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By S. Banisi, M. Poorkani, M. Farzaneh, M. Askari

"At the Sarcheshmeh copper mine 40,000 t of ore per day with an average grade of 0.9 % Cu is ground to 70% passing 75 microns. Grinding is effected in 8 parallel lines of 8 x 5 m ball mills in a closed circuit with cyclones. The make-up balls are 80-mm forged alloy steel balls and the average ball consumption is 750 gh of ore ground. In order to optimize ball size distribution inside the mill, based on the previous investigation instead of using only 80 mm make-up balls a combination of 80 and 60 mm (75% to 25% by weight) ball charge was used in one of the mills. To evaluate the performance of three ball types namely forged alloy steel balls (A), ductile cast iron (C), high chromium cast iron (D) and also a combined (80 and 60 mm) charge of forged alloy steel balls (B), four identical parallel mills were charged accordingly. These four mills were sampled during a period of six months. The amount of material finer than 75 microns of cyclone overflows was selected as a criterion for the performance evaluation. It was observed that in a mill with the combined make-up balls the amount of fine produced was 4% higher than the other mills. The consumption of ball types A, C and D were 730, 710 and 534 g/t, respectively. The results of laboratory flotation tests showed that due to an improvement in the production of fines an increase of 1.4% in the overall copper recovery is obtainable. Due to the promising results, the new make-up ball regime was implemented in all mills in the plant.INTRODUCTIONThe Sarcheshmeh copper ore body which may rank as third or fourth largest in the world contains 1 billion tonnes averaging 0.90 % copper and 0.03 % molybdenum. It is located southeast of Iran and has been processing 40,000 t/d of ore since 1982. The mine produces 100,000 tonnes of copper and 2,200 tonnes of molybednite concentrate per year. After three stages of crushing, the ore with a F80 of 12.7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70% finer than 75 microns. The concentrate of the first stage of flotation is reground and the tailing constitutes the main component of the plant final tailings. A concentrate with an average grade of 31% Cu is obtained after cleaning and re-cleaning stages. Total recovery of the plant varies between 83 and 87 % depending on the operating conditions and ore type."

Jan 1, 2002

By K. Izumi

Ultra-grain refinement and high strengthening of metals by accumulative roll bonding (ARB) was widely reported. However, applications of ARB to magnesium alloys were rather limited. In this study, Mg-9%Li-1%Y sheets were applied to ARB at room temperature. Six 0.5 mm thick sheets were stacked and reduced into 0.5 mm thick by four passes. The procedure was repeated up to three cycles, so that the equivalent strain of 6.2 was applied. The sheets show dual phase structure with a (hcp) and ß (bcc). Grains elongates to the rolling direction with increasing number of ARB cycles. After three cycles, fragmented a grains with average size of about 300 nm are uniformly distributed. After the first cycle, the ultimate tensile strength increases to 180 MPa from 133 MPa, while the elongation decreases, however, still high (26%). The tensile strength slightly decreases by the second cycle and does not change at the third cycle. Meanwhile the elongation increases by the second cycle and the sheets show 41% of the elongation after the third cycle.

Jan 1, 2006

By H. Kim

"IntroductionThe Hat Creek coal field contains low-grade coal deposits which are the thickest in the world. The diamond drilling and geophysical surveys conducted by B.C. Hydro over the last six years have indicated in excess of 2 billion tonnes of sub-bituminous to lignitic coal. The coal field is in the Interior Plateau Dry Belt, about 240 km northeast of Vancouver, and contains two explored, nearsurface coal deposits amenable to surface mining (Fig. I). The No. I deposit contains approximately 740 million tonnes of coal at 17.71 MJ / kg, or 7,600 Btu/lb, at 34.82% ash and 24% moisture. The No. 2 deposit to the south contains appreciably more coal resources at somewhat lower grade, but it has not been explored so extensively because of its higher stripping ratio. Therefore most of the exploration activities to date have been directed toward the development of the No. I deposit. The No . I coal deposit has been selected as the source of fuel for a proposed thermal powerplant to be built about 5 km east of the deposit. The purpose of this paper is to summarize the data obtained from the diamond drilling and the geophysical logging in the No. I deposit between 1974 and 1979. An attempt is made to explain the depositional environment of the Hat Creek coal measures. Because the understanding of the depositional environment in.a particular basin is essentially an evaluation of all the geologic properties of the area, the available geological information in the No. I deposit has been compiled on the basis of consistent criteria. This includes data on the lithology of the coal measures, thickness and areal distribution of the elastic sediments, and on the changes in the megascopic stratigraphic profile based on geophysical correlation. The palynopetrographic relationship and detailed sedimentological aspects are not examined in this paper. Such studies should provide important information relating the causal vegetal and chemical responses of the coals to -environmental changes. Extensive deposition of surficial materials during de-glaciation left most of the area of the Upper Hat Creek Valley devoid of bedrock exposures. Structural and stratigraphic features are hidden beneath glacial deposits and/or post-Eocene volcanics. As a result, the geological interpretation of the Hat Creek coal basin has been based primarily on drilling and geophysical data. Because of this, any explanation of the depositional environment details is tentative until the deposits are stripped for development."

