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By L. N. Ertzeva

The present work is dedicated to investigation of the sulfidizing process of ore pyrrhotite concentrate with recovery of a sulfide material, enriched with non-ferrous metals, and waste pyrite, with downstream separation by a certain beneficiation method.

Jan 1, 2006

By Howard K. Worner

Several features of smelting and refining operations make them appropriate technology to adapt to the processing of "wastes" not only from the minerals Industry itself, but for wastes in general. These features include significantly higher temperatures than are achieved in conventional Incinerators and also good thermal stability derived from the mass of molten metal and slag in the furnace. This paper expands on Information contributed to the Mervyn Willis Symposium in July 1992 and includes knowledge generated in the last two years of waste processing R&D in a sealed 100kg capacity DC arc furnace specially constructed for the "Environment" process being developed in Wollongong. As one product of-the process is a foundry-type iron, the feed always contained ferruginous dusts or heavily contaminated scrap. For the dusts, sewage sludge has been used as a binder and also as a proportion of the fuel-reductant. To achieve the necessary bath carburisation, It is beneficial to add other lower reactivity carbons such as "kish' graphite, carbon from electrode butts, dusts from coke ovens, carbon from aluminium pot line residues, dry cell batteries etc. Metallurgical factors involved In process control, Including metal and slag, compositions, are discussed.

Jan 1, 1994

By John M. Rogers

Risk management has rapidly developed to become an integrated, holistic approach that now encompasses the main risk elements such as product quality control, occupational health and safety, security, environmental liability, social issues and related management information systems. Given the obvious economic benefits, a seamless blend of risk management components has become essential to allowing organisations to sustain a competitive advantage, and is also looked upon as an important attribute in organisational growth. Juxtaposed with this management philosophy is the global trend towards outsourcing, which has seen the emergence of independent, and specialist risk management organisations. The New Millennium will undoubtedly see a shift away from "in-house" risk management practices, and consequently, the selection of a suitable risk management partner - a major vehicle for improving shareholder value - will become an important strategic management decision.

Jan 1, 1999

By P. M. Pincheira Brown

The widely accepted inverse relationship between copper prices ail stocks, has been commonly used by analysts to explain the behavior of the copper market and to forecast film copper pries. However, empirical data have not shown such a clear relationship between copper prices and stacks. Existing evidence only indicates a weak tong-nut relationship that vanishes in some periods. In this paper a simple comprehensive model is provided which explains both parallel and opposite direction movements between prices and stocks. Former are explained mainly by stocks demand expansions-contractions while the latter are in essence due to increases in the supply curve. Furthermore, econometric estimations are provided, thus giving a powerful tool to forecast and explain price developments of the copper market.

Jan 1, 1999

By Joel K. Witt

San Manuel Oxide operations of BHP Copper, located in Southeastern Arizona, operates a leach-solvent extraction/electrowinning (SXEW) facility that produces high quality cathode copper from low-grade oxide ores. Permanent heap leaching and in-situ leaching methods accomplish the dissolution of copper from the oxide ores. Open pit mining and heap leach construction took place from 1985 to 1995. Run-of-mine oxide ore from the pit was hauled to the heap dumps and leached by the soaking cure and continuous irrigation method. Solution application to the heaps still continues and acid soluble copper recovery has reached 86%. This paper presents and discusses the current operating practices and innovations applied to the leach facilities to maximize copper recovery from the heap leached residue. Factors such as irrigation methods, solution chemistry, sideslope treatment, post curing, lixiviant acid strength, and "rice paddies" irrigation, will be discussed. Heap leach solution control and sampling methodologies will be also presented.

Jan 1, 1999

By Mahin Rameshni

WorleyParsons innovative SO2 reduction process efficiently recovers sulfur from SO2 streams. Effluent gases from ore roasters and smelters and coal-fired power plants can be treated to reduce sulfur emissions. This exciting new process is an innovative combination of well-established processes of reaction of CH4 and sulfur vapor to produce CS2, followed by catalytic hydrolysis of CS2 to H2S, and Claus reaction of H2S and SO2 to sulfur. Key advantages are lower fuel consumption, reduced emissions, better product sulfur quality and better operational stability. The Production of elemental sulfur from SO2 is being called Rameshni SO2 Reduction (RSR) and it is patent pending.

