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By N. Aslin, R. Clark, G. Heferen

The methods of harvesting copper from stainless steel mother plates has been investigated from fundamental and operational experience perspectives. At least five different harvesting techniques have been identified that have different effects on product quality, current efficiency, current distribution, growth morphology and ease of stripping. Each method is examined from fundamental principles to understand what occurs during the harvesting process and why the particular effects are manifested. Experience from plants operating the harvesting method is provided to show that the fundamental understanding is relevant. Best practice harvesting method and harvesting management are described.

Jan 1, 2014

By B. K. Gorain

"The Air-Metabisulfite (AMBS) process has been developed to treat complex copper, molybdenum and precious metals (gold, silver) bearing ores using brackish and sea water. This process was able to produce significantly better copper concentrate grades and higher recovery than possible using conventional lime and/or cyanide based processes for certain complex ores with high sulphide gangue minerals. The AMBS technology in now used commercially following a rigorous evaluation process emanating from laboratory curiosity to plant applications. In addition, many projects have embraced this technology at a feasibility level involving various complex ore bodies.This paper presents a summary of the findings from testing the AMBS technology on various ores types. Experiences gained from this successful development from bench to piloting and then to plant applications are also presented in this paper.INTRODUCTIONProcessing of sulphide copper, molybdenum and precious metal ores typically involves flotation of copper bearing minerals while depressing non-sulphide and other non-copper sulphide minerals such as pyrite, pyrrhotite and sometimes arsenopyrite. Though in many precious metal ores, the values are in these sulphide minerals as well. The conventional method employed in the industry to produce a saleable copper concentrate requires depression of these non-copper sulphide minerals using an alkaline pH above 9.5, though 10.5 to 11.5 is more common. Alkalinity is controlled by the addition of a pH modifier. Lime is normally employed as a pH modifier due to its relatively low cost; however, the costs associated with adding lime can be significant and the effectiveness of lime as a depressant could be drastically reduced when the process water supplied to the flotation circuit contains high level of dissolved salts. In some cases, a small amount of cyanide is used along with lime to depress non-copper sulphide minerals especially when its proportion to copper sulphide minerals in the ore is higher than three."

Jan 1, 2016

By A. R. House, G. W. Shepherd

Newmont USA Limited owns and operates the Phoenix Mine near Battle Mountain, Nevada, USA. The existing milling facility has operated since 2006 (House, 2010). Following the startup of the milling operation, and coupled with the upswing in the copper market, Newmont realized that Phoenix had no process option to treat transition and oxide copper ores. This meant that potentially revenue generating ore would be mined as waste. With no system in place to treat the transition and oxide copper, work began to determine the most feasible approach. After evaluating multiple options, the flow sheet was set for a runof- mine (ROM) heap leach pad and solvent extraction/ electrowinning plant (L-SX/EW). This paper will discuss the eight years of successes and challenges with developing the copper L-SX/EW plant and achieving commercial production of copper cathode.