Jan 1, 1985

By E. N. Gilje

"IntroductionDURING the past five years, over two miles of shaft sinking have been completed at Falconbridge. As sinking has continued, we have improved our equipment and technique with a resulting increase in efficiency. Throughout this period, all sinking has been done by contracting firms, under our direction and to our equipment specifications, with highly satisfactory results. Since 1949, Riddell shaft mucking machines have been successfully used in conjunction with the •benching method of sinking. Our most recent practice can best be illustrated by describing the method used in sinking No. 1 shaft at the Fecunis Lake mine.No. 1 Shaft, Fecunis Lake MineNo. 1 shaft, consisting of six compartments and measuring 13 ft. 11 l/2 in. by 19 ft. 9 3/8 in., outside timber (Figure 1), will be sunk to a depth of 4,170 feet. It was designed to accommodate two 10-ft.diam. Koepe hoists."

Jan 1, 1955

By M. Vallée

"Geological and technical problems are often considered the most important ones affecting new mining projects. Typical problems and likely causes are reviewed based on current Quality Management and Continuous Improvement (QMCI) perspectives, giving particular attention to the work of W.E. Deming. As the “system approach” is an essential part of these policies, its characteristics are described with particular attention given to cultural- behavioural, organizational and systembased constraints described by J. Gharajedaghi. Given that poor communication and interaction among geologists, mineral processors and mining engineers/operators can seriously affect the adequacy of tests, project planning and execution, and mine profitability, these interrelated processes within the mining systems are analyzed and modelled. The impacts on models and simulations of ignoring typical data, information and knowledge uncertainties are addressed. Adapting W.E. Deming’s Fourteen Points, System of Profound Knowledge and insistence on leadership, and the analysis of mining system constraints, will allow the effective QMCI approach required to reduce geological and technical risks. Whenever we achieve this goal, we will be in a better position to overcome environment-, market-, finance- and community-related problems, achieve higher company and industry profitability as well as more sustained development. RÉSUMÉLes problèmes géologiques et techniques sont souvent considérés les plus importants parmi ceux qui affectent les nouveaux projets miniers. Des problèmes typiques et leur causes sont étudiés dans la perspective de gestion de la qualité et d’amélioration continue (GQAC), en relation avec les travaux de W.E. Deming. Comme l’approche système est au centre de ces méthodes, ses caractéristiques sont décrites en donnant une attention particulière aux contraintes de types culturel-comportemental, organisationnel, et systémique décrites par J. Gharajedaghi. Compte-tenu que les lacunes dans les communications et les interactions entre géologues, minéralurgistes, et ingénieurs/opérateurs miniers peuvent affecter sérieusement la validité des essais, de la planification et de l’exécution des projets ainsi que la rentabilité des exploitations, ces processus connexes font l’objet d’analyse et de modélisation. Les impacts sur les modèles et les simulations de l’incertitude des données, informations et connaissances sont soulignés. En adaptant au système minier les Quatorze Obligations et le Système de connaissance approfondie de W.E. Deming ainsi que l’analyse des trois types de contraintes, nous pourrons développer une approche GQAC permettant de réduire les risques géologiques et techniques des projets miniers et des exploitations. Ceci nous pemettra de mieux faire face aux problèmes reliés à l’environnement, aux marchés, au financement et aux conditions sociales, d’améliorer la rentabilité des exploitations minières et de l’industrie, tout en contribuant de façon accrue au développement durable."