Jan 1, 2006

By J. H. de. Visser

The transfer of molten metal in smelting or refining operations is typically performed in open trough-type launders that are constructed of either water-cooled copper troughs or refractory lined steel jackets. This transfer can be either continuous or batch. Batch operations transfer metal through an open launder. The uncovered launder has many operational and environmental drawbacks. In order to improve workplace hygiene, designs have evolved toward ventilated launder covers that .are connected to secondary exhaust systems that use negative pressure under the cover removing fume and hot gases to secondary fume control devices. In smelting operations, a variety of covers have been employed which insulate the launder and contain the fumes and also provide additional heat along the length of the launder through a series of premix or inspiration-type burners that add combustion products to the normal fume load in the launder. Cover designs have proven to be inadequate in that hinged unventilated covers hinder convenient access while heated ventilated covers are costly to maintain. Covers that employ refractory bricks and overhead enclosure-type exhaust hoods have been somewhat successful, but restrict operator movement and require large volumes of exhaust air. An example is given of a cover and off-gas system for launders that is designed to provide superior insulation and heating capabilities, as well: as better control of the fume gases-and ease of maintenance. The cover system must maintain the balance between maintaining launder heat and fume removal. The construction of the covers must be able to withstand high internal temperatures and maintain its structural properties.

Jan 1, 1999

By Qingcai Liu

The effect of the TiC addition on corrosion resistance of the Al2O3-C refractories in smelting reduction melts has been studied by quasi-station immersion and rotary immersion. The corrosion rate of Al2O3-C refractories is decreased with the TiC addition. The corrosion mechanism of Al2O3-C refractories is oxidization of graphite carbon by the oxides of the melts and the formation of deteriorate layer.

Jan 1, 2006

By Tomas Astorga

APEC, the Asia Pacific Economic Cooperation is the forum of 21 countries having approximately 56% of the total world income, and over 45% of global trade. In 1997, APEC economies produced 67% of the world copper output, 55% of gold, and over 45% of other base metals. Mining in APEC captures more than 60% of the total mining investment in the world. New and emerging economies are now appearing in the demand scenery, such as China. New trends in the international environmental regulations are posing questions related to the use of copper in different industrial and consumption applications. These may have a strong impact on future trade of copper. New applications are also appearing based in new technology fields. The paper examines the growth potential of the copper market in main consumer ad highly populated economies of APEC, incorporating analysis of various interrelated factors. It also analyses the outlook of the copper supply. Its conclusions point to the need to implement demand outlook models. Finance and economic reforms will open important avenues for trade growth in basic metals, particularly copper. Changes in the consumption patterns of highly populated countries will add to better perspectives of copper demands. The recovery of a fast pace of economic growth in the APEC region will bring new demands for copper, especially as a consequence of high tech applications. More extended policies focused in the need for developing energy efficiency programs and schemes will add to this picture.

Jan 1, 1999

By Christine Wenzl, Andreas Filzwieser, Stefan Konetschnik

"The METTOP-BRX-Technology is a novel manifold electrolyte inlet, which allows improved productivity and production in new and existing tankhouses by achieving higher current efficiency and cathode quality, as well as using current densities higher than 400 A/m2. Two installation examples are shown: Montanwerke Brixlegg AG, Brixlegg, Austria (upgrade of existing tankhouse) and Xiangguang Copper, Yanggu, China (new tank house). Montanwerke Brixlegg AG has been using the METTOP-BRX-Technology since 2005, and converted half of the whole tankhouse to METTOP-BRX in 2011 in order to use a current density of more than 400 A/m2. Xiangguang Copper started up their second tankhouse in May 2011. This tankhouse was constructed in the same way as the existing tankhouse, but was designed for 292,000 t/a cathode copper (existing tankhouse: 200,000 t/a) by using the METTOP-BRX-Technology. This production increase is a consequence of a much higher current density, namely 410 A/m2, compared to 280 A/m2 in the old tankhouse.IntroductionCopper electrorefining has been practised for more than hundred years, the last big change being the implementation of stainless steel cathodes in the 1980s [1], In 2005, the METTOP-BRXTechnology was first introduced. This technology was developed jointly by METTOP and Montanwerke Brixlegg, Austria, and allows improvements in productivity and production in new and existing tankhouses in an economic way. The METTOP-BRX-Technology is a novel manifold inlet that allows improved tankhouse productivity by increasing current density and/or current efficiency while maintaining or improving cathode quality [2]."

