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By C. J. Kerr

"A recent information sheet from the Mining Health and Safety Branch of the Ontario Ministry of Labour was sent to all Ministry inspectors and engineers. The subject title was' 'Two Brakes on a Hoist Carrying Persons"" and it quotes mining regulation 699, sub-section 206(i):No hoist shall be used for the transporting of persons unless it has a braking system consisting of at least two sets of mechanical brakes to stop and hold the drum for the shaft conveyance transporting the persons.The intent of the regulation is that each of these brakes is to be set so that, individually, they can safely stop the drum carrying persons and also hold the drum without movement with the maximum manload.This can be achieved in the following ways: Single Drum Hoist-one brake on each side of the drum, one brake on the drum, one brake on the pinion shaft, where disc brakes are used two separate disc brake assemblies on the disc. Double Drum Hoist, brakes on companion drum can serve as backup brake only pinion brake with one drum unclutched.Friction Hoist, one brake on each side of drum As new hoists can be manufactured easily with a two-brake system, attention will be focused on retrofitting pinion brakes to older hoists.A brake mounted on a pinion shaft is designed purely as an emergency brake in the event of main brake failure , controls malfunction, and power loss."

Jan 1, 1989

By D. Pearcey, S. T. Vessey, V. Hegde, J. Staples

"Pellet quality has taken on a new dimension during the last ten years. Quality in the seventies was generally defined as adherence to certain physical and chemical specifications. Today, the talk is in terms of how the business is managed, how customer's expectations can be exceeded, not only in product quality, but in service responsiveness.Coke breeze and flux additions, lower silica levels, and improved furnace control practices have all contributed to the improvement of pellet physical and metallurgical properties. Statistical process control has provided additional insight into the parameters that affect pellet quality.Increased customer contact and product quality surveys have heightened our awareness of customer needs and also provide direction for quality improvement test work. Current work is focussed on improving reducibility and understanding the relationship between tumble, fired compression and metallurgical properties.This paper will review the Iron Ore Company of Canada's efforts during the past decade and describe some of its initiatives for the future.IntroductionThe Carol Pellet PlantThe Iron Ore Company of Canada's Carol Project is located in Labrador City in the southwestern portion of Newfoundland and Labrador , approximately 965 Ian northeast of Montreal. The project consists of mining facilities, beneficiation complex and a pellet plant, which began operations in 1962. The pellet plant consists of six Dravo-Lurgi straight grate machines, regrinding, filtering and balling facilities. The current capacity of the Carol pellet plant is approximately 10.5 million tonnes , while the concentrator has the capacity to produce about 18 million tonnes of concentrate.The orebody consists of specular hematite, magnetite and small quantities of limonite and goethite. The average grade of the orebody is approximately 39% iron."

Jan 1, 1991

By Yu. V. Ponomarenko, A. I. Meka, P. A. Witherspoon, Yu. I. Volkov, J. E. Gale

"The mining of iron ore in the Kursk Magnetic Anomaly (KMA) region of the U.S.S.R. is done mostly by the open-cut method. An assembly of open pits capable of producing about 100 million tons of ore per year makes KMA the largest iron ore field in the world. Three gigantic open pits are currently in operation: Lebedinsky, Mikhailovsky and Stoilensky. These pits are as large as 13 km2 on the surface and as deep as 230 m. The mining operations are constantly faced with the problem of flooding from aquifers that overlie the orebodies; the magnitude of the problem is evident from the fact that the present groundwater inflow to these three pits is about 110 million mt /yr.Under such conditions, safe operations and pit wall stability are of great importance, and this has been accomplished very effectively by the appropriate use of seepage barriers and drainage systems. At KMA, the most important items used in the system of groundwater control are standard pumping wells, raise wells that drain into a 20 km to 30 km long underground drift located just outside the perimeter of the pit, horizontal wells driven through the pit walls, and horizontal drains. This paper describes the mining and engineering technology that have been developed at KMA to control the groundwater systems and protect the mines from flooding."

