Search Documents

By Iwueze Anaekperechi Rose

The International Labor Organization has declared mandatory adequate provision of safe workplace and safety for all workers in all occupations including the mining sector. Early scientists like Agricola (1559) who studied the health of Miners, found that there are peculiar health problems associated to their work and working environment. This unsafe working condition was one of the major factors that resulted to the Industrial revolution in England and eventually led to the establishment of regulations and laws guiding operations in all workplaces and workers in England and all over the world. Recent studies by Heinrich suggested chains of events of safety issues in the mining sector. Occupational injuries, accidents and ill health have huge social and economic implications on workers, their families and communities. Top mining top issues are respiratory diseases, noise, explosives, ventilation, fire, and explosion. However, one of the principal mechanisms for achieving Occupational Health and Safety (OHS) goals and mapping the future is government regulations of employers. In Nigeria, the situation is not different; mining operations are equally hazardous and have far reaching implications. In 1995 the Ministry for Solid Minerals was established to focus on the development of other categories of mineral products ranging from gold, coal, uranium, and tantalum deposited across the country. Prior to this an Act of Parliament Act Cap 121 of 1946, was in place to regulate amongst other contents mining safety. This was subsequently reviewed following the incidence of Lead poisoning resulting from small scale miners processing gold ore highly contaminated with lead in Zamfara state (northern Nigeria). Hundreds of children died as a result of exposure to lead poisoning, it was clear that the regulations were not sufficient (details to be discussed). However, advances have been achieved in mining engineering since then. A review team was constituted to provide a more stringent law to regulate mining operations in Nigeria. The strategies for mapping the future of OHS in mining engineering will employ amongst others setting and adopting ISO/ILO standards and enforcement; providing technical assistance; and establishing sustainable developmental structures as surveillance and compensation. The management systems approach was also developed as a result of cases of accidents. The accepted international standards guidelines and requirements will be proposed. Furthermore in mapping the future for Mining Engineering, it is suggested that most countries have their own management strategies and legislation to improve safety of workers through greater consistency and efficiency of OHS programs. Some American researchers came up with the Safety Engineering Model. The Australian Mining Council of mineral and petroleum resources after the Catastrophic Maura Disaster developed the National Mine and Safety Framework. In Canada, after the Hillcrest mine disaster in 1914, Allan shaft coal mine catastrophe in 1918, Westray mine explosion in 1992 and other disasters, Occupational Health and Safety Act R.R.O 1990 was sufficiently developed to provide adequate safety conditions and standards. In Nigeria after the disastrous Zamfara lead poisoning, which claimed the lives of hundreds of children due to exposure and lack of appropriate safety measures, stringent measures were developed by the federal ministry of Justice to address and regulate mining process in Nigeria.

Aug 1, 2013

By G. Brooks, M. Hamed, S. Nightingale, K. Coley

The Marangoni effect plays a significant role in slag line corrosion of refractories. Previous experimental studies for various refractory /slag systems and mathematical models are reviewed and show that Marangoni flow is important in slag line corrosion under static conditions. Recent work by the authors is presented which also shows significant slag-line corrosion of MgO refractory in SiO2-CaO-FeOx-MgO slag. The rate of attack of the MgO was marginally slower in the case of slags containing alumina. A semi-empirical model developed by Hrma based on mass transfer control described reasonably well the observed progression of corrosion with time. Further work is proposed to evaluate this model.

Jan 1, 2004

By Subrata Dutta

Sindesar Khurd Mine is situated in Rajasthan, India, and operated by Hindustan Zinc Ltd, under Vedanta Group. The base metal mine is high in reserves of Lead, Zinc and silver and has been producing since 2007 with initial production of 0.3 mtpa. Recently the mine has gained prominence as a base metal underground mine in introduction of latest mining techniques and achieving high production at lowest costs. The promising Lead-Zinc reserves of Sindesar Khurd Mine (SKM) and high-tech exploration adopted by Hindustan Zinc Ltd (HZL), (Vedanta Group), raising the reserves and resources from a meager 9 Mt (1997) to 81 Mt (2012), has prompted HZL management to ramp up the mine production from 0.3 mtpa (2006-07) to 2 mtpa by 2013-14 with ambitious plans to reach 3.5mtpa subsequently (presently largest underground metal mine in India). The complete trackless system underground mine, recently equipped with latest leaky feeder communication system (unique in India), utilize modern drilling, mucking and hauling equipment aided with various utility/service vehicles. Excavation optimization and quality recovery maximization from the open and post filled stoping methods, continual expert analysis and feedback from International consultants like AMC (Australia) and SRK (UK), and involvement of renowned bodies in management excellence, have lead the mine towards highest productivity and lowest mine operating cost, earning the mine a prominent place in the global base metal industry. The paper deals with how the various challenges in mine planning and designing, mine development, operator skill, equipment introduction and maintenance, expertise availability, provide training and exposure to officials, prompt and effective communication/service, control of ground vibrations, maintain ventilation standards etc are faced in attaining high operational excellence and thus attain a record mine output/man shift (OMS) of 14 ton/man shift with targets to reach 20 ton/man /shift. Scientific designing using 2D/3D numerical mine-modeling techniques, faster stope sequencing with introduction of paste filling ( first time in India),latest leaky feeder communication system, control ground vibration to stringent standards using electronic delay system, faster raising techniques using raise borers to enhance development and ventilation, cavity scanners to monitor large stope voids, fast shaft sinking at 100 m/month(Chinese expertise) and maintaining adequate ventilation with close software monitoring are some of the highlights discussed in the paper towards achieving the targets.

