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By J. R. D. Gravel, D. A. Poland

"The induration of iron ore pellets has always utilized prefired pellets to protect the pallet cars from the environment of the induration furnace. This paper presents the process used to obtain superior upper sidewalls. These heat resistant castings are used on induration pallet cars, and their life improvements by as much as 400% is a significant step towards the reduction of the prefired (or hearth layer pellets.) The benefit to the industry in the removal of the hearth layer is improved overall productivity. IntroductionThe Iron Ore Company of Canada (IOC) operates with production facilities located in Labrador City, Newfoundland and Sept Iles, Quebec. It has recently been acquired by North Limited, an Australian based resource oriented company. Prior to its acquisition, IOC has examined several methods of operational cost reductions. One of these was an examination of indurrating pallets. Pallets are composed of numerous assemblies and sub-assemblies. The examination of the upper sidewalls began as an intent to increase the operational life of the component. The anticipated net effect was to be a reduction in the overall pallet maintenance cost. All of the components and assemblies have undergone a severe scrutiny. IOC has found that the success of the project has depended upon not only the technical competency of all parties involved, but also upon the ability to share risk, to be innovative, and to find a partner with whom the development can proceed without fear and yet with accountability. IOC has found in Cast Steel Products (CSP) such a partner in the field of pallet development. This paper will undertake to explore the progression into the arena of partnering between IOC and CSP. CSP and IOC met in the fall of 1994. The work of re-engineering the pallets began with an initial order for 36 pallets in March, 1995. The work on the upper sidewalls involved segregation of the effect of alloy development versus physical geometry development. The nature of partnering between the two companies allocated alloy development to IOC and physical geometry development to CSP, yet no advancements were made in either area without the close co-operation or the involvement of both partners."

Jan 1, 1999

By E. De Souza

Two comprehensive surveys, which focus upon backfill practices and the economics of backfilling in underground mines in Canada, have been conducted. The two surveys were designed to assess operational practices and costs associated with the wide scope of filling operations that must be met by individual mines, ranging from raw material feed to the preparation plant, through underground backfill transportation, to in-stope product placement. This paper presents the current state of backfill usage in Canada, identifies trends in minefill practices and provides mine operators with an updated database of information upon which they might compare their own practices and costs with present trends throughout the industry.

May 1, 2003

By C. L. Monroe

It has been the custom in recent years to look upon Atlin as a worked-out placer camp. This is a conception, however, which is far from the real situation. The placer-gold deposits of Atlin are today, after thirty-one years of continuous working, a field well worth the attention of the mining world. It is true that the shallow diggings (the 'easy money') have been practically cleaned out, but although there have been perhaps ten millions, or more, in gold already taken from the district, there are still many more millions left in the creek beds . A conservative estimate of the gold still remaining in one creek alone, Spruce creek, for a long time known as the 'prospector's meal ticket', would place the amount at anywhere from fifteen to twenty million .dollars, and there are a number of other creeks that have never been thoroughly worked, and some only partially prospected. That the true situation is beginning to be recognized by those who are on the lookout for a profitable field for investment, is born out by the fact that, within the last few years, New York capital directed by Mr. Charles V. Bob, who is also responsible for the opening up of the Engineer mine, has installed on Pine creek, where the first discovery of gold in the district was made, one of the largest hydraulic mining plants on the continent, utilizing six miles of the old hydraulic ditch of the Discovery Mining and Power Company, and over two miles of pipe line. On Boulder creek, where already two millions have been taken out, the Consolidated Mining and Smelting Company are on their third year of development work in opening up the unworked ground, while on Otter creek a newly organized French company have started a plan of development which will involve an expenditure in the neighbourhood of $200,000, and two or three years' work, before they can hope to find gold in paying quantities. It is probably safe to prophesy that placer gold will be produced in the Atlin district for the next fifty years

