickel Min.es Ltd.

Jan 1, 1971

By K. Swedburg, M. Samuels

"The expansion of the concentrator at New Gold’s New Afton copper-gold mine in British Columbia, Canada, completed in 2015, included an increase in the required retention time of the cleaning circuit. On site pilot testing of a Woodgrove Staged Flotation Reactor (SFR) had shown that a high grade copper concentrate would be produced with excellent recovery. The SFR was selected rather than conventional tank cell technology based on the much smaller footprint (which rendered a separate and expensive building extension unnecessary), high concentrate grades demonstrated in testing, and the lower energy requirement. Three SFRs, each capable of taking a nominal feed of 700 cubic meters per hour were installed and commissioned 10 months after the receipt of order. The SFRs operate in series and all of the cells produce a final concentrate typically grading 32% Cu, while the overall SFR stage recovery averages 55%. The tailings from the SFRs are treated in the original conventional three-stage cleaner circuit where the remaining values are recovered in a concentrate grading 28% Cu. Design production was achieved within days of the initial start-up of the SFR circuit.INTRODUCTIONThe New Afton concentrator, located near Kamloops, British Columbia, Canada processes a copper-gold ore with a designed head grade of 0.96% Cu, 0.72 g/tonne Au, and 2.22 g/t Ag.The New Afton Mine is a block cave mining operation. Ore is undercut from the bottom up and removed at the extraction level from a grid of draw points. Ore is trammed to the ore passes by underground loader and dropped to a haulage level for transport by trucks to the gyratory crusher. From the crusher, the ore is conveyed to the mill via a 4.5 kilometre long conveyor system. Block caving was chosen for the New Afton deposit because the underground infrastructure could be built below the historical open pit of the Afton Mine (a previous operation of Teck Resources) and this method is favorable to large-scale low-cost mining.The New Afton deposit is a copper-gold, alkalic porphyry system. Hypogene mineralization is characterized by discontinuous copper sulphide veinlets and disseminations, principally chalcopyrite and minor bornite, along with pyrite as the second most dominant sulphide. Gold particles vary in size from 5 µm to 40 µm and occur as native gold and electrum, associated mostly with the chalcopyrite grains and never with the pyrite. In some instances, a second alteration phase has resulted in the copper sulphides being replaced by tennantite-tetrahedrite locally and along faults that transect the mineralized body. The design head grade of arsenic is 244 PPM, although the presence of tennantite is inconsistent and can vary from trace levels to 15% of the total copper. No arsenopyrite is present in the hypogene ores. Supergene mineralization, consisting of native copper with accessory chalcocite occurs in minor amounts along faults and highly oxidized near-surface portions of the deposit."

Jan 1, 2016

By B. D. H. Knights, M. A. W. Bryson

Flotation of PGM ores, specifically UG-2, presents a number of technical challenges. These centre on the prevalence of chromite. Subject to over-grinding, chromite is primarily recovered to the flotation product through entrainment. This is of unique concern as it must be kept below a threshold for downstream smelting, with significant operational and monetary penalties being imposed should it exceed this concentration. A number of strategies have been developed to maximise PGM recovery in the presence of this unwanted contaminant. Specialised flowsheets form a vital basis and advanced control algorithms further enhance PGM recovery while minimising the recovery of chromite. Advances in Mineral Processing Science and Technology Proceedings of the 48th Annual Conference of Metallurgists of CIM Sudbury, Ontario, Canada Edited by

Jan 1, 2009

By J. R. Donald

"Project development has been increasingly formalized in the past decade, with most organizations having extensive and descriptive deliverables documents and processes to govern the stage gate progress of capital projects. Although this has improved the general governance of capital project development and execution, it has perhaps not led to improved business success. This paper identifies specific challenges associated with developing complex projects with multiple stakeholder interests over the long timeframe of the project life cycle. The paper outlines these challenges and suggests management approaches and aspects of project development where increased focus is required to achieve improved business outcomes."

Jan 1, 2015

By G. W. Toop

"The Cominco smeller in Trail, British Columbia, is a large integrated lead-zinc production facility. In the plant description, emphasis is given to the pyrometallurgical operations including zinc concentrate roasting, lead singer-blast furnace processing and silver refining. Production figures for the main metal products - zinc, lead, silver and gold - are provided.IntroductionIncorporated in 1906, Cominco Ltd. is an integrated natural resource company with principal activities in mining, smelting and refining, mineral exploration, fertilizer production and electrical power generation.Cominco is one of the world&apos;s largest producers of zinc and lead, accoW1ting for about 10070 of mine production in the western world. The company also produces and sells copper concentrate, copper sulphate, copper arsenate, sodium antirnonate, silver, gold, cadmium, bismuth, indium, and germanium dioxide and a range of fertilizers and sulphur products.Zinc OperationsRoastingThe roasters currently treat about 1400 t/d of zinc concentrates. Over half of the total concentrate treated originates from the Red Dog Mine in Alaska. During the summer, concentrate is shipped from Alaska to Vancouver where it is loaded into rail cars and hauled inland, transferred to trucks and delivered to Trail. The remainder of the roaster feed is made up of Sullivan concentrate and various custom concentrates. These arrive either by train or by truck.There are three roasters available for roasting the concentrate. The two major roasters are Lurgi fluid bed units. Each Lurgi roaster can process concentrate at about 1:7 tonnes per hour (tlb). A smaller Cominco suspension roaster with a capacity of 10 tlb is also used. The flowsheet for the high temperature section of the fluid bed circuit is shown in Figure 1.Concentrates fed to fluid bed roasting are conditioned with 7 1/min water to give 8% moisture in feed. Two slinger belts throw the mixture into the fluidized bed. The fluid bed roasters are 10.4 m in diameter with a bed depth of 1 m. Grate area is 84 m2• Normal operating conditions include bed temperatures of 930°C to 950°C, fluidizing air at 750 Nm3/min and a wind box pressure of 2000 mm H2O."

Jan 1, 1994