Aug 1, 2013

By L. P. Connolly, M. J. Fraser

"Hydraulic transport of solids has long been an important technique in mining and beneficiation. More recently, slurry pipelines have proved to be economic for longdistance overland transport of many commoditieis, including iron ore concentrates and coal. Now, the Marconaflo system brings the many advantages of hydraulic transport to bulk storage, loading, transportation and unloading of ships and other carrying equipment, thus providing important new means for delivering mineral commodities to market. In this paper, the authors describe the Marconaflo system and the potential economies which can be realized when applying it for loading, transporting, storing, reclaiming and blending a variety of mineral commodities, using several commercial installations as examples."

Jan 1, 1972

By Derek V. Ellis, Jack L. Littlepage

"Marine ecosystem effects ar1smg from the discharge of man-generated wastes to the sea can be schematized as: acute poisoning, chronic poisoning, enrichment, suffocation, temperature effects, salinity effects, toxin bio-concentration, changed production rates and changed species equilibria. A professionally designed site-specific monitoring program to check for such effects can not only safeguard the marine ecosystem from degradation, but it can also protect the industry involved from unanticipated remedial action after expensive construction has been undertaken. Monitoring programs should consist of three steps. Step 1 is an ecosystem survey which should be undertaken prior to final design of the discharge system and submission of applications for permission to discharge, because there can be considerable cost savings in obtaining information at an early stage in development. Step 2 involves location of the effluent field at the time of starting discharge, and analysing its dispersal behaviour. Step 3 consists of ecosystem monitoring with sampling stations and specific tests based on the accumulated prior information."

Jan 1, 1972

By A. Roy MacLean

"In the Maritimes, there are twelve coal areas. From east to west, these include the Sydney coal field, the St. Rose - Chimney Corner, Inverness, Mabou, Port Hood, Pictou, Colchester - Debert, Springhill, Joggins - Chignecto, Beersville, Lake Stream, and Minto. The first eight are in Nova Scotia while the remaining four are in New Brunswick.In all these areas, the coal was formed during the Carboniferous period, which existed some 300 million years ago. However, within this period not all coal formation took place during the same time. There were three main intervals, which occurred at the time that the Riversdale, Cumberland and Pictou groups were laid down (Hacquebard, 1970). The oldest coals are those of the Riversdale Group. These coals were of rather limited extent, and only a few mineable seams are present, particularly at St. Rose -Chimney Corner and Port Hood. From these two areas only 2 M tons have been extracted, and 'measured' resources of 7 and 9 M tons respectively remain. The Cumberland Group coals are confined to Cumberland County and include the coals of Springhill and Joggins River Herbert -Chignecto. Some 43 M tons have been removed and only 7 M tons of 'measured' coal remain, with an addit10nal 39 M tons of 'inferred' resources. However, there are additional resources at Springhill, which will be discussed in more detail in a later section. The coals of the Pictou Group are the youngest and the most abundant, both in actual number of seams and in regional distnbution. These coals were formed during the Westphalian C and D, a time during which the main coal deposition in Europe also took place. Here belong the coals of the Sydney, Inverness, Mabou, Pictou, Debert, Beersville, Lake Stream and Minto fields. Their total production amounted to 469 M tons or 91 % of the Maritime total of 514 M tons. The remaining resources of all Pictou Group coals have been calculated at 254 M tons of 'measured' coal and 949 M tons of 'inferred' coal. As can readily be seen, the bulk of both past production and remaining resources occur in the Sydney coal field. The Sydney figures represent 73% of total production, and 87% of total 'demonstrated' resources in the Maritime Provinces. Next to Sydney, the Pictou coal field has been the greatest producer, with 59 M tons; it also has the second largest 'measured' resources, amounting to 25 M tons. However in terms of 'inferred' coal resources, the Mabou coal field, ~ith 140 M tons, ranks second to Sydney."