Jan 1, 2003

By T. L. Sadlier-Brown, Andrew E. Nevin

"Common properties of commercial geothermal steam reservoirs are a magmatic heat source, the presence of water in vapour and liquid phases, and a surrounding seal of low permeability. The latter may be due to a combination of hydrologic load, argillic alteration and mineral precipitates. The temperature and pressure of vapour and liquid co-existing in equilibrium at maximum enthalpy may approximate 451°F and 450 psi. Steam reservoirs do not necessarily vent steam, but fluid which breaches and mixes with meteoric waters may emerge as hot springs. A systematic exploration program in Western Canada would involve a sequence of four stages utilizing geological, geochemical and geophysical techniques. The geochemical parameters of hot spring waters, such as silica, lithium and potassium content, give some indication of the basic reservoir temperature. The geology of Quaternary volcanics, including reservoir rocks, structure and rock alteration, is of prime importance. The costs of preliminary indirect methods are no more than those of oil and gas exploration; however, high temperatures compound drilling problems and costs. Exploration expenditures of twenty million dollars or so might be needed for a significant discovery. British Columbia and the Yukon Territory contain abundant Cenozoic volcanic rocks and over 50 thermal spring complexes (some with as many as 20 springs in one complex). Six regions are tentatively picked for exploration. Four regions coincide geographically with post-1980 electric power facilities and loads, and with possible alternatives such as potential dam sites. The Lillooet River region, Terrace region and Western Vancouver Island region have inferred potential for the existence of a plus-500-Mw geothermal reservoir. The Kootenay region may or may not have such potential. The Stikine River region has strong evidence of geothermal endowment, but the anticipated power market of the middle future might be only 30-50 Mw. The Whitehorse, Y.T., and Atlin, B.C., region has a belt of thermal springs and Recent cinder cones. The anticipated middle-future needs are real enough, but in absolute terms they are small, say 20-30 Mw. Legislation and policy on geothermal resource rights are lacking in British Columbia and the Yukon Territory at this time. As well as making policy, governmental organizations will play a significant role in geothermal development as buyers of steam or electricity. The role of industry is visualized as assuming the high-cost and high-risk exploration effort, provided the nature of this effort is understood by government."

Jan 1, 1973

By T. Salman

Most authorities agree that the dissolution of gold from an ore takes place according to the Elsner equation first stated in 1846. The main requirements for the dissolution reaction to proceed are:(1) that the gold be clean.(2) that the gold be exposed to the solution.(3) that the cyanide solution be active, i.e., not over loaded with impurities which could retard or inhibit the reaction.(4) that an adequate supply of oxygen be available (from air).When the above conditions are met, cyanidation becomes basically a mechanical operation.Minerals such as quartz, calcium carbonate are relatively inert to cyanide though they may give rise to mechanical troubles. Most ores present an assortment of chemical problems, depending upon the constituent present, which react to the solution to varying degrees. It should be borne in mind that minerals which are disturbing to the operation, though present in small amounts, usually exceed the weight of the gold by several hundred times. In addition, the application of flotation and other forms of concentration to gold ores, previous to cyanidation, concentrates not only the gold, but also the other heavy minerals and these complicate the chemistry of the process.

Jan 1, 1975

By H. A. Steane

"This presentation will cover some crushing and grinding considerations in plant design and operation. There is nothing basically new in the subject matter presented here; however, the viewpoint and interpretation may be novel and some of it controversial.The presentation is based on experience gained in the metallurgical design of plants for Placer Development Limited from 1960 to the present. The plants are listed on SLIDE No. 1.These plants have conventional crushing, followed by rod mill and ball mill grinding. I would like to think that autogenous grinding plants are the answer for eliminating secondary crushing plants and reducing the capital and operating costs; however, the autogenous plants seem to have some problems of their own and I have had no experience with them.Fineness of Grinding RequiredFirst let us consider the fineness of grinding required.The fineness of grind will affect the recovery obtained, and the relationship must be determined. If the grinding is too coarse, some of the valuable mineral, either free or locked in middling grains, will not be floated. However, as grinding is probably the greatest single operating cost, we do not want to grind any finer than is justified economically.Finer grinding should not be carried beyond the point where the net smelter return for the increment saved becomes less than the added operating cost. Even this fineness will be beyond the economic limit because of the additional capital cost for the equipment needed to achieve it. These factors will be discussed in more detail later.The Bond work index is the commonest method of expressing a measure of the effort that has to be expended in grinding. It is the kilowatt-hours required to reduce a ton of rock from an infinite size to 80% passing 100 microns. The formula allows a calculation to be made for other size ranges."

