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By A. L. Mular

Some specific cases of the collection of data from industrial grinding and classifying operations, and the development of models from the data so obtained, will be described. The problems encountered, the effort involved, and the value of the derived models in improving the plant efficiencies will be discussed and documented where possible.

Jan 1, 1971

By V. Schwinn, P. Fluess, N. Cauderlier, J. Bauer

From a strategic and economic point of view, the development of fine grain high strength steels for long distance pipelines is intensified world wide to satisfy the demand for natural gas in the future.The project related property profiles based on strength, toughness, crack arrest and sometimes resistance against HIC at defined design temperatures require an effective structural refinement using advanced steelmaking and processing in the rolling mill. The microstructure of modern line pipe steels ranges from ferritic pearlitic to ferritic-bainitic and structures where bainite is the dominant component, possibly upgraded by secondary phases. This paper illustrates microstructures and properties of recent orders on line pipe steels both for onshore and offshore application using different processing routes in the plate mill. Examples will be given for SAWL 485 offshore grades, X65 HIC and X70 HIC onshore grades, respectively. Finally, production results of a recent X80 order will be presented.

Jan 1, 2005

By T E. Tibbetts

This paper deals with coal sampling in general and with mechanical coal sampling in particular. The necessity of obtaining representative samples is emphasized. Other sections of the paper are devoted to the design and selection of automatic samplers, with a consideration of the three main types, and the testing, operation and maintenance of these samplers. The cost of the installation of an automated sampling system must be related to the value of the material to be sampled, to the volume of coal involved, and to the savings in labour and economy which can be achieved. Introduction T HE Committee?:; on Coal Sampling of the Coal Study Subsection, Thermal Power Section (Eastern Zone), Canadian Electrical Association, was established in November, 1963, to "study the various problem areas of coal sampling." The first undertaking of the Committee was to at-tempt to survey the problem areas of coal sampling through an evaluation of coal sampling difficulties as experienced at both the plant design and operational levels within the electric utilities represented on the Committee. The results of this enquiry indicated that satisfactory answers to almost any conceivable

Jan 1, 1965

By Juliana Parreira

The past decade shows record increases in global demand for minerals and metals with an accompanying significant decline in skilled personnel. Mining companies today are examining new technologies to maximize production, reduce costs, and create safer work conditions to deal with this shortfall. Automation of an open-pit mine haulage system is receiving attention as a beneficial option since it provides more consistent and efficient operation of mining equipment, it removes workers from potential danger, it reduces fuel consumption significantly reducing greenhouse gas (GHG) emissions, and it can help optimize vehicle repairs and equipment replacement because of more-predictable and better-controlled maintenance. This paper describes a simulation model under development using the EXTENDSIM software package to examine scale-up issues and constraints of autonomous vehicles in comparison to a manual system. The software can predict and manage Key Performance Indicators (KPIs), such as productivity, safety, cost, equipment failures, fuel consumption, and tire wear under different road and load conditions. By breaking-down the various systems of an autonomous haulage truck and simulating the overall haulage system using a Monte Carlo approach, the model becomes a flexible and powerful tool to use within a mining organization. Direct comparison to a manuallyrun system can be done to show the cost and operational benefits of automation. Project managers can use this tool to guide decision-making about possible application of autonomous haulage trucks at a specific mine site.

May 1, 2010

By S. H. Ash

Introduction Probably the newest thing in mining safety is the apparent dissatisfaction on the part of the mineral industry, as represented by both management and labour, and the general public of many nations in which mining is conducted, with the safety record of the mining industry. This is reflected by published comments in the technical press;' in labour periodicals, in popular Journals and periodicals, and in the daily press (5, 11). Despite what may be said to the contrary, mining in the United States is becoming safer, and this trend has been evident for several years (see Figures 1 to 4). Because the author's experience has been mostly in the United States this paper will discuss briefly some recent observations in the United States that have a bearing on mining safety. Because coal mining is of primary interest to the Mining Society of Nova Scotia, the paper treats mostly of coal-mining safety; however, many hazards in mining .are common to all mines, regardless of the minerals mined.

