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By W. J. Taylor, T. D. Parris

"Over 90,000 feet of raise have been bored at International Nickel underground mining operations throughout the Sudbury District since the advent of raise boring in the early part of July, 1964. With a total of 10 raise borers on hand at this time, techniques have improved steadily since introduction at INCO mines. The first unit, designed for use in rock of low compressive strength, had to be modified and redesigned to cope with Sudbury Area Precambrian rock. As equipment and boring techniques improved, a specially designed machine for larger holes was developed and is now in use. More powerful units, with a thrust capacity of up to 750,000 pounds, are under investigation. Raises have been bored up to 84-inch diameter, and the changeover to 5- and 6-foot flat reaming heads with improved cutter design has increased performance substantially. As a result, 5-foot-diameter raises have been completed to a length of 750 feet and 6- and 7-foot raises to over 500 feet. Reference is also made to the drilling of over 23,000 feet of drainage and sand-fill holes, ranging up to 7% inches in diameter, with smaller underground rotary drill equipment.Finally, a look into the future indicates the need for further improvements in equipment design to permit economic boring of 7- to 8-foot-diameter raises in Sudbury Area ground types."

Jan 1, 1972

By Q. Zhang, J. A. Finch

"Sphalerite flotation in the absence of copper activation at moderately alkaline pH has been observed in laboratory studies. An in-plant test of this observation was conducted at Kidd Creek Mine LTD. using a portable minicell flotation circuit. The results confirm that raising the pH causes sphalerite flotation.The testwork with the minicell circuit is described. The circuit, built around 2, 51 cells donated by the Noranda Technology Centre, was funded by Air Liquide and NSERC. It includes a data acquisition system to monitor continuously dissolved oxygen, pH and Pulp potential.INTRODUCTIONFlotation of sphalerite is normally practised by adding CuSO4 as an activator under alkaline pH. Recently there have been a number of laboratory and plant examples of sphalerite flotation without deliberate addition of cu++ ions (Girczys, 1972; Mukherjee, 1976; McTavish, 1980; Marouf et al., 1986; Mielczarski, 1986; Leroux et al., 1987; Palsson and Forssberg, 1989; Sandoval-Caballero et al., 1990; Zhang et al., 1991).In batch tests, with a sample of Pb/Zn ore from Polaris, Leroux et al. (1987) found that sphalerite became floatable after adjusting pH to 9. 5-11: they ruled out natural floatability or the formation of elemental sulphur on the surface but suspected iron hydroxy compounds were responsible. Sandoval-Caballero (1990) conducted a continuous minicell test at Brunswick Mining and obtained a 44 % Zn recovery and 40.5 % Zn grade concentrate without deliberately adding CuS04 at pH= 10.5. With single mineral studies, Zhang et al. (1991) revealed good sphalerite floatability (over 80% recovery) in pH range 8 to 11 and found that this floatability was related to pH, dissolved oxygen (DO) level and Fe++ species present in the system.To explore further the conditions under which sphalerite can float without addition of CuSO4 , a continuous pilot test using minicells was performed at Falconbridge Ltd., Kidd Creek division. The set-up is briefly described (a more detailed description is given elsewhere in these proceedings) with emphasis on the data acquisition system - dissolved oxygen, pulp potential and pH were monitored continuously. Results of testwork investigating pH, CuS04 addition and gas composition are presented."

Jan 1, 1992

By A. E. M. Warner, A. Vahed, P. J. Mackey

"Since early 2015, the price of nickel has dropped from the region of US$6/pound to current levels of around US$4.60/pound (March 2017), reflecting several market factors, but principally due to lower demand from China. Under such conditions, nickel companies have been under pressure to contain operating costs. In addition, labor and energy costs will continue to rise, while nickel ore grades will likely continue to drop. All major companies now accept the need for climate change action and consequently efforts are being made towards lowering carbon-based emissions. Nevertheless, meeting these challenges can also contribute to higher operating costs without parallel innovative developments - which at the same time, under current conditions, major companies are tending to curtail. In this paper, several productivity improvement opportunities to reduce unit operating costs at nickel sulphide and nickel laterite plants are reviewed. Opportunities include: (a) process technology and energy-type selection, production capability, optimization of process intensity and implementation of newer technologies; (b) improved productivity, equipment availability including maintenance best practice; (c) energy savings and recovery opportunities and use of energy surveys and, (d) process modeling and improved scheduling. Such improvements along with an uptick seen in nickel demand going forward should better position the world nickel industry.INTRODUCTION Nickel is an essential metal to modern society, primarily through its use as an important ingredient in stainless steel. Thus, stainless steel finds vital applications in food preparation facilities, as well as important uses in transportation and industrial applications. Canada has always played an important role in nickel production and nickel metallurgy. In the 1940s and 1950s, Canada supplied over 90% of the world’s nickel. However, this proportion has declined considerably to around 10% of the world nickel supply today. Still, Canada remains an important nickel supplier and contributor to nickel extractive technology. Due to the importance of nickel to society, nickel demand is expected to continually rise. On the other hand, nickel companies have been under pressure to contain production costs amid languishing nickel prices. While demand projections show nickel growth, there are uncertainties in actual levels of future market growth. Ore grades are dropping, while labour and energy costs, which are key cost contributors are rising, hence efforts to lower production costs will generally require innovative approaches."