Jan 1, 1976

By D. E. Gorse, R. G. Anderson

"Indusmin's history dates back to 1937 when they developed the Blue Mountain Nepheline Syenite deposit at Nephton, Ontario, and began supplying material for the glass, fiberglass, paint, ceramics and rubber industries.Since then, as a subsidiary of Falconbridge Nickel Mines, Indusmin has expanded the Nephton operation, diversified into the aggregate quarries for the construction industries, with operations at Acton and Halton, Ontario, established silica plants at St. Canut, Quebec and Midland, Ontario, to supply the glass, carbide, ceramics, cleanser and concrete products industries, and the purchase of a foundry, Fahramet Limited, Orillia, Ontario, supplying steel and alloy castings to the mining, construction cement and petrochemical industries.Indusmin also has a Technical Resource Centre and Head Office facilities in Toronto.As this paper deals with Indusmin's experience with dust abatement, and although dust control is a concern at the Nephton, St. Canut and Orillia plants, we will be confining this paper to the experience gained at the Badgeley Quarry and Midland plant of the Ontario Silica Operation."

Jan 1, 1980

By Bjarne Ekberg

"The most economical way of dewatering mineral concentrates is to reduce the moisture content in the material mechanically using thickeners and filtration avoiding thermal drying whenever possible. In addition to this, the dewatering process should produce low moisture cake, high quality liquid, consume little energy. As a part of the dewatering process The CERAMEC® capillary filter has been proven to meet these requirements in over 150 installations. The filtration is done by using ceramic filter plates with small pore size. The capillary action in the filter medium secures gas free filtration at good vacuum, and due to the small pore size, filtrate is crystal clean and particle free. The energy consumption is minimal. This paper will discuss results from filters installed at Pyhäsalmi Mine Oy in Finland where the technology was has been used since the late eighties. Results from more recent installations like Los Pelambres in Chile and LKAB in Sweden will also be discussed.INTRODUCTIONThe idea of using capillary action to make dewatering more efficient was invented two decades ago. Ten years later whole filter plants utilizing the new method were delivered to mine concentrators for dewatering of mineral concentrates. Further development of ceramic membrane plates made it possible to meet the requirements in iron ore dewatering. In addition to low cake moisture, high capacity and low energy consumption, there are a lot of environmental advantages in using capillary filtration. One of them is clear filtrate.CAPILLARY FILTRATIONA micro-porous filter material behaves like a large number of narrow capillaries forming a network. When a pressure difference ?P is applied over the wetted, hydrophilic pore with the radius r, the force striving to push the water out of the pore will be ?Ppr2. The force striving to hold the water in the pore will be the vector force 2pr? cosa of the surface tension ? and the cosine contact angle a. Equalling those forces and solving the equation for ?P we get"

Jan 1, 2003

By O. Mejia

"As study was undertaken to investigate the relationship between mill liner wear and grinding energy efficiency and to assess the opportunity to control mill speed to improve energy performance as mill liner wears. The study involved analysis of plant operating data and liner wear profiles over time. The operating work index was found to be an effective tool to identify the decrease of grinding efficiency along the liner service. The plant data show that the mill grinding efficiency as determined by monitoring the operating work index, and throughput decreases as liner wears. However, efficiency and throughput can be maintained by either changing the liner more frequently or by increasing the mill speed. Two scenarios for increasing mill throughput were analyzed. The first one involves changing the liner before the efficiency drops and the second one requires increasing the mill speed from 75% to 79%. Both scenarios show financial benefits that can be used in mill operations.INTRODUCTION The analysis of the mill power draw is used in this study as a key parameter for comparing mill liner profile and its effect on mill performance. Current technology and simulation software used in the mining industry do not factor in the impact of liner wear profiles in grinding efficiency and mill throughput (Toor, 2013). To address this gap, this study provides an analysis of key factors affecting mill throughput and grinding efficiency: mill speed, ball loading, and liner profiles. Several years of plant mill operating data, published research papers, and MillTraj® simulation results are used to demonstrate that face angles impact grinding efficiency and throughput and that mill speed can be used to overcome this problem. Moreover, the liner profile wear analyses clarify a mismatch between actual and estimated power draw calculations."

