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The Port Kembla Copper (PKC) copper smelting facilities were commissioned during 2000. Numerous difficulties were encountered during the commissioning such as multiple reactor tuyere line failures, absorbing acid tower refractory collapse, and Noranda Reactor and Mitsubishi Converter process control problems. These problems are described along with the actions taken to overcome them. Process development is described particularly for the Mitsubishi Converter and Acid Plant.

Jan 1, 2002

The increasing need for robust pyrometallurgical furnace construction is driven by two trends in the copper and other base metals smelting industry: ? the desire for increased production within a single furnace line by greatly increasing smelting intensities, which generates high heat fluxes to the crucible. walls, and ? the operational and economic imperatives of maintaining high percentage on- line times and long campaign lives between rebuilds. A key feature of furnaces capable of producing at high rates, while containing intense processes, is a strong, thermally robust wall cooling system. Equally important design aspects include the furnace steel structure, refractories, a cooling water supply and piping arrangment for safety from leaks and disruptions, and instrumentation/controls for monitoring and rapid mitigation of process excursions. Integration of the cooling elements into these furnace systems is essential for optimum performance of the cooling elements, and indeed the entire furnace. This paper discusses the development of a composite copper / refractory water- cooled design, which has been successfully implemented on several copper smelting and converting furnaces, including Kennecott's flash converting furnace, INCO's MK reactor, and Kidd Creek's converting furnace.

Jan 1, 1999

By M. D. Strachan

Technical & Procurement Services Limited (TECHPRO) in Ashford, Kent, UK, have been appointed as Project Managers for the major rehabilitation of the Copper Smelting complex of Nkana Division, Zambia Consolidated Copper Mines Limited, (ZCCM) Zambia. In outline, the overall scope covers three main areas: a) Transfer and implementation of new technology into Zambia for the production of primary copper. b) Replacement of gas collection and gas treatment circuits to guarantee high quality feed to the acid plants. c) Completion of a number of minor projects in the copper smelter and associated utility plants to complement changes in the primary smelting technique. This paper describes the Project Management methodology and style used by TECHPRO to tackle typical problems that arise in retrofit projects of this type. Reference is made specific aspects of the smelter projects to illustrate solutions to the problems. The subjects. addressed highlight the complexities not only of having a -Client 5,000 miles from the Project Office, but also the difficulty of co-ordinating and controlling the performance of min sub-contractors who are also geographically distant.

Jan 1, 1991

By K. P. Nishad

The origin of many casting defects can be traced at the mold filling stage. Entrapped air/gas pockets and oxide film formation are notable examples. In the present work, the mold-filling process is simulated using a mathematical model, built on a multi-physics based commercial package PHYSICA. The simulation code has the capability to solve multi-phase problems. The numerical model addresses a complicated dynamics of filling operation including free surface flow and subsequent flow behavior and is based on conservation of mass and momentum. The Free surface is modeled using the scalar equation method (SEM). The model is validated with benchmark experimental results from the literature. The role of turbulence and the pouring rate on variables affecting sites prone to oxide film formation are investigated using a simple but novel technique. Key findings of the work are presented.

Jan 1, 2006

By Kouji Mimura, Masahito Uchikoshi, Minoru Isshiki

"HfO2 is expected to be a gate dielectric used in ULSI alternatives to S1O2. Although the materials used in ULSI are required to be significantly pure, commercial Hf contains > 2 mass% Zr. It is important to establish a process for removing Zr from Hf. In the present study, anion-exchange separation using a multi-column method was employed. The separation tests were carried out at variety of temperatures and flow rates. The decrease in the flow rate of the mobile phase made the elution curves of both Hf(IV) and Zr(IV) broaden contrary to the case of Co(II), Cu(II), or Fe(III). This is caused by the difference in adsorption rate on the anion exchange resin. In addition, more than one column was connected in series in order to enhance the separation. As a result, the content of Zr(IV) was successfully reduced to 1/100 of that relative to the raw material.IntroductionHafnium is one of the most important materials in modem society. The main applications of Hf metal are as a control rod in a nuclear reactors because of its large neutron-capture cross-section and as an additive to various alloys because of its corrosion resistance [1]. In addition to those applications, attention has been recently paid to HfCh as a high-x"" dielectric used in ultra large scale integration, ULSI, as well as ZrCh, AI2O3 and La2C>3, which are expected to be alternatives to conventional S1O2 thin films [2].The materials used in ULSI are required to have a high purity in order to avoid unexpected errors due to impurities. Furthermore, high purity Hf is indispensable for investigating the intrinsic properties of Hf metal. Thus, it is significant to establish the purification process for Hf from both the industrial and academic perspectives."