Jan 1, 2017

By C. Blais, G. L’Espérance

Characterization of second phase particles is important with regard to their influence on mechanical properties of materials. Analytical electron microscopy offers the possibility to achieve complete characterization of inclusions. Complete characterization of inclusions means quantitative evaluation of their chemistry and the stereological parameters. A characterization technique based on integrated microscopy and involving scanning electron microscopy, image analysis and energy dispersive X-ray spectrometry is presented. A discussion of the use of transmission electron microscopy and electron energy loss spectroscopy is also presented for the characterization of very small particles and compounds (>100 nm).

Jan 1, 1998

By A. Osouli, B. Moradi Bajestani

"Increase in permeability of rock mass is vital for both petroleum and geothermal applications. Hydraulic fracturing is a common method to create and increase the permeability for production. Due to the complexity of fracture propagation in a naturally fractured medium, understanding the interaction between hydraulic fracture (HF) and natural fracture (NF) is of great importance to optimize the fracturing process. The possibility of interaction between HF and NF is partly a function of orientation. Various scenarios are predictable for hydraulic fracture regarding the intersection with NF such as being arrested by NF, crossing NF or crossing the fissure while injecting water into it. Different parameters such as geomechanical and geometrical properties of surrounding rock mass, the operational parameters such as injection rate and the angle between created hydraulic fracture and natural fracture (approach angle) can affect the result of hydraulic fracture and natural fracture intersection. In this paper, using a series of flow-coupled Distinct Fracture Network (DFN) simulations, hydraulic fractures were analyzed to investigate the influence of the aforementioned parameters on the hydraulic fracture propagating. Results show that the most significant parameters affecting the interaction of natural and hydraulic fracture are orientation of the intersection as well as injection rate. The interaction and fracture propagation in NF and HF intersections are also studied and discussed in detail.INTRODUCTIONThe hydraulic fracture technology has substantially changed the oil, gas and geothermal industries. With the help of this technology, extraction of fossil resources from tight shale reservoirs will be economical, feasible and sustainable. Due to presence of massive oil and gas trapped in these reservoirs, this technology has been the center of attention for the past 40 years (King, 2012). Hydraulic fracturing is the process in which high pressure water is pumped into shale unconventional reservoirs with low to ultralow permeabilities. With this process paths are created in these mediums for delivering oil and gas to horizontal wellbore and increase the surrounding rock medium permeability. Economical and sustainable stimulation of these tight reservoirs is highly dependable on our understanding in regard to fracture propagation in the highly complex rock medium. Hydraulic fracturing process in rock mediums with preexisting natural fractures is more complex because of the high possibility of Hydraulic Fracture (HF) being arrested or deviated by Natural Fracture (NF). Also, HF and NF intersection can influence the required pumping pressure, injection rate, the outcome of horizontal wellbore and the affected geological underground zones. Since the 1950s, numerous studies have been conducted to predict and plan fracture propagation with the help of modeling and simulation methods. Having a thorough and accurate prediction of fracturing process will not only prevent stimulation of unwanted geological zones or pollution of aquifers, but also will improve the efficiency of the fracturing process. Previously, several studies have been conducted in order to investigate and analyze the interaction of hydraulic fracture and natural fracture (Cottrell, Hosseinpour, & Dershowitz, 2013; Doe, Lacazette, Dershowitz, & Knitter, 2013; Shakib, 2013; Zhang & Jeffrey, 2006)."

