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By Ryan L. Veenstra

This paper presents a modelling study of a cemented paste backfill in an underground stope. The model was developed to help provide a better understanding of what is happening in the stope during the filling stage of the stope. In order to do this, the model incorporates the paste rise rate, stope geometry, and time-dependent input parameters. This paper looks at the effect of geometry in two parts. The first part compares a series of simple rectangular stope models. These models differ in size both in two and three dimensions. The second part compares the results of four 2D models together and then to the field instrumentation data. Part of this section introduces the geometry and instrumentation within the test stope.

Jun 1, 2012

By E. G. Joe

"Recent trends in Canadian mineral processing were reported in seven areas of interest covered by seventeen technical papers at the 1976 Annual Meeting of the Canadian Mineral Processors, held at Energy, Mines and Resources' Camsell Hall, Ottawa. New milling equipment included the Enviro-Clear thickener, large-volume Outokumpu flotation machines and abrasion-resistant polyurethane screens. Grinding experiences from a variety of milling operations were reported. Opportunities for increased sizing and grinding efficiency were presented. Flotation control by digital computer and by chemical additions were described in two mill operations. Slurry pumping and sampling techniques were described for various operations. Environmental control in milling was reported concerning dust suppression, arsenic removal and tailings disposal. Several aspects of gold milling were described by the most recently commissioned gold mine and by CANMET. Potash operations were reported showing the similarity of processing and process control to that of metallic minerals."

Jan 1, 1976

By Niklas Willemsen

Introduction to SVCs ? SVC = Static var Compensator ? Dynamic step-less control of reactive power without switching of passive components: ? Voltage control/stabilization ? Harmonics- and flicker mitigation ? Dip mitigation ? Main components: ? TCR (Thyristor Controlled Reactor) ? Tuned harmonic filters ? Control- and cooling systems ? Typical applications: ? Mine hoists ? Large mining complexes ? EAF, SAF, rolling mills, wind/solar farms etc..

Aug 1, 2013

By Mohsen Mohammadi, Edward Cyr

"To date, several studies have been performed on the static mechanical properties of SLM-AlSi10Mg alloy. There have also been more recent studies on the relation between scan strategy, texture, and mechanical properties of SLM metals and composites. However, there is a huge knowledge gap in the available literature regarding texture and mechanical behavior of SLM-AlSi10Mg alloy under high strain rates. Therefore, in this study, dynamic mechanical behavior of AlSi10Mg_200C alloy manufactured by DMLS technique was investigated at high strain rates ranging from 900/s to 1700/s using Split Hopkinson Pressure Bar. Texture using X-ray diffraction technique of the initial samples were measured. The yield strength, peak flow stress, and ductility increased in all samples with increase of strain rate. TEM studies have also revealed evidence of continuous dynamic recrystallization in grains after 900/s–1700/s strain-rate tests. A Taylor polycrystal crystal plasticity constitutive model was then developed to capture and predict the texture evolution and mechanical response under dynamic loading, using plastic work as a critical parameter for the onset of recrystallization.INTRODUCTION Additive manufacturing (AM) powder techniques are among the fastest advancing breakthroughs in manufacturing in recent years, defined by a bottom-up layer by layer process of joining with energy input from lasers or electron beam (Herzog et al., 2016; Gibson et al., 2015). Among alloys fabricated by SLM, AlSi10Mg is of high interest to industry and academia due to its low density, high specific strength and excellent corrosion resistance, making this alloy a viable contender for aerospace, automotive, and marine applications. Circumstances such as car crash or bird aircraft strike hazards subject potential additively manufactured AlSi10Mg parts to impact loadings. This drives an interest in understanding and predicting dynamic behaviour of these alloys. AlSi10Mg is the AM counterpart of A360 die-cast aluminum, which possess hypoeutectic microstructure (Li et al., 2015). Up to the present time, many studies have presented the mechanical properties of SLM-AlSi10Mg alloy. The mechanical properties and microstructure of AlSi10Mg produced by selective laser melting (SLM) or DMLS techniques can be controlled using different parameters, such as feedstock powder (Asgari et al., 2017), and process parameters (Olakanmi et al., 2015). The microstructure and mechanical properties of AlSi10Mg can also be controlled using post heat treatment after SLM process Li et al., 2016). The mechanical properties of SLM-AlSi10Mg are sensitive to strain rate and can both change under quasi-static (Rosenthal et al., 2017) and high strain rates (Asgari et al., 2018). However, a significant knowledge gap in available literature regarding modeling these behaviours, and especially micromechanical modeling of dynamic behaviour."