Jan 1, 1950

By D. J. Charlton

"IntroductionMaintenance is a business, which to be successful, requires good management, systems and reporting. The prime objective of the maintenance management group, be they large or small, must be to anticipate and prevent interruptions in operations by keeping equipment in good mechanical condition. This objective should be carried out at minimum cost consistent with maximum productiveness.The objective of this chapter is to give an insight into the various aspects of maintenance management that must be considered to effectively and efficiently operate a mill complex. The degree to which the maintenance sub-systems are developed in an operating mill will be determined by the size of the mill and the needs of the operation.The criterion of the management system used is that the system serve the operation and not vice versa. The systems presented should be considered as tools and, as with all tools, they must be sharpened and replaced as the need arises or as more effective tools become available.To understand what is involved in maintenance management, it is worthwhile to consider a systems approach to analyzing management problems. This approach was developed by J.A.B. Rae while reviewing maintenance management systems for Cominco Ltd.A very simple system involving managing results and objectives is shown diagrammatically in Figure 1.The systems approach to organizational development involves four basic elements: an objective, a result, an activity and feedback. In the analysis, the activity element is broken down into individual actions that people could be held responsible for. If we introduce the action of operating into the diagram of Figure l, we arrive diagrammatically in Figure 2."

Jan 1, 1989

By L. Yuan, J. Qin, J. Xie, Q. D. Qu, Y. P. Liang

"This paper presents key outcomes of a major Asia-Pacific Partnership project between the Commonwealth Scientific and Industrial Research Organisation and Huainan Mining Industry Group Co. Ltd. to develop and demonstrate advanced technologies at Pansan mine, Huainan, China. A comprehensive approach assessed fundamental strata and coal seam methane conditions during mining and optimized mining sequences and coal mine methane capture systems. The project demonstrated a practical approach and procedures for advanced coal and methane co-extraction systems, improved mining safety and efficiency, increased methane capture and use, and reduced fugitive methane emissions.RÉSUMÉ Le présent article donne les principaux résultats d’un grand projet de partenariat Asie- Pacifique entre le CSIRO (Commonwealth Scientific and Industrial Research Organisation) [Organisation de recherche scientifique et industrielle du Commonwealth australien] et le Huainan Mining Industry Group Co. Ltd.; ce projet cherche à développer et à démontrer des technologies avancées à la mine Pansan, à Huainan, en Chine. Une perspective globale a évalué les conditions fondamentales des strates et du méthane dans les couches de charbon durant l’exploitation et a optimisé les séquences d’extraction et les systèmes de captage du méthane dans les mines de charbon. Le projet a permis de démontrer une approche pratique et des procédures pour des systèmes avancés d’extraction conjointe du charbon et du méthane, pour améliorer la sécurité et l’efficacité minières, accroître le captage et l’utilisation du méthane et réduire les émissions fugitives de méthane."