Jan 1, 2015

By The Staff

Development of the Eldorado Mine THE pitchblende-silver deposits of Great Bear lake, Northwest Territories, were discovered by Gilbert LaBine in 1930. The property owned by Eldorado Gold Mines, Limited, consists of 53 claims situated, for the most part, on LaBine point, on the northeast shore of the lake. The Company also holds a group of 10 claims on Dowdell point, 7 miles to the southeast of the main group and across Echo bay. The fractures traversing the ridge on LaBine point can be readily seen from the air. Lack of overburden and the scantiness of vegetation leave rock exposures which are visible for miles. The years 1931 and 1932 were spent largely in staking, prospecting, and examination of the outcrops. A small Diesel plant was shipped to the property in 1932 and underground operations were started. Entry was made into the ore-body by means of an adit. A 20-ton mill was completed in the winter of 1933-34, and since then operations have been continuous, except for temporary shut-downs for additions to the mill. TRANSPORTATION The mine is situated 28 miles south of the Arctic Circle and is reached by an air route of 1,140 miles from Edmonton. The water route follows the course of the Mackenzie River system from Waterways, Alberta, the end of steel, and is approximately 1,450 miles in length. Two portages, at Fort Smith and on the Bear river, respectively, are necessitated by the occurrence of fast water. Transportation was one of the major problems to be solved, and Eldorado Gold Mines, Limited, found it necessary to embark upon both water and air freighting on its own account. The Company now operates a Bellanca 'plane with a payload of 4,400 pounds, and a complete water transportation system. The latter was established some years ago by the Northern Transportation Company and it is still operated under that name, but the Company is now a subsidiary of Eldorado. Modern steel boats, oil tankers, and barges were added to the fleet this season. The greater part of the ore shipments are made by water, aircraft being used for this purpose only when occasion demands. Freight rates have been greatly reduced by direct ownership of carriers. For example, water-borne freight is now quoted 'to the mine at $ll0 per ton, as compared with $240 per tan four years ago.

Jan 1, 1938

By Dennis Z. F. Mraz

"Because rock salt and pot ash formations contain particles capable of elastic deformation, the material has usually been compared with various rheological models containing elastic elements. Extensive laboratory testing of salt and potash samples resulted in various theoretical conclusions based on conditions quite different from those in a deep mine. It is felt that sufficient data have now been collected from underground measurements and observations to demonstrate the inelastic behaviour of salt masses in a deep mine. The conditions in deep salt strata can be defined as near hydrostatic, because the acting pressures are very high compared to the negligible elastic limit of the salt. The pressure field and creep around the single opening is a function of its shape, size and age. The same factors, together with extraction, determine the behaviour of the mining a rea. The application of the correct analytical method in mine design can significantly improve the excavation techniques and predetermine the long-term behaviour of openings."

Jan 1, 1973

By B. Hohenstein, B. McBain, B. de Jong

"The automated fire assay system (Fast In-line Fire Assay or FIFA) has not found acceptance in the Au mining industry as the lower measurable limit of 0.20 ppm did not allow Au tailings to be measured with confidence. The development of arrested cupellation has overcome this hurdle which was a limiting factor in the FIFA 1 process. In the new automated fire assay process, automated sample preparation, fluxing, fusion and separation of a Pb button are essentially similar to the FIFA 1 process, albeit with some improvements. However, the game-changer is the development and incorporation of arrested cupellation into the automated system, now called FIFA 2. The purpose of arrested cupellation is to reduce the 50 g Pb button to a 5 g Pb button by partial cupellation in a specially developed arrested cupellation system thereby concentrating the Au in the Pb by a factor of 10 and in so doing moving them into higher concentration ranges in the mini-button where they can be read on the spark spectrometer. Results show that concentrations down to 0.02 ppm Au in geological materials can now be determined using arrested cupellation in the FIFA 2 process, an order of magnitude improvement over FIFA 1.INTRODUCTION Traditional fire assay for Au has remained virtually unchanged for 3000 years. It has survived for so long because it is accurate, has relatively low detection limits and is relatively inexpensive. However, it is labour intensive, has a long turn-around time (typically at least 7 hours), is environmentally unfriendly and exposes assay operators to potentially unsafe conditions (toxic fumes, toxic dust and extreme heat from furnaces). The NiS collection method is not as effective for the assay of Au as it is for the PGEs. A rapid, accurate, cost-effective method for the determination of Au and the Platinum Group Elements (PGEs) in geological materials would be a tremendous benefit to mining companies. Many of these objectives have been met by the FIFA 1 (Fast In-line Fire Assay) developed some 15 years ago in which automated methods have replaced the manual procedures which are part and parcel of conventional fire assay. However, concentrations below 0.2 ppm have been very difficult to achieve with sufficient reliability."