Jan 1, 1992

By P. R. A. Andrews, R. K. Collings

"SUMMARYIn cooperation with the Ontario Ministry of Natural Resources, selected deposits of Potsdam sandstone in the Ottawa-Kingston area were core-drilled and evaluated by CANMET as potential glass and foundry sand. Analyses of cores ranged from 84.6 to 98.5% Si02, 0.09 to 0.65% Fe203' and 0.07 to 2.10% A12°3' The cores were largely composed of white to grey, relatively tough sandstone. Impurities included iron as pyrite, iron oxides and staining on the quartz grains; carbonates as calcite; and aluminum oxide as feldspar. Beneficiation included size reduction to grain size, about 600 um, by jaw, roll and cone crushers, and grinding in a muller-mixer. Removal of fines was achieved by attrition scrubbing and washing. Further removal of impurities was achieved by reverse flotation of pyrite, iron oxide, feldspar, and carbonate minerals employing both anionic and cationic collectors. Flotation resulted in a substantial improvement in the quality of most samples; analyses of quartz concentrates showed 98.5 to 99.7% Sial> 0.022 to 0.156% Fe203' and 0.07 to 0.62% A1203. Further reduction of the iron content by wet magnetic separation and acid leaching also was investigated. On the basis of the samples submitted, sands/ones from six of the seven deposits studied have potential as sources of glass sand. Foundry sand tests were inconclusive because of the small quantities available for study."

Jan 1, 1986

By K. Musgrave, E. Solis

"This paper tells the story of how the Dome Mine in South Porcupine increased its maintenance effectiveness and reduced its maintenance costs in two phases. In the first phase, a maintenance audit was conducted, and the results led to some changes that improved maintenance, especially in the underground equipment area. The audit methods, and the changes made will be reviewed. In the second phase, management made changes in the maintenance organization and methods, following a prolonged strike during which management operated the mine. These changes were in part the result of insights learned from their hands-on operating experience. IntroductionEarly in 1989 the Dome Mine of Placer Dome Inc. in South Porcupine, Ontario, decided to improve the effectiveness of the Plant Department. The Plant Department was centralized, except for a mill mechanical crew, and serviced all operations, a townsite of 120 houses, a curling rink, and an arena. The department also operated the powerhouse, the hoists, the mine dry and provided mechanical/ electrical engineer services.At that time the Dome Mine, located in the east end of the city of Timmins and Canada's first large gold mine originally discovered in 1909, was producing about 3500 tons of ore per day with about 742 employees. Over the 83 years of continuous operation of Dome over 50 million short tons of gold ore have been processed. The Plant Department consisted of 156 hourly and 24 staff employees. At present, the mine is producing 4000 tons of ore per day with a total of 341 employees on the payroll. The Plant Department consists of 80 hourly-rated and 18 staff employees."

Jan 1, 1993

By Anna Szostak-Chrzanowski, Adam Chrzanowski

"New techniques in monitoring surveys and new methods in the analysis and prediction of ground subsidence are being developed in the Department of Surveying Engineering at the University of New Brunswick (UNB). The new surveying techniques include a telemetry monitoring system developed at UNB in cooperation with CANMET, and use of the satellite Global Positioning System. A generalized approach to the analysis of deformation surveys has been developed which permits an integrated analysis of geodetic and geotechnical measurements in geometrical modelling of ground subsidence. A computer program, FEMMA, has been developed for the elastic and non-linear elastic analysis and the deterministic prediction of deformations using the finite element method.IntroductionResearch and development of new monitoring techniques and new methods in the analysis and prediction of ground subsidence in mining areas is an integral part of a broad research program on deformation surveys which is being carried out in the Department of Surveying Engineering at the University of New Brunswick.The research concentrates on:developmentof a general method for predicting deformations with an emphasis on the use of the non-linear elastic finite element analysis; development of a generalized approach to the geometrical analysis of deformation surveys with an integration of geodetic and geotechnical measurements; and development of new monitoring techniques with an emphasis on continuous data acquisition and application of new space techniques such as the satellite Global Positioning System (GPS).This paper gives a brief report on the progress and recent developments within the above program."