Jan 1, 2014

By A. Gakwaya, K. Ba, M. Guillot, J. Levesque

"In the aerospace industry, parts requiring tight dimensional tolerances and high mechanical properties are often produced by forging. This forming process allows for an optimal use of the material and can produce high quality parts at a reasonable cost. Thanks to CAD techniques, it is now easier to predict flow profiles and in-process defects occurrence as well as wear of the forging dies. However, in order to determine the properties of the forged part with computer simulation methods, a good material constitutive law is a prerequisite. This paper presents a virtual manufacturing process modeling for the closed die forging of a workpiece performed with Abaqus. The hot closed die forging is a regular process applied to manufacture metallic components used in aerospace industry. In this forming process, the material flow and final properties depend on the microstructure evolution during the process that is why it is important to include the microstructure effects in the material model. Based on the stress-strain data measured experimentally, the material parameters of the standard (classical) Johnson-Cook constitutive model and of a modified Johnson-Cook constitutive law including the microstructure effects have been determined. The obtained simulation results are compared with the experimental results for validation.INTRODUCTIONDue to their good physical and mechanical properties such as ductility, fatigue strength, corrosion resistance and rupture, aluminium alloys are often used in the aeronautic and the automobile industries. In this work, we present the forging of an Al-Zn-Mg-Cu alloy, a high strength aerospace alloy recognized for his good combination of physical and mechanical properties. The forging process is simulated in Abaqus Explicit using both the standard Johnson-Cook law (Johnson & Cook, 1983; Hor, 2011; Lin et al., 2012), and its modified version as proposed by Andrade et al., (1994). The Johnson-Cook law offers the advantage of considering the coupled effect of the plastic strain, the plastic strain rate, the temperature of forging and the hardening effect. However, it is a phenomenological model which does not account for the effect of the microstructure evolution. In this work, a modified Johnson-Cook model implemented in a user subroutine is used. It includes the effect of the dynamic recrystallization phenomenon during the hot deformation. The dynamic recrystallization has a noticeable influence on the microstructure and on the properties of the material. The term dynamic means that the process starts and acts during the deformation and this is different from the static mechanism of recrystallization which occurs during an annealing and after cold or hot deformation. Since properties of the alloy used in this work are not readily available in the literature then characterization tests have been done at various temperatures and strain rates, in order to determine the thermomechanical properties and the material behavior during the process of hot forming, more precisely during the hot forging process."

Jan 1, 2016

By J. R. Levin, E. J. Schelter

"We present some of our recent efforts in the development of predictive, directed oxidation chemistry of cerium(III) complexes under non-aqueous conditions. The electrochemistry of cerium(III)- alkali metal heterobimetallic aryloxide complexes is reported and compared with cerium aryloxide complexes that are kinetically stabilized by hydrogen bonding cations that span between the complexed aryloxide ligands. Comparative electrochemical measurements reveal differences between the heterobimetallic complexes and the hydrogen-bonded complexes.INTRODUCTIONThe rare earth elements comprise the lanthanides, La–Lu, and the element yttrium (Aspinall, 2001). Rare earth ores such as monazite, LnPO4, and bastnäsite, LnFCO3, typically bear mixtures of light rare earths: La–Sm while monazite, LnPO4, contains mixtures of heavy rare earths (Eu–Lu) (Cotton, 2006). Pure rare earth elements typically are isolated using a liquid-liquid separations process.(Bautista, 1995) The hydrometallurgy of these elements is a difficult problem because the separation factors between neighboring rare earths, which are predicated on the small differences in the sizes of the trivalent ions, are quite small (Cox, 1992). The element cerium, with its 4f1 electronic configuration in the trivalent state, is unique among the rare earth elements due to a relatively accessible 4f0 electronic configuration. The accessibility of the 4f0 configuration underlies the chemistry of cerium(IV), the only rare earth ion with molecular chemistry in the tetravalent oxidation state (Cotton, 2006). Cerium is trivially separated from mixtures of light rare earths by making use of its unique oxidation chemistry. In an effort to extend separations chemistry by oxidation reactions to other rare earth elements such as terbium and praseodymium, the solution electrochemistry of well-defined cerium complexes is of interest."

Jan 1, 2012

By Terence M. Gordon, Mati Raudsepp, Gregory M. Dipple

Four methods of measuring mineral abundance in a rock are examined for their potential in assaying for high-tech industrial minerals. One method uses X-ray powder-diffraction data and the other three rely on whole rock chemical data and information on mineral assemblages and mineral compositions. All four methods were employed to estimate wollastonite content in diamond drill core of skarn collected as part of an exploration program and are compared to visual estimates of wollastonite content from core logs. These techniques for assaying wollastonite span a considerable range ofaccuracy and expense, and combined, define a non-linear relationship between these variables. Accuracy increases rapidly relative lo expense up to total costs of about $50 per analysis. Assay methods in the $50-100 per analysis range have associated errors of 5-10% relative and probably suffice for most exploration programs. Improvements in accuracy above this level require a much larger investment. The most expensive assay technique (-$300 per analysis) yields the most accurate measurement of grade (relative error -1%). Its application may best be limited to periodic checks on other assay techniques and for fine-tuning ofmineral separation procedures.