Jan 1, 2018

By Dean S. Rogers

"In February 1980, Dome Mines Limited announced a $50 million expansion program which would result in a 50% increase in mill capacity from the present 1,815 tonnes per day to an eventual production rate of 2, 720 tonnes per day in the year 1984. As an integral and necessary part of this planned expansion, a new vertical production shaft, No. 8 Shaft, would be sunk from surface to a depth of 1,645 metres.Throughout the seventy-year history of mining at the Dome, gold has been found in a number of different rock types and in association with a number of different structural settings. However, the key to successfully locating ore deposits lies in the recognition of the favourable environments in which they generally occur. First and foremost, the exercise of locating the No. 8 shaft became an exercise in geological deduction based on the projection of these favourable lithologic environments.In November 1980, after detailed engineering work was completed, the total cost of the project was estimated at $75.5 million 1980 dollars or $91 million dollars allowing for inflation over a four-year construction period. These estimates include the shaft, significant replacement and alterations to the milling process, and an upgrading of the plant."

Jan 1, 1982

By J. H. C. Scrimgeour, T. Toong, R. E. Hamilton

"The principles involved in the use and application of mathematical models as an aid to the development of advanced process control computer systems are described briefly. This is followed by a brief survey of known models of this kind for the simulation of mining industry processes.The main part of the paper describes a dynamic model of the flotation process developed by Canadian General Electric. Using flotation rate constants for each species of mineral and gangue, the model provides a numerical solution of the differential equations describing cell behaviour. The cell mode] is used repeatedly as a subroutine in the •over-all-plant model. The features of the cell and plant models are described.Simulation runs from the plant model show stream .assays and other indications of plant behaviour printed typically in 1-to 10-minute steps for several hours of •Operation following typical disturbances such as changes in feed rate or reagent addition rate. The simulation can :Show expected behaviour for both uncontrolled and computer-controlled plants."

Jan 1, 1970

By G E. Craig, W. M. Williams

A simple, easily constructed apparatus suitable for the zone refining of iron and other reactive materials is described. After eight passes at one inch per hour, the iron produced showed a marked drop in hardness to 49 Brinell. In addition, an arbitrarily -defined recrystallization temperature was lowered by about 35°C and the rate of grain growth greatly increased. CERTAIN materials, of which iron is one, are so reactive that they cannot be zone refined in any known container without becoming contaminated. For such substances, the floating zone method ( 1) may be used. In this method, the specimen is supported vertically in an inert atmosphere and the molten zone supports itself by its own sur-face tension. The method was first applied to silicon (2) and has since been used for other reactive metals such as zirconium and titanium. Smith and Rutherford (3) have previously reported on the floating zone refining of iron; the efficiency of the method for reducing the car-bon content was demonstrated on

Jan 1, 1962

By Y. Duna

The reliability of mine ventilation systems is critical to normal and safe production in a mine and includes reliability of the following parts: ventilation system branch (or passage), ventilation structures, ventilation network, and the fan. Among these, the reliability of a ventilation branch may be considered the foundation of the whole ventilation system. The branch ventilation flow includes four parameters: air volume; toxic and hazardous gas concentrations; temperature, and dust concentration. The calculation model for the reliability of a branch was established based on the analysis of normal distribution of flows in any one branch. Then, the efficiency of the ventilation structures and fire risk compromising the reliability of branch was studied. The results obtained were as follows: if the air volume, toxic and hazardous gas concentrations, temperature and coal dust concentrations of the branch are within reasonable limits, set at any stable state and at the same time, then this branch is reliable.