Jan 1, 2015

By M. Nzotta, L. Teng, S. Seetharaman, A. Chychko

The objective of the present work is to optimize the EAF practice towards Mo alloying with maximum retention of the alloying element in molten steel. During Mo additions, there were significant losses to the dust (ca 7 %) and to the slag phase (ca 2 %), which had serious economic and environmental impacts. The present work was aimed at designing a suitable Mo precursor, an alternative to ferromolybdenum, as the Mo source and a process sequence for optimal retention of Mo in the steel. The design of the Mo source should be in such a way that low cost raw materials such as MoO3 concentrate have to be used, stable during the addition so that the vapour phase losses as MoO3 are kept minimum and the dissolution of the precursor in molten steel is easy without loss to the slag phase. After thermodynamic considerations, three precursor materials were chosen, viz. CaMoO4, MgMoO4 and Fe2MoO4. Synthetic mixtures of the component oxides in each case as well as pure MoO3 were investigated by TGA and high temperature XRD in order to find out the temperature range in which the compounds were formed. Experiments were also conducted separately where the evolved gases were analyzed. All the three precursors were formed easily and the loss of MoO3 to the vapour phase was found to be extremely low. Addition of the oxide mixtures to steel melts were conducted in three different scales, viz. 16 g, 500 g and 3 tons (induction furnacle). Initial experiments showed that MgMoO4 was not suitable since the Mo yield in the steel melt was not very high. Fe2MoO4 was found to perform best, the Mo yield reaching 98 %. Further trials were conducted in the 65 ton Electric Arc Furnace (EAF) at Uddeholms AB in Hagfors. Mixtures of mill scale, MoO3 and carbon in suitable proportions were added in a pre-determined addition sequence. It was found that, in the actual practice, the Mo yield reached 99 %, equaling in performance the addition of ferromolybdenum. The process offers an effective use of cheaper raw materials and very high Mo yield avoiding a pre-treatment step like the production of ferromolybdenum. This is both cost effective and environmentally advantageous. The process has been patented and is being currently implemented at Uddeholms AB, Hagfors, Sweden.

Jan 1, 2011

By E. H. Dudgeon

In order to make increased use of automation in copper smelting, it is evident that a useful first step .world be the accurate determination of the copper end point in the converter operation. After laboratory tests, the copper end points in a copper converter at Gaspe Copper Mmes Ltd. were determined without reference to melt samples or other observations. The results indicated that the rapid measurement of the S02 level in the gas released from the converter has potential as a new and independent method of determining the copper end point in converter operation.

Jan 1, 1966

By K. U. Kainer

Magnesium and its alloys as the lightest available construction metal offer a wide range of opportunities for the usage in transportation industries, especially Magnesium wrought alloys with their improved mechanical properties show a high potential for structural applications, While magnesium cast components have found their application the interest is now spreading to wrought alloys due to the possibility to get even more homogeneous and better properties compared to cast parts, Therefore alloy and process development especially for extruded and sheet material is a main concern to enhance the application of Magnesium wrought alloys, Castings are still form the majority of applications of magnesium alloys, although efforts to develop adequate wrought alloys have increased, In the presentation, the alloy requirements for processing of cast and wrought alloys will be discussed, The various processing routes and alloy compositions result in specific microstructures and properties which determine the potential use of these alloys, Today, the spectrum of available alloys covers standard alloys as well as alloys for use at elevated temperatures, The trend will be to further diversify the alloy compositions and to improve the alloy properties, Areas of concern still remain the wrought processing and the high temperature (creep) and corrosion properties of magnesium alloys, Examples of recent developments in these sectors will be given, The presentation will also provide an overview of the historical and current use of magnesium and an outlook on future applications.

Jan 1, 2006

By J. Peterson

A review of blast designs and improved blasting practices at the Ekati??Diamond Mine is presented along with the results of three blast-monitoring experiments. Blast monitoring was undertaken to investigate blast damage mechanisms in the mine's well jointed rock mass. Rock mass damage caused by production, pre-shear and wall control blasts was measured. Ekati??uses 270mm holes for production blasting, and 165mm holes loaded with a decoupled charge for pre-shearing. The production blasts are loaded with bulk emulsion / ANFO blends. The mine plan involves using 30m double benches. A 30m high pre-shear is drilled and blasted prior to the production blasting that is done with sequential 15m benches. This paper summarizes the monitoring equipment and data gathered to date.

May 1, 2001

By J. M. Whatley

"IntroductionIN UNDERGROUND mining operations, the mine hoist has become one of the most important and one of the most expensive single pieces of equipment. As the means of transporting men and materials to the face, broken ore to the mill, and waste to the dump, it is often the very lifeline of a mine and must operate with dependability and efficiency or the whole operation will suffer. The mine hoist has become synonymous with safety. In few other types of mechanical equipment do so many men so frequently and completely place their lives. In Canada, more has probably been done to assure safe hoisting than in most other countries, but, unfortunately, this has resulted, in many cases, in the mines having to pay a high price for equipment. Hoist manufacturers have carried out much research in recent years in the endeavour to keep down these costs and at the same time maintain or improve the efficiency and safety of their products. Broadly classified, the bases for design research are dependability, efficiency, safety, and first cost.Probably the greatest single factor influencing the design of mine hoists was the introduction of electric motor drives. It was not until about 1905 that an effective start was made in the development of electric mine hoists, and then only with machines of small size. From that time on, however, progress was rapid, as may be gauged from the fact that by 1910 one large group of mines in Johannesburg had in use, or on order, fifty-four three-phase hoists and four Ward-Leonard. type hoists."