Jan 1, 2019

By D. Prince, G. Nollet

"Since 1994, Aur Ressources has operated Louvicourt mine, a zinc and copper mine close to Val d’Or, at a rate of 4300 t/d. Ever since the start-up of the plant, management has encouraged innovative approaches in reliability.The first of three papers will discuss the vibration monitoring program in place. The program will be described and two examples will be given: detection of a rolling bearing defect on a pinion driving the ball mill and identification of wear on the bearings of the flotation cells. Figures on the return on investment and the costs of a monitoring program will also be given.The second article will discuss the lubrication aspect. Since the establishment of a good monitoring and oil analyses, Louvicourt mine decreased its oil consumption by more than 38 000 L/yr. In addition, the company set up an oil regeneration system that restores the original properties of oil.The third article will cover the management aspect. Work organization as well as the management philosophy enabling the employees to push predictive technology to higher levels will be examined in detail. The key elements which made it possible for Louvicourt mine to position itself among world-class companies in the organization of maintenance will be discussed. IntroductionThis article is the second of three on predictive maintenance at the Louvicourt mine operated by Aur Resources Inc. The first article, published in the October 2002 issue, was about vibration analysis for rotating machines. This article describes how lubrication and oil analysis for stationary machines permitted Louvicourt to save more than $150,000 within two years and presents the evolution of the oil analysis program.Louvicourt mine, located near Val-d’Or, Quebec, is a copper and zinc mining and milling operation that processes 4300 t/d of ore and employs 289 people. Production began in 1994. Louvicourt mine is a partnership between Aur Ressources (30%), Teck Corp. (25%), and Novicourt (45%)."

Jan 1, 2003

By Shuan-cheng Gu

Roof bed separation often occurred due to the deformation incoordination of surrounding rock following the excavation of mine roadway. Bed separation has effect on the bolts, and the estimation of the influence will directly affect the safety of support systems. In this paper, the hyperbolic function model to analyze the load transfer mechanism on the bolts was simplified as the exponential function form for easy calculation. An elastic-plastic analysis model of the bolt loading occurred by the bed separation was established. And the development low that the bed separation affected to the bolt loading was discussed. According to the parameters analysis of different separation values and locations, the influence law of the bolt loading caused by roof bed separation was summarized. Finally, the effects of bed separation were considered for the bolting design, it was able to provide a reference to the anchorage design of stratified rock.

Aug 1, 2013

By Gorzalczynski. Stan

The recent trend in underground mine developments is ?big is better?. This is most certainly evident in the mine shaft and the conveyances that operate within its compartments. Today, there are several new installations requiring mine cages that can transport up to 170 passengers. The technology in mine hoisting is advancing to address a combination of higher capacity requirements, deeper hoisting depths and faster winding rates, however, some areas of the hoist plant have not changed for the past fifty years. The most notable of these areas is the shaft compartment guide string and the conveyance mounted safety arrest mechanism. The technology in use today for the protection of passengers in a shaft conveyance from a hoist rope severance incident, remains conceptually unchanged from Elisha Otis? design of 1850. The actual retardation components, the safety dogs, have taken on several forms since Elisha?s invention with the last major design change occurring in the late 1940?s. The arrest of a free falling shaft conveyance requires that the shaft guides withstand the energy imparted on them by the safety dogs. There are some very real limitations presented by the use of wood for this application. The new hoisting era will most certainly continue to demand larger capacity equipment but also, an increased awareness toward safety.