Jan 1, 1929

By E. L. C. Martins, M. J. Nicol, D. Majuste, A. D. Souza

The effects of organic compounds on the current efficiency (CE), morphology, crystal structure and mechanical properties of the metal deposited during the electrowinning of zinc are described. A flotation collector and lubricating oil were selected based on observations made during the industrial production of zinc from silicate ores, in Brazil. The analysis by Fourier transform infrared spectroscopy of these compounds, which may be present in minor amounts in the electrolyte solution, indicated the presence of a polar amine group in the collector, while the lubricating oil is a non-polar compound. The average CE value obtained from organic-free industrial solution was 91.15 ± 0.26 %. The CE dropped to 54.35 ± 0.73 % in the presence of 100 mg·L-1 of collector in the solution, and a negative effect was also observed in the presence of similar amounts of oil (88.84 ± 0.61 %). The characterization of the deposits by scanning electron microscopy and X-ray diffraction revealed the formation of pores in deposits obtained from solutions containing the oil, while a different growth pattern (perpendicular zinc platelets) was identified when the flotation collector was added to the industrial solution. In the presence of these contaminants in the solution, guided-bend tests revealed that the deposits have a higher resistance to deformation, but lower ductility, properties that may affect the performance of the stripping stage. As a result of this work, simple control and optimization actions were applied in the industrial plant, which resulted in important improvements in the electrowinning process.

Jan 1, 2014

By J. S. Roberts

"Campbell mines has been in operation since 1948. Part of the process consists of roasting of a flotation concentrate which contains arsenopyrite.At present operation level the milling rate averages about 850 t.p.d. and about 48 t.p.d. of concentrate is roasted. The gas emissions at present contain between 3 and 3.5 t.p.d. of arsenic trioxide, about2 - 2.5 t.p.d. of particulate matter and between 19 - 25 t.p.d. of sulphur dioxide. The particulate is extremely fine calcine dust and it assays about 4 oz. Of gold per ton.Until 1974 the gas was discharged untreated through a 125' stack.UntreatedThe decision was made in 1972 to erect a gas treatment plant, construction ran through 1973 and operation began in 1974. The cost of the installation was about 1.3 million dollars.On investigation the process technology, it was apparent that the plant operated by giant Yellowknife for the same purpose was the model we should study. I would like to acknowledge the fine cooperation we had from giant, the plant that emerged is very similar to theirs and incorporates some improvements suggested by them and based on their operating experience.The plant is designed to remove arsenic and solid dust and it has no provisions to remove sulphur dioxide.We depend upon the 125' stack to assure adequate dilution. Because of the nearby airport the stack cannot exceed 125'. A stack burner is provided that can ""y used to heat the stack gas and carry it higher into the atmosphere when there is an inversion condition.The removal of arsenic from hot gas is fairly simple. The sublimation point is about 425°f, a few degrees above this point the arsenic is a gas and a few degrees below it condenses into a solid form. The arsenic could have been removed by simply dropping the temperature below the condensation point and collecting all the solids in a baghouse. This would have removed the possibility of recovering the gold in the calcine dust and would have produced an impure and more bulky arsenic material to be placed in safe storage. The decision was made to collect the solid dust in a hot electrostatic precipitator operating above the sublimation point and subsequently lower the temperature below the condensation point and collect the arsenic in a baghouse."