Jan 1, 1953

By J. A. Finch

In this paper, the author offers a personal view of what the next 30 years holds for mineral processing. Restating that mineral processing will remain a vibrant industry in raw material production, growth opportunities in waste management are identified. The processing sequence familiar now (mining ?mineral processing ?extraction) will become more interwoven. In situ processing (i.e., milling underground) will evolve from concept to demonstration. Opportunities to exploit physical properties altered in chemical (pyro- and hydro-) processing will present themselves. In primary grinding, the path to AG/SAG milling will progress with little deviation but opportunities in regrinding are wide open. Flotation will see the trend to designing bubble/particle reactors accelerate simultaneously with a vigorous response from mechanical cell suppliers. Gravity separation remains a bastion of the lone inventor but this author anticipates that the new lines will come from the waste management business. The paper concludes with the examination of the “research cycle” and identification of growth in small “high tech” companies and university research centres

Jan 1, 1998

By M. Peshko, J. C. Gingerich, L. W. Matthews

"Noranda has successfully developed and implemented two leading-edge mineral exploration technologies — hyperspectral remote sensing and 3-D seismic surveying. Airborne hyperspectral imaging provides detailed geological and mineralogical mapping capability at both a regional and project scale that facilitates improved selection of prospective terrain and an accelerated exploration cycle. Noranda, in partnership with Falconbridge, has licensed the exclusive use of the Earth Search Sciences Inc. (ESSI) Probe-1 hyperspectral scanners (128- channel, 0.43 µm to 2.5 µm spectral range) that are capable of mapping in excess of 3500 km2 per day at 10 m pixel resolution. The technology has been successfully deployed on four continents over a broad range of terrain from desert to boreal forest and the high Arctic.To augment the company’s deep search initiatives, Noranda has successfully modified and implemented existing 3-D seismic technology to help targeting massive sulphides located at depths ranging from 500 m to 2000 m. In the fall of 1998 and early 1999, Noranda completed an 18 km2, 3-D seismic program in eastern Canada by successfully drill testing acoustic impedance anomalies locating massive sulphides at depths in excess of 1100 m."

Jan 1, 2002

By M. Zamalloa, P. J. Mackey, P. Coursol, Y. Prévost

"Over the last decade or so, the availability of commercial thermodynamic modelling packages, such as FactSageTM, have been utilized to help the plant optimize slag chemistry and to minimize slag handling issues that can arise, such as those due to a process upset, for example, by undue feed variability. This paper illustrates an extension of the application of this software in examining a large range of NCV operating parameters, such as the %Fe/SiO2 ratio in the slag and the level of minor gangue components in the slag including CaO, Al2O3, ZnO, MgO, and PbO. The conditions influencing the slag liquidus range of NCV slag are discussed with respect to the overall process chemistry.Given that a sufficiently low %Fe/SiO2 ratio is used in NCV slag, most components such as CaO-ZnOPbO- Al2O3-MgO, in small concentration, all contribute to lowering the NCV slag liquidus. Considering the present level of these minor components, the NCV can operate consistently at 1200°C if the %Fe/SiO2 is between 0.6 and 0.8 in the slag. Using the type of phase diagrams presented in this paper, it is possible to develop different Noranda reactor/Noranda converter operating strategies adapted to the feedstocks available at Xstrata mines/plants or from other sources. The NCV is unique in that a fayalite-based slag is employed for high-efficiency continuous converting with excellent operating results."