Jan 1, 1987

"Technological innovation is an extremely complex activity. The author presents his interpretation of innovation and the innovative process. He reviews the strategy used by participants in coal mining innovation in the past and discusses changes required to meet the challenges of the future.Introduction if an industry is to be successful and viable in today's world, the companies active within the industry must remain close to the frontiers of knowledge. The coal mining industry is no exception. Technological problems facing the coal mining industry are basically economic and social. Economic problems are those concerned with the long-term growth and profitability and social problems, with the health and safety of the mine worker and the impact of the mining operation on the environment.Technological innovation can be a key factor in meeting these problems successfully. The general belief is that the information base for technological innovation exists within mining companies and governmental agencies but current industrial and governmental strategies and structures impede the transformation of this knowledge into the mining products and processes required for growth.The purpose of this paper is to determine where Canada is in terms of coal mining on the innovative ladder. The paper as presented: defines innovation and innovative process; gives an historical ""broad brush"" review o f innovation in the industry; and suggests the challenges to be faced in the future."

Jan 1, 1985

By J. R. Meyer, P. L. Dean

"The Department of Mines and Energy is at present investigating the dimension-stone potential of the Nain anorthosite complex. These rocks are known to host occurrences of labradorite, a semiprecious gemstone known for its beautiful play of colours (chatoyance). Test blocks that contain 5% to 18% chatoyant labradorite were extracted from three prospects south of Nain. These have been slabbed and polished for further evaluation.Second-grade labradorite stockpiled around the Grenfell quarry on Tabor Island is also being evaluated as a potential source of aggregate for use in terrazzo tiles, precast concrete and epoxy-backed wall panels.IntroductionThe Nain anorthosite complex consists of approximately 10000 km2 of anorthosite and related basic rocks , which are well exposed along the coast of Northern Labrador (Fig. 1) (Emslie et al., 1972). These rocks have been known for centuries to host deposits of gem-quality labradorite. The chatoyant nature (i.e. the play of colours or labradorescence) of this semiprecious feldspar has been utilized mostly in the making of jewelry and other polished, handcrafted products. In the early sixties, Brinex Limited (now Brinco Limited) attempted larger scale commercial exploitation of labradorite, including use 'as building stone and in polished precast concrete for facings on buildings' (Brummer, 1984). After six years of work, which included market studies, Brinex decided that, at that time, the demand did not warrant further production.In recent years, there has been a dramatic increase in the markets for dimension-stone. In the period from 1980 to 1985, the demand in the United States for granite, much of which is imported, has increased 1735070 (Marble Institute of America, 1986). The dimension-stone industry's remarkable growth rate has, in part, resulted from new technology that makes it easier and faster to quarry and cut stone. This has allowed natural storie to compete with other building materials. Now, it is not only used for exterior cladding and walkways, but also on interior walls and floors, and in home and office furnishings, such as countertops for kitchens and bathrooms, table and desk tops, stairways, window sills, and fireplaces."

Jan 1, 1988

By J. W. Smith, J. Van Dusen, A. Papachristodoulou

"As part of a study to evaluate factors affecting tankroom air quality, the mechanism of aerosol generation from bursting bubbles in electrowinning operations has been investigated. Typically 2 to 3 mg/m2.s are produced in zinc tankrooms. Analysis shows that the rate of production of film drops (geometric mean diameter - 2 urn] increases with decreasing bubble size, and that jet droplets (geometric mean diameter - 20 um) are not produced with gas bubble larger than - 4 mm. Both mechanisms of drop formation and current efficiency are affected by surface active agents, with an over-all reduction in emission of up to 60% to 70% being achievable. A source control system which does not adversely affect electrolyte properties is always preferred, and coalescence of all gas bubbles in to a continuous stream of gas at a single point on the electrolyte surface would eliminate aerosol emissions. This objective was the basis for design of a coalescence device which, in laboratory tests, reduced the emission rate by over 95%.The control device fit s over the electrodes in the electrowinning cell and is partially immersed in the electrolyte. A number of changes in the design which resulted in significant improvement in the performance of the device are reported.Field tests have shown that only about 75% of the aerosol below 10 um can be eliminated by coalescence. The remainder (up to 95% of the total) is controlled by coalescence of droplets, by impaction on the exposed collector surface and gravitational settling.The device does not interfere with operation of the tankroom, handles the effect of surges in power during harvesting, and is simple and inexpensive to maintain. IntroductionDuring the electrowinning of metals (such as zinc and copper) gases are evolved along the electrode surface forming small bubbles. The bubbles travel upwards and burst on the electrolyte free surface generating, in this way, small droplets. Because the electrolyte is often highly acidic or contains toxic materials, the whole process can result in the formation of an aerosol in the atmosphere above the electrowinning cells which poses a serious health hazard to workers in the area, and corrodes equipment."

