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By David D. Davidson

Commodities remain hot for the time being, but for how much longer? The bulls point to global economic growth lead by China?s insatiable demand for raw materials. To further emphasis the bullish view they point to the emergence of India for follow through demand. The bears remain convinced China?s growth is unsustainable and with higher interest rates and high oil prices, the United States economy is poised to slow. Both groups can make a convincing argument and both will be proven right in the fullness of time. Profitability and balance sheet strength for the mining industry has rarely been better. Is this a time to be bold or cautious? In this paper, the author will address the dilemma facing today?s management as they pursue growth and try to minimize risk.

Apr 1, 2005

By Daven N. Compton

The optical properties of Au nanoparticles have been known for some time, with both Au colloids and Au nanoparticles embedded in glasses having been extensively studied. In this study, Pt nanoparticles have been incorporated into Au colloids, and the linear and non-linear optical properties investigated. UV-VIS spectrophotometry, fluorescence spectroscopy and the z-scan method have been used to examine the effects of such additions.

Oct 1, 2003

By Bradford C. Wesstrom, Ricardo Parra

The Freeport McMoRan El Paso Refinery uses co-generation to produce some of its electricity and all of its steam. This paper will cover the operation of the co-generation plant natural gas turbine at a fixed RPM for blade longevity and energy output. The by-product heat from the turbine passes through boilers with additional heat from a duct burner to produce steam for the Tank House and auxiliary operations. The steam demand varies dramatically throughout the day based on unloading activities in the Tank House. The use of an automated steam control system within the El Paso Refinery will help stabilize line pressure by incrementally controlling steam consumption based on electrolyte temperature. This will minimize steam line pressure fluctuations. INTRODUCTION In the mid 1920’s the Nichols Copper Company of Laurel Hill, New York recognized the need for a modern copper refining facility in the southwest. Due to the many railroad heads, affordable power and abundant labor supply, and the close proximity to regional copper smelters in Mexico, Arizona, and New Mexico, El Paso became the logical location. In December 1928, ground was broken for the joint venture refinery between the Nichols Copper Company, Phelps Dodge, and the Calumet and Arizona Mining Company. In September 1930, Nichols Copper Company became a part of Phelps Dodge Corporation after a stock exchange. In July 1938, Nichols Division officially became Phelps Dodge Refining Corporation. In March 2007, Freeport McMoRan Copper & Gold acquired Phelps Dodge. Energy costs (electrical and thermal) are critically important in the viability of modern copper electrorefineries. The El Paso Refinery produces electricity and steam through its cogeneration system. The El Paso cogeneration facility is a natural gas, 15-megawatt facility containing five turbine generators and associated waste heat recovery boilers. The facility is divided into two phases. Phase I consists of two Allison 2.2-megawatt turbine generators. Phase II consists of three Solar Taurus 3.5-megawatt turbine generators. Presently three units in Phase II are operated. The Phase I units were purchased and installed in 1986 and the Phase II units in 1992 (Solar 1991). The facility operated at full capacity until 2003 when steam demand was significantly reduced due to decrease in cathode production and closure of the copper sulfate and precious metal operations. Phase I units were taken out of service and put on care and maintenance status.

Jan 1, 2019

By Linda Duncan, Trevor Yeomans, Chris Potorieko, Michael Fullam

"NVI Mining’s Myra Falls Operation is a 4,000 mtpd copper/zinc flotation circuit with by product gold of ~28,000 ounces per year. Gold recovery has historically averaged 40-55%, however, a portion of this was recovered in the zinc concentrate and received poor payment. Two Knelson CD-30 Concentrators have been operating in the grinding circuit since 1992, with gravity recovery averaging about 2-5% over that time period.The Myra Falls gravity circuit was one of the very first hard rock mining installations operating in the world with automated Knelsons. The mine has employed a unique and unusual upgrading method for the Knelson concentrate that had never been evaluated as to its efficiency. Recent Gravity Recoverable Gold Testing by McGill University, and mathematical modelling of the Gravity Circuit by Knelson Gravity Solutions indicated the gravity circuit was not living up to its potential. Myra Falls Personnel changed the upgrade system-operating regime, and a complete gravity audit of the grinding circuit was carried out, with the results confirming the initial suspicions. Gravity recovery increased from 5% to 15%, with overall gold recovery improving by 5%.INTRODUCTIONNVI Mining operates a 4000 tpd mine and mill complex on Vancouver Island. The milling circuit consists of open circuit rod milling, closed circuit ball milling, gravity recovery, copper flotation, zinc flotation, and tails disposal. There are two milling circuits, “A” circuit, and “B” circuit."