Jan 1, 2012

By Milorad Cirkovic, Mile Bugarin, Vlastimir Trujic

"Industrial scale testing was performed in the plant-site of Bor Company. Charging sample was from 4-5 tons for each particular test. All operations in industrial scale investigations were carried out in one furnace. For the aim of successful realization of experiments, and primarily for safety and prevention the risk of toxic contamination the working environment, a plant was designed and constructed for cooling and wet dedusting of gases formed during smelting process, zinc removal and flame refinement of molten metal. For the requirements of industrial investigations a complete plant for cooling and wet dedusting of gases has been constructed for brass scrap processing. In this plant, the original ultra-sonic water spraying devices have been installed. The efficiency of such simplified system for gas treatment has been 98,6%. Introduction Permanent development of techniques and technology causes formation the considerable quantities of secondary raw materials that are much more relevant as the raw material base for many metals. Due to a fact that large quantities of metal, are concentrated in the waste materials, large consideration is given to this topic, and numerous technologies for this waste recycling are developed in the world nowadays. High energz price and permanent increase of metal price on the world market have made that secondary raw material tretament, for the aim of various metals production, becomes more and more relevant in the world. In comparison of metal production using enrichment and metallurgical treatment of primary raw materials, the non-ferrous metals production from secondary raw materials has a range of advantages, as well as: - Low level of capital investments, - High technological recovery of qualitative secondary raw materils, - Considerably low consumption of energetic resources regarding to the treatment of primary raw materials (ore and concentrate), - Reduced consumption of unrecoverable mineral resources, - Reduced enviroment pollution [1,6]."

Jan 1, 2008

By O. Tiitu

Drying is a unit process that has numerous applications in metallurgical process industry. Kumera Technology Center is a worldwide equipment and process supplier, who has expertise on both direct and indirect drying. In a conventional direct heated dryer, the required energy is obtained from combustion of fossil fuels emitting a considerable amount of off-gases. However, thermal energy can be already available in some metallurgical plants such as modem copper smelters where steam is produced by waste heat boilers of flash smelting furnaces. The total volume of off-gases, and especially the amount of harmful gases, released into atmosphere can be remarkably reduced when using steam as an indirect energy source for drying. Kumera Technology Center has developed a new type of steam dryer for drying of, for example, abrasive copper concentrate with silica sand. In the development of the new dryer, Kumera's approach has been to combine the best properties of both the existing steam dryers and the rotating drum dryers. In the design, special attention has been paid to overcoming the reported problems of excessive wear and clogging of steam tubes and to reducing the required maintenance operations. The Kumera Steam Dryer, having a patented flexible steam tube arrangement inside the rotating shell, has a high effective heating area - drum volume ratio without leading to problems with build-up and clogging. It can also be easily scaled up so that a single dryer can dry all of the feed for a large flash furnace. In this paper, we will present the operational and maintenance experiences from two years operation of the first full-scale Kumera Steam Dryer at Norddeutsche Affinerie Aktiengesellschaft in Hamburg, Germany. We will also provide an overview of the future developments with respect to construction and scale up as a response to market demands.

Jan 1, 2002

By Osamu Yamamoto

In antibacterial evaluation of carbon-ceramic composites, we prepared two type composites with emphasis on carbon-ZnO system; one was porous carbon materials containing ZnO nano-particles and another was porous ZnO coated with carbon thin film. Porous carbon samples containing ZnO at highly dispersed state were prepared by carbonizing the resin exchanged by Zn2+ ion. Porous ZnO coated with carbon thin film was obtained by the pyrolysis of poly (vinyl alcohol). Antibacterial activity of these composites obtained was evaluated by measuring the changes in electrical conductivity with bacteria growth. The antibacterial activity on the composites increased with the increase of t he amount of ZnO in composite and decreased with the increase of carbonization temperature. The antibacterial activity for Staphylococcus aureuswas found to be stronger than that for Escherichia coli. No activity of the carbon samples without ZnO was observed. The occurrence of antibacterial activity was supposed to be due to the generation of hydrogen peroxide from ZnO in composite. In the present work, antibacterial activity of carbon-ZnO composites was studied in the details.

Jan 1, 2006

By T. A. Edison

A distinct hydrocarbon maturation anomaly coincides with the Gold Acres open pit, Nevada (Figure 1). Both atomic hydrogen to carbon (H-C) ratios and reflectance measurements of contained organic matter indicate significantly higher maturity in samples collected within the confines of the open pit than in samples from the surrounding region (not shown in Figure 1).

Jan 1, 1987

By Carla Lupi

In this work, nickel-cobalt electrodeposition under galvanostatic conditions was investigated. Ni-Co alloy was electrowon from an acid sulphate bath containing 40 g/L Ni and2-8 g/L Co.. The effect of electrolyte composition, current density, temperature, solution pH and presence of buffers such as H3BO3 and (NH4)2SO4 on Co content of the binary alloy has been investigated. In particular, current densities ranging from 180 to 400 A/m2 and temperatures ranging from 27 to 60°C were tested. The composition of Ni-Co alloys may be diversified through the selection of process parameters. The experiments show that the highest cobalt content of the alloy is reached by using a buffer free electrolyte without solution pH control. Though, in these conditions, the most homogeneous, fine and regular deposit morphology is obtained, energy requirements are the highest in tests lasting just two hours.