Jan 1, 1976

By R. A. May, P. J. Brooks, W. M. Smith

"Neill and Gunter Limited (NGL) has prepared a preliminary design and a cost estimate for a ferric chloride leach plant to recover copper, lead, zinc, and silver from a typical complex sulphide ore. This plant design is specifically intended to treat unconcentrated ground ore (flotation feed), but can be readily adapted to treat bulk concentrates. Samples of ground ore and bulk concentrate were obtained from Heath Steele Mines, Miramichi, New Brunswick, laboratory testing, and preliminary process flow sheet preparation was carried out by the Research and Productivity Council in Fredericton, New Brunswick. Approximately thirty drawings have been produced, including process and equipment flowsheets, process piping and instrumentation drawings, and preliminary general arrangements. Preliminary capital and operating cost estimates were prepared for a plant that would treat 1000 t/d of crushed and ground ore to produce about 30 000 tpy of zinc. Capital and operating cost estimates were also projected for plants up to 4000 t/d of processed ore. Recoveries of 99% for zinc, 98% for lead, and 96% for copper were achieved in laboratory tests on unconcentrated ore. These recoveries were higher than the overall recoveries obtained from bulk concentrate, yielding approximately 10% more revenue.A 1000 tonne per day plant was determined to have a low return on investment, however, depending on the size and type of mining operations employed and the FCL plant throughput. DCF-ROI projections of 20% to over 30% were calculated for 100% equity financed “green field” mine, mill and FCL plant operations of 2000 t/d and higher"

Jan 1, 1997

By Z. Yang, M. J. Collins, N. E. Tuffrey, R. J. Kalanchey, I. M. Masters

The high elevation of China Western Mining Company (WMC)' s Ganhe refinery, and the high iron content of concentrates produced by the WMC mines, were key factors in the selection of pressure leaching by WMC for their new zinc refinery. This paper describes the results of pressure leaching test work conducted by Sherritt in Fort Saskatchewan with a sample of WMC concentrate from Qinghai Province in China. Results from batch pressure leach tests and a four-day pilot plant campaign are reported. The pilot plant campaign included continuous operation of a two-stage pressure leach circuit, as well as neutralization and iron removal steps, resulting in the production of iron-free zinc sulphate solution. Greater than 98% zinc extraction was achieved in pressure leaching, while producing solution containing about 9 g/L H2SO4 and 2 g/L Fe. Following neutralization and iron removal, the solution contained about 170 g/L Zn and less than 10 mg/L Fe. Overall recovery of sulphur in the zinc concentrate feed to elemental sulphur byproduct was about 85%, while 75 to 80% of the indium in the feed was recoverable from the neutralization residue. The test results highlighted the technical and economic advantages offered by the Sherritt Zinc Pressure Leach Process and provided the required data for the engineering design.

Jan 1, 2008

By E. H. Mulligan

THE ERRINGTON B-I mine is located on the Errington orebody of Steep Rock Iron Mines, Limited, at Steep Rock Lake, Ontario. In 1946, this orebody entered the shipping lists of the Lake Superior iron ranges as an open-pit operation. During the period 1946 through 1953, the mine produced a total of 9,000,000 tons of iron ?ore. In 1950, as the mine approached the economic limits for open-pit operations, ground was broken for an underground development to exploit the deposit at depth. The mine is designed for an ultimate production of 1,500,000 tons per year by the block-caving system of mining. The initial shaft is 1,200 feet deep and will produce or-e from the 700 and the 900 levels. The 1,100 level will be used as a drainage level and as a haulageway for waste rock, which is hoisted to surface by skip. Ore from the two production levels moves by a system of ?ore passes to a crushing plant located below the 900 horizon and is hoisted from this point to surface by conveyor belt. At the present time, all material handling on the levels is by tramming, but as tram distances increase conveyor haulage will probably be installed. The initial stage of the Errington B-1 development is expected to produce 6,000,000 tons of ore over a period of four years. The second stage will require deepening of the shaft and development of lowe1? production levels. The conveyor hoisting plant will be extended to serve these new levels. We visualize the mining of this orebcdy down to 2,500 feet by these methods.