Jan 1, 2001

By K. G. (Ken) Thomas

"This paper gives an insight into the various processes available to treat gold ores. A brief overview is given of the various types of refractory gold ores. Particular emphasis is given /0 comparing the costs of oxide vs refractory gold ore processes, inclusive of grinding through to dore bar.HistoryThro ugh time gold has been recovered from the earth's crust by various mean s. Five major historical steps can be identified for metallurgical processing as shown in Table I .Gravity concent ration started with, for example, river bed panning and developed to more sophisticated processes such as the Johnson concentrator, belt concentrator and jigs. The South African gold fields were a major developer of gravity concentration processes during the first half of the twentieth century.As coarse free gold became depleted, stamp milling, in conjunction with amalgamat ion , was developed. Basically, rock was crushed under large mechanical hammers an d the gold collected in mercury . The mercury was then evaporated in a retort to leave sponge gold for further fire refining.As deposits became deeper and gold finer, the gold became more difficult to recover ; fine grinding was required to liberate the gold. In the 18905, MacArthur and the Forrest Brothers of Glasgow, Scotland, introduced the cyanide pro cess for dissolution of gold and its subsequent precipitaiton by means of zinc. This process, in vogue until the early 1970s, was commonly referred to as the Merrill-Crowe process for recovering fine gold .Activated charcoal was used as a means of recovering gold from solution in the 1880s, especially in chlorination plants in Australia( l). Two factors probably retarded the development of carbon instead of zinc-based processes during those year s. First , there was no satisfactory procedure for the elution of carbon to allow its recycling and, second, the development of the Merrill-Crewe process for gold recovery by zinc cementation probably discouraged any further work on the use of carbon"

Jan 1, 1991

By H. Hitchen

THE object of this paper is to present the various facts that l1ave been revealed during lengthy investigations into the performance of all types of ropes on different hoisting installations. It then goes on to suggest means by which most of these findings could be usefully employed to obtain more economical rope lives with increased safety. SHAFT HOISTING ROPES Four basic designs of ropes are now employed for hoisting duties: (1) Six-strand, round strand ropes with fibre cores. (2) Six-strand, triangular strand ropes with fibre cores. (3) Non-rotating, multi-strand ropes. 0) Locked coil ropes. Round Strand Ropes (Figure 1) Very solid and reliable ropes can be obtained with this simple geo-metric design of strand. 1'1?iangula1? Strand Ropes (Figure 2) Owing to the fact that the wires in the strands are bent over a triangle, they do not seat quite so solidly as when they are bent over a circular core wire, as is the case with

Jan 1, 1963

By A. Christoffersson, T. Nillson-Wullf, H. R. Manouchehri

"Mining industry has been the building blocks for human development through millennia and will continue to play its role in sustainability and meeting society’s needs for raw material. In the way towards sustainability, the next generation of efficient and heavy duty of Sandvik’s crushers, CH860 and CH865, are introduced for efficient crushing. As the secondary, tertiary and/or pebble crusher, these new crushers are designed to over perform in tough mining environment. Featuring higher crushing forces relative to the mantel diameter and 500 kW motor, combined with advanced automation system, i.e., sophisticated HydrosetTM and Automated Setting Regulation (ASRTM), combined with overpressure system with dedicated air supply in dust collar, etc., the new crushers provide higher safety, productivity, and reliability with the same foot-print of conventional cone crushers.Since crushers are more energy efficient than mills it makes sense to effort in fine crushing to save energy and protect environment. That has been the logic behind development and introducing stronger and more efficient crushers by Sandvik. The results on crushing hard iron and gold ores by CH865 have proven its efficiency in fine crushing at a higher productivity, availability and reliability rates through increasing throughput for defined size fraction and extended crushing chamber liner life.Within this paper the performance of the CH865 to deal with two different ores are presented discussed with a glance at how the downstream milling process can be benefited by saving energy and reducing the operation cost. In plant practice, the implementation of the new CH865 provides between 25 and 30% of the crushed ore in the size range of first step milling, i.e., < 2 mm, that offers opportunity for reduction in energy consumption in milling and even changing the process plant configuration by directly forwarded that part to gravity separation. Furthermore, potential of converting the rod mill to ball mill to improve productivity has been considered by plant engineers. Furthermore, some potential applications for such efficient crushers are brought into considerations and discussed. The new developments provide about 30% higher crushing force to efficiently deal with competent ores and pebbles. The CH860 and CH865 crushers are well suited to replace conventional secondary and tertiary crushers respectively; nevertheless, CH865 is virtual option for pebble crushing in SAG and AG milling circuits."