Jan 1, 2003

By Y. Moriya, Y. Sadayoshi, Y. Nonogaki, Y. Takeda

"Preparation and growth processes of CaF2 on Si(111) and of . InxGa1-x,As islands on CaF2 by molecular beam epitaxy (MBE) are described. It was found that first of all the Si(111) surface treatment process to obtain the 7x7 reconstructed structure was necessary to ensure the cleanness of the surface and to grow a flat and high quality CaF2 on it. Growth of InxGa11-x,As islands on CaF2 was tried by droplet heteroepitaxy using the same MBE reactor. In,GaxGa1-xAs islands were successfully grown epitaxially, and the size and density of the islands dependent on the In composition were investigated.IntroductionThough semiconductor/semiconductor heterostructures are widely used for many device applications, small band off-sets of the conduction bands and the valence bands restrict the utilization of the intra-subband transitions to far-infrared regions. With InAs as the quantum well and fluorides as the barrier layers, we can design three-electronic-level systems in the infrared region, which is the low loss transmission window of the silica optical fibers. To realize those structures, we have grown InxGa1-xAs islands on CaF2 thin films that were epitaxially formed on Si(111) substrates by molecular beam epitaxy. By the droplet heteroepitaxy that we invented, the InxGa1-xAs islands with height of -10 nm have been obtained successfully. Optimum processing to obtain atomically smooth surfaces of Si and CaF2 and high quality InxGa1-xAs islands is reported.ExperimentsMBEMachineCaF2 was grown on Si(111) and InxGa1-xAs islands were grown on CaF2 successively by MBE. The MBE machine consisted of a growth (or reactor) chamber and a loading chamber. The reactor chamber was equipped with Ga, In, As and Er metal source cells and CaF2 and BaF2 source cells. Cell materials were P-BN for Ga, In and As metals, and were graphite for CaF 2, BaF 2 and Er to avoid reaction with BN cells. The electron gun and screen were attached to the reactor to observe the RHEED pattern during the substrate surface treatment and the growth of CaF2 and InxGa1-xAs islands. The substrate manipulator was designed to heat up the Si substrate up to 1,200°C for the surface cleaning. The QMS was also equipped to analyze the residual gas species in the reactor chamber. The base pressure of the reactor chamber was 2-5x10-11 Torr, being pumped by ion pump and the liquid nitrogen shroud"

Jan 1, 2000

By A. D. Zunkel

Increasing amounts of electric arc furnace dust (EAFD) are being generated worldwide as more steel is produced from electric furnace melting of galvanized steel scrap. In most countries, the management of this material is a costly technical, economic, and legal problem for minimill steelmakers. Many technologies and processes are being developed and implemented worldwide to manage this material to recover contained zinc, lead, and iron values and render it nonhazardous. These processes are pyrometallurgical, hydrometallurgical, or hybrid in nature. Some produce zinc oxide, some zinc metal, some lead metal, and some lead cement. Some are successful, some have failed, many are dormant. or abandoned, and others continue to be developed and emerge. This paper updates the current status of 20-30 processes in various stages of commercial application and development used worldwide to manage EAFD and recover its nonferrous, particularly zinc and lead, and ferrous values.

Jan 1, 2000

By Roberto Javier Santiago

The main properties of Calcium Carbide seem to be the grain size and the CaC2 content. This paper tries to describe the Calcium Carbide used in the South-American steel plants and how and where it is added.

Jan 1, 2006

By W. Marnette

Norddeutsche Affinerie is the largest West European copper producer with an annual output of more than 350,000 tonnes of refined copper, about half of which is produced from copper concentrates. However, in addition to concentrates, Norddeutsche Affinerie processes secondary raw materials and recycling materials which contain a combination of copper and lead. These materials were previously treated in blast furnaces, a technology which has meanwhile been superseded at NA by the electric furnace process, primarily owing to the necessity of complying with the increasingly stringent requirements for environmental protection.

Jan 1, 1994

By R. J. Batterham

This paper sets the scene for the Australian-Asian Pacific Course and Conference on Pyrometallurgy for complex materials and wastes. The relentless presence of competitiveness is rehearsed as the source of the current trends towards continuous improvement and benchmarking. While this might be expected to lead to more spending on pyrometallurgy, the opposite appears to be the case. The paper examines the reasons and suggests that we face an increasing challenge for selective developments that can lead to sustainable competitive advantage - both in mineral and in waste processing.

Jan 1, 1994