Jan 1, 1956

By Rob Morrison, Peter Cameron

"Many products and technologies have been developed from outcomes of research projects carried out by the Julius Kruttschnitt Mineral Research Centre (JKMRC). When these products and technologies are applied to the design and optimisation of blasting, comminution and separation, improvements in profitability can be realised.In 1970 Alban Lynch promoted two practical ideas to improve plant operations:• Ore and equipment properties can be separated allowing experience with one type of ore or equipment to be transferred to other types of ore and equipment. If this experience was encapsulated in a mathematical model, then these properties could be combined and used to simulate (ie. to design and to optimise) complete mineral processing circuits.• Many problems associated with scale-up from laboratory to industrial equipment could be eliminated by experimental work on full-scale equipment in the plant.Many JKMRC research projects have focussed on the development of models of unit operations in mineral processing and their application to process simulation.Models of comminution and classification developed at the JKMRC have been used since the early 1980's. Ore characterisation techniques developed to support these models are licensed world wide through JKTech. The application of comminution modelling techniques to blasting, which optimises the process feed size distribution is used in Mine-to-Mill® projects. The advances in the understanding and modelling of froth flotation over recent years have provided the opportunity for integrated ore characterisation and process optimisation from resource to product.JKMRC project outcomes often provide proven opportunities for the mineral industry to improve performance and productivity. JKTech was established in 1986 to commercialise and market the most promising outcomes and thus ensure their continuing availability to the mineral industry.They include:• Commercial software (JKSimMet, JKSimBlast and JKMetAccount).• Monographs (Comminution and Blasting).• Technologies (Mine-to-Mill® and flotation optimisation).• Hardware products (JKFrothCam, JKJetLift® and the Mineral Liberation Analyser).This paper summarises these technologies and their benefits."

Jan 1, 2003

By L. B. Kilius

The composite cathode system based on Ce0.9Gdo.1O2_,5 electrolyte with a painted cathode was used for an intermediate temperature (500-700°C) solid oxide fuel cell. This cathode system was chosen due to its excellent thermal expansion match to the electrolyte, its relatively high conductivity (115 S cm-1 at 700°C), and its low activation energy for oxygen reduction (99 kJ/mol). It was found that the decrease of sintering temperature of the composite cathode system produces a significant decrease in charge transfer resistances to a level of 0.25 SI cm2. The conductivity measurements of porous samples produced values between 40 and 88 S/cm for porosities of 30-40%.

Jan 1, 2005

By E. Bongajum

We present results from petrophysical studies to characterize a Zn-Pb-Ag deposit in Nash Creek, New Brunswick. The measurements are part of an integrated study that includes geological and geophysical data acquired on the property. In order to successfully characterize the ore body, an understanding of the relevant physical parameters and their change with vertical and lateral variations of the target lithology is necessary. The quality of the estimated 3D variation in the physical properties is supported by the presence of several boreholes that randomly span the survey region. Density was measured from cores of thirty-two boreholes across the area. Seventeen of these boreholes constitute two intersecting borehole profiles, which is ideal for locally modeling the 3D distribution of the ore deposit. High densities (>3.2g/cm3) correlate strongly with Zn-rich mineralization zones (low resistivity). Compression and shear wave velocity measurements made from representative core samples of the regional geology range from ~2.91 to ~6.41 km/s for P-waves and from ~1.41 to ~4.20 km/s for S-waves. The lower bounds of these velocity values correspond to regions with a high degree of alteration. Moreover, porosity estimates from rocks on the property suggest that porosities range from 0.35% to 11.79%. Induced polarization (IP) measurements confirm that mineralized samples show a significant chargeability and resistivity contrast with respect to the host rock. Thus, chargeability and resistivity information can be combined to adequately identify conductors associated with mineralization in electrical survey data. Information on these physical parameters and their 3D statistical distribution have serious implications on various aspects of mineral exploration that include: resource estimation, choice of geophysical data acquisition and interpretation, and information for preliminary rock stability assessment.

May 1, 2009

By R. Poulin, M. R. Samis

Real options valuation is an alternative net present value framework that is able to incorporate both management flexibility and dynamic project risks. In this paper, management is considering the development of a satellite low-grade zone while operations in a developed high-grade zone continue. If the lowgrade zone is developed prior to high-grade zone exhaustion, mine capacity must be expanded before additional production from the low-grade zone can be processed. This expansion can be avoided only if low-grade zone development is delayed until the high-grade zone is exhausted. The real option model presented here allows the development and capacity expansion decisions to be reconsidered on a discrete half-year basis. It delineates price regions, for given levels of high-grade zone reserves, in which it is optimal to develop the low-grade zone, defer low-grade zone development and abandon the mine irrevocably.

