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By B. K. Gorain, A. W. Stradling

"The traditional metallurgical scale-up techniques for flotation plants are based on lumped flotation rate constants, dimensionless hydrodynamic numbers and the use of safety factors. Once the plant has been designed, the flotation principles that govern scale-up play almost no role in the optimization of the circuit to meet its metallurgical targets. This deficiency can potentially lead to a plant design incapable of meeting its targets, especially when circuits incorporate large flotation cells. This paper demonstrates the application of the k = PSbRf model in providing a suitable framework for flotation modelling, scale-up and circuit optimization, thus presenting an integrated approach to the problem. Studies were conducted at Teck Cominco’s Red Dog concentrator to characterize cell hydrodynamics, gas dispersion properties, froth flow behaviour, entrainment and ore floatability to obtain the key data necessary to develop a model for the flotation circuit. The findings of these studies are presented in this paper, which provide valuable insights into the modelling and optimization of the Red Dog flotation circuit. IntroductionThe traditional methodology for flotation scale-up and plant design is based on the ruleof- thumb with safety factors and dimensionless hydrodynamic group similitude considerations. With the recent trend toward larger flotation cells with volumes of 150 m3 and greater in concentrators, the problem of scale-up has become even more acute. The scale-up factors that may have been tolerated on smaller cells are not applicable to larger cells. The transportation of froth in these large cells adds further complexity to the problem. Arbiter et al. (1980) foresaw this problem and pointed out that if scale-up were attempted by rule-ofthumb and trial-and-error, the probability of failure would then increase with scale. This problem is confounded by the fact that the design and scale-up considerations used for a new flotation circuit play almost no role in optimization of the circuit to meet its metallurgical target. This results in a plant design, which may be incapable of meeting its metallurgical targets. There have been several instances where new concentrators have required significant circuit modifications and additional capacity to achieve design targets."

Jan 1, 2003

By J. H. Crocket, J. Andy Fyon

"All gold deposits within the Tisdale Group are spatially associated with carbonate alteration zones; however, not all carbonate alteration zones are host to gold mineralization.Within the komatiitic and magnesium tholeiitic volcanic rocks at the base of the Tisdale Group, discordant and stratabound carbonate alteration zones occur throughout. The alteration zones consist of a ferroan dolomite - quartz inner assemblage which is enveloped by calcite-quartz and an outer chlorite-rich subzone. Factors which control the distribution of carbonate alteration include joint systems, flow contacts, synvolcanic faults and bulk composition of the host rock.Two environments of carbonate alteration can be recognized: 1) The subsea-floor alteration zones developed within the volcanic rock succession where hydrothermal fluids did not discharge directly onto the sea floor. Insignificant gold production has come from this alteration environment. 2) Seafloor zones, which represent points of hydrothermal fluid discharge into the hydrosphere, are spatially associated with felsic volcanic rock complexes and are host to syngenetic, auriferous cherty dolomite.Carbonatized, magnesium tholeiitic basalts, which are host to the auriferous, cherty dolomite, are enriched in antimony (>0.35 ppm), boron (>30 ppm), gold (>5 ppb) and lithium (> 35 ppm), but are depleted in copper ( < 70 ppm), with respect to carbonatized basalts not associated with gold. Orerelated, altered komatiitic flows can be screened using gold (>5 ppb), lead(> 10 ppm), arsenic(> 70 ppm) and antimony (>1 ppm).The habit, petrographic characteristics and certain geochemical characteristics of the altered volcanic rocks suggest that the hydrothermal fluid was of sea-water origin."