Jan 1, 1985

By G. D. West, J. D. Purdue

"Marked Ball Wear Testing (MBWT) employs identified grinding balls which are placed in an operating mill for a period of time, retrieved from the mill, and then measured to determine the amount of wear experienced. This is an excellent method to evaluate the relative differences in the wear rates of various grinding ball materials and/ or manufacturing process variables simultaneously and under actual production milling conditions. This paper outlines the methods of ball identification, testing and evaluation procedures and discusses the strengths, weaknesses, and proper application of marked Ball Wear Test results. INTRODUCTIONThe consumption of grinding media in the mineral processing industry represents a substantial cost to the comminution process. Grinding media is most often found to be the second highest consumable cost next to energy. To determine the selection of the most cost effective media, one must determine the specific wear mechanisms present in a given grinding application and decide which media system addresses these mechanisms most economically.A MBWT has definite advantages over other methods used to evaluate the relative consumption rates of grinding media. It allows the comparative testing of a large number of different ball types under identical operating conditions in a very short period of time. In addition, production wear rates can be accurately predicted directly from MBWT results. Typical MBWT test periods are in the order of 350 to 700 operating hours for high wear rate application and upwards of 2000 or 3000 hours for low wear rate applications. These times are much less than the 5000 or more hours required to purge a mill of the incumbent ball charge (to convert it to the test ball) and then provide even a minimal test period in which to conduct a full production test, for just one type of ball. Under production test conditions the evaluation of competitive product or the development of improved grinding balls is necessarily slow."

Jan 1, 1991

By L. Flett, S. Woods, C. Deredin

"Following a significant reduction in world Imperial Smelting Furnace (ISF) capacity from 2003 to 2008, a major optimization initiative was successfully carried out on the lead upgrading and bulk (zinclead) flotation circuits in the Brunswick Concentrator.This paper describes the process improvements that have taken place in order to reduce the quantity of bulk concentrate:•,Increase in lead upgrading rougher flotation circuit capacity•,Installation of a closed-circuit bulk regrind utilizing MillPebs and 150 mm Cavex hydrocyclones•,Installation of two additional cleaner flotation stages on the bulk circuit•,Optimization of the manipulated variables in the lead upgrading and bulk circuitsINTRODUCTIONThe Brunswick Mine (Xstrata Zinc Canada) is located near Bathurst, New Brunswick and is one of the world’s largest lead/zinc mines. Milling of ore commenced in 1964 from the No. 12 orebody, with an expansion in 1966 to accommodate ore from the No. 6 open pit mine. The planned closure of the mine will take place at the end of the first quarter in 2013. The ore is a complex massive sulphide, consisting of approximately 20% valuable minerals, 60% pyrite and 20% silicates.A simplified flowsheet for the concentrator is given in Figure 1. The overall flowsheet involves SAG milling, secondary ball milling, selective flotation, and dewatering by thickening, filtering and drying. The complexity of the flowsheet evolves from the requirements for fine grinding and the production of four concentrates: zinc (sphalerite), lead (galena), copper (chalcopyrite) and bulk (sphalerite plus galena).Primary hydrocyclone overflow feeds the copper-lead aerator-roughers for flotation at pH 9.0 with soda ash. Plant xanthate (80-20 sodium isopropyl and potassium amyl) and AP407 are used as collectors in the copper-lead circuit. The rougher concentrate is directed to the copper-lead regrind circuit and the tailings are fed to the secondary grinding circuit. The secondary hydrocyclone overflow from the secondary grinding circuit feeds the copper-lead rougher-scavenger banks. Rougher concentrates are reground to a P80 of 28 µm prior to three stages of copper-lead cleaning. The first stage of cleaning is done in an open circuit with the tail reporting to the cleaner scavenger. The cleaner scavenger concentrate reports to the regrind circuit and the cleaner scavenger tail combines with the rougher/scavenger tail to feed the zinc circuit. The second and third stages of cleaning are performed in closed circuit with the cleaner tail being recycled to the copper-lead regrind circuit. The average final concentrate grades 23% Pb, 3% Cu and 704 g/t Ag, and is fed to the copper separation circuit."