Aug 1, 2013

By C. Andrews

Fuel cell testing requires fully automated operation, on-site configuration of tests, and real-time monitoring for performance and failures. Balancing the flexibility and programmability of a test station with reliability, cost, and user interface can be a daunting challenge to the test equipment engineer. Endurance testing of fuel cells requires the highest level of reliability for test stand hardware and software without compromising automation capabilities or users interface. Techniques for implementing an ultra-reliable test platform addressing hardware limitations, sophisticated watchdog monitoring to prevent inadvertent shutdowns, and software limitations (e.g., balancing a highly-functional graphical users interface with reliability) are presented.

Jan 1, 2005

By J. E. Nesset

"Significant progress has been made over the past few years on characterizing and understanding the hydrodynamic properties of frothers and collectors and their effect on flotation performance. This new understanding of the relationship between chemistry and hydrodynamics has dramatic implications for how flotation circuits should be controlled and optimized. Previous work has shown that choosing a frother of the right ‘strength’ is critical to the optimization process, and the work and discussion presented here serve to strengthen the argument. In addition, we know that collector chemistry will also influence hydrodynamic properties and needs to be taken into consideration. To achieve the desired outcome, the overall system of reagents and operating parameters must be considered. This paper describes and discusses some of the findings from recent research on frother and collector chemistry effects (on hydrodynamics), and how this knowledge can be used to improve flotation performance. Examples from plant experience are discussed.INTRODUCTIONFrothers perform various functions in flotation but the primary ones are control of bubble size in the pulp zone and stabilization of the froth zone. Laskowski (2003) was among the first to try to capture both roles in characterizing frothers in order to provide a basis for frother selection for a given duty, as well as to explore the link between function and frother chemistry (structure). The method he used requires bubble size data and a frothing index; the procedure has been simplified by Cappuccitti and Finch (2008) using gas hold-up to substitute for bubble size, and froth height (without overflow) as the froth stability metric. The gas hold-up/froth height relationship will be referred to as ‘hydrodynamic characterization’. Essentially, the gas hold-up parameter reflects the sum of the hydrodynamic conditions in the pulp phase (water in this case), i.e. the effect of bubble size plus the apparent impact of the water surrounding the bubble due to the frother (Finch, Nesset and Acuna, 2008). Similarly, the stable froth height parameter reflects the sum of hydrodynamic conditions in the froth, i.e. the effect of bubble size undergoing coalescence plus the influence of the water in the lamellae and Plateau borders between bubbles. It could be argued that the gas hold-up/froth height relationship is a superior one to simple bubble size/froth index for discerning differences in frother behaviour"

Jan 1, 2010

By R. W. Watson, H. D. Peer

"This paper outlines the history of steel linings in the Autogenous Mills, the factors influencing the decision to convert to rubber lining, and the operating and cost experience with the rubber liners to date. INTRODUCTIONSherman Mine is an open pit iron ore mining, concentrating and pelletizing operation located at Temagami, Ontario. The operation employs 392 hourly employees and 81 salaried employees and has an annual capacity of over one million L.T. of high quality iron ore pellets produced from low-grade magnetite ore.The Sherman Mine is a joint venture; 90% owned by Dominion Foundries and Steel Limited (Dofasco) of Hamilton, Ontario, and 10% owned by the Tetapaga Mining Company, a wholly-owned subsidiary of the Cleveland Cliffs Iron Company of Cleveland, Ohio. The operation and management of the mine is by Cliffs of Canada, Limited. Development of the property was started in 1965, with pellet plant production beginning on March 17, 1968. At the present time, the orebodies contain sufficient reserves to sustain operations at current production levels for 30 years. Mining was originally carried out in three orebodies, the North, South, and West pits. The North Pit has been exhausted and mining operations ceased in the spring of 1980. A fourth pit, the East Pit, will be developed during the early 1980's."