Jan 1, 2017

By M. H. Kotze, V. Yahorava

A gold-selective ion exchange resin, containing tributylamine groups, was developed by Mintek for the recovery of gold from cyanide leach solutions. The Dow Chemical Company and, more recently, Purolite commercialized the production of this gold selective resin for use in the gold mining industry, and it is marketed as Dow XZ-91419.00 and Purolite A194 respectively. A novel application of this resin is the selective recovery and separation of AuCl4 - f rom p latinum group metals (PGMs) in chloride and nitrate solutions. The current paper describes potential benefits of this type of resin for selective recovery and upgrading of gold from low grade chloride or nitrate waste streams, and the possibility of gold separation from PGMs during their refining in chloride media.

Jan 1, 2014

By A. Sheikh, S. Hardcastle

"Various methods of leaching are being used by Denison Mines Ltd. Uranium Operations. This study was designed to investigate the flood leaching operation of two parallel inter-connected stopes contained by pressure bulkheads. The teaching muck piles, created from large scale uppers production blasts, are aerated by compressed air lines laid beneath the pile prior to blasting.A SFr, tracer gas, injection technique has been employed to determine the post-blast integrity of the single-ended air distribution system. SF6 was injected into the compressed air line feed to the stopes and collected at borehole exhausts from the stopes in grab-sampling bags. Analyses of the air samples were performed with a gas chromatograph.The system was designed to give a sufficiency of oxygen to sustain bacterial activities used to enhance the leaching recovery in the muck piles. The results obtained indicated that there is a minor anomaly in the distribution system that may not be critical to the operation. Compared to an idealized case, the over-all efficiency of aeration throughout the muck is estimated at over 85%."

Jan 1, 1988

By T. K. Dichmann, J. A. Finch

"Microflotation, laboratory batch, and in-plant minicell continuous tests were conducted to determine if copper ions not only activate sphalerite but also depress pyrite when the minerals are together. Microflotation tests showed that pyrite recovery increased with addition of copper ions in the pH range of 5-10 when alone, but decreased when sphalerite was also present. Batch flotation tests (Red Dog ore) showed that upon addition of copper, pyrite recovery decreased significantly. The continuous tests (Louvicourt Mine) confirmed this and indicated that with excess copper pyrite recovery can increase. The results suggest there is competition for copper and xanthate in favour of sphalerite. To take advantage of this competition it may be necessary to control the sequence and rate of copper, collector, and lime addition. INTRODUCTIONFlotation, in common with all physical separations, is an imperfect process that results in misplacement of minerals. One source of this imperfection is accidental activation by contaminating metal ions. An important practical example is the misplacement of pyrite to zinc concentrates. Flotation of sphalerite generally requires activation by copper ions, added as copper sulphate. Copper ions are also used to activate pyrite [l] hence there is the suspicion that accidental activation contributes to the recovery of pyrite (Py) with the sphalerite (Sp). However, recent literature has shown that copper ions may make Py less floatable if Sp is also present. Xu et al. [2] conducted continuous minicell tests in-plant at Kidd Creek Operations (division of Falconbridge Ltd.) and showed that while the addition of copper sulphate improved zinc/iron selectivity, it did so as much by reducing the recovery of pyrite as increasing zinc recovery (Figure 1)."

Jan 1, 2000

By G. Morin, F. Chiesa, B. Tougas, B. Duchesne, Jocelyn Baril, N. Giguère

"An aluminum A356 compressor impeller was sand cast using the Low Pressure technique. The casting was limited in size (170 mm in diameter, 1.2 kg in weight) and very intricate in shape thus making 3D mold printing particularly favorable; indeed, producing this part by the traditional pattern-core box route would involve mounting 12 cores inside the mold while stringent dimensional tolerances are required as the impeller blades are only 2 mm thick. Consequently the molds were produce on the X-One MFlex printer of Quebec Metallurgy Center - CMQ. A dozen castings were produced with different casting temperatures and filling times so that it was possible to assess under which conditions complete filling of the mold cavity would be achieved. Filling and solidification modeling allowed predicting misruns and metallurgical properties inside the A356 (AlSi7Mg04) casting.INTRODUCTION Recent advancements in additive manufacturing enable foundries to produce molds without the tooling (pattern and core boxes) necessary when conventional technology is used (Eyad, 2016). This is particularly advantageous when dealing with intricate shapes and/or when a limited number of parts must be produced within a few days rather than in 5 weeks. An additional advantage is gained when producing prototypes (Johnson, 2016) as changes are much less costly and time consuming when made on a numerical 3D drawing rather than on patterns and core boxes. 3D printing is normally economical for a small number of parts; however, if the part is not too big and very intricate in shape such as the part that will be studied in the present work, 3D printing can be economical even for an important number of castings to be produced. On the other hand, low pressure casting is a high integrity casting process in which the mold cavity is filled from the bottom via a transfer tube in which the liquid aluminum rises under the pressure applied at the surface of the melt as illustrated in Figure 1. The filling can thus be precisely controlled, eliminating the turbulence created when the mold is filled from the top (gravity casting). Also, the pressure applied on the melt during solidification results in excellent feeding of the casting when conditions of directional solidification are met. In the present work, the compressor impeller shown in Figure 2 will be sand cast by low pressure."