Jan 1, 2012

By Carlos Carnurri

A characterization of mechanical properties of fire refined copper has been done in order to link ductility with oxygen content. The results show four different copper mechanical behaviours as temperature increases, where the oxygen con- tent, as Cu20 segregated, has a deleterious effect on ductility. It is concluded that until 500 ppm oxygen content, the fire refined copper could be rolled without remelting for deoxidation. Also a subsequent cold rolling could be done without intermediate annealing.

Jan 1, 1994

By John K. Wright

The segregation process involves heating oxide-type ores with a halide salt in the presence of a solid reductant. By a complex series of cyclic vapour-phase reactions, the desired metal is extracted from its original position in the ore and segregated to the vicinity of the reductant. In this form it is then amenable to concentration by physical methods. In this work the segregation behaviour or eight different nickel laterite ores has been examined using a laboratory rotary kiln. It was found that the silicate (serpentine) ores responded better to the segregation conditions used than did the limonitic ores. An examination of the segregated metal particles showed that they consisted of ferro-nickel. The concentration of nickel in the metallics was sensitive to the ore types and the segregation roasting conditions.

Jan 1, 1994

By P. H. Scaife

The pyrometallurgy industry faces a series of environmental challenges, based on local, national and global issues. While local impacts continue to be important, national and global concerns with Sustainable Development, Greenhouse emissions, Acid Rain and water resources are key strategic drivers for the industry. The environmental problems of the industry are well known: emissions of sulphur dioxides and carbon dioxide, disposal of arsenic wastes, consumption of fresh water, fate and impact of minor components/trace elements in raw materials (whether conventional or complex, or wastes). Solutions to these problems require the application of Cleaner Production principles (waste minimisation, energy conservation, product design to enable ease of post consumer recycling), new technology and scientific studies to assess impacts of discharges. A number of opportunities, driven by environmental concerns, have also been identified

Jan 1, 1994

By Michael J. Virnig

The formation of crud is a normal part of operating a solvent extraction circuit for the recovery of copper. It periodically must be removed from the circuit. This results in significant costs in terms of manpower, downtime, and loss of circuit organic. Field studies have been carried out that show that the presence of a thermodynamic modifier in the organic phase contributes to crud formation. In an effort to better understand what factors contribute to crud formation, laboratory studies involving competitive adsorption studies with model solids have been carried out. The results of these laboratory studies will be integrated with the results of the field studies to present a better understanding of crud formation.

Jan 1, 1999

By A. Mikula, S. Karlhuber

"Unique physical and mechanical properties made the Pb-Sn solders attractive for low temperature joining of electronic parts. But since lead in solder materials has become a great enviromental problem and health concern, lead will be slowly replaced by other materials in soft solders. Some of these materials which are currently under investigation are ternary tin alloys. Many different physical properties like wetting behavior, electrical and thermal conductivity and surface tension are measured on these alloys, but on the thennodynamic properties and the phase diagram of the alloys under discussion there is only little information available. We investigated the (Ag, Au, Cu)-Sn-Zn systems and determined the thermodynamic properties over the whole composition range by emf-measurements. From these measurements we also got some information on the liquidus. In the Sn-rich corner the phase diagrams are still under investigation.IntroductionSoldering is technically defined as the joining of two base materials, mostly metals or metal coated nonmetallic substrates, with a third metal. The melting temperature of the third metal or metal alloy should be well below those of the substrates. Solder alloys can be categorized in soft and hard solders. Soft solder alloys usually contain lead, tin, bismuth, indium or cadmium and hard solders gold, zinc, aluminium or silicon. The difference between soft and hard solders is the melting temperature of the soldering material. This temperature is around 350°C.An interesting brief history of solders is given by Vianco and Frear [1]. They report, that in 4000 B.C. solders were already used in Mesopotamia. From archaeoligical evidence those solders were gold-based hard solders.Tin-lead soft solders and their use are not easily found, because in course of time tin has been reduced to stannic acid, making the identification quite difficult. Well preserved soft solder artifacts were discovered in King Tut's tomb dating from 1350 B.C. In ancient time Pb-Sn solders were used primarily for the manufacture and repair of cooking utensils and metal tools. The Romans used lead-tin solders extensively in the construction of the aqueducts."

Jan 1, 1996

By José Roberto de Oliveira

Based on literature review one can see that the main objectives of MnO reduction is the comprehension of slag interactions and reactions with other elements beyond carbon. That's because it is worthwhile to study pure MnO reduction, where there will be not oxides interaction and just carbon will be the reduction agent. By a thermodynamic analysis we know that Si can react with MnO, then it's important to study this influence, so as Mn content. Our work aims to develop kinetics parameters for the MnO reduction, varying Mn and Si contents in bath. This has been given by pressure measure of CO in a Fe-C bath. The CO is generated by the oxide reduction with carbon. It has been proved that: - Mn content decreases the MnO reduction; - the MnO reduction is mainly influenced by Si content in a bath containing Iron, Carbon and Manganese so as Silicium