Jan 1, 1981

By M. W. Lewis, J. Werner

Fluctuating metal prices, declining head grade, and increased operational costs are forcing many open pit mining companies to look to their balance sheets for significant cost reductions in order to remain competitive. Maintenance continues to represent a significant proportion of the total operating costs in the mining industry. Compared with the other major cost components of the mining process, very little effort has gone into maintenance optimization. The potential payoff from maintenance optimization on the cash cost of the commodity is enormous. A large percentage of these costs are incurred in unscheduled maintenance events, which typically cause serious disruptions to the production process. These maintenance-induced production losses can be a significant contributor to the overall operating costs. A structured proactive maintenance approach using the latest advances in technology can achieve dramatic cost reductions and productivity improvements. Remote condition monitoring systems are becoming increasingly commonplace and have the potential to identify problems prior to failure. Detection of equipment degradation prior to failure will enable repairs to be scheduled thereby reducing costs and interruptions to production. Remote condition monitoring technology has evolved rapidly in recent years, with a host of new tools becoming available to assist mine operators in improving their maintenance operations. These tools have capabilities such as remote real-time vital signs and performance monitoring, alarm/event handling, trend analysis, and maintenance workflow management. When these monitoring tools are used in conjunction with a mine management system, the vital signs data can be integrated and associated with maintenance history, predictive maintenance data, operational information, and geographical information. This integrated approach to the management of vital maintenance data will help shift the mobile equipment maintenance paradigm from reactive to proactive. This paper will introduce a proactive approach to the management of the maintenance process and the tools required to facilitate this process.

Jan 1, 2005

By Bin Tang, Suping Yao

In the last decade, the copper industry in China has developed rapidly and attracted the world’s attention. The production capacity of refined copper has grown remarkably from 4.578 million tons in 2010 up to 9.029 million tons in 2018, accounting for about 40% of the global refined copper production. And now, China has become the biggest refined copper producer in the world. This paper summarizes the application of modern copper metallurgical technologies such as Outotec flash smelting/converting technology, Cyclone smelting technology, TSL (ISA/Ausmelt) smelting/converting technology, Jinfeng side blown smelting and Baiyin side blown smelting technology, Chifeng side blown smelting and continuous top blown converting technology, SKS bottom blowing technology, Dongying two-step smelting technology, copper electrorefining with high current density, etc. in China’s copper industry, analyzes and compares the characteristics of those technologies and presents the great efforts of China’s copper smelters in adapting to the increasingly strict emission standards and improving economic benefits of copper smelters. INTRODUCTION China has been the biggest refined copper producer in the world for many years. China produced million tons of refined copper in 2018, accounting for 40% of the copper smelting production in the world, and of which, roughly, 70% of the copper concentrate was imported, mainly from Chile, Peru and Australia. ICSG (International Copper Study Group, 2017) shows clearly the position of top 20 countries of copper production and copper mine production (Figures 1 and 2). Blast Furnaces, Reverb Furnaces and Electric Furnaces dominated China Copper Smelting for quite long time till 1980s. The first modern copper smelting technology (flash copper smelting) was introduced into China in 1980s, then followed by Noranda, Ausmelt and ISA. Since then, China copper smelting technology stepped into modern time. Since 2000, old processes (Blast Furnace, Reverb Furnaces and Electric Furnaces) were phased out and replaced by modern smelting technologies. China Copper Production has been increasing dramatically (Figure 3).