Jan 1, 2016

By L. Xia, B. Hart, G. Gingras, M. Furlotte

Plant and laboratory test work was performed in order to optimize a copper/zinc flotation separation circuit at Matagami concentrator, Canada. The testing identified a significant difference between the laboratory testing and the plant flotation, particularly for the sphalerite recovery in the rougher copper concentrate. Tests indicate that sphalerite recovery of the flotation concentrate in the laboratory testing was significantly higher than in the plant. The ToF-SIMS surface analysis identifies surface species responsible for the discrepancy in Zn recovery. It shows that sphalerite flotation is in response to the collector attachment and a significant enrichment of Cu on the surface of sphalerite grains. A comparative surface chemical analysis was performed on both sphalerite and chalcopyrite grains from the plant flotation and laboratory testing in order to identify surface species variability between the two testing. Two significant observations were revealed. First, there is considerably more hydrophilic iron oxyhydroxide on sphalerite surface from the plant flotation sample relative to those from the lab testing. The secondary coating likely completely or partially passivates sphalerite surfaces, reducing Cu enrichment and hence sphalerite floatability. Secondly, comparing the surface chemistry on sphalerite and chalcopyrite, the hydrophilic iron oxyhydroxide species have preference for the sphalerite grains relative to chalcopyrite. Despite numerous studies on the effect of galvanic coupling during grinding, there is limited documented evidence on the effect of the milling environment on the flotation and plant operations. This observation suggests that interaction between sulphide minerals and grinding media have a significant influence on subsequent flotation. This paper discusses the results of a detailed surface chemical evaluation of sphalerite grains from both the plant and laboratory testing in the context of grinding environments and pulp chemistry.

Jan 1, 2016

By S. Jeon, T. H. Kim

"Understanding the frictional properties of discontinuities is crucial to ensure the stability of underground structures. In particular, the frictional behavior at depth depends on the complex interaction among mechanical, hydrological, thermal and chemical characteristics and their coupled effects. In this study, a series of triaxial compression tests were carried out to investigate the behavior of rough shear surface of synthetic rocks. The frictional behavior showed little variation at different confining and water pressures. The test results were analyzed using Coulomb’s failure criterion. In addition, numerical analysis was carried out using PFC2D to simulate the test.INTRODUCTIONUnderstanding coupled behavior of rock at depth is of great importance in design, construction and operation of underground structures such as a disposal facility of radioactive waste, hot dry rock geothermal system and oil reservoir. In particular, many uncertainties are involved in characterizing deep rock mass deformation in the designing process and interactions among fluid flow of groundwater, high temperature and stress disturbance should be considered. Many independent studies have been carried out to investigate the thermal, hydro, mechanical and chemical coupled effects in numerical and experimental methods. They include the researches by Lockner, Summers, Moore and Byerlee (1982), Jafari, Amini Hosseini, Pellet, Boulon and Buzzi (2003), Tembe, Lockner and Wong (2010), Lee, Lee and Jeon (2012), Indraratna, Premadasa, Brown, Gens and Heitor (2014)."

Jan 1, 2015

By David Weiss

There is significant interest in magnesium alloy castings because of their low density and high strength-to-weight ratio. Lightweight, structural materials are in demand for aerospace components, hand tools, electronics enclosures and have found increased use in automobiles. Increased use of magnesium will depend on the resolution of a number of materials issues and development of more robust and economical casting processes. Most magnesium components are produced via high-pressure die-casting. High levels of porosity generally prevent die-castings from being used for structural applications. Structural castings are usually produced using sand casting, a relatively expensive casting process. Some work has been done on development of lower cost structural casting processes, such as lost foam casting, permanent mold casting or low-pressure casting. New programs are also emphasizing improvements to the die casting process. Research and cost reduction needs are discussed with respect to current programs and future components.