Jan 1, 2007

By P. -M. Tardif, S. Outalha, R. Le

"This paper proposes a new direction to implement an underground mine communication system. It presents actual underground communication systems and discusses their technological limits. A new system based on a wireless local area network (WLAN), together with its main systems characteristics, is then proposed. This paper also presents an experimental protocol for radio frequency propagation measurements. Finally, the paper describes the projected implementation of a WLAN in an experimental mine. IntroductionDuring the last decade, a number of Canadian mining companies have invested in modern communications systems in order to automate processes and reduce operational costs. Safety of miners is also a concern, regulated by health and safety regimes.Underground communication systems rely mainly on analog technology (especially the leaky feeder). Digital upgrades have been made to modernize this technology using a coaxial or fibre optic cable to transmit voice, documents, commands, controls, and video. Therefore, all wired equipment can benefit from an increase in efficiency from the digital technology.However, when it comes to mobile equipment, the only medium was, and is, still radio waves. With the advent of the wireless local area network (WLAN) standard, one can use a technology similar to that of the cellular phone to connect transparently different equipment. WLAN enables the transmission at rates higher than 2 M bits of voice, documents, commands, controls, identification, and of course, digital video. This technology was developed with inbuilding use in mind. Now, one can try to adapt it to underground mines."

Jan 1, 2000

By Shek N. Lau, Nicola Samman

"Enclosed gear cases on board heavy mining equipment have traditionally been lubricated with regular heavy duty gear oils. However, equipment manufacturers, have recommended the use of an ISO-1000 gear oil for this application to ensure adequate lubricant film strength, especially at the higher end of the working temperature range. The majority of these ISO-1000 gear oils are based either on residual/asphaltic oil or synthetics, primarily higher viscosity polyalphaolefins. Although the performance of these lubricants has been satisfactory, they suffered other shortcomings that equipment users have lived with over the years.The major requirement at the user’s mine was to provide lubrication for the shovel Hoist gear case. Within such a gear case design, the gears and the roller bearings, that have different lubrication requirements, are lubricated with the same lubricant. Several lubricants were used, light gear oils as well as the recommended ISO-1000 heavy gear oils. On the one hand, the lighter oils performed adequately for the lubrication of the bearings that formed part of the enclosed gear system. These lighter oils did not perform as well for the lubrication of the gears due to their lower viscosities, resulting in shorter gear servicelives.On the other hand, the ISO-1000 gear oils performed well for the lubrication of the gears, but were too viscous to creep into the bearing elements to lubricate them adequately, especially during the cold northern Canadian winters. This resulted in catastrophic bearing failures and secondary damages to the gears.The challenge, then, was to formulate a lubricant which met the 1000 cSt at 40°C viscosity requirement as stipulated by the equipment manufacturer, while satisfactorily lubricating the bearings at the full working temperature range. This was achieved by the development of a semi-fluid grease lubricant, which has proven in field trials to give adequate performance in this application for the lubrication of both the bearings and gears down to -40°C.This product met the equipment manufacturer’s performance criteria and resolved, to a large extent, leakage of the lubricant through seals experienced with the use of conventional and synthetic gear oils.Although the main performance criteria of the fluid was its capability to lubricate the “Hoist” gear case, it was also used during the field trial in other gear cases on board the shovel to test its full capabilities.This unusual alternative lubricant was field tested and evaluated for more than two years. Based on this assessment, the product was reformulated to improve its fluidity, slumpability and the settling of debris/wear metals to the bottom of the gear cases. This reformulated softer grade, a semi-fluid grease, has been performing satisfactorily for more than eight months and is still undergoing longer term assessment."