May 1, 2002

By A. E. Aho

"The Pacific Nickel property lies 7 miles northwest of Hope and 100 miles east of Vancouver, in the Coast Mountains of southwestern British Columbia. Nickel-copper sulphides were discovered in ultrabasic rocks on this property in 1923 and the deposits were explored by Pacific Nickel Mines until 1937, then again between 1951 and 1954 by Pacific Nickel Mines and by Newmont Mining Corporation through its subsidiary,Canadian Ore DepositsWestern Nickel. The property was studied by C. E. Cairnes (1) in 1924, by W. E. Cockfield and J. F. Walker (2) in 1933, by H. C. Horwood (3), (4) in 1936 and 1937, and by the writer in 1951 and 1952. Except for a few thousand tons for trial shipments, the property has never been mined. Indicated ore reserves now total somewhat over one million tons averaging about 1.4 per cent nickel and 0.5 per cent copper, with lesser values in precious metals and cobalt.GEOLOGIC SETTINGThe nickeliferous ultrabasic rocks form part of the core of a 15-milewide block of Late Palæozoic metamorphic rocks and Mesozoic intrusives which extend north-south between the coast batholith of British Columbia and the Chelan batholith of Washington. Margins of this block are faulted in part against less metamorphosed volcanic and sedimentary rocks largely of Jurassic and Lower Cretaceous age (Geo/. Surv., Canada, Map 737 A, 1942). Serpentinites, suggestive of deep transgressive structure, occur within the block, and also at its east margin along faults which are southern extensions of the regional Yalakom-Fraser River fault zone. Some of the other mineral deposits in the Hope area appear to be spatially related to these major faults.The mineralization at Pacific Nickel occurs almost exclusively within a stock-like mass of ultra basic rocks which mingle with, and partly cut, a larger batholithic mass of genetically related diorites and norites of late Mesozoic age (Figure 1 ). The ultra basic mass consists essentially of fresh, medium-grained hornblendic pyroxenite with peridotitic cores and with a remarkable margin of pegmatitic hornblendite. The most hornblendic rocks appear to be chiefly products of reaction and replacement of the pyroxene and olivine rocks. The mineralization consists of disseminated and massive pyrrhotite, with subordinate pentlandite and chalcopyrite, amongst fresh olivine, bronzite, and, Jess commonly, augite and hornblende. Both the ultrabasics and mineralization are cut by small hornblenditic and dioritic dykes, and by veins and alteration zones."

Jan 1, 1949

By H. Fuchs, W. Hilger, E. Prosser

"The Lone Gull discovery of Urangesellschaft Canada Limited was made in 1974 as a result of extensive exploration activities for unconformity related uranium deposits in the Baker Lake area of the Northwest Territories. The structurally controlled mineralization is hosted in Aphebian metasediments and intrusive granitic stocks located approximately 2 km south of the unconformity between the Lower Proterozoic Aphebian and the Middle Proterozoic The/on Formation.The original discovery was made with a helicopter mounted radiometric system during systematic prospection over the unconformity. Diamond drilling was first carried out in 1977 and continued, with an interruption in 1981, to the present. A total of 25,500 metres and 199 holes have been drilled and outlined three ore zones. Preliminary geological reserves are estimated at some 16 million kgs. U30 8 at an average grade of approximately 0.4%.IntroductionUrangesellschaft initially entered exploration in Canada as a participant in joint ventures in 1968, and was incorporated in Canada in 1974 as Urangesellschaft Canada Limited. Subsequently, UG was among the first companies to apply exploration criteria developed from the Athabasca Basin, namely the Middle Proterozoic unconformity over Archean/ Aphebian basement, for selection of exploration targets in the geologically similar Thelon Basin.The Baker Lake area in the Keewatin District of the Northwest Territories was selected from the extensive Thelon Basin because it had the best accessibility (Fig. 1). The hamlet of Baker Lake located close to the geographical centre of Canada, is largely an Inuit settlement with a population of approximately 1,100 inhabitants. The distance from Baker Lake to the Lone Gull property is about 80 km. Baker Lake is connected to the tidewater of Hudson's Bay via Chesterfield inlet and is serviced by scheduled domestic flights several times weekly from Churchill, Manitoba, about 650 km to the south."

