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By Saravarim A.

"The aim in flotation systems is to control the grade and recovery of the product., numerical method or sampling and analysis is used to achieve this goal. Weakness of measuring instruments, lack of process knowledge, deficiencies in management and data processing in the control of flotation cells, has led the academic and industrial units to use numerical models. In this regard, using the results obtained from the experimental design carried out in the DTP line of Gol Gohar industrial and mining complex, a regression model was developed based on the analysis of variance. To present this model, after variance analysis of factors and interactions, all models were investigated and the final model was created based on 75% of the data. The model was tested with the remaining 25% of the data to confirm the goodness of the fit. The coefficient of determination for training and testing resulted 71% and 74%. Moreover, a feed forward back propagation neural network with different layers and neuron was used to model the results. The best network structure was 6-27-1 and the coefficient of determination for this network was 99% and 98% for training and test respectively. Given the complexity of neural network models and the relatively low accuracy of the regression model, neural network has a priority assuming we have access to a specialist. In addition, the results obtained from neural network can be used as expert systems to control and optimize the flotation cells.INTRODUCTIONThe primary objective of the flotation cell control is to maintain the product's (in this case tailing) recovery and grade, which represents the index for process efficiency and product quality. Continuous estimation of these indexes requires a significant amount of maintenance, and calibration of the continuous analyzers, in order to maintain an acceptable level of accuracy. Weakness of measurement equipment, lack of process knowledge and the general deficiency in management and processing of data in the flotation cell control, will lead industrial units to use smart methods such as mathematical models, regression and neural networks in near future (Panahi, Abdollahzadeh, & Sam, 2010). Artificial neural networks are inspired by the very complex structure of human brain in which millions of nerve cells solve problems or store information by communicating with each other. The duty of neural networks learning. It should be noted that learning in artificial neural networks is limited, and what is practically considered is the computing power of the network. A neural network consists of units called neurons, and has the capacity to handle a set of input data to produce a desired output data set. Each of these input and output data sets can be assumed as a vector (Soltanmohammadi & Noparast, 2006)."

Jan 1, 2016

By R. F. Favreau, R. A. Morin, G. W. Kuzyk, P. J. Babulic, N. J. Tienkamp

"Atomic Energy of Canada Limited is constructing an Underground Research Laboratory (URL) as part of a comprehensive program to evaluate the concept of nuclear fuel waste disposal deep in crystalline rock formations. Careful blasting methods have been used to minimize damage to the excavation surfaces. Good wall quality is desirable in any excavation. In excavations required for nuclear waste disposal, the objective will be to minimize blast-induced fractures which may complicate the sealing requirements necessary to control subsequent movement of groundwater around a sealed disposal vault. The construction of the URL has provided an opportunity for the development of controlled blasting methods, especially for drilling accuracy and optimization of explosive loads in the perimeter and cushion holes. The work has been assisted by the use of blast simulations with the mathematical model Blaspa.This paper reviews the results of a recent project to develop a controlled method of full-face blasting, and compares the observed field results with the results of a blast simulator called Blaspa. Good agreement is found between the two, and the Blaspa results indicate quantitatively how the blasting may induce damage in the final excavation surface. In particular, the rock in the final wall may be stressed more severely by the cushion holes than by the perimeter holes. Bootleg of the rock between the perimeter and cushion rows occurs when the burst out velocity imparted to it by the explosive loads in the perimeter holes is inadequate. In practice, these findings indicate that quantitative rock stress and rock burst-out velocity criteria can be established to minimize wall damage and bootleg. Thus, blast simulations become an efficient way to design controlled blasting and to optimize quality of the excavation surf ace."