Jan 1, 1996

By B. Panton, J. Carvalho, E. T. Brown

High-capacity, post-tensioned anchors have found wide-spread use in initial dam design and construction, and in the strengthening and rehabilitation of concrete dams to meet modern design and safety standards. Despite the advances that have been made in rock mechanics and rock engineering during the almost 80 years in which post-tensioned anchors have been used in dam engineering, some aspects of the rock engineering design of high-capacity rock anchors for dams have changed relatively little over the last 30 or 40 years. This applies, in particular, to the calculations usually carried out to establish the grouted embedment lengths required for deep, post-tensioned anchors. These calculations which involve a number of aleatory and epistemic uncertainties, usually make simplified assumptions about the distribution and values of rock-grout interface shear strengths, the shape of the volume of rock likely to be involved in uplift failure under the influence of a system of post-tensioned anchors, and the mechanism of that failure. The resulting designs are generally conservative. These aspects of the rock engineering design of large, post-tensioned rock anchors for dams could be improved by making greater use of modern, comprehensive, numerical analyses in conjunction with 3D models of the rock mass structure, realistic rock and rock mass properties, and the results of prototype anchor tests in the rock mass concerned.

Jan 1, 2015

By Cedric E. Gregory

"A study of model rectangular mine shafts has been made in the wind tunnel, with the aim of reducing air-flow resistance elements to a practicable minimum. An analysis of Table 7 shows an indicated average decrease in resistance of 28 per cent by adopting the over-all modifications involved in the configurations actually tested. Much greater reductions (up to 68 per cent) are indicated by extrapolating beyond the test results directly achieved. Intermediate partial reductions in aerodynamic resistance are shown for individual modifications, such as: (1) about 3 per cent for locating the lagging in the No. 4 (inside flush) position as against the No. 1 position - 8 per cent as against the No. 2 position - and 23 per cent as compared with position No. 3; (2) about 12 per cent for using lagging instead of steel meshwork along the divider separating the skipway from the service compartment; (3) about 14 per cent for using steel gridwork ladder stagings at 3-set intervals instead of similarly spaced wooden stagings; (4) about 12 per cent for using steel gridwork ladder stagings at 3-set instead of at 1-set intervals; (5) about 13 per cent for fitting a streamlined fairing (see Fig. 5) to the upstream face of the skipway divider. Contrary to expectations, an advantage of only 3 per cent is indicated for lagging in the inside flush (No. 4) position over the outside position (No. 1). This slight gain does not appear to warrant the cost of moving the lagging. However, if the lagging is already in the No. 2 or No. 3 position, there is an 8 and 23 per cent advantage respectively."

Jan 1, 1973

By D. B. Hyma

"The Raglan Ni/Cu property is located on the Ungava Peninsula in Northern Quebec, Canada, at a latitude of61°42' and a longitude of73°40', approximately 40 km southwest of Douglas Harbor. Geological reserves are estimated at 18 million tonnes, grading 3. 1 % nickel, 0.9% copper and smaller amounts of cobalt and platinum group metals.Extensive project development has defined the concentration process, concentrator sizing, tailings and environmental management required for this project.The grinding circuit selected is a fully autogenous primary grind, with pebble crushing and a pebble mill for secondary grinding to produce a product of 80% -70 microns for flotation.The flotation circuit is a simple circuit utilizing roughing, a regrind of rougher concentrate to 80% -20 microns, two stages of column cleaning with a cleaner scavenger bank on the column tails.Concentrate handling options were thoroughly reviewed because of the pyrophoric nature of the concentrate, remote site location and long distance to downstream processing. The preferred option, currently.is to dry the concentrate at Raglan to less than l % moisture and then pneumatically handle the powder.A detailed analysis of tailings placement options, suggests filtered tailings placement to be the preferable route for the Raglan site.INTRODUCTIONThe Raglan Project, as proposed by Falconbridge Limited, will develop extensive nickel-copper deposits in the Ungava Peninsula, Quebec, Canada. The project schedule and construction conditions in the project area are demanding. The Raglan mineral deposits have been the subject of numerous studies and evaluations over the last thirty years and the Phase I 1991 pre-feasibility document includes exploration information obtained in the 1989 and 1990 drilling seasons. This review concluded that an 800,000 tonnes of ore per year mining and concentrating complex located at Katinniq could produce 20,000 tonnes per year of nickel at competitive costs."

Jan 1, 1993