Jan 1, 1988

By S. Srinivasan, R. Coté

"India is undergoing a massive electrification program using local coal to provide fuel for thermal generating plants. The Rajmahal mine in northern Bihar is scheduled to produce coal at the rate of 10 million tonnes per year by the end ofa sixty six month contract with MET-CHEM Canada Inc. for mine development. In order to control maintenance performance and warehouse inventory MET-CHEM is installing some proven computer-controlled programs and will provide extensive training to ensure that the systems are properly used. The programs are Maintenance Planning and Control System (MPCS) and Materials Management System (MMS), both of which were developed and used by Quebec Cartier Mining Company at its iron ore mine in northern Quebec. In addition, a Predictive Maintenance Program (PMP) using vibration analysis will be introduced . This paper discusses the three systems.IntroductionIndia is currently undergoing a massive countrywide industrialization and electrification program. Most of the power will be supplied by coal-fired thermal electric plants.One of the mines being developed as part of the over-all program is the Rajmahal Open Cast Coal project in the Godda District of Bihar, approximately 270 km north , and slightly west of Calcutta.The project is based on an agreement signed in January, 1989 between two government organizations - Canadian Commercial Corporation (Ccq and Coal India Limited (CIL). MET-CHEM Canada Inc. (MET-CHEM), an international consulting engineering organization which has worked in India since 1976, is CCCs Canadian executing agency for the project. METCHEM was the engineer-constructor and mining associate for the development of the 7.5 mtpy Kudremukh Iron Ore Project. This US$430 million project was completed on schedule and under the original budget estimate. The Rajmahal deposit is the responsibility of Eastern Coalfields Limited (ECL), a subsidiary of CIL. The project is to produce coal at the rate of 10.5 million tonnes per year in 1994."

Jan 1, 1991

By T. Alan O'Hara

"The decision to invest capital in developing a mine and constructing a mineral processing plant and services is usually made after a feasibility study shows 'that the estimated future cash flow from mine operations will yield an adequate return on the estimated capital expenditures.The actual return on investment may differ substantially from that estimated in the feasibility study, because of the probabilities of errors in estimating capital costs, ore reserves, operating costs, mineral revenue and operating productivity. This paper outlines the R.S.S. (root sum of squares) risk analysis procedure of computing the overall probability of the actual project D.C.F. (rate of discounted cash flow), differing from that estimated in the feasibility study.Variation in Project D.C.F.It is assumed that a feasibility study of the project has been completed which has defined the estimated values for all the project parameters, such as ore reserve tons and grade, capital cost, concentrate recovery, metal revenue, daily milling capacity and operating costs.The financial analysis of the mining project will have determined that the cumulative cash flow will yield an expected D.C.F. on the capital cost if all project parameters attain the estimated values. If, however, the actual value of any parameter varies from that estimated, the actual project D.C.F. will vary from the estimated D.C.F. Risk analysis methods attempt to determine the overall effect of probable variations in the estimated values of all project parameters on the D.C.F. of the mining project. This overall effect is expressed as a probability profile, which shows the likelihood of actual D.C.F. values greater or less than that estimated.Thus, a completed risk analysis of a mine project, with an expected D.C.F. of 15.51%, would display the characteristics shown in the preceding diagram."

Jan 1, 1982

By P. Mottahed, E. K. S. Passaris, J. Q. Ran

"The jointed roof of underground mine openings in stratified rock can be analyzed in terms of a voussoir beam. Because of the essential indeterminacy of the structure, previous attempts of theoretically solving the equilibrium equation have been unsuccessful. Numericalanalysisby the finite element method taking the geometrical and joint non-linearity into consideration combined with the experimental method has been adopted to study the performance isopara of the voussoir beam. Deformation and failure mechanism is analyzed in relation to the failure modes. Equations are proposed to estimate the elastic buckling strength and the crushing strength of the voussoir beam and to verify the failure mode of shear sliding. For application of the mechanism of the voussoir beam in mining operations, methods are described to predict the stability of a jointed roof and to design the dimensions of mining openings.IntroductionThe roof stability of an underground mine opening has direct effects on the selection of support methods, opening dimensions and, more importantly, on the safety of mining personnel. The prediction of the roof stability can be of importance in the design of a mining method and in mining operations. The jointed roof of mine openings in stratified rock can be stable under transverse load depending on the roof geometry and properties of the roof material and joints. The stability of this type of roof can be analyzed in terms of a voussoir beam which was introduced by Evans (1941) to study the strength of underground strata. Brady and Brown (1985) analyzed the voussoir beam and suggested that the mechanism of the voussoir beam could be used in the design of underground mine openings in stratified rock instead of the traditional continuous beam theory."