Jan 1, 1989

By Scott L. Ewart, William M. Bryden, Donald E. Wakefield

"Osler, Hoskin & Harcourt develops commentaries from time to time on topics of legal interest. These may deal with new legislation, changes or developments in government policy or recent judicial decisions of importance to its clients. The commentaries are, of necessity, general in nature. Because the law which they deal with is often new and untested, it is hard to arrive at precise statements of the way in which the principle s discussed in a commentary might be applied in specific circumstances. When further guidance is needed , consult a solicitor.The purpose of the Bill is to simplify, modernize and standardize the regulation of mineral exploration and development in Ontario. Many of the changes proposed by the Bill are of an administrative nature and move much of the detail with respect to staking, assessment work, prospecting work, surveys, quarry permits and leases contained in the existing Mining Act to the Regulations contemplated under the Bill.The Bill will undergo revision and be re-introduced and therefore it is not the intention of this present article to detail the specific changes contemplated by the Bill; however , its more significant changes are as follows:1. Provision is made for a lifetime prospector's licence with the elimination of annual renewals;2. Perimeter staking of a block o f claims is permitted to reduce the cost of staking;3. Assessment work requirements are expressed in term s of dollars spent rather than days worked;4. Persons doing exploratory work are required to furnish notice to owners of surface rights of intention to perform assessment work;5. Annual work summaries will be available to the industry to lessen duplication in exploration work;6. The option of continuing assessment work rather than applying for a lease is provided;"

Jan 1, 1984

By Craig M. Sams

"Variable speed mill popularity has grown during the last 10 years with almost every SAG mill fitted with a variable speed drive. In addition, many of today’s larger ball mills are running a variable speed drive for various reasons. In the past, motor suppliers, especially gearless drive suppliers, have considered mills as being an overpriced rotor. This has lead to mills demanding more torque than what a motor can generate. This paper identifies the reasoning of what has happened and how to mitigate the mismatch in the future. Technical and economical issues are discussed, allowing mill operators to make an informed decision of which path to take in deciding what motor to put on a mill.INTRODUCTIONIt has been generally accepted in the past that motor suppliers and specialists in engineering companies understand the workings of a SAG mill or a ball mill and although there is a fair knowledge within the industry, in regards to mill torque requirements, the advent of variable speed drives in ball mills has shown the writer that a complete understanding of the mill torque requirements are not fully understood.This paper will discuss two aspects of mill torque requirements, (operating torque at various charge levels and start up torque), and how it relates to specifying the proper motor torque requirements.MILL OPERATING TORQUEMill operating torque at a given charge level and density in a mill is essentially constant throughout the entire speed range. For the purpose of this paper, we will take a 38’x 22.5’, 20’ EGL, SAG mill and provide the power draw at variable speeds but fixed loading conditions.The power draw and mill torque of this mill at 8% ball charge and 28% total loading (Highlighted) is shown below as Figure 1, at variable speeds."

Jan 1, 2007

By Robert B. Parsons

"The budget that was tabled by Finance Minister MacEachen on November 12, 1981 will result in a major tax reform of Canada's income and sales tax systems, the likes of which have not been witnessed by taxpayers since 1971. All segments of the economy will be affected one way or another by the far-reaching budget proposals; the mining industry did not escape untouched.Important changes will be introduced which will alter some of the fundamentals of structuring mineral resource ventures in Canada. This month, Tax Notes examines these changes, and also summarizes the other highlights of this key federal budget.IntroductionFinance Minister MacEachen's budget, with its lower personal tax rates, loophole plugging and tax shelter bashing, represents the biggest shakeup in our tax system since tax reform in 1971. In his budget, presented in the House of Commons on November 12, Mr. MacEachen proposed substantially lower tax rates for middle and upper income individuals, with the top federal and provincial tax rate dropping to about 50%, but in return he eliminated most of the opportunities for individuals, and corporations, to reduce or defer taxes through a wide variety of tax shelter and tax planning mechanisms.Although many of those budget proposals that dealt with the resource industries focused on the implementation of the September 1, 1981 agreement reached by the federal and Alberta governments concerning the National Energy Program (see Tax Notes in the December 1981 issue of the Bulletin), the budget also contained some proposed amendments that would have significant implications for investment in the mining industry.This month, Tax Notes examines these latter proposals, and also summarizes very briefly those budget proposals which are not unique to the resource sector."