Jan 1, 2006

By Victor Azbe

Azbe System of Controlled Calcination To obtain good and cheap lime there are certain fundamental requirements that need to be satisfied. These are : (1) Proper combustion of fuel and steady supply of heat to the kiln. (2) Proper heat distribution in the kiln. (3) Uniform drawing of lime through the several shaft sections. (4) Complete cooling of the lime and recovery of the heat. (5) Temperature control of the hot zone by economical means. (6) Ample draft to obtain high capacity. (7) Arrangements to facilitate operation. Figure 17 shows diagrammatically one of the smaller kilns, intended for large stone. Such a kiln can be supplied with gas from a centrally located automatic gas producer, or, as shown, from an integral producer located snugly against the kiln. These producers make very good gas and have a gasification capacity of either 10 or 15 tons of coal a day. The producers have water-sealed ash pits, a rather thick fuel bed that is conducive to the making of high-CO gas, and are under forced draft. No steam is used. Clinkering is prevented by admixing some spent gas from the kiln with the air. Coal feeding is from a coal bunker through spouts into the hoppers over the producer. This is done, at proper intervals, by manual operation of slides, but it is planned to install mechanical feeders. Central mechanical gas producers have the advantage of requiring little labour, but the blowing of soot is a problem, as also is the proper distribution of the gas among several kilns. In the case of integral gas producers, soot from the centre burner is blown back into the producer to be burned, and the supply of gas to the kiln is controlled by regulation of air to the producer. In large plants, the mechanical producer may be preferable, but in small ones, the integral producer is cheaper, better, and more reliable. The kiln shown in Figure 17 is suitable for both systems of gas supply. It will be noticed that there are no side gas burners. All gas enters the kiln through the centre burner in a manner that permits any desired amount of gas to be directed to any of the kiln sections by the aid of regulating slides.

Jan 1, 1946

By Sukumar Bandopadhyay, Arunapuram Sundararajan

"Unique production and environmental problems are associated with multiple seam mining where dragfines are used for overburden and interburden removal. On the production side, the problems are decreased dragfine efficiency in chopdown operations, the general need for spoil rehandle, complications in sequencing stripping and coal handling operations, and potential stability problems in highly stacked spoil. Many variations of dragline methods have been reported in the literature to encounter these problems. Because of the physical properties and peculiar hydrology of sub-arctic region mining of multiple seams in such areas probably could not be done with the methods used in temperate regions.The properties of thawed material would make spoil hard to place in a stable manner and thus would influence the mini sequence. For instance, multiple seam mining which requires some rehandling of spoil and prolonged exposure of overburden and interburden material might be precluded by the instability of thawed spoil and therefore mining techniques have to be modified. Since the deployment and operation of a dragline in modes different from conventional schemes will affect productivity, it will be necessary to study the effects on production of changing the dragfine operational schemes. This paper presents a heuristic simulation model of multi-seam dragline operation of a sub-arctic mine that can be used to analyze the handling of overburden and detailed study of the dragfine performance."

Jan 1, 1986

By Baisheng Nie, Longlong Yang, Tao Yang, Wenjie Jia

"Gas adsorption in coal is an exothermic and physical process. Temperature might change during the dynamical process. In order to get the temperature variation of gas adsorption process, the experiment system which can test the temperature variation and analyze the thermal effect was established. Gas adsorption experiments under different conditions were done by using the test system. The results show that temperature increases during the adsorption process. It is an exothermic reaction process. Also, the temperature variation and the variation gradient increase with the increasing of equilibrium pressure. The temperature variation value is smaller if the experiment temperature is higher. The paper will provide basic experimental data for explaining gas adsorption mechanism better.INTRODUCTIONChina is the largest coal producer in the world while it also has the most serious coal mine disasters. According to the statistics, there are nearly a thousand coal mines in China including more than 110 the key state-owned mines risking to happen coal and gas outburst. Hundreds of coal and gas outburst occur each year which often causes serious casualties and economic losses (State Administration of Work Safety, 2007). With the continuing exploitation of the coal resources, the depth of the Chinese coal mines increases about 100 meters every year which causes the situation of gas accident becoming more and more serious (Xie et al., 2006).At present, the real mechanism of gas adsorption, desorption and the diffusion process in coal and the influence factor of it are not so clear. And because of the limit of prediction method and the technological level caused gas accident prevention theory and technology not so valid."