Jan 1, 1997

By Karen Tempel

Newmont's Lone Tree Mine is located 30, miles east of Winnemucca in Humboldt County, Nevada. Starting in February 1994 a pressure oxidation circuit was commissioned to treat refractory gold ores. Gold is leached and recovered from the oxidized slurry in a six-stage carbon-in-leach (CIL) circuit. Lone Tree has been able to maintain tighter control' of cyanide addition and reduce cyanide consumption its CIL circuit through the installation of Degussa's Cyplus® CCS Cyanide Control System in the spring of 2000. 'The Cyplus® CCS, along with additional inputs' from plant sensors, has allowed tor a more efficient and effective control strategy over the manual control method used ,in the past. This paper documents the key aspects of the Cyplus® CCS installation; the development of the control strategy, and the benefits achieved from enhanced control.

Jan 1, 1998

TiO2 and Ti/TiO2 thin films were deposited on a quartz substrate by laser ablation of Ti02 and Ti targets using Nd:YAG pulsed laser. After sulfurization of the Ti02 film in H2S or CS2 gas at 1273 K for 1 hour, the surface atomic structure was changed. Furthermore, the Ti/TiO2 film was successfully prepared by the subsequent ablation of Ti and TiO2 targets. The morphology and structure of the films were characterized by XRD, XPS and AFM analyses.

Jan 1, 2003

By Li Cheng

The SKS copper smelting process was jointly developed by Shuikoushan Mining Corp. and ENFI (Beijing Central Engineering and Research Institute for Non-ferrous Metallurgical Industries) in China. It is a new bath copper concentrate smelting process with oxygen enriched air. The pilot plant testwork was completed successfully in 1993. SKS has demonstrated to be an advanced bottom blown smelting process. This technology got the First Class Prize of Scientific and Technological Progress awarded by CNNC (China National Non-ferrous Metal Industry Corp.) in 1994. The SKS process has significant capital and operating cost advantages. Its environmental and industrial safety and hygiene performance represents a substantial improvement when compared to conventional technologies. The technology has generated great interest in the Chinese metallurgical industry. Feasibility studies and basic designs have been carried out to incorporate in retrofit and green field smelter projects in China and abroad. This paper describes the history of the pilot plant operating data (50 tonnes dry feed/day), and discusses the features of the SKS technology, its application and possible future trends.

Jan 1, 1999

By Saskia Duyvesteyn

For many applications in hydrometallurgy and water treatment it would be advantageous to use ion-exchange resins in stirred reactors. However, attrition of the resin may lead to significant losses of both resin and metal values and prevent water quality goals from being reached. We have studied the recovery of fine resin particles by froth flotation, using the model copper - Dow XFS4195 chelating resin system. As the functional group on the resin is a bis-picolylamine, the resin should be amenable to flotation by anionic collectors, such as sodium dodecylsulfate and sodium dodecylsulfonate. The kinetics of copper loading from dilute aqueous solutions in an agitated vessel were studied as a function of copper concentration, pH and resin bead size. The flotation of unloaded resin was investigated for different types of collector, collector concentration, conditioning time, and resin bead size. Potential applications are discussed.

Jan 1, 1995

By R. Parada

In January 1995, Disputada Mining Company Ltd. (Compañia Minera Disputada de Las Condes) started up the Expansion Project for the Chagres Smelter, following an investment of US$M 2 15. The new smelter replaced the 44,000 tomes per year revervatory furnace with an Outokumpu Flash Smelting Furnace (FSF) designed to produce 118,000 tonnes per year of copper. Nowadays, this smelting unit has achieved a 40% over design performance. The landmarks of this modernization project are described. The start up period in 1995-1996 was characterized by the impacts of several restrictions that prevented the smelter from reach design production. The design performance was reached in 1997-1998 through the implementation of solutions designed to eliminate, or at least mitigate, the restrictions found early on. The smelter has been further optimized in the 1999-2000 period, leading to a new record anode copper production rate of 148,000 tonnes in 2000 while obtaining 98% approval for our different anode shapes. The objective of this paper is to discuss the consecutive processes of start-up, achievement of design capacity, and operational improvements to go well beyond the design capacity. These processes took place between early 1995 and late 2000, under the principles of Continuous Improvement that promotes the effective participation of the workers in the technology innovation and Enterprise Management.