Jan 1, 1986

By Galen Bauer

"Up until the mid 1960's, the only available methods for making continuous weight measurements were through the use of mechanical and electro-mechanical weigh scales. It was during this time period that a new concept in weighing was introduced. It was known and is still known as the nuclear belt weigh scale.During the early days of its appearance in the market place, many things were learned about its advantages and disadvantages for weighing various materials. As with many new devices, it had to go through a ""wringing out stage"" before it became accepted by the weighing industry. Even today, even though it is a proven device, there are skeptics who believe the nuclear belt weigh scale will not survive. Let me assure you, it is here to stay.. 'PRINCIPLE OF MEASUREMENTThe nuclear belt weigh scale consists of a ""C"" Frame assembly which houses the radioactive source (Cesiwn 137) and the radiation detector (Ionization chamber). The ""C"" Frame assembly is put in place around the conveyor belt as shown in Figure 1. The radiation source emits a fan shaped beam of radiation which covers the full width of the material being conveyed on the belt. Radiation which has passed through the material on the belt is detected by the ionization chamber which is located in the lower arm of the ""C"" Frame assembly. The ionization chamber changes the radiation energy into an electrical signal which is related to pounds per foot belt loading. This signal is transmitted to a highly stable amplifier which combines the pounds per foot signal with a belt travel signal from a digital tachometer which allowed the scale user to be able to monitor total mass being conveyed. Many so-called conventional type scales use belt speed rather than travel to obtain mass per unit time, and then integrate the signal to obtain their weight signal. This unnecessary step tends to erode the overall accuracy of the weighing system."

Jan 1, 1975

By A. Akerman, C. P. O’Connor, N. Vayenas

"Stereolithography is a well-known rapid prototyping technique in the manufacturing sector. Essentially, it is a three-dimensional printing process that produces plastic prototype parts from standard CAD files. At present, Canadian mining companies are not fully aware of the potential of rapid prototyping techniques (RPTs) for their production and mine design systems. Mining engineers and geologists attempt to visualize and understand the characteristics and layouts of orebodies on computer models, and in cases where it is decided to develop physical models, the process is time-consuming, based on simplified constructions. RPTs, such as stereolithography, can facilitate engineers and geologists to quickly, and with satisfactory accuracy, visualize sections of orebodies and evaluate alternative ore extraction techniques using 3D solid models.The research discussed in this paper is carried out by the Laurentian University Mining Automation Laboratory (LUMAL) in collaboration with Inco Limited and the Integrated Manufacturing Technologies Institute (IMTI) of the National Research Council of Canada. The main objective with this research is to evaluate the applicability of state-of-the-art RPTs to underground hard rock mining systems. RPTs can play a significant role in accelerating the design and development process of mining systems."

Jan 1, 2006

By D. A. Karvonen

In 1970, the Government of Saskatchewan instituted a program aimed at resolving the dilemma of excess productive capacity over the market demand which existed for potash produced in Saskatchewan. The two primary elements of the program were prorationing of potash production to market demand and a minimum selling price. The paper reviews the factors, both local and international in nature that led to the introduction of the program. The licensing mechanics and the operation of the program, along with the changes that have been introduced in two and one-half years of operation, are discussed. Attention is given to the results of the controls as they affect the industry and the province. Also discussed is the outlook for Saskatchewan potash in world markets.

Jan 1, 1973

By J. G. Kelly, C. P. Brown

"In June 1983 a new borehole hoisting system was commissioned at Sherritt Gordon's Fox Mine. Twelve hundred tons-per-day of ore from the 2600 and 2800 levels are being hoisted to the 2000 level through an 8-jt diameter bored winze. This new method replaces the diesel truck haulage system which had been in operation at the mine since 1975.A study was initiated in 1980to determine the most effective method of achieving the required production. The study examined several hoisting alternatives including: expanding the existing trucking system; converting to electrically -powered truck haulage; and deepening the skip compartments of the existing main shaft. The alternative selected as the hoisting method most suited to the requirements was borehole hoisting.Development of the new system commenced in April 1982. Underground excavations included 700 feet of 8-ft diameter borehole, a hoistroom and headframe, storage bins, and a grizzly and rockbreaker station. Equipment installations included: a 5-ft diameter double-drum Nordberg hoist; a counterweighted Kimberley-type skip; two rockbreakers; and the steel sets in the winze. These installations were completed in June 1983. Some problems were encountered after the initial commissioning but these were solved, and since August 1983, the system has proven that the designed capacity is achievable within expected costs."

Jan 1, 1985