Jan 1, 1982

By Pravin Kumar

Goldcorp Inc.?s Red Lake Mine (RLM) is situated in the Red Lake Mining District, a history rich North Western Ontario mining community. Red Lake Mine formerly known as the Dickenson Mine has experienced various degree and type of bursting since the 1960?s. During the 1960?s burst were common in shrinkage stope box hole pillars. After discovering the High Grade Zone (HGZ) between its 30th and 39th levels, the mine has changed its mining method to mechanized cut and fill with cemented paste fill. The rock mass at RLM is mainly massive basalt-ultramafic and behaves in a manner consistent with massive brittle rock. This paper presents the use of empirical and numerical design techniques. The use of the Span versus RMR graph to determine critical stope spans at RLM and the use of numerical design techniques to determine the stability of the sills and post pillars. Selecting of a sill pillar dimension is illustrated using four different failure criteria?s. The four failure criteria are m & s failure criteria, the Pillar Stability Graph, deviatoric stress ???-?3), and induced stress level criteria ?1 /UCS, which are calibrated to RLM?s ground conditions. A wide range of case histories has been studied ranging from stable to highly burst prone ground conditions in order to calibrate the failure criteria to observed conditions and quantified to local micro seismic system.

May 1, 2002

By W. G. Johnson

"As we move into 1983, Canada is not only in a deep recession, there are major changes taking place.International competition is growing fiercer.Major core industries such as automobile, steel, mining, oil, agriculture, forestry, fishing, major manufacturing and others are just not expanding.If and when recovery comes starting in mid-1983, as many predict, don't expect industries to suddenly resume former growth patterns. It's just not possible.Companies, by necessity, are becoming lean and mean, and they are still in the process of reducing staff to meet changing times and conditions. Many of the staff now being released may never return to fulltime work with a single employer, particularly if they cannot measure up to more exacting performance standards and management expectations.There are clear cut instances of people who lose a job for reasons beyond their control. A merger, the loss of function, or a major reorganization sometimes creates casualties of people who were excellent performers. Such people can survive well, based on the tongue of good report and with some help from associates or others. However, even good performers often have difficulty in adjusting to the rigors of finding a new job and to become their own personal salesman."

Jan 1, 1983

By R. A. Bergman, C. A. Pickles, J. M. Toguri

"Black calcium cyanide is utilized mainly as a reagent for gold extraction. It is produced by reacting calcium cyanamide, sodium chloride and calcium carbide at temperatures in the range of 1200°C to 1400°C in a smothered arc furnace. The equivalent sodium cyanide content of the product is in the range of 45% to 50% and the calcium cyanamide conversion efficiency is in the range of 90% to 95%. Since black cyanide contains impurities such as salt and lime and also because the conversion efficiencies are below 100%, the product contains unwanted materials which significantly increase the shipping costs.The impurity content of the raw materials can not be lowered without increasing their cost and/or the processes to produce them, and therefore the present research was focussed on studying those factors which affect the cyanide grade. The major variables investigated were: the heating rate, the reaction temperature, the salt to cyanamide ratio, the nitrogen content of the calcium cyanamide, moisture additions and calcium carbide additions. It was found that each of these variables had a significant effect on the product grade. The highest cyanide content of the product was obtained for salt to cyanamide mass ratios of 0.55 to 0.60. The salt reduces the decomposition rate of the cyanide and, therefore, at low salt to cyanamide ratios and at higher temperatures, the product grade is decreased. It is likely that the salt evaporates at the higher reaction temperatures and this decreases the cyanide capacity of the melt. High heating rates minimize the residence time and thus salt evaporation is reduced and higher grades can be obtained. As expected, the cyanide content increased with the nitrogen content of the cyanamide. Calcium carbide additions resulted in an increase in the product grade. The presence of small amounts of moisture in the charge caused a significant decrease in the cyanide content of the black cyanide. An equilibrium reaction is postulated in order to explain the black cyanide process and in particular the effect of calcium carbide on the product grade."

Jan 1, 2002

By Peter Raziszewski

"A ball charge dynamics model is presented. Simulation results are compared with observed data showing good correlation. Based on the charge dynamics models, a liner wear model is presented along with some wear simulation results. Using the charge dynamics model with the liner wear model, it is possible to envision the predictions of mill power consumption as a function of liner wear. Further work is needed to validate the liner wear model.IntroductionFrom a process control point of view, industrial systems can be considered stationary or non-stationary. For example, the physical properties, such as geometric and/or material, of a system considered stationary do not change with time. However, this is not true for non-stationary systems such as those found in the mining industry where process dynamics are often violent with wear being an intrinsic process phenomenon.In this paper, a model for ball charge dynamics will be presented along with a description for liner wear. Simulation results for power draft prediction using the charge model will be compared with observed data. Further, liner wear results will also be presented."