Jan 1, 2006

By P. T. Bloomer

Introduction Mining of the orebody of the Sullivan mine, which is owned and operated by the Consolidated Mining & Smelting Company of Canada, Limited, has reached a point where pillar extraction is rapidly becoming a major part of the operation. Very few of the larger pillars have been completely extracted; consequently, this paper contains much that is theory and expectation. Due to early mining methods and the physical characteristics of the Sullivan deposit, similar conditions may not exist in other older mines facing the problems of pillar extraction, but it is thought that the methods employed and those contemplated may be of general interest. History The Sullivan orebody, which is at Kimberley in the Fort Steele mining division of the East Kootenay district of British Columbia, was discovered in May, 1892, by Messrs. Sullivan, Smith, Cleaver, and Burchett. After passing through the hands of several owners the property was optioned in 1909, and purchased in 1910, by The Consolidated Mining and Smelting Company of Canada, Limited. Early mining was highly selective, the objective being a clean, high-grade silver-lead ore. By 1923 the difficulties of milling the very complex ore had been overcome and the first unit of a concentrator was completed with a capacity of 2,500 tons daily. Capacity was increased by stages to the present rate of 8,500 tons per day. Concentrates are shipped over the Canadian Pacific railway ? to the Company smelter at Tadanac, British Columbia, for final treatment. Approximately 45,000,000 tons of ore has been mined to date.

Jan 1, 1948

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 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 Baoquan An

The energy required to fragment a rock is proportional to the increase in the fracture surface area and hence is proportional to the rock?s surface area. In comminution, the slope of the linear relationship between size reduction ratio and specific energy is usually defined as grindability. Another definition of grindability based on newly created specific surface area and specific energy is introduced. The two definitions for grindability reflect the grindability properties of rocks and can be used to measure of the efficiency of mills or crushers. The feed particle size distribution influences the energy needed to comminute the rock. For a given ratio of average feed size to product size, the smaller feed size requires more energy.

May 1, 2004

By S. Banisi, M Nesari, J. A. Finch, N. Nobari, H. Javani

"The flotation circuit of the Sarcheshmeh copper mine, which processes 40,000 t/d of ore at 0.9% Cu, consists of rougher, cleaning and recleaning stages. Mechanical flotation cells are used in all stages. To investigate the amenability of flotation columns in the plant especially for cleaning and recleaning stages, a column was designed, constructed, and installed at the Sarcheshmeh pilot plant. The pilot plant, which has an identical circuit configuration compared to the plant, can process up to 2 t/h of ore. The overall rate constant of the ore along with the target recovery of 94% were used to size the column. A 26 cm by 550 cm column with two filter cloth spargers and a submerged froth washing system using perforated tubes was constructed. To detect the interface level a 180 cm conductivity probe consisting of 1.5 cm diameter ring electrodes was installed. The tailings flowrate controlled by a variable speed pump was used as the main control variable. The initial testing program revealed that the optimum superficial gas and wash water flowrate were 1.5 and 0.3 cds, respectively. It was observed that the cleaning stage grade when using the column could increase by 2-3% at constant overall copper recovery.IntroductionThe Sarcheshmeh copper ore body which may rank as third or fourth largest in the world contains 1 billion tomes averaging 0.90 % copper and 0.03 % molybdenum. It is in located south-east Iran and has been processing 40,000 t/d of ore since 1982. After three stages of crushing, the ore with a F80 of 12.7 mm is fed to 8 parallel ball mills in closed circuit with cyclones to produce a product 70% finer than 75 microns. The concentrate of the first stage of flotation is reground and the tailings constitutes the main component of the plant final tailings. A concentrate with an average grade of 31% Cu (chalcopyrite and chalcocite) is obtained after cleaning and re-cleaning stages in mechanical cells. Total recovery of the plant varies between 83-87 % depending on ore type and operating conditions."