Jan 1, 1982

By G. A. Kosick, M. Freberg, L. A. Kuehn

"Highly variable and higher than forecast lead miff feed grades were problems experienced at the Polaris Concentrator. Limited flotation capacity and poor operating flexibility prevented the plant operators from overcoming these difficulties, and resulted in grades and recoveries which were lower than necessary.Two column cells were integrated into the lead circuit in an effort to give the operators the tools they required to achieve the best grades and recoveries possible, regardless of the miff feed grade. Installation of the column cells increased lead concentrate grade from 76% to 79.3% Pb, and increased lead recovery from 9/% to 91.3% Pb.This paper reviews the design, development and operation of column flotation cells in the lead circuit at the Polaris Mine.IntroductionThe Polaris Concentrator was constructed in 1980 on a barge in Trois Rivieres, Quebec, and towed to its pre sent location on Little Cornwallis Island, Northwest Territories, about 1450 km from the North Pole. The plant presently treat s about 2800 mtpd of new feed with average feed grades of 3010 Pb, 13% Zn and 5% Fe. Current production averages 36 000 tonnes of lead concentrate and 220 000 tonnes of zinc concentrate annually.The barge design and min e location dictated that the concentrator .be compact with very little unused floor space. As a result, flexibility was limited in terms of expanding the plant.Mill feed grades were highly variable and above forecast and the lead flotation circuit was found to be under capacity. This caused continued overloads in the lead cleaning circuit, resulting in low concentrate grades and recoveries. It was evident that an increase in lead flotation capacity and flexibility was necessary. The existing floor space did not allow for the installation of additional conventional flotation cells, but one alternative was the installation of column cells."

Jan 1, 1988

By G. H. Blackwell, A. J. Sinclair

"The main components of a ""PC” -based mineral inventory system are described in a sequence common to many real reserve/ resource estimation projects and in the practical context of problems and decision-making typically encountered in such studies. Some components are designed particuarly to improve the geostatistical instructional capability of the package. An important part of this approach involves the use of widely available software for data manipulation and evaluation in the design of a mineral inventory study progressing to mine design and feasibility. A variety of more or- less fixed routines written in high level languages provide acceptable computational speeds on a personal computer. These critical segments are linked by simple, short, compiled Basic programs easily adjustable to various data configurations and needs. IntroductionGeostatistical mineral inventory estimation has progressed greatly since its slow dissemination during the 1960s. The mining industry generally has accepted the benefits of the technique, notably the quantification of grade and geology, an indication of error in grade estimation, and of the mined volume / grade variance relationship (Clark, 1979, Isaacs and Srivastava, 1989).Acceptance has been slowed, first by complexities of geostatistical theory and second by a bewildering variety of computer systems and applications programs. Continuing improvements in education will facilitate a better understanding of the underlying theory.The purpose of this paper is to describe, in a practical context, the development of a geostatistical-based approach to reserve/resource estimation. The approach integrates various existing commercial software packages with a wide selection of programs developed by the authors for personal computers which estimate mineral inventories and educate users in the techniques applied; that is, the QMIN system.It is hoped that the approach presented here will convince mining and geological engineers concerned with resource estimation, of the soundness of geostatistical methods and its broad potential to their problems."

Jan 1, 1992

By D. A. Nelson, Wedding. R. E.