Jan 1, 2013

By G. Couture

In the introduction to this presentation, we will cover the market of motorized recreational products. We will introduce the public to what is produced and sold worldwide, what is the nature and general behaviour of the customers for such products. We will cover the evolution of this market and put in evidence how drastic must be the changes in the manufacturers organizations in order to, in one hand, constantly adjust to the customer demand, and in the other hand, react to the competitors' offensives on the market.

Jan 1, 2006

By J. M. Toye

The Canadian nuclear fuel business relates primarily to supplying fuel for Candu reactors. The product development, manufacturing and marketing activities of our nuclear fuel industry will therefore be determined by the rate of growth of the Candu nuclear reactor business. The nature of this relationship between the Canadian nuclear fuel industry and the Canadian Heavy Water Reactor program will be considered, with particular reference to the factors influencing future economic growth.

Jan 1, 1969

By J. S. Vanderploeg

I WILL begin this presentation by citing the annual per capita use of copper in Canada. This is best calculated by taking refinery domestic sales, plus imports of the products of foreign fabricating mills (very little refinery copper is imported), and deducting the exports of Canadian mills. No attempt has been made to estimate the copper content of imports or exports of machinery, motors, etc., but the trade balance here is probably against Canada. In any event, we find that, though varying somewhat since the war, the estimated yearly per capita figure has reached a high of 18 pounds. This is practically on a par with the United States. The rest of the world uses an average of about 2 pounds per capita, yearly, though this includes some countries, such as Sweden, Germany and England, which consume much better than average quantities. It looks, therefore, as if the Canadian copper industry has not (as has been generally charged) been asleep after all.

Jan 1, 1962

By E. M. Yates, H. M. Hamilton

"For the assent of any new mining project it is essential to determine a realistic value of revenue from the sale of concentrates.A description of the market factors influencing the concentrate terms will be presented along with a detailed review of historical terms of a smelter contract for zinc concentrates. OverviewFor the assessment of any new mining project it is essential todetermine a realistic value of revenue from the sale of concentrates.This applies at all stages of assessment through to the final feasibilitystudy. In forecasting revenue for a zinc mine the followingfactors must be considered:(a) mill recovery and zinc concentrate grade;(b) metal price forecast for all payable metals;(c) smelter terms; and(d) other selling costs.Normally, data from test work are used to determine mill recovery and concentrate grade.Market forecasting, and indeed all economic prediction is an inexact science and probably will always remain so. We have our econometric models our input/output models and a lot of other tools. But they are of no help in predicting the unpredictable. OPEC's huge increase in the price of oil was certainly the most dramatic example of this. It had a tremendous effect on the cost of producing most products world wide and on the price of these products. Any forecasts made prior to the OPEC action were obviously proven wrong."

Jan 1, 1994

By Jacque Trottier, Marcel Vallée, Gratien Gélinas

"Mineral exploration in Canada traditionally has gone from boom to bust in cyclical pat-terns following market and discovery cycles, but other endemic factors related to exploration financing and performance have contributed to the amplitude and recurrence of these fluctuations. In view of these problems, junior exploration is reviewed here in a marketing perspective, looking at the 4 Ps: Product, Price, Placement and Promotion.In the 1980s, MEDA incentives gave the shares of junior and mining companies significant price and promotion advantages, and contributed to excessive exploration funding. Many were thus led to minimize the basic values needed for continued investor interest: appropriate levels of product quality, sustained share value and customer satisfaction. Basic changes are needed to improve the marketing of junior mineral exploration in the future, with or without improved fiscal incentives. To be successful, the required improvements must come from the technical participants, but the financial partners also need to be involved.Exploration in Canada must be marketed with vigour, both in Canada and internationally. Exploration, mine development and mine production are essential to our economy. They are environmentally acceptable and they are welcome in Quebec and in most Canadian provinces and territories. Canadian exploration and mining are entrepreneurial industries that must take better advantage of their strengths and achievements and remove the shortcomings that hinder them: nobody can do it for them!"

Jan 1, 1996

By George A. Guess

The making of contracts for the purchase of ores is a business which the metallurgist usually understands better than the miner. Companies in the custom ore business often employ an ore buyer who is aware of the class of ore which the smelter needs, and is thoroughly conversant with the business. The miner on the other hand makes ore contracts but seldom, and it is often only after a settlement has been made that he realizes the meaning of the terms of the contract under which he has sold his ores. He has expectations usually greatly in excess of the amount 'net proceeds' shown at the bottom of the settlement sheet. Seldom does the occasional shipper really know his contract. A somewhat similar parallel is to be found in insurance policies. We all have insurance policies; we never know the conditions contained in them until after the fire. The clauses in the policy are for the protection of the Insurance Company. An Insurance Company has no friends.