Jan 1, 2002

By D. W. Collins

Several organic and inorganic substances are widely used to control deposit structure and morphology during the electroprocessing of copper. Methods for monitoring the levels of thiourea, glue and guar gum during electrorefining and electrowinning have been successfully developed under the trade names of Reatrol and CollaMat. Other instrumental methods have been developed for additives and decomposition products associated with the electroplating of copper and other metals. Generally, these methods have been found to be either insufficiently sensitive or lacking in the desired selectivity for some or all of the additives. These procedures have mostly employed DC techniques; i.e., cyclic voltammetry, Tafel analysis, etc. In this work, chronopotentiometry (CP) and AC voltammetry were used to examine the interaction of glue, guar gum, thiourea and chloride during the electroplating of copper onto a platinum electrode. In addition, the interactions between the additives have been explored. It was found that glue in pure electrolyte (H2S04 and CuS04 only) had no effect on the chronopotentiogram. Glue was only active if chloride ions were present. The addition of thiourea resulted in several different chronopotentiograms depending on the presence of either chloride or chloride and glue. Thiourea used in conjunction with glue and chloride showed a significant increase in the polarization during copper deposition when compared to the electrolyte containing only glue and chloride. The use of a modified channel electrode further increased the sensitivity of CP. The use of AC voltammetry was explored as a technique to monitor some of the additives. AC voltammograms have more spectral detail then their DC counterparts and it is possible to monitor some of the additives at very low concentrations with AC techniques.

Jan 1, 1999

By Mitsuru Tanahashi

Oxidation removal of boron from molten silicon by injecting oxygen and highly basic CaO-CaF2flux powder has been investigated with special attention to the dynamic behavior of the injected flux particles and gas bubbles. Since oxygen gas is injected into the melt, high oxygen partial pressure is maintained at the flux-O2-Si interface and the removal of boron proceeds under nonequilibrium conditions. By applying this process, boron concentration in metallurgical-grade silicon can be reduced to a single-ppm level. In this paper, the effects of the dynamic behavior of the flux particles injected into the silicon melt and the area of the reaction field (the flux-O2-Siinterface) formed in the vicinity of the flux-gas exit of the injection nozzle on the rate of the boron removal are discussed from the viewpoint of process dynamics. The experimental results clarified that the boron removal rate is affected by the kinetic energy of the flux particles which is determined by the injection conditions, such as the gas-flow rate of oxygen and the size of the flux particles. At higher oxygen gas-flow rates, the injected flux particles are expected to possess a significantly high kinetic energy such that they penetrate the O2-Si interface formed at the nozzle exit, which results in the formation of a new reaction field for boron removal. On the other hand, at lower gas-flow rates, the injected flux particles possess too low kinetic energy to penetrate the interface. In this case where the formation of the reaction field is limited, it is shown experimentally that the rate of the boron removal is constant, independently of the flux injection rate.

Jan 1, 2006

By V. L. Richards, S. N. Lekakh, S. A. Dutler

"This study presents determination on the thermal properties of investment casting shell molds used in casting process modeling. Superheat and latent heat from solidification and cooling of a casting can either be accumulated by ceramic shell for thin-walled casting or transfer to environment for massive casting. Heat capacity and thermal conductivity both play important roles in casting solidification. Thermal properties of ceramic shell depend on shell composition and fabrication techniques as well as thermal history during shell preparation process due to multiple phase transformations. Inverse modeling was combined with corrected Laser Flash method to determine the applicable thermal properties of the shell during casting solidification. Pure nickel was poured into ceramic shells containing two thermocouples and experimental cooling curves were obtained. These curves were then fitted to the model by adjusting temperature dependent heat capacity and thermal conductivity.IntroductionCasting solidification in investment casting shell affected by shell thermal properties including specific heat capacity and thermal conductivity. For relatively thin walled casting, most of the melt superheat and part of latent heat are accumulated by the shell. This process is mainly controlled by shell heat capacity. In the case of massive casting, significant part of latent heat transfers to environment through the shell so that this process is mainly controlled by shell thermal conductivity."

Jan 1, 2012

By Florian Kongoli

The optimal operation of the blast furnace depends considerably on the properties of the sinter fed into the furnace. As a result, the optimization of the sintering processes has a direct effect on the overall effectiveness of the iron making processes. In order to produce a good sinter special care needs to be taken in order to assure it has a good permeability and reducibility and it is able to retain these properties for a certain time. If the sinter starts to melt down early in the upper part of the blast furnace, where its solid state reduction is essential, permeability decreases, the gas channels get blocked, reductibility diminishes and serious problems may also follow. Among the factors that influences the above mentioned sinter properties are the oxygen potential and fluxing components. Nevertheless, their effect on the phase relations during sintering and sinter reduction conditions has not yet entirely clarified and confusion exists in literature. This quantification becomes even more important today where many new minor components such as Al2O3 and MgO enter the sinter through raw materials. This work quantifies the effect of oxygen potential and fluxing components such as alumina and magnesia on the liquidus and phase relations of the sinter primary melts in the iron rich portion of CaO-FeO-Fe2O3-SiO2 system at sintering conditions. This is carried out by the means of new type of industrial diagrams in the form of Fe/CaO vs. SiO2 that can directly help the optimization of the sintering processes.

Jan 1, 2006