Jan 1, 2006

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

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

Jan 1, 2012

By Brad Thrall

"Viceroy Resource Corporation of Vancouver, B.C. has recently developed the Brewery Creek Mine, an open pit heap leach gold mine 55km East of Dawson City in Yukon, Canada. Mineable reserves are 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797000oz) of gold. Ore processing employs the heap leach technology using run of mine ore. 1996 highlights included construction of 158,000 m2 of leach pad, placing 1.9 million tonnes of ore at a grade of 1.46 gpt on to the leach pad, construction and successful commissioning of the ADR plant, and pouring of the first gold bar on November 15th.Permitting this mine has drawn significant attention because the heap leach technology, while proven in other jurisdictions, has not been used in Yukon where winter site temperatures routinely reach -45 C for extended periods.IntroductionFollowing a comprehensive governmental and public review of the proposed project, a Class A Yukon Water license was issued in August, 1995. Construction started in 1995 and leaching commenced in October 1996. The Brewery Creek Mine is in Yukon, the home of the Klondike Gold Rush nearly 100 years ago. This is the only part of Canada not glaciated in the Wisconsin advance so there is oxide ore resulting from about 80,000 years of weathering -unique in Canada. Discontinuous permafrost is present on site and has required special consideration in the design. Winter temperatures dip below minus 50 C, demanding an approach to mining and leaching that is different than in more temperate climates.Project DescriptionThe mine comprises 8 shallow, largely oxidized gold deposits along a 7km corridor. An 8 year mining program will extract 17.1 million tonnes of ore grading 1.45 grams/tonne, containing 24.8 tonnes (797,000 oz) of gold. The strip ratio will be 1.35: 1. Overall gold recovery is projected at 78%. There will be 2.3 million tonnes of ore placed on the pad annually, with an average of 2.57 tonnes (83, 000 oz) of gold recovered per year. Because of the cold winters, the mine will operate approximately 210 days per year, while the leaching process will operate on a year round basis. Run of mine ore is placed on the heap 150 days per year. The recovery process utilizes conventional sodium cyanide leaching , carbon adsorption, caustic desorption, and on-site smelting. Peak employment during mining is 145 and winter staff is reduced to 45."

Jan 1, 1997

By L. H. Bergmann

THE blasting practices described are fairly representative of those employed in the coal mines of Eastern Canada. As such, they may be of interest to Western Canadian coal mine operators. The treatment of the subject is general, no attempt being made to discuss blasting operations at any particular coal mine in detail. All the mines dealt with are mining bituminous coal and are classified under the Coal Mines Regulation Act of the Province of Nova Scotia as &apos;closed light&apos; mines. As such, they are required to use only &apos;permitted&apos; explosives and to apply them in a &apos;permitted&apos; manner, except where authority is given by the Mines Department to do otherwise.

Jan 1, 1945

By W. R. A. Graeser

"The Nordenham finishing mill is situated in the town of Nordenham, Fede1•al Republic of Germany, on the banks of the Weser River opposite the town of Bremerhaven, with access by water to the North Sea.The unfinished fibre, shipped j?•om Deception Bay during the sub-Arctic summer shipping season, is unloaded from bulk ocean carriers, stored and then processed throughout the year until the following shipping season. This paper describes the unloading and storage facilities,the finishing mill and the finished-fibre storage arrangement. Details of environmental and dust control practices and West German environmental standards are discussed. A resumé of fibre markets is included."