Jan 1, 2019

By W. N. Roman

This paper will examine the challenges involved in ventilating and cooling South African mines, with particular emphasis on solutions to the issues of heat (generally associated with depth), mechanization and energy efficiency. Comparisons will be made with other international mining areas. Some of the deepest mines in the world are to be found in the South African goldfields. The Mponeng mine is approaching 4,000 m below surface, with virgin rock temperatures (VRT) of between 60°C and 70°C. Mining at these depths has only been possible with the use of large refrigeration plants supplying cold air, water and ice to the workings. In the Bushveld Igneous Complex, where most of South Africa?s platinum mines are located, similar VRTs are being experienced at significantly shallower depths. This is due to the different geothermal properties of the host rock between the two areas. Existing mines are being forced to go deeper and new underground mines are being planned and constructed in other areas with widely differing thermal conditions. South African metal mining has traditionally been labour intensive for historical reasons as well as for the narrow tabular nature of many ore bodies. Due to cost pressures and labour problems, some mines have been investigating the possibility of using mechanized equipment, both diesel and electric, to increase production and to improve efficiency. Studies have been carried out to determine the effect of the additional equipment on the overall ventilation system and some of the conclusions are discussed. The use of diesel equipment adds heat and pollutants to the ventilation air but, although electrical equipment has a lesser effect on the ventilation systems, it is generally less favoured due to claims of lower flexibility/manoeuvrability. Mechanization holds the promise of more concentrated mining activities but, with higher localized ventilation and cooling needs. Systems which will control the provision of air and cooling more effectively are required and are being implemented. In the 1990s and early 2000s, the South African economy experienced significant growth which was not matched by the growth in infrastructure. Consequently, at present there is a shortage of electricity generation capacity which affects large industrial consumers, including mines. Increasing levels of heat and mechanization will require more electrical energy for ventilation and cooling. There are many initiatives underway to save power or to shift consumption to periods of national low demand and these will be described.

Aug 1, 2013

By Rees J. Llewellyn

Improved product development, assessment methods and evaluation studies of materials for oil sands applications have traditionally focused on low and high stress abrasion and slurry erosion resistance mechanisms, because they were considered to be the predominant wear modes prevailing in oil sands mining, transportation and bitumen recovery. More recently with the very successful introduction of oil sands hydraulic transportation systems, there has been increasing use of crusher systems in which materials of construction are also required to have good toughness and gouging abrasion properties to withstand impact and the severe indentation and ploughing forces that are involved. To assess material property requirements for mitigating this additional wear mechanism, jaw crusher gouging abrasion tests using a modified ASTM G81 procedure, have been carried out on a range of wear materials of interest for oil sands mining service. The method involves a comparison of the wear losses that occur for reference and selected test plates when a controlled amount of standard feed rock is comminuted in a laboratory jaw crusher. Among the classes of material evaluated have been Q&T plate steels, austenitic manganese steel, chromium and chromium molybdenum white irons as plain castings and in laminated forms and also chromium carbide and tungsten carbide overlaid wear plates.

May 1, 2004

By Brian Hart, Stamen S. Dimov

"The naturally occurring carbonaceous material (CM) in gold bearing ores often exhibits strong-preg-robbing properties. It can adversely affect the process of gold recovery during the cyanidation due to its ability to adsorb, or preg-rob gold from the cyanide leach solution.Treatments of carbonaceous ores with chemical surfactants as blinding agents to limit preg-robbing have shown promising results but at the same time have demonstrated that, if not properly used, could have a strong detrimental effect on the gold recovery process. High dosages of surfactants used as passivating agents for carbonaceous matter could lead to unwanted partial passivation of the activated carbon added during the CIL process and severely impact the gold recovery. Optimal dosage for various surfactants would strongly depend on the ore mineralogy and the parameters of the pulp (temperature, pH, surface area and maturity of the carbonaceous material, etc).This paper describes an experimental study on the effectiveness of various commercially available blinding agents used to minimize the preg-robbing capacity of naturally occurring carbonaceous matter. The scope of the study was to: i) establish the optimum addition of blanking agent (surfactant) to minimize the preg-robbing capacity of the CM in the ore, and ii) establish maximum threshold amounts of blanking agents to be used before it negatively impacts the preg-robbing capacity of the activated carbon used in the CIL process. The study procedure involves standardized doping tests to evaluate the maximum preg-robbing capacity of treated CM, coupled with surface analysis with ToF-SIMS to monitor the presence and the degree of loading of these chemical surfactants on both the naturally occurring CM and the added activated carbon.INTRODUCTIONNaturally occurring carbonaceous material (CM) in gold bearing ores often exhibits strong-preg-robbing properties. Thus, it can adversely affect the process of gold recovery during cyanidation due to its ability to adsorb, or preg-rob gold from the cyanide leach solution. The preg-robbing properties of this naturally occurring carbonaceous matter can vary widely between ores, and within a single ore body (Dunne et al.,2013;Helm et al.,2009;Miller et al.,2005). The degree of preg-robbing related to the CM within an ore is defined by several parameters: total organic carbon (TOC) content, surface area, maturity (i.e., crystallinity) of the CM and the presence of various functional groups on the surface of the CM. Preg-robbing gold ores continue to be a significant challenge because of the lack of a single or universal solutions."