Jan 1, 1997

By Bob Robinson

In 1990, the European Space Agency (ESA) initiated a technology transfer program to stimulate the wider use of technology developed by the European and Canadian space communities. This paper focuses on the method of technology transfer from the space industry to terrestrial industries, with a focus on the mining resource sector within a program called the Harsh Environments Initiative (HEI) created in 1997. Other resource sector applications include forestry and oil & gas. C-CORE in partnership with the Mining Innovation, Rehabilitation and Applied Research Corporation (MIRARCO) supported by ESA, Canadian Space Agency (CSA) and European R&D organizations conduct projects to promote and demonstrate the transfer of innovative technologies from space to non-space industries. Space programs have and continue to develop new knowledge for extra-terrestrial application, e.g., satellite earth observation, manned missions and unmanned planetary exploration. Many of which hold the potential for application on land and ocean. Currently, space technologies of interest to the mine sector range from robotics and image analysis to sensors, software and advanced materials. The HEI works to identify and apply these types of technologies in the areas of automated/tele-controlled mine operations and mine monitoring.

May 1, 2001

By R. N. Murarka

"Hydrocyclone modelling and selection procedure is illustrated. Computerized procedure for hydrocyclone cut size determination for grinding and non-grinding applications is described.A standard procedure for evaluating operating hydrocyclones is described in detail. Many case studies are illustrated comparing actual plant performance with the computer simulation output in terms of overflow product size distributions.INTRODUCTION Cyclones are widely used for applications such as: close circuit grinding, backfill, tailings and dewatering. Normally, cyclones are used for very fine separations where screens are not suitable or too expensive. Figure 1 shows the separation size range of various classifying devices. Cyclones are popular because of their low capital and operating cost. Cyclone selection procedure for different applications depends on the amount of information available on the cyclone feed slurry characteristics. Closed circuit grinding applications will be discussed in detail in this paper. The Cut Size:The size of the material in the feed which reports 50% to each product stream (i.e. underflow and overflow), after correcting for the feed solids by-passing with the underflow liquid, is termed the cut size or ""d50c"". This is often used as the criterion and the basis for cyclone design.When the corrected recovery to underflow of each mesh size in the feed is plotted against the geometric mean size in microns on a log scale, the micron size corresponding to 50% recovery is the d50c size."

Jan 1, 1992

By Karl Hoover, Cassandra Spence, Brent Bachewich, Jaakko Levanaho

"Since year 2000 the gold recovery into copper concentrate at Hudson Bay Mining and Smelting has reduced considerably during the summer months. This initiated a testwork program in the fall 2003 to find reasons and solutions for such change. During the testwork mineralogical factors, water quality effects and different reagents were evaluated. The reason for the lower recovery appeared to be the sensitivity of some collectors to pulp temperature. As a result of the work different collectors are being used in the mill in the summer than in the winter. A modification to the water system was also made to provide cooler water to the mill in the summer months.INTRODUCTIONHudson Bay Mining and Smelting (HBMS) is located in Northern Manitoba, just on the border of Manitoba and Saskatchewan. The complex consist of four different mines, Callinan, Trout Lake, Konuto Lake and 777 mine including copper smelter and zinc hydrometallurgical plants producing metallic copper and zinc. Gold is a very important byproduct providing about 30% of the mine revenue. In early 1990s when the company was facing declining ore reserves and was starting to gradually close down the operations, the 777’th exploration drill hole discovered a new orebody, which initiated a $0.5 billion expansion program. The main projects were a new 777 hoist with underground development and a new zinc cell house. About $30 million was used to increase the mill throughput to the present 2.27 million tonnes or 2.5 million short tons per year. The expansion programs were finished by the end of the year 2003.Historically the gold recovery at HBMS has varied between 60 and 70%. The recovery has been somewhat lower during the summer months. Gold recovery improvement projects were conducted throughout the 1990s, but were not focused on the seasonal gold recovery variance. However, since 2000, when the water system modifications to meet the increased water demand were completed, the gold recovery during the summer has been much lower than in the past. In August 2003 gold recovery fell below 30%, which initiated a metallurgical research program to discover the reasons behind the low gold recovery in the summer."