Jan 1, 2018

By M. Zanini, D. Wong

ABSTRACT: Metals market improvements in 2005 drove the desire to increase nickel throughput and the production of nickel oxide sinter at the Vale Ltd. Copper Cliff smelter. Significant difficulties were encountered due to the unreliable quality of Bessemer matte being produced. Concentrate feed changes and the loss of technical and operational expertise during the previous market downturn contributed to the challenge of making the required improvements. Significant progress has been made in the converter aisle by focusing on employee engagement and standardizing best operating practices for a new generation of skimmers. This paper documents these initiatives and seeks to balance the art and science of converting.

Jan 1, 2012

By J. J. Brummer

"A reconnaissance geochemical survey, using the stream sediment technique, is described. The survey covered an area of about 400 square miles, in the Seal Lake area of central Labrador, underlain by basaltic flows, diabase and metadiabase sills, and sedimentary rocks. Previous work had indicated numerous small copper occurrences within the Seal Lake group of rocks. Stream sediments were tested for the readily extractable copper content and total heavy metal content. The results of the copper survey did not yield any new data on the distribution of copper mineralization. Results of the total heavy metal survey attracted attention to a remote portion of the area (Ten Mile Lake), which had hitherto been regarded as having no economic interest. The anomalous values found, suggested that zinc mineralization should occur in this region. Geological mapping indicated that the rocks exposed belonged to the Letitia Lake Group, which is older than the Seal Lake Group exposed to the east, which contains the copper mineralization of the district.Investigation of the area lead to the discovery of: (1) uneconomic lead-zinc mineralization; (2) radioactivity extending over a considerable area. Evaluation of the radioactive rocks led to the discovery of columbium-thorium mineralization in amphibolite and in diopside-actinolite schists along a contact with intrusive alkali syenite.Thus a geochemical survey, which was planned to evaluate a copper province, resulted in the discovery of lead-zinc-columbium-thorium mineralization."

Jan 1, 1960

By J. M. Rios

Without conscious effort and understanding, a number of factors peculiar to mineral exploration campaigns conspire against building sustainability in host communities. These include the episodic and transitory presence of an exploration team in the community and the inherent uncertainty of outcomes; most projects fail. Given these circumstances, there is a strong tendency to apply a simple formula of providing employment, pragmatic philanthropy and supporting infrastructure improvements (roads, schools and clinics) to demonstrate that mining provides benefits. Experience in rural native communities of Mesoamerica has shown that it is possible to create positive, sustainable outcomes quite rapidly within communities, which build capacity, improve quality of life and support a strong social license to operate. Success comes from an understanding of community structure and dynamics; engaging with all segments of the community; creating healthy, transparent and accountable relationships based on clearly defined roles and responsibilities; and supporting and strengthening the role of women in a culturally appropriate way. To this are added innovative and culturally appropriate ways of incorporating sustainability through genuine social investment in areas more typically addressed by exploration companies; health, education, and environmental management.

Aug 1, 2013

By Mitchell P. Rothman

This paper concentrates on profits and other measures of return in the Canadian mining industry, especially in the non-mineral-fuels sector. The paper examines the historical patterns of mining profits, both before and after taxes, as compared with profits in other sectors of the Canadian economy, as well as some of the more important influences on mining profits. These include the prices of mineral products, provincial and federal tax policies with respect to mining , and the effect of inflation on mining profits and the financial position of mining firms - in each case, comparing mining with the other sectors of the economy. Finally, the paper provides an analysis of current and prospective rates of mining profits in relation to the capital required to ensure the future viability of the Canadian mining industry.