"A planned production increase of 1.25 million tonnes per year at Domtar's salt mine in Goderich, Ontario required an increase in the underground mine ventilation system from 320,000 to 700,000 scfm, The design of the expanded facility included the addition of a 22-foot-diameter shaft to augment the existing production and service shafts.A preliminary review of the ventilation requirement s indicated that in order to pr ovide good economic design for the expanded system, a comprehensive ventilation survey of the existing system was required. The survey was completed in the latter part of 1980, and subsequent engineering design and equipment selection proceeded throughout 1981.This paper presents the methods used to carry out the survey. Particular attention is given to the numerous challenges presented in determining air flows in the large 45-ftwide by 43-ft-high airways. Emphasis is placed on practical field survey techniques.A mathematical model of the ventilation system using a computer program is described, and the application of this program to provide design data and assist in equipment selection is discussed. Economic sizing of airways and fan selection are analyzed considering horsepower and operating costs.IntroductionThe Goderich Mine of Sifto Salt Division, Domtar Inc., is located on the eastern shore of Lake Huron in the town of Goderich, Ontario, and has been operating since November 1959. The salt is extracted by a modified room-and-pillar method, and the workings advance at a rate of 1.5 miles per year by undercutting, drilling and blasting. The surface mine area consists of a 12-acre site in the Goderich harbour, at the mouth of the Maitland River, and the underground property consists of approximately 2,700 acres lying mainly under Lake Huron."

Jan 1, 1983

By C. J. Newman, K. Molnar, A. G. Storey, G. Macfarlane

"The Kidd Creek copper smelter started operation in June 1981 using the Mitsubishi Continuous Smelting Process. A steady increase in plant production rates has been demonstrated, and the annual tonnage of concentrate smelted is now double the original design rate. This paper summarizes recent modifications made to increase concentrate feed rates, increase on-line time, reduce copper losses and control the impurity level in anode copper. It includes improvements made to furnace design, improvements to reduce downtime f or boiler cleaning, and improvements made to the acid plant to allow handling of increased gas flowrates and higher gas strengths while maintaining low acid plant emission rates. IntroductionThe Kidd Creek Division of Fal conbridge Limited operates a base-metal mining and metallurgical complex, located in Timmins, Ontario, which includes an underground mine, a 13 500 tonne/day concentrator, a 130000 tonne/year zinc plant and a copper smelter and refinery, The copper smelter and refinery were commissioned in 1981, with an installed capacity of 59 000 tonnes/ year of cathode. The smelter, utilizing the continuous smelting technology of the Mitsubishi Process, has subsequently been expanded in production capacity, and in 1991 produced 113 500 tonnes of blister copper The capacity of the refinery, which uses Onahama No. 3 tankhouse technology, has been increased to 96 000 tonnes/year of cathode. The capacity increase at the smelter has been realized through the input of additional oxygen to both the smelting and converting furnaces, without increasing the process off-gas flowrate through the associated waste heat boilers.In this paper, a brief review of smelter operation and modifications in the period 1982 to 1987 is presented, together with a more detailed discussion of operation during 1988 to 1991, and a discussion of future planned improvements."

Jan 1, 1992

By Dennis L. Murr, James E. Wennen

"The through-put and energy efficiency of an autogenous (AG) grinding mill are adversely affected by variability in rock size and rock competency. This applies to both fully autogenous and semi-autogenous (SAG) grinding circuits. In this paper we focus on an approach to overcome the problem of inconsistent mill through-put related to variability in mill feed size and rock competency. The focus is on ores containing hard, competent rock. This approach consists of preparing feed to an autogenous mill that contains 20% coarse media rock and 80% of material crushed to pass 37 mm. Results of pilot-scale testing for two iron-ores will be presented to show that a 10% to 12% reduction in unit energy consumption is possible with prepared feed, compared with feeding the mill with conventional primary crusher discharge.INTRODUCTIONIn the past 30 years or so, autogenous grinding and semi-autogenous grinding have been the comminution technologies of choice for most mining and mineral processing operations. These technologies saved both capital and operating expenses associated with the installation and operation of multi-stage crushing and screening plants required for conventional rod mill – ball mill circuits. However, SAG and AG are inherently inefficient in terms of energy consumption, especially for very hard ores. In cases of hard ore, changing characteristics of rock fed to the mills causes wide fluctuations in mill capacity, which contributes to the inefficiency. Rising electric power costs make this the most expensive unit operation used in the extraction of valuable minerals from an ore. The objective of the concept discussed here is to reduce the energy consumption in AG grinding for hard ore and eliminate the use of large-diameter steel grinding balls that are required for SAG grinding"