Jan 1, 2005

By P. H. Oliver

The current theory of how explosives fracture rock offers no explanation for the improvements in fragmentation and the reduction of fly rock and back break which occurs when an adequate inter-row delay time is used. Nor does it explain why fragmentation improves with rectangular drill patterns where the hole spacing may be as much as four times the hole burden. A new theory of rock fragmentation is proposed which builds on the existing theory. It offers rational explanations for the many blast effects which the current theory does not address and the need for adequate timing delays between rows. It improves on the design of inter-row delay timing by defining the length of free-blasted face needed in front of a hole when selecting the delay element which will provide an adequate inter-row delay time.

May 1, 2003

By P. H. Oliver

"The current theory of how explosives fracture rock offers no explanation for the improvements in fragmentation and the reduction of fly rock and back break which occurs when an adequate inter-row delay time is used. Nor does it explain why fragmentation improves with rectangular drill patterns where the hole spacing may be as much as four times the hole burden.A new theory of rock fragmentation is proposed which builds on the existing theory. It offers rational explanations for the many blast effects which the current theory does not address and the need for adequate timing delays between rows. It improves on the design of inter-row delay timing by defining the length of free-blasted face needed in front of a hole *Retired from Inco Ltd., Sudbury, Ontario when selecting the delay element which will provide an adequate inter-row delay time."

Jan 1, 2003

By J. W. Austin

"Introduction The Brenda dust collection system was originally designed to handle air at the 5000 ft. elevation with less than 1 grain of dust per cubic feet of air handled. The temperature variation is from 32°C in the summer to -20°C in the winter.DUST COLLECTIONOriginal Equipment 1. Primary Crusher 2 compartment baghouse, shaker type design capacity - 17,000 cfm2. Primary Screening 3 compartment baghouse, shaker type design capacity - 30,000 cfm3. Secondary Crusher 4 compartment baghouse, shaker type design capacity - 45,000 cfm4. Secondary Screening 4 compartment baghouse, shaker typedesign capacity - 60,000 cfmThe original dust collecting equipment was designed using a napped terylene fabric at an air to cloth ratio of 5:1. The ducting was designed to handle the dust laden air at 3200 ft. per minute with all elbows and blast gate sections rubber lined. The hoods and the pickup velocities were designed to handle the anticipated low dust counts."

Jan 1, 1976

By H. E. Urtubia

"BHP-Billiton’s Minera Escondida Limitada, in Chile, is one of the world’s largest copper producers. It treats a combined 10,500 tph of copper ore through its two concentrators: Los Colorados and Laguna Seca. The performance of the rougher circuit at each concentrator was measured and analysed using the JKTech flotation optimisation methodology. This involved developing a flotation model for each concentrator based on cell operating parameters (for example bubble surface area flux and froth recovery) and feed ore floatability characteristics. The rougher circuit performance was evaluated in terms of traditional measures, such as grade and recovery. The operation was also analysed using the measured cell operating parameters and ore floatability and the effect of these with regard to performance (grade / recovery) was assessed.This paper presents a comparison of the rougher circuit at each concentrator in terms of these parameters. The main differences in rougher circuit performance between the two plants were attributed to differences in feed ore floatability characteristics and froth recovery. The comparison highlighted opportunities where performance improvements could be made. The study also showed the usefulness of separating the flotation process into easily measurable subprocesses to further identify the different mechanisms occurring in each rougher circuit. Traditional measures like grade and recovery are useful for monitoring flotation operation but this data lacks the depth to determine the root cause behind operational issues. Determining the operating parameters and ore floatability provides the operating plant metallurgist better tools to assess and manage these issues."