Jan 1, 1977

By A. A. Nourbakhsha

The main application of refractories based on andalusite in ferrous metallurgy are in air heaters of blast furnaces, mobile mixers, and hot-metal transfer, pig iron ladle, steel-casting, and intermediate ladles. Three specific properties of andalusite are very interesting for the production of high-quality shaped and unshaped mullite refractories: being free of water, its crystal a remains stable without changing its density or volume after firing and therefore has no internal porosity .Graphite additives due to its great wetting ability play an important role in raising the property of refractory bodies. In order to improve properties of andalusite graphite bodies, oxidant agent for increasing in hot strength and oxidation resistance can not be avoided. In this research, firstly 8 pig iron ladles from ESC(esfahan Steel company) with different conditions selected and monitored during usage to determine of main factors affecting on corrosion of refractories. Results showed that tap to tap time, undischarged pig iron ,penetrated pig iron are the main ones.Literature studies showed that the graphite addition help to thermal shock resistance and liquid penetration(steel,pig iron) effect. In this research particle size distribution of aggregates containing andalusite and graphite determined by andreazen equation. Then different mixes with different percentage of graphite,Si, FeSi, SiC prepared by uniaxially pressing under 1500kgf/cm2 pressure by adding 4%wt novalak resin and 0.4%wt HMTA as hardner. Samples fired at 1100-1500oC under reduction atmosphere. According to specific standards density, porosity and CCS measured. Analytical tests such as XRD, SEM were carried out on sample selected from point of view of mechanical properties at different temperatures. Results showed that optimized amount of Si and Fe-Si for _-SiC formation in body is 4 and 6 %wt respectively at 1500OC. XRD and SEM analysis on sample with Fe-Si additives showed no destructive phase through the matrix, also SiC additives not only increase oxidation resistance but also no effect on thermo-mechanical properties.

Oct 1, 2011

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 Phillip J. Mackey, Gerardo R. F. Alvear F.

It is now 38 years since the publication of the first edition of "Extractive Metallurgy of Copper" by Professor W.G. Davenport and the late Professor A.K. Biswas. The text book would be issued in a total of five editions, soon became the standard for students and those in industry. Interestingly it was published at the onset of great change in the industry. This was a time when sulphur dioxide controls in the USA were introduced, and almost simultaneously, world oil shocks caused significant increases in the cost of fuel - all leading to efforts to adopt new technology and move away from the reverberatory furnace, which had no potential for sulfur capture and required large amounts of fuel. At the time of publication of the book, new processes such as the Noranda Process and the Mitsubishi Process were in their infancy, while flash smelting (which was first commercialized in 1949 at Harjavalta, Finland) had made significant in-roads in boosting copper output, with some 22 new flash smelters licensed by 1976. Computer technology and associated process control techniques were rudimentary compared to systems today, available physico-chemical data remained largely in tabulated format and needed to be manually entered into the main frame computers of the era, while modeling techniques common today had not yet been developed. The copper industry has therefore seen immense changes since the time of this textbook: world tonnage of smelted copper has risen from 7.34 million tonnes/year in 1976 to 16.7 million tonnes/year in 2012, over a two times increase. Technologies such as the El Teniente Process, or Top Submerged Lance technologies, typified by the ISASMELTTM, not commercialized at the time, now treat large tonnages of copper concentrate in a single furnace. Advanced heat and mass balance software and thermochemical modeling are now used extensively to examine chemical and physical characteristics for process design and to support process optimization. These changes in the industry have been chronicled in subsequent editions of the book. This paper looks at the issues and problems seen in 1976 and over the intervening years, and compares this with the challenges facing the industry with the available tools and technologies today. Some ideas looking into the future are also discussed in the paper.

Jan 1, 2014

By Fr. -W. Bach

In the past years the enormous weight saving potential of magnesium sheet has been demonstrated by various research projects all over the world. It has been shown magnesium flat products can benefit automotive, aviation, machine tool and consumer electronics industries. Major material problems such as poor formability, corrosion resistance and high production cost still inhibit the application of magnesium sheets in large scale production. The present contribution outlines achievements in casting and rolling technology. The authors developed an adapted strip casting process in which near-net-shape rolling feedstock of several wrought alloys has been produced. During the rolling process, various parameters were varied in order to modify the microstructure and surface quality of sheet. Several temperature cycles, strains, lubricants, roll surface structures and roll coatings have been analyzed. The sheets were examined and tested in deep-drawing experiments. Suitable rolling schedules have been developed for standard and modified wrought alloys. The study concludes with an overview of current industrial solutions and an estimation of the potential cost savings that might result from the adaptation of the process that has been developed.

Jan 1, 2006