Jan 1, 2012

By Tim Gartner

This paper introduces a new application of a proven technology to provide dynamic, voltage regulation in underground mine electrical distribution systems. This technology acts to ?stiffen? the electrical power feeding continuous miners and generally raise and improve the voltage regulation at the continuous mining machines which may be located over long cable distances from the mine incoming electrical substation. This is extremely valuable for large underground continuous mining operations that use high power electrical mining machines fed over very long cable lengths (measured in 10s of km, from mine shaft to mine operating face). This new technology provides fast acting dynamic voltage regulation (voltage support) while starting continuous borers and extensible conveyor belts. Additionally, if the mine suffers from a lower distribution voltage due to long cable lengths, this new technology will raise the overall voltage at the mining machine, which can increased mining machine production and lead to longer motor life. The technology is based on voltage source converters operating as static VAR compensators specially packaged for the harsh underground mine environment. While static VAR compensator technology has been successfully used in utility and large industrial applications for many years (including open pit mining and arc furnaces), it has not (until now) been applied in underground mining. The paper will present the problem of poor voltage regulation in underground mines on weak electrical utility networks. It will then discuss some of the alternatives that have been used to resolve this voltage problem. It will then introduce the new technology used to solve the problem and review the issues involved in using this technology in the harsh underground environment. Finally, the paper will present preliminary performance results from an actual installation in a large underground continuous mining operation in Canada.

May 1, 2003

By Todd Kennedy, Kurt Tischler

"This paper presents the field experience of Siemens with regard to Gearless Drives in the mining industry … We consider the elapsed production hours of Siemens Gearless Drives to be extensive enough to provide a reliable estimation of availability calculated on the basis of data representing repair time, downtime, and operating time. The users of Siemens Gearless Drives confirm an availability of more than 98% after exclusion of some major issues. The paper addresses all of these major issues of Siemens Gearless Drives, describes successfully applied corrective measures, explains the influences on the design of the drives, and lists the downtimes associated with each of these issues. INTRODUCTIONThe first Siemens Gearless Drive in mining began operation in 1980 and was installed on an iron ore grinding mill. As of September 2011, 40 Siemens Gearless Drives will have accumulated 136,000 machine days of operating time. According to pure rules of statistical analysis, this accumulated operating time may be too low to be used for a sample of field data to provide precise statistical values of availability, however we consider it large enough to provide indicative values of worthwhile consideration. This paper deduces the availability statistics of Siemens Gearless Drives in the mining industry from information received from end users and factors in all major issues that Siemens has experienced with our Gearless Mill drives. This paper does not consider Gearless Drives in other industries such as the cement industry. The cement plants, especially in the northern hemisphere, interrupt production for several months in the winter. This lengthy downtime is used to maintain the complete plant including the mills, their motors and their drives. The mining industry has more stringent and higher production requirements. In the mining industry, production must run 24 hours per day, 365 days a year."