Jan 1, 2016

By François Robert, Steve Green, Tyson Birkett, Dan Richardson

Abstract -Detailed sampling using a portable diamond drill, and interlaboratory comparison of selected samples have been combined with statistical studies of truncated populations to establish the gold content of several outcrops in the Val d'Or area. The outcrops chosen are non-mineralized. The background gold concentration in the rocks of the region is 5 ppb or Jess. Gold is distributed relatively homogeneously within the outcrops studied except for slightly increased concentrations within quartz-tourmaline veinlets. Three samples, of which 20 grams of powder are analyzed for each, can adequately determine the gold concentration of a structurally simple outcrop in the Val d'Or area.

Jan 1, 1992

By A. E. McIlhinney, I. E. Puddington, C. E. Capes, A. F. Sirianni

"Two main problems are associated with the removal of pyritic sulphur from coals. The first is due to the fine state of dissemination of pyrite, which requires grindin1 to a very fine size to accomplish liberation. The second problem is caused by the similar surface chemical characteristics of coal and pyrite, which complicates separatio11 methods based on this property. In the work described here, the problem of fine particle size was overcome by using the selective oil agglomeratioa method developed at the National Research Council of Canada. Recovery of more than 90% of the combustible values was possible, even with particles only a few microns in diameter. Experiments using conventional chemical depressants for pyrite met with little success. It was found, however, that pyrite may be rejected during coal agglomeration through treatment with the iron.oxidizing bacteria, thiobacillus-ferrooxidans. The conditions for maximum pyrite separation are described and possible mechanisms by which the bacteria act are discussed."

Jan 1, 1973

By Jeffrey D. Oke

While significant progress in underground construction engineering has occurred in the past few decades, a number of fundamental deficiencies persist regarding the recognition, prediction, and mitigation of underground construction hazards associated with complex geological conditions in rock and soil works, such as tunnelling. Many of these shortcomings could be addressed by improving geomechanical models which, in turn, would provide more realistic frameworks for determining input parameters for design analysis. This would improve predictions of construction efficiency for tunnelling and the formulation of more accurate modelling techniques (2D, 3D and 4D) required to optimize the design of engineered rock structures. This research focuses primarily on the issues related to forepole temporary tunnel support within weak rock masses. This research attempts to determine how best to numerically model forepole support. The behaviour and mechanics of forepole support has not been quantified and/or optimized. As well, there is a lack of in-situ and/or laboratory forepole and weak rockmass interaction parameters available. In terms of numerical modelling, there is a lack of understanding of the use of proper interaction parameters associated with the forepole and the rockmass. The parametric study that has been conducted by the authors demonstrates the influence of each of the forepole-rockmass interaction parameters and their sensitivity. Introduction

Jun 1, 2012

By J. H. McMillan

Most of the recent papers read before the Institute have dealt with purely scientific matters, or with experiences in the various phases of mining operations. Very little, if anything, has been said concerning the part played by the human element in the industry. It is now opportune to consider this vital factor if we are to cope with the complex work of the present-day miner and, at the same time, meet the demands of the executive for greater efficiency. It is time we made an inventory of our knowledge to determine if we are absorbing the information so essential to modern mining practice. We must keep in close touch with all new ideas and developments in our chosen field and keep ourselves up-to-date in regard to everything pertaining to mining operations in general. The man who ceases to study ceases to advance. There are men who on attaining an executive chair give up all study, because they think they have reached the pinnacle of success. Modern industrial business, and coal-mining is no exception, demands that executive officers shall be 'live wires' -- men who are not only well-informed as to their immediate duties, but who are closely in touch with all matters of importance affecting the industry as a whole. We may be graduates of schools and colleges, but the training we receive in these institutions is only the foundation for our later work. Certainly no executive officer can know too much concerning the work he is engaged in, and the more he knows the more pleasure he will get out of his work.

Jan 1, 1925