Jan 1, 2015

By J. M. Harrison

FIELD PARTIES of the Geological Survey of Canada have, in recent years, mapped several areas east and northeast of Flin Flon (9, 10, 12, 13, 14, 15, 118) (1). In all these areas the mineral deposits show a close geographical relation to faults although the immediate control of most of the known ore deposits appears to be folded structures in the rocks (8, 11, 18, 19). Air photographs and published geological maps were studied in order to ascertain whether or not the mineral deposits in the Flin Flon-Snow Lake mineral belt as a whole show any spatial relationship to faults. It was found that most of them do show a distinct geographical association with faults, or with topographic features that may be faults. It is further apparent on air photographs that a major lineament, for composite of lineaments, follows approximately the contact between gneisses and schists of the Kisseynew complex on the north, and Amisk volcanic rocks on the south. However, this Kisseynew lineament is not continuous and, especially in the eastern half of the district, it is exceedingly irregular in plan. Parts of this lineament have been mapped as faults (9, 10, 12, 14), other parts have been shown as stratigraphic contacts (1, 2, 21, 27), and still other parts have not been studied except by reconnaissance methods. It is suggested that the Kisseynew lineament may be due to a deformed fault that extends easterly from a point about 25 miles west-northwest of Flin Flon to a point at least 10 miles northeast of Wekusko lake and that the mineral deposits.

Jan 1, 1951

By M. Stogran-Baker, E. Legault-Seguin

"Fluorspar mining in the St. Lawrence area of Newfoundland and Labrador began in the 1930s and ended in the mid-1980s. In 2013, Canada Fluorspar (NL) Inc (CFI) discovered a new ore body, the AGS vein, which proved amenable to more economic open pit mining methods and began developing this resource. This paper discusses the flowsheet development of the AGS vein deposit. Testing at SGS began in 2009 with samples from other deposits in the area. The testwork included pilot-scale dense medium separation (DMS), laboratory-scale flotation tests to develop the flowsheet and a flotation pilot plant. The more recent work that is presented here has been devoted to the AGS vein, and included a variability testing program that gave tremendous insight into the metallurgical drivers of processing the deposit. The ore was found to be fairly variable in terms of fluorite grade, but also gangue mineralogy, which had greater implications on the DMS performance. The gangue mineralogy was also found to significantly impact the grindability characteristics of the DMS product. This paper will detail the testing conducted and the mitigating steps which were identified for the operation.INTRODUCTION Fluorspar is the industrial trade name for the mineral fluorite (CaF2), which is the primary industrial source of fluoride. There are a number of categories of fluorspar, most notably acid-grade fluorspar and metallurgical fluorspar (metspar). Acid-grade fluorspar has stringent specifications and is suitable for the production of hydrofluoric acid that is used for many applications. The typical specifications of acid-grade fluorspar are >97% CaF2 and less than 1% each of SiO2 and CaCO3, with a particle size distribution in the order of 80% passing 100 µm. Metspar is typically used for metallurgical purposes, typically as a flux in smelting, and has significantly more relaxed specifications (< 15% SiO2). The principle source of fluorspar in Canada has been from the Burin Peninsula in Newfoundland and Labrador. More than 3 million tonnes of fluorspar were produced there between 1940 and 1978 and from 1987 to 1990, when production ceased (Fulton & Montgomery, 1994)."