Jan 1, 1976

By C. Schuffeneger

"The design of SAG milling circuits for mining projects requires the incorporation of the energy consumption considerations and the evaluation between different flexibility-adding options to absorb the time-dependent variation in the ore lithology. In order to expand the focus of the engineering design, a higher level of deepness and quality in the baseline information must be achieved to elucidate all of the constraints on throughput, energy consumption and product quality generating a design optimization consistent with an integrated vision of the process. This paper presents a review of a collection of typical examples of the copper and gold mining project in the Chilean Andes, in which both process and energy efficiency criteria are considered when the focus is to deliver an integral solution that incorporate those areas in the design. The intensive use of energy in the SAG milling, the process continuity and the quality of the product are a function of the proper design and selection of grinding equipment and plant layout, aligned with the mining plan and associated with projected future expansions and production increases.INTRODUCTION Autogenous and Semiautogenous grinding technology, large diameter and short length mills, begins with the Handsel design. During the decade of 1930’s, Handsel-Hardinge studies led to cascade mill development. Nowadays, 80 years later, continuous improvements in design and technology have been conducted to a completely new generation of gearless SAG mills that have led to an increasing capacity at the concentrator plants. Considering the existing alternatives, SAG mills are the most implemented option for the grinding circuit today. This work presents a review of the SAG mill implementation parameters and circuit considerations and its correlations in the most recent projects in Chile with an ore treatment capacity above 50 ktpd since the decade of the 90’s up to now. From this period, the tendencies will be analyzed using project design data. Based on process design information, the recent SAG mill history in relevant projects related to the new generation of commercial SAG mills, technical associated considerations and performance will be discussed. Circuit selection based on energy utilization will be revised to bring up a more holistic perspective on the SAG mill circuit design concepts. As is now well known, the heart of every concentrator plant are the grinding mills. Higher demands on throughput, availability and power consumption optimizations require not only high performance electrical equipment but also a well selected grinding circuit. The energy efficiency issues associated to the circuits design will be reviewed."

Jan 1, 2012

SOFCs with thin electrolyte of two types: SDC (15um) single-layer and YSZ (5um) + SDC (15um) bi-layer were fabricated by screen printing and co-firing on Ni¬YSZ cermet substrates. Using in-situ sintered Sm0.5Sr0.5CoO3 cathode the SDC-cell shows high performance at low temperature, 1180mW/cm2 peak power density around 650°C, while the YSZ+SDC bi-layer cell generates about 340mW/cm2 at 650°C, and good performance at 700-800°C with almost theoretical OCV value. Many Zr-content micro-islands were found on the SDC electrolyte surface. The influence of co-firing temperature and thin film preparation methods on the Zr-islands&apos; appearance was investigated.

Jan 1, 2005

By R. B. Hyde

"Severe drilling conditions and difficult mud problems are briefly out-lined as the major cost items in all production operations. The chief problems discussed are abnormal pressures, high temperature, trouble-some shales, and low rates of penetration. These problems have been eliminated or greatly reduced in many areas by• the proper application of recently developed drilling mud products and techniques. These severe problems and their solutions are discussed generally: the application of high-density weighting materials to overcome abnormal pressures; surfactant muds with sodium polyacrylate as a solution for deep and high-temperature drilling; shale control muds and new dispersants for severe shale problems; and low-solids emulsions and •extreme-pressure lubricants for greatly improved rates of penetration."

Jan 1, 1959

By I. R. Ward

"The need for energy conservation has been of increasing concern since the early 1970's, when the cost of petroleum based energy began to escalate rapidly and security of supply became uncertain. The cost of energy from alternative sources has also increased due to development costs and environmental restrictions.These developments have had a serious impact on the mining industry, which is energy intensive. The impact is magnified as lower grade ores are treated, and more energy is consumed per unit of product. In many cases increased operating cost is not compensated by the rise in product selling price.The magnitude of energy consumption in the mining industry is indicated by recent studies conducted in the U.S.A. and Canada. Based on 1970 figures, it was reported that the production of 1 ton of copper in the U.S.A. required 111. 8 x 106 BTU of energy, of which 60. 7 x 106 BTU (54.3%) was consumed in mining and processing (l)The survey of Canadian mills, conducted by CANMET and reported to the CMP meeting of 1978 (2), showed the following milling energy consumption figures (approximate averages):"

Jan 1, 1981