Jan 1, 2012

Introduction A Hypothetical Scenario: Suppose that your company's research department has developed a new device which represents a significant innovation. You would like to begin selling it as soon as possible. The new device has not been publicly disclosed. You're not sure about what type of intellectual property protection you should be seeking, or when you should be seeking it. As discussed below, assuming that the costs are worth it, a patent application probably should be filed before any public disclosure is made. In general, if you do not file a patent application prior to a public disclosure, you will lose rights. Major Types of Intellectual Property In this paper, intellectual property protection is broadly discussed. Practical steps which can be taken to minimize the possibility of losing intellectual property rights (and maximizing the possibility of benefiting from your company's intellectual property) are outlined at the end of this paper. The issues discussed in this paper are somewhat complex, because a number of outcomes are possible, depending on the facts. It is strongly recommended that you seek legal advice in your jurisdiction in connection with any particular circumstances relating to intellectual property rights. "Intellectual property" refers to a number of different types of rights. The major types of intellectual property are: (i) patents; (ii) trademarks; and (iii) copyright. Trade secrets are also usually considered to be a type of intellectual property, and they are also discussed in this paper because of their importance. In general, each of these types of intellectual property protects different subject matter, although there can be some overlap. Intellectual property rights are generally territorial in nature. The scope of protection of a type of intellectual property in a country (e.g., patent protection) depends on whether the specific national requirements for protection have been met.

Feb 1, 2008

By M. Lahtinen, B. Saxén, M. Latva-Kokko

The conventional jarosite precipitation process with neutralization by zinc calcine is widely utilized in the zinc industry. However, it has a significant drawback of causing losses of valuable metals like zinc, lead and silver to the jarosite. This comes mainly from the content of these metals in the calcine used for neutralization. As the zinc plants today want to maximize metal recoveries and minimize the amount of residues, this matter has become more and more relevant for zinc producers. Outotec developed and patented in early 2000 an improved version of the jarosite precipitation process in which the need for neutralization can be minimized, thus the metal losses to the jarosite also can be minimized. At the same time, the iron content of the jarosite increases and the amount of produced jarosite is smaller. The main feature of this process is to start the precipitation from ferrous iron after having reduced all the iron by zinc concentrate in a separate step before jarosite precipitation. Iron is then oxidised back to the ferric form simultaneously with jarosite precipitation. By this method, the formation of sulphuric acid is only half that compared to the conventional method and the need for calcine for neutralization can be avoided. High mixing and oxygen dispersion capability are needed in this jarosite precipitation process. Such capabilities are found in the Outotec OKTOP® reactor series. High performance reactors are not only needed to generate high quality precipitates, but also to maximize oxygen utilization; i.e., to minimize operation costs. Outotec’s latest development in this area is the OKTOP® plant product in which not only the reactors, but also all the accessories are designed, manufactured and delivered by Outotec. One responsible supplier ensures efficient and fast delivery and can provide mechanical and performance guarantees for the entire plant unit.

Jan 1, 2016

By G. W. Zhang, Changsha Research Institute of Mining and Metallurgy, X. Xiao, Y. Long, L. L. Huang

"The paper presents a scale-up and design method of vertical screw stirred mill, in which the closed circuit of mill and hydrocyclone was assumed as one factor, theoretically regardless the affects inside system of the mill and hydrocylone. The specific energy is chosen as a scale-up criterion, based on the premise that when fed the same feed material, mills of different sizes delivering the same specific energy will yield products.Batch grinding tests are conducted to determine the specific energy, and combined with industrial production data, scale-up and design of vertical screw stirred mill for industrial production are accomplished. Having developed this method for the vertical screw stirred mill used in regrinding duty of iron ore in Ma Steel, it has now been successfully applied in other installations.INTRODUCTIONThe Towermill was developed in Japan in the 1950s, by the Tower Mill Kubota Corporation, it was fine and ultra-fine grinding mill of the metallic ores and concentrates. Due to the rapid development of metal mining and useful minerals disseminated fine, fine grinding and ultrafine grinding equipment has also been more wide used in minerals processing industry. Typical fine and ultra-fine grinding mil are the Vertimill and Stirred Media Detritor (SMD) Mill of Metso, Eirich Towemill, Outotec HIGmill, FLSmidth VXPmill, Xstrata Isamill and the vertical screw stirred mill (JM) of CRIMM, etc.JM series of vertical screw stirred mill were invented by Changsha Research Institute of Mining and Metallurgy in the 1980s. Energy saving and consumption reducing have been achieved through the optimization and engineering practice. More than 500 units JM series of vertical screw stirred mill are used in the iron ore, copper ore, copper-molybdenum ore, molybdenum ore, Pb-Zn ore and Au ore."