Jan 1, 2018

By L. Don Leet

Abstract Earthborne vibrations from blasting and other sources, including rock bursts, can now be recorded effectively. The nature and magnitude of vibrations from various sources have been investigated and certain applications of the knowledge thus gained have been made. Vibrations from blasting have been measured on special equipment over a range from an electric blasting cap at a few feet, through the largest quarry shot in history to date ( 1,-362,985 lb.), to the first atomic bomb, in uew Mexico on July 16th, 1945. Laws relating amount of explosive to amount of vibration at different distances have been developed and tested. Special studies have been made of the effects of vibrations on buildings, particularly from the standpoint of possible structural damage. Recorded vibrations are used to study the effects of modern short-period delay shooting. It ?has been found that short-period delay firing is extremely effective in reducing vibrations under the right conditions, but with certain limitations. In quarry shooting, there appears to be a minimum number of holes below which vibrations are not appreciably reduced by short-period delay firing. In several instances this minimum has been near 7. Vibrations in the ground from rock bursts and the effects of mining in stresesd ground have been studied both underground and on the surface in a search for a rock burst warning system. Introduction Earthborne vibrations from blasting and other sources, including rock bursts, can now be recorded effectively. Analyses of blasting records have been yielding increasing funds of information of practical as well as theoretical interest. The nature and magnitude of the vibrations have been investigated with special reference to their effects on structures.

Jan 1, 1951

By J. O. Pitts

"Background The preponderance of Canada's coal resources is located in areas remote from high demand domestic users and at some significant distances from deepsea ports. This places great demands on the transportation system and has forced the coal and the transportation industries to adopt highly efficient methods of handling the product and hauling it to market position. Most of the coal not consumed in minemouth thermal power stations is carried by rail over lines operated by the two transcontinental railway systems, Canadian National and Canadian Pacific. These rail networks are extensive and have the advantage (as compared to most other North American railways) of being able to handle coal movements from origin through to destination without interchange to other rail carriers. Coal SourcesWith exception of the coal produced in Cape Breton, Nova iScotia, all the significant shipping volumes in Canada emanate ifrom mines located in the three most westerly provinces. Figure I ishows the geographic distribution of the major mining operaitions shipping coal to domestic and export markets. The prinicipal routes and the tonnages carried (1980 calendar year) are ialso indicated. iThe 1980 shipping data are summarized in Table I. Saskatchewan lignite began moving from Bienfait to Thunder Bay by CP Rail unit trains in mid-1981 at the rate of one million tonnes per year. The product is handled through Thunder Bay Terminals and delivered directly to a nearby Ontario Hydro electrical generating station."

Jan 1, 1985

By Jr. Watts, B. K. Cantrell, K. L. Bickel, J. F. McDonald

"A field trial was conducted at an underground gold mine to evaluate diesel fuel derived from soybean oil (soy-methyl-esters or “biodiesel”) as an alternative to commercial, low-sulphur, number 2 diesel fuel (D2). A 2.7 m3, 18-ton load-haul-dump (LHD) unit, powered by a naturally aspirated, indirect injection (pre-chamber), 100 kW diesel engine was used as the test vehicle. The LHD was equipped with a diesel oxidation catalyst. The LHD operated satisfactorily on the biodiesel fuel. Operators observed a slight decrease in power and an absence of black smoke.Diesel particulate matter (DPM) concentrations were monitored for a six-week period while the LHD was operated with either the biodiesel fuel or the D2 fuel. DPM concentrations were measured in the mining section’s clean air intake, exhaust and on the LHD. Reduction in DPM emissions was determined from the measured difference in DPM concentrations between the clean air intake and the exhaust. The biodiesel fuel reduced energyspecific DPM emissions approximately 75%, from 3.6 ± 1.8 g/kW-hr to 0.86 ± 0.27 g/kWhr. Time-weighted average DPM exposure, measured near the LHD operator, was reduced from 0.67 ± 0.13 mg/sm3 to 0.28 ± 0.12 mg/sm3, or approximately 58%, when the biodiesel fuel was used. IntroductionDiesel exhaust consists of noxious gases and diesel particulate matter (DPM). Recent attention has focussed on the potential carcinogenicity of DPM and the potential health impact on miners. The National Institute for Occupational Safety and Health (NIOSH) recommended that whole diesel exhaust be regarded as a “potential occupational carcinogen”, and that reductions in workplace exposure would reduce cancer risks (NIOSH, 1988). The International Agency for Research on Cancer (IARC) declared that “diesel engine exhaust is probably carcinogenic to humans” (IARC, 1989)."

Jan 1, 1997