Jan 1, 2006

By P. A. Selvadurai

This paper presents the results of a research investigation leading to the development of a technique for the measurement of the surface permeability of Indiana Limestone. The tests are conducted on a cuboidal block of the limestone with a flat surface that can be sealed to create a circular aperture through which water influx can take place. Computational results for Darcy flow are used to interpret the results of the experiments. The water entry area can be moved over the surface area of the block to investigate, quite conveniently, the distribution of permeability across the surface of the limestone block sample.

May 1, 2009

By B. Simser

Noranda?s Brunswick mine is a 10 000 t/d producer of lead-zinc-copper-silver ore that has been in operation since 1964. Mining of this multiple lens deposit is primarily by blasthole stoping techniques between 400 m and 1200 m below surface. The combination of a high overall extraction ratio, an overall steeply dipping tabular shape, and high horizontal stresses (twice the vertical) have elevated the induced stress regime to levels comparable to much deeper operations. Improved mine design, and a better understanding of how the rock mass responds to mining in high-stress environments is essential to improve overall recoveries and maintain safety. Seismic monitoring has proven to be an essential tool at Brunswick, for both short-term safety of workers, and long-term strategic planning. Practical case studies illustrate how seismic data, particularly source parameter information, can be used to measure the rockmass response to mining and improve mining layouts in difficult regions. As the global trend continues toward mining in deeper, higher stress environments (e.g., South African Witswatersrand Basin, Sudbury Basin) and as local extraction and thus ground stresses continue to increase in existing deposits, seismic monitoring will play a critical role in mining safely and economically.

May 1, 2004

By B. Simser, V. Falmagne

"Noranda’s Brunswick mine is a 10 000 t/d producer of lead-zinc-copper-silver ore that has been in operation since 1964. Mining of this multiple lens deposit is primarily by blasthole stoping techniques between 400 m and 1200 m below surface. The combination of a high overall extraction ratio, an overall steeply dipping tabular shape, and high horizontal stresses (twice the vertical) have elevated the induced stress regime to levels comparable to much deeper operations. Improved mine design, and a better understanding of how the rock mass responds to mining in high-stress environments is essential to improve overall recoveries and maintain safety. Seismic monitoring has proven to be an essential tool at Brunswick, for both short-term safety of workers, and long-term strategic planning.Practical case studies illustrate how seismic data, particularly source parameter information, can be used to measure the rockmass response to mining and improve mining layouts in difficult regions. As the global trend continues toward mining in deeper, higher stress environments (e.g., South African Witswatersrand Basin, Sudbury Basin) and as local extraction and thus ground stresses continue to increase in existing deposits, seismic monitoring will play a critical role in mining safely and economically."

Jan 1, 2004

By P. D. R. Maltby

"1. INTRODUCTIONMy talk today will discuss a new development in the thickening of slurries and clarification of waste water - the Enviro-Clear thickener. Several industrial installations of the thickener have been made in North America in the following applications:1.,water clarification in sugar beet processing plants.2.,separation of pregnant liquors from solid wastes following acid leaching in uranium mills3.,clarification of waste water from coal treatment plants as described in a paper in the June 1975 transactions of the SME entitled ""Application and Utilization of the Enviro Clear Thickener in a U.S. Steel Coal Preparation Plant"" by A.A. Terchnik, D.T. King and J.S. Anderson.2. HISTORYThe application of the Enviro-Clear thickener can be traced back to the filing of U.S. Patent 3523889 in 1970 by the inventor F. Eis. The claims of this patent are shown in Slide 1.The new concept was developed for sugar beet processing by the Spreckels Division of Amstar Corporation, and several such thickeners have subsequently been installed in various sugar beet plants. The Enviro-Clear Co. or New York took over the world-wide manufacturing and marketing of the thickener. Experience in the sugar beet industry indicated that the Enviro-Clear thickener volume requirements could be reduced to as low as one tenth that of a conventional type thickener. Various coal samples were supplied by U.S. Steel Research Laboratories for testing. The tests indicated that feed rate loadings of 3 gpm/ft.2 could be obtained by the Enviro-Clear thickener. Such results led to several industrial applications in the coal industry. Subsequently other branches of the mineral processing industry have come to learn of the possibilities of using this thickener. Slide 2 shows a list of commercial Enviro-Clear installations at the end of 1975."