Jan 1, 1993

By J. Erik Scheel

Overview ? About Hard Creek Nickel ? Turnagain property ? Proposed power line ? Recent Preliminary Assessment ? Favourable economics ? Property Geology ? Mineralization and metallurgical characteristics of major lithologies ? Development of the acNi (ammonimum-citrate H2O2) technique ? Overview of necessary steps ? Results of the technique ? Conclusions

May 1, 2008

By K. Enns, J. J. Byerley

"While thiocyanate (SCN-) is used in a number of industrial processes (production of polyacrylonitrile filaments, synthesis of agricultural chemicals and certain metallurgical solvent extraction and flotation circuits) it is recognized more as an undesirable by-product associated with ' the metallurgical industry. Thiocyanate is present at low concentrations in some waste streams from the iron and steel industry. Of particular significance is the formation of thiocyanate during cyanidation of gold and silver ores, concentrates, tailing s and residues. The thiocyanate levels present in the resulting effluents may range from a few mg/I to several thousand mg/I.At present, thiocyanate does not appear to be as hazardous in the environment as cyanide (CN-) at the same concentration although its interaction with other species and resulting decomposition of products may be unacceptable. Of course the presence of thiocyanate in the leaching circuit and ultimately in the effluent streams may add considerably to the oxidative requirments of any non-selective treatment process for cyanidation wastes.With respect to the thiocyanate as it relates to the cyanidation process, two aspects are evident. Thiocyanate forms and persists in the cyanidation circuit resulting in a ""fouling"" condition with subsequent loss of leaching activity. In order to reduce or control this problem, it is common practice for some mills to discharge daily as much as 20% of the barren leach liquor. Besides contributing to fouling of the leach liquor the formation of thiocyanate represents an irreversible loss of reagent cyanide. It is noteworthy that in some present or proposed mill practice reagent cyanide loss through thiocyanate formation may reach 50%(1). The purpose of this paper is to discus s the application of controlled electrooxidation of thiocyanate with the view of suggesting a process for regenerating cyanide from waste thiocyanate(2). The paper describes the important theoretical aspects and presents experimental data obtained for thiocyanate electrooxidation using both small and large scale electrochemical reactors. Some economic conclusions are presented."

Jan 1, 1984

By B. J. Morash

"The six mineable coal seams at Quintette Coal Limited (QCL) vary in thickness from 0.75 m to 9.5 m and include waste partings varying from 0.2 m to 4 m thick. They are highly faulted and folded in some areas and dip angles range from horizontal to 90 degrees. Due to this variation in thickness and orientation of the seams, several different mining methods are used to economically recover the coal. The key to QCL's success depends on the timely collection of detailed geology data and on mine planning which allows selection of the best method of mining to achieve maximum coal recovery with minimum dilution and cost. This paper will describe the various methods of mining employed and the criteria used to select them. IntroductionThe unique challenge in mining at Quintette Coal Limited (QCL) is to extract large quantities of coal and waste, from a complex orebody, with constricted areas for mining and waste disposal. This challenge dictates the mining of as many as four 10 m benches per year, through complicated coal structures, from three separate open pits with a total of 19coal seams. This total is made up of 5 seams at Mesa, 8 seams at Wolverine and 6 seams at Shikano (Fig. 1).Computer-aided mine planning and scheduling is carried out on a routine basis to ensure the prudent selection of methods of mining, to produce plans which ensure delivery of appropriately blended raw coals to the plant, and to coordinate disposal of large quantities of waste.Several methods of mining are applied simultaneously, and as a result coal and waste are released at different rates from twelve to fifteen mining faces. In order to ensure uninterrupted flow of material from excavators and to utilize the truck fleet effectively, a computerized dispatch system is employed.GeologyGenerally, geological conditions can be related to structural (faults and dip angle) and/or stratigraphic (coal seam and interseam waste thickness) sources"