Jan 1, 1926

By H. T. Fargey

This paper considers the social, economic and political factors and their influence on future production and marketing of Western Canadian minerals. Among the subjects discussed are inflation, taxation, anti-combines legislation, unstable international currency relationships, economic nationalism and protectionism, the European Common Market and environmentalism.

Jan 1, 1973

By H. Stutchbury

Alberta is labouring, and has laboured, under serious difficulties in the marketing of ?her coals, due to a number of conditions which now obtain, but all of which appear capable of solution, and their elimination would insure a very largely increased market for the vast coal resources of that province. It is perhaps necessary to again mention the fact that 15 per cent of the world's coal resources are to be found in Alberta; 21 per cent of that of North America; 72 per cent of that of the British Empire, and 87 per cent of that of all Canada. While we talk largely of the great wealth of Canada, the immensity of her vast natural resources, it is axiomatic that the mere presence of any natural product in a country does not in itself constitute wealth for that country, unless these raw materials can find a market, either in their raw state, or by the process of manufacture. There are many factors, however, which enter into the marketing of any commodity. The chief of these, in my opinion, is price competition. High costs of production materially reduce the radius in which any product can be marketed, and this applies particularly to coal. Mining costs in the province of Alberta are necessarily high at the present time, due in a large measure to the ease with which the 'gopher hole' mine can be opened with small capital.

Jan 1, 1925

By DON E. MacDONALD

Marl in Alberta is confined to highly specific geological, hydrogeologica/ and climatic settings. Tufa is fa irly abundant in those areas of western Alberta where bedrock is of the Paskapoo Formation. Marl and tufa originate when the following conditions are met: presence of a carbonate source in drift or nearsurface bedrock; leaching of the carbonate by percolating groundwater; transportation of calcium and bicarbonate ions in a permeable aquifer; discharge at the surface as springs, seeps or lakes; re-precipitation of calcium carbonate. Alberta has seven categories of marl and tufa deposits, based upon over-all depositional environment and calcium carbonate

Jan 1, 1984

By P. Duran

The metallurgical gas handling system at Chagres Smelter, like that of many smelters, can be the limiting constraint to processing more concentrate through the smelter. Mass and energy balances for the metallurgical gas handling system processing off-gases from the flash furnace and Peirce-Smith converters have been used by both operations and process engineering groups to help evaluate different operational scenarios in which the use of the installed capacity could be maximized and/or an operational strategy can be change with the purpose of removing a bottleneck or justifying an investment to relieve a constraint in the gas handling system. The present work describes the development of these process balances that were carried out in Exce®. The results were validated with operational data and, subsequently, some cases of industrial interest were simulated, detecting some conditions that were limiting the operation due to the present installed capacity in the Chagres Smelter.

Jan 1, 2007

By C. R. Larsen, R. G. Bradburn, A. L. Mular, B. C. Flintoff

"Following the acquisition of grinding- circuit data at Brenda Mines Limited for simulation purposes, various methods to mass balance the circuit were evaluated. Unfortunately, different answers were obtained for different balancing methods. A data-adjustment procedure was therefore developed. The procedure assumes that all ""best-fit"" criterion. A search is conducted with the minimum set of water masses and narrow size ranges of solids around the circuit (called search variables), which permit the computation of any of the measured data points. Search variables are used to calculate measured values for an objective function of the form: [ ] where W, is a weighting factor•, M1 is a measured value and M. is a corresponding . value calculated from search vanables. The best values of M, are those which minimize R. The above method is compared with others that have been utilized for mass balancing circuits."

Jan 1, 1976

By R. Tipman, T. C. Burnett

"A general computer program has been written to calculate material balances using multiple regression techniques. The program can handle metal assays or size distribution data obtained in multiple surveys of the flotation circuit. The ""best fit"" weight split is calculated between the input and product streams by minimizing the sum of squares of the residual errors using all of the available data. The program includes an assay adjustment feature in which each assay is recalculated to fit the ""best fit"" mass balance. Thus assay or sampling errors can be easily identified. Also the assays can be statistically weighted so the most precise measurements are given the most influence on the material balance. The computer output reports the mass balance, the actual and corrected assays, the percent metal recoveries and the significance and confidence levels for the weight splits.The program enables a rapid and accurate evaluation of mass balances from large masses of data obtained in multiple surveys around a flotation circuit. The effects of changing process variables can be quickly evaluated with statistical confidence."

Jan 1, 1978