Jan 1, 2000

By M. Kolahdoozan, H. Noori

"Molybdenite flotation at the Sarcheshmeh Copper Complex has been studied as a function of pulp potential controlled using two types of sodium sulfide (mineral and chemical origin). Air and either plant or laboratory nitrogen was used as a flotation carrier. Potential measurements were taken in the rougher cells as it was proved to be vital for molybdenite flotation. Flotation test with reducing potentials between -525 and -575 mv gave the highest molybdenum recovery (93%) and the lowest copper recovery of between 4 to 15% can be achieved. These potentials did not change considerably by adding increasing amounts of sodium sulfide. At more oxidizing potentials, i.e. more than -450 mv, the recovery of copper increases while the recovery of Molybdenite drops.INTRODUCTIONThe average copper ore feed grade to the Sarcheshmeh flotation circuit is typically set at about 1.2% Cu. to be delivered to processing unit is set at 1.2%. There is no control of molybdenum (Mo) which usually varies between 0.01 and 0.04%. During concentration, a Cu-Mo concentrate is produced by one stage of roughing, one stage of scavenging and two stages of cleaning. Final concentrate contains 0.5% of Mo and 32% of Cu while the particle size is 90% under 42 microns (325 mesh). Because of the high grade of Mo in this concentrate and economic interests, a molybdenite flotation circuit plant was built in 1984. This plant was designed to treat 1432 tons of Cu-Mo concentrate (on dry basis) and consists of one stage of roughing followed by seven stages of cleaning. After dewatering the concentrate contains 53.7% Mo which is dried and shipped overseas.The majority of molybdenite production worldwide comes as byproduct of copper porphyry ores. The Mo grade typically varies between 0.01 and 0.06% and accompanies chalcopyrite and chalcocite. Due to the hydrophobic nature of molybdenite, it can be floated along with copper sulfides. Thus the overall concentrate of Cu and Mo contains 0.2-1% of molybdenum as well as 20-42% of copper. To separate the Mo, Cu and Fe minerals, depressants are used. The most important of which are sodium sulfide, sodium hydrosulfide, Anomal D, sodium cyanide, ferropottasium and ferro-cyanide. The first three regeants have been extensively used for successfully treating porphyry ores [1]. In the molybdenum plant of the Sarcheshmeh Copper Complex only sodium sulfide has been used to date."

Jan 1, 2006

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 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 Richard C. Banting

Excessive vibration is known to have an adverse affect on soft body tissue and operators of heavy mining equipment can be exposed to vibration that exceeds levels recommended in international guidelines (ISO 2631-1, for example). Research has found that many of the seat and suspension systems currently used in mine haul trucks and load haul dump vehicles are actually amplifying the vibration. This overview presentation will outline the current research being conducted at Laurentian University and the University of Western Ontario, and the roles of partners in rating the ability of a number of commonly used mine vehicle seats to isolate harmful vibration.

Oct 1, 2010

By Tony Lipiec, Chris Fleming, Larry Urbanoski

In 2009, the Canadian Mineral Processors (CMP) became aware that Canadian securities regulators were amending the contents of National Instrument 43-101. NI 43-101 is a set of regulations which establish how ore resources and reserves are presented to the investing public. The documents produced under NI 43-101 are central to the ability of many companies to raise financing for their projects. With the increase of metallurgical complexity, and decrease of head grades encountered in new deposits, the role of the Qualified Person (QP) in determining process performance has become increasingly critical in determining the classification category of resources and reserves. Given the challenges confronted by those involved in defining the concentration and extraction of minerals and metals, there is a need to provide support to these QPs. To address these concerns, the CMP established a sub-committee in 2010 to create a set of guideline documents to assist the QP involved in process matters as to what should be included at the various levels of study supporting the establishment of resources and reserves in NI 43- 101. The results of the sub-committee work are presented and the considerations in the writing of the documents are discussed.

Jan 1, 2011

By Norman O. Lotter

The problem of quantifying the full performance potential of an ore body in a concentrator, and how to configure a flowsheet to achieve that potential, either for a new operation or an existing one, is a strategic challenge. Modern flowsheeting technology that has been developed over the last twenty years has provided a suitable platform to achieve this. The integrated use of geology, compositional and quantitative mineralogy, sampling models, quality controls, and mineral processing, including flotation testing, has evolved into what is now called process mineralogy. Two specific tools have been developed and validated as standard methods in this toollbox. These are statistical benchmark surveying and high-confidence flotation testing. Both of these have borrowed from the sampling theories of Pierre Gy and from geostatistics. Additionally, they work on a replicate measurement and averaging basis, thus reducing the overall random error level. With this arrangement, one is in a position to characterize the ore from true samples and identify and quantify the economic minerals present in a manner that easily brings out the processing implications and likely grades and recoveries. In particular, the approach captures the variation in the ore body, which, if properly translated into the flowsheet design, minimizes the risk that unexpected responses will develop in the concentrator operations. A further advantage is that successful plant trials are now possible and practical. An overview of this approach is presented with two case studies.