Jan 1, 1988

By M. Maldonado, P. Olivares

"A submersible sensor for real-time gas holdup measurement in the collection zone of industrial flotation machines is introduced. The working principle is based on the generation and measurement of a pulp flow using a gas-exclusion cell immersed in the aerated slurry. The gas exclusion cell consists of a variable-area open vertical tube designed to be filled only with pulp by preventing gas bubbles entrance. The higher density of the fluid column within the cell generates a downward flow of pulp; the rate of this flow is proportional to the gas holdup outside the cell. The gas holdup measurement is achieved by tracking the velocity of the pulp flow leaving the gas-exclusion cell, using a magnetic flowmeter. Construction details of a prototype and its testing in two- and three-phases are discussed.INTRODUCTIONFlotation process optimization consists of finding and maintaining operating conditions that maximize flotation performance measured in terms of recovery and grade. The selective separation of mineral particles proceeds in two interactive zones where different and simultaneous phenomena take place: in the collection zone, the valuable particles are separated by collection on the surface of bubbles, while in the froth zone, the bubble-particle aggregates are gathered, drained to remove entrained particles, and taken into the concentrate stream. The cell overall performance, which can be determined from proper stream sampling, is a function of the recoveries in the individual zones. These zone recoveries cannot be independently measured nor calculated from operating variables. Progress in the assessment of these recoveries has been slow because on-line and reliable sensors to measure properties of the drastically different dispersions existing in both zones are not available.In the case of the collection zone, it has been demonstrated that the recovery of hydrophobic particles on the surface of bubbles, considered as a process with first-order kinetics, correlates with the bubble surface area flux (Finch et al., 2000; Hernandez, et al., 2003; Lopez-Saucedo et al., 2012). Bubble surface area flux (bubble area generated per unit time and cell cross-sectional area), is a variable affected by gas flow rate, bubble size distribution, and frother type and concentration. Gas holdup (volumetric fraction of gas dispersed in the slurry) is also affected by the same variables, and as such, carries information on the interacting variables that define the performance of the process. Therefore, a correlation between gas holdup and bubble surface area flux was expected and demonstrated (Finch et al, 2000), and since gas holdup is easier to measure as no bubble size is required, it has the potential to be the basis of a cell control and optimization strategy if a continuous sensor is available."

Jan 1, 2016

By J. G. Schofield, R. C. Francki, K. M. Donaldson, F. E. Ham

"Developments in pyrometallurgical technology have led to larger furnaces operating under more intense process conditions. In order to maintain the reliability of these furnaces, which are frequently single-line units, the design of the refractories, cooling systems and bindings has become more critical. Traditional thermal and chemical requirements for the refractory to resist slag attack must still be carefully determined. The larger, modem furnaces have placed a new emphasis on the structural properties of the refractories as well as their thermal properties to suit the extensive cooling systems. Based on operating experience, supported by computer models, the refractories and bindings are designed to work together to accommodate the thermal expansions and contractions in order to minimize permanent furnace growth and the risks of leaks. IntroductionElectric furnaces are used extensively in smelting copper and nickel ores and concentrates. Laterite nickel ores and high-magnesia copper, nickel and platinum sulphide concentrates are smelted virtually exclusively in electric furnaces to accommodate the high melting point of the slags produced. Although a number of smelting processes using oxygen-enriched and/or preheated air have been developed to replace reverberatory furnace smelting of conventional copper and copper-nickel concentrates, (lnco, Noranda, Outokumpu, Mitsubishi) electric matte furnaces remain a strong process alternative for these concentrates, either as the primary smelting vessel or for cleaning the slags produced from these processes.The development of large, high-powered furnaces has been an important factor in the growth of electric smelting technology, as evidenced by the list of operating matte and ferronickel furnaces shown in Table I. Because the compressive forces required to maintain a tight, leak-free furnace increase with furnace dimensions, the selection and design of the furnace refractories, cooling systems and bindings require increased attention."