Jan 1, 1976

By A. W. Stradling, M. J. Fairweather

"The selective flotation of lead, zinc and iron sulphide minerals is key to the economic performance of concentrators treating zinc-lead ores. Diagnostic metallurgy is a tool to quantify mineral behaviour as a function of particle size and liberation. The result of such analysis may be used to select preferred strategies to improve metallurgical performance. The zinc flotation circuits at three Teck Cominco operations: Sullivan, Polaris and Red Dog are compared here. This paper analyses operating data from each of these circuits. The effects of mineralogy and performance by particle size are emphasized. Metallurgical performance at these three concentrators varies substantially. Liberation size is the major factor in determining metallurgical performance. Complex mineralogy requires a fine grind to achieve effective liberation. Fine grinding results in offsetting decreases in concentrate grade through entrainment. The economic treatment of complex fine-grained deposits requires optimisation of regrind size for liberation without unduly compromising concentrate grade through gangue entrainment.INTRODUCTIONUntil recently Teck Cominco Metals Ltd. operated three mines treating zinc-lead ore. In order of increasing mineralogical complexity they are: the Polaris Mine on Little Cornwallis Island in Nunavut in the eastern Arctic, the Sullivan Mine in southeastern British Columbia and the Red Dog Mine in northwestern Alaska. Both the Polaris and Sullivan Mines have recently ceased to operate due to depletion of ore reserves.The ore type and associated gangue, mineralogy and iron solid solution vary significantly between these deposits. Table 1 summarizes some of the important differences"

Jan 1, 2003

By William Winsor, Harold L. Snyder

"AbstractShould oil and gas be proven in commercial quantities on the Labrador Shelf, current technology is not adequate for production operations in this severe environment, which includes yearly invasion of pack ice and icebergs. The fishery of this section of the North Atlantic is a vital resource to which a major oil spill or blow-out would impose an intolerable burden, This means that production systems must be designed and built to be fail-safe.The experiences of mining in Bell Island and Cape Breton have shown that it is possible to operate beneath the ocean floor, and this technology may hold the key for safe, reliable and economic production, This paper attempts to define particular problems and outline possible solutions.IntroductionOUR DISCUSSION is subject to the assumption that large hydrocarbon reservoirs will be discovered in the sedimentary basin of the Labrador continental margin. The petroleum industry has not attempted to operate in a harsher area. The Labrador coastline is exposed to North Atlantic storms and icebergs year’round, Arctic pack ice occurs up to six months of each year. However, there is no doubt that, if sufficient hydrocarbon potential is outlined, development will proceed."

Jan 1, 1977

By X. Gu

Mining operations, especially surface coal mines, have great impacts on the local ecosystem and the environment. However, it has been a common practice in mine design that the economic evaluation considers only the operating and capital costs, while the costs incurred due to ecological damage are left out. Such practice underestimates the total cost of mining and ignores the difference in ecological impacts between different mine design alternatives. With growing interest in sustainable development, the mining industry is under increasing pressure to operate not only based on economic and engineering principles but also on principles of sustainability. Therefore, estimating ecological costs of mining and considering such costs in the mine design process is an important step towards reducing ecological impacts at the design stage. The objective of this paper is to quantify the ecological costs of open pit coal mining and to demonstrate the influence of such costs on the ultimate pit design. The ecological costs of mining are estimated based on the areas and types of land damaged by mining activities and the carbon emission from energy consumption. Four major components of ecological cost are identified, namely, lost value of direct eco-services, lost value of indirect eco-services, prevention and restoration costs, and the cost of carbon emission from energy consumption. Necessary equations are given for estimating these costs. An algorithm is described for ultimate pit optimization in coal deposits with near-horizontal coal seams. A case study is presented in which the ultimate pits with and without ecological costs are optimized and compared to show the influence of ecological costs on the pit design outcome.

Aug 1, 2013