Jan 1, 2011

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 F. W. Gray

IN 1922, the writer communicated to the Institute a paper entitled The Development of the Coal Industry in Canada (1), which summarized the considerations set out in a series of papers (2) concerned with coal-mining in Canada which he had presented in 1920 and 1921. This paper contained a forecast by decades, commencing 1920, of Canadian coal production, importation, consumption, and exports, based on anticipated rate of population increase, and continuation of the gradual increase in the per capita rate of coal consumption in Canada that had taken place every year up to 1920. The following comparative statement brings our the differences between the forecast and actual experience:

Jan 1, 1936

By Alain Langlais, Caroline Boudrias Chapleau, Claude Bazin, Ahmed Bouajila

"Slurry «viscosity» has been recognised for several decades as a variable that significantly influences the operation of grinding mills. This paper describes an instrument that can be used in a laboratory or a plant to measure and monitor the flow properties of mineral slurries. Laboratory results obtained for two different ore samples are consistent with results obtained during a full scale trial. The results provide a basis for analysing the effect of the solids concentration and particle size distribution on the slurry flow properties. Grinding tests were also conducted in an attempt to link the grinding efficiency to the rheological properties of mineral slurries.INTRODUCTIONThe flow properties, or incorrectly called «viscosity», of a slurry influence the operation of mineral processing devices. Work has been conducted for instance to assess the effect of this variable on the operation of hydrocyclones (Kawatra et al. 1996; Klimpel, 1982a) and dense media separators for coal (Napier-Munn, 1996). However, most of the research effort has been oriented toward the grinding processes which is still the most energy demanding operation for ore dressing (Fuerstenau et al., 1995).Results of investigations of the influence of slurry flow properties upon grinding performances are presented regularly in the literature since 1950. In the 70's, most of the research work was conducted with the aim of using slurry flow properties for the control of grinding mill and to analyze the effect of that variable upon the population balance model breakage and rate functions (Austin et al., 1984; Hemmings et Boyes, 1977). In the 80's, most of the litterature dealing with slurry rheology was devoted to the use of viscosity modifiers to adjust the slurry flow properties, allowing an increase of grinding mill throughputs (Klimpel, 1982b; Fuerstenau et al., 1985). Although laboratory and pilot plant results show the benefits of adding these modifiers to the slurry, few plants have published results concerning the advantages of such addition (Fuerstenau et al., 1985). It is felt that the use of these modifiers introduce operating difficulties with the concentration circuits, especially flotation (Kawatra et Eisele, 1988)."

Jan 1, 2003

By A. C. Wilson

In 1991, local prospector C. ?Mickey? Clement recovered at least three alluvial diamonds from the Michipicoten River. Two of these stones were sent to the Department of Mineralogy, Royal Ontario Museum, where they were identified as industrial grade diamonds with weights of 1.05 and 1.13 carats. Both stones were described as frosted and graphite-inclusion riddled. In 1995, prospector Sandor Surmacz and geologist Marcelle Hauseux discovered diamonds in bedrock approximately 20 km north of the Michipicoten River. An 18.1-kg bulk sample of a xenolith-rich lamprophyre, taken from an outcrop at the side of the Trans Canada Highway north of Wawa, yielded 1 macro diamond and 5 micro diamonds. All but one was gem quality (Sage 2000). Since then, more than 36 occurrences of diamonds in bedrock have been reported in an approximately 30 km2 area centred 20 km north of the town of Wawa. The occurrences are hosted within a sequence of unusual, Archean-aged, heterolithic breccias previously considered to have no economic significance. Ten kimberlite occurrences also have been confirmed in the Michipicoten greenstone belt in the last 5 years. Two of these kimberlites are diamondiferous. To date, expenditures on property acquisition and diamond exploration in the Wawa are estimated at $120 million (CAN). This paper summarizes the geological observations made on these occurrences and discusses including the relationship between the occurrences and the regional geology.

May 1, 2003

By Alan D. Akerman

This paper describes the significant advantages and improvements in operational availability, reduced breakdowns, and overall cost reductions that can be achieved through the application of a Reliability Centred Maintenance (RCM) program, including Condition Based Maintenance (CBM) and Equipment Health Monitoring (EHM), in a mine environment. It uses a case study to illustrate the essential elements that constitute the basic requirements to establish such programs. This CBM case study analyzed the Load-Haul- Dump (LHD) vehicle sub-systems and their dominant failure modes, as a precursor to the development of condition indicators. The case study describes a disciplined process to enable condition indicator development and qualification in support of a CBM program. The identified condition indicators vary from readily applicable off-the-shelf monitoring systems and techniques, through to "leading edge" technologies that require further research and development. The paper also explores the developments that have been made in the combination of expert system software associated with modern computer based control systems, and the availability of "intelligent? sensor technology that complement the control system capability.

May 1, 2002