Jan 1, 1993

By G. Wang, L. R. Moore, Y. Xiong, A. Gorken

"Mining is a very water intensive industry. As such, the industry has become dependent on applying alternate sources in efforts to minimize the impact on the locally available fresh water. Sources such as recycled water, sea water, and even acid mine drainage have been applied at some limited applications, while other mines may not even have the option of fresh water available in their region. However, the different sources of water will have varying concentrations and types of soluble salts and suspended solids, which can lead to dramatic differences in mineral processing when comparing these types of waters. Water quality is known to affect bubble generation and strength, mineral surface charge, and even reagent coordination properties. This paper focuses on the exploration of how water quality and soluble salts affect the flotation of iron and titanium containing minerals from feldspar, and the design of flotation collectors for optimal performance in this water.INTRODUCTIONFeldspar is defined as a tectosilicate mineral with the generic structure of MAlxSixO8, where M represents the cation (Celik, 2001). Feldspar is most often found naturally occurring with quartz, iron containing minerals (i.e mica), and titanium containing minerals (i.e. rutile). The alumina component of feldspar is of interest to glass making, while the alkali metal component is of interest to ceramics (Vidyadhar, 2002). In glass making, the alumina is known to improve product hardness, durability, and resistance to chemical corrosion. In ceramics, the alkalis act as a flux; a flux lowers the melting temperature of the mineral mixture, and assists in connecting the other components present in ceramics. Quartz is stated as having a negative effect on the melting point of the feldspar. Although quartz is typically not removed during the feldspar applications in the glass industry, it needs to be reduced for the ceramics industry. Iron and titanium based minerals are known to have negative effects on color and quality of the products in both glass and ceramics. Thus, these “contaminants” must be reduced to a certain product specification via feldspar beneficiation (Table 1)."

Jan 1, 2016

By Andrew L. Mular, Robert P. Edwards

"The operation of flotation circuits is often regarded as a combination of art and science. Expert systems offer a method by which the art may be captured and supervisory control of flotation circuits fully realized. Operating knowledge, the art, can be consistently employed to enhance regulatory control through the judicious application of an expert system. Using an expert system, a supervisory control routine was developed, and success- fully implemented, in the copper flotation circuit at Brenda Mines Ltd.The expert system ran in conjunction with regulatory PI controllers on a personal computer. The expert system received assays via an on-stream analyzer and adjusted regulatory loop set points as required in real-time. From its commissioning in November, 1989, to the end of the mine 's operation in June, 1990, it was enthusiastically embraced by the operators and attained operating levels superior to those achievable manually.IntroductionExpert system (ES) software springs from research into artificial intelligence and is currently making significant inroads into business and industry. ES proponents make many attractive claims; they are a means of capturing the knowledge of experts and they can be programmed by non-programmers. To date, most uses of this software in the process industry are in off-line applications, meaning that the applications are not tied directly to operating (on-line) environments. Moreover, in on-line environments, they are typically employed as advisors and only suggest changes. Human operators are required to close-the-loop to the process. Yet, an ES should be applicable to operating environments and, if the claims of the proponents are valid, should also be better than existing tools. As an intelligent controller an ES must use the knowledge of experienced operators, apply it directly to a process and do this without the intervention of human operators. On-line applications have been successfully employed in the closed loop control of SAG circuits (Herbst et al., 1989) and flotation circuits (Hales, 1989). Harris and Kosick (1988)detail an implementation for flotation control at the Polaris Mine."

Jan 1, 1992

By K. Poorhaydari, B. M. Patchett, D. G. Ivey

In this paper, some applications of carbon extraction replicas, as samples for transmission electron microscopy (TEM), are discussed. Modern high strength microalloyed (HSMA) steels, used as structural or pipeline materials, have very small grains with substructures. Replicas used in TEM can resolve the grain boundaries and can be used for grain size measurements in cases where the small size of the grains pushes the resolution of conventional optical microscopes. The grain size variations obtained from replicas correlated very well with mechanical property variations, indicated by hardness, in the fine-grained heat-affected zone and base metal of some welded HSMA steels. Replicas are also very suitable samples for precipitate examination with analytical TEM. Advantages and limitations of the application of replicas, as well as some corrections for the estimation of the volume fraction of fine precipitates, are discussed.

Jan 1, 2005