Jan 1, 2016

By R. D. Brown

"Concerns over possible additional involvement of governments in Canada's mining industry and its adverse effects on the industry 's growth were a frequent topic of conversation at the recent Annual General Meeting of the CIM.Still painfully fresh in the minds of industry leaders are the disastrous results of the federal/provincial scramble over resource revenues which followed the relatively high metal prices witnessed in 1973/1974. At current metal prices, it is not surprising, then, that a nagging fear persists that these governments may once again restructure tax and other rules to the detriment of the industry and the country.This month, Tax Notes recalls some of the progress which the industry and governments have made in 1979 in the taxation of the resource sector, and urges that higher metal prices be viewed in light of the costly exploration, development and production efforts which will be required for the industry to continue to play its important role in our economy.IntroductionAt the Annual General Meeting of The Canadian Institute of Mining and Metallurgy, held in April, 1980, it was abundantly clear that there is widespread concern in Canada's mining industry that this country's tax regime may once again be blasted by ill winds of change.A stable and more favourable tax climate, as well as higher metal prices and profits, made 1979 almost a golden year for Canadian mining. However, from the tax viewpoint at least, there are some spots on the silver lining as apprehensions grow that the well-heralded battle between federal and provincial governments over oil and gas may spread to the mining sector, with serious damage to the industry and its newfound federal-provincial cooperation."

Jan 1, 1980

By W. A. Plachner, Schiller E. A., S. P. Santiago

"The Monkman Coal Property is located in the Northeast Coal Block of British Columbia. It is divided into the Duke Mountain Block on the north east and the Dip Slope on the west. Together, these areas cover 39,503 ha of coal licences.The property is underlain by Jurassic and Lower Cretaceous marine and continental sedimentary rocks. Economic coal measures are contained within the Gates Formation. Exploration of the property began in the early I970s, with drilling commencing in 1975. To date, 255 holes have been drilled and nine adits have been driven to recover unoxidized coal samples.The property has a geological resource potential of 2.8 billion tonnes of medium and high-volatile bituminous coal. Medium-volatile bituminous reserves, totalling 68.9 million ROM tonnes at an over-all strip ratio of 6.3:1, have been identified in three pit areas in the Duke Mountain Block.Construction start-up will commence when sales contracts are arranged. The clean coal will be exported via the Ridley Island Terminal at Prince Rupert.IntroductionThe Monkman Coal Property is located in the Northeast Coal Block of British Columbia in the southern port ion of the Peace River Coalfield. The coal field encompasses a strike length of 250 km of Lower Cretaceous coal-bearing strata in which 13 companies have identified several billion tonnes of resources and several hundred million tonnes of reserves. Currently, two companies with contracts are in the construction phase, and are scheduled to produce coal by early 1984. Quintette Coal Ltd. has a contract with Japanese steel mills to supply annually 5.0 million tonnes of metallurgical and 1.5 million tonnes of thermal coal. Teck Corporation (Bullmoose property) has a contract to supply 1.7 million tonnes of metallurgical coal annually."

Jan 1, 1983

By Michel David

"The usual complaint of mines is that grade does not match exploration expectations. Quite often, more tons are mined than expected but at a lower grade. This can be seen as dilution. Geostatistics can help predict which dilution can be expected both in terms of grade and tonnage for different mining methods.The usual vocabulary of geostatistics speaks of block distribution; block variance, size effect, information effect, all terms which say very little to the practitioner. In f act, all this can be rephrased in terms of dilution .In this paper, the following is presented - an example which shows how reserves change with the size of selection units and number of samples taken, and tables which show the dilution that are bound to happen when dealing with the commonly encountered log-normal distribution. Finally, the paper shows how grade tonnage computations should be made in the case of an arbitrary distribution. IntroductionGeostatistics progresses more and more rapidly if one judge s by the number and quality of papers published in Mathematical Geology or at APCOM meetings. More and more case studies describing successful applications are published (David et al., 1986)(Kwa and Mousset-Jones, 1987). It is estimated that more than 270/0 of the gold mines around the world use geostatistics. There is still, however, a lot of resistance from the remaining 73%. Geostatistics has more formulae and equations than it needs to reach year 2000. We will be well into the third millenium before all the models available now are actually used. The progress may come in the form of finding better ways to present known statistical results and getting away from the jargon of geostatisticians. One example may be in trying to explain how we can answer the most common plea of the mining industry: production grade is not what was expected in the feasibility study."

Jan 1, 1988

By C. V. Sibbald

"This paper provides a description of the Highmont copper-molybdenum concentrator from primary crushing through grinding, flotation, tailings disposal and water reclamation. The unique features of the operation will be emphasized.IntroductionThe Highmont property is located in the southern portion of the Highland Valley adjacent to and east of Lornex and about 4 miles south of Bethlehem Copper. The plantsite is at an elevation of 5100 ft.Highmont acquired the property in 1966 and in 1969 Teck Corporation entered into an exploration agreement which contained the option to finance the property to production . A detailed feasibility study of the project was completed in 1971. A positive production decision was deferred at that time because of the prevailing soft copper market and relatively low molybdenum price. The development of a strong molybdenum market in late 1978 and early 1979 led to a re-examination of project economics, and a decision to proceed to production was made in April 1979.The Highmont ore zones occur adjacent to and on either side of an east-west-trending quartz porphyry dyke. The two major zones , the east and west pits, contain 122 million tons of ore assaying 0.27070 Cu and 0.029% Mo. Chalcopyrite, bornite and molybdenite are the minerals of economic interest. Chalcopyrite is the predominant copper mineral. Mineralization occurs primarily along fractures and is zoned according to fracture density. Some pyrite is present, but for the most part it is outside the ore zone. Surface oxidation is shallow throughout the orebody.Wright Engineers Limited were responsible for the major part of the engineering design. Site construction, which began in the spring of 1979, is under the direction of Commonwealth Construction. The first concentrator line is scheduled for completion late in 1980, the other for early in 1981."

Jan 1, 1981

By Keith Jones, Largo Albert

"Decelerometer testing of a rigid guide system in a mine shaft pro vides usefuI information to operating and maintenance people. High acceleration/deceleration rates can lead to high maintenance costs to bath conveyances and shaft and can also present an operating risk . Possible disastrous results in the shaft have been avoided by restricting the maximum conveyance speed until the shaft and/ or conveyance problems have been solved.The test instrument is a valuable aid especially during commissioning or updating of a hoisting installation. High acceleration/deceleration rates also lead to reduced hoist rope life. During the past fourteen years, a total of 15,000,000 feet of testing was performed in 74 assorted shaft compartments.Based on this experience, it is possible to establish acceptable conveyance maximum speeds provided that all other conditions in the shaft compartment are normal. The body of the paper will present examples of several tests made under actual operating conditions.IntroductionMore and more mine operators are recognizing the real value in the use of the decelerometer for determining the state of shaft guide alignment in their shaft compartments , not only during the initial mine start-up periods, but also on a regular basis while the mine is in production.Decelerometer testing, is a technique in which an accelerometer , commonly known as a decelerometer, is used for measuring conveyance acceleration/deceleration in a lateral plane. lts purpose is to determine the severity of shock loads produced by misaligned shaft guides. Testing is performed by mounting the instrument on the conveyance and operating the conveyance (empty and loaded) at various speeds up to and including full speed . However, full speed may not be attained due to conditions indicated by the tests. These conditions may present an operating risk to the plant."

Jan 1, 1984