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By W. P. lmrie

The recent years have seen many copper smelting operations become uneconomic due to a combination of low metal prices, high energy and labor costs, environmental requirements and high investment costs for modernization or replacement. Since a copper commodity requirement remains, the industry will recover, but many operations will need to determine which processes can offer the best prospect for economic operation and readiness for reliable investment and implementation. Corporate investment decisions involve the judgment of many factors in addition to topical technical aspects. Consideration of plant management and operational aspects are thus included. Taking account of such proven processes as conventional, flash and continuous smelting, plus modified conventional and new unproven processes, this paper gives a systematic approach to aid optimum choice for a modernization or grassroots investment. Actual achievements in energy form alternates, conservation and cost effectiveness are highlighted, and areas of remaining potential for energy saving are discussed.

Jan 1, 1983

By Frederick W. DeVries

The author was invited by "60 Minutes Australia" to provide on-site technical background on cyanide, mining, and the environment, in their investigation of the January 30, 2000, spill at the Aurul gold-recovery site in Baia Mare, Romania. Some remarks on the incident ?and its implications surround a showing of the fourteen-minute telecast. The thrust of the TV reporter was that aspects of the dam implied the owners' use of standards Jess than would have been met for installations in technologically more advanced locations (like Australia). As a result, the public-relations impact is one of embarrassment for the world mining industry.

Jan 1, 1998

By Olli Järvinen

The capacity of the Outokumpu Pori refinery is today about 125 000 mt in 1998. The anode slime amount is about 700-800 mt. The copper is removed with pressure leaching. Selenium roasting is done with the gas roasting. The doré smelting in the furnace is done with the tilting rotating converter with oxy-fuel burner (TROP). Doré anodes are treated in the silver electrolysis. Gold is recovered from the gold mud with the quick hydrochloric acid leaching process. The important point in the leaching is to get into contact the solid copper with the oxygen and liquid. Outokumpu has an efficient agitator for this purpose. The GLS-agitator (GLS=gas, liquid and solid) is powerful for mixing oxygen, liquid and solid together. The current production in Pori plant is 40000 kg of silver, 5000 kg gold, 40000 kg of selenium and one hundred kilograms of platinum-palladium concentrate.

Jan 1, 2000

By Robert A. Medower

This paper will review the operational benefits of applying contemporary control technology to balance the blast to a cupola. Reported benefits from existing installations include reduced channelling, higher pour temperature, reduced oxygen consumption, lower coke consumption & reduced emissions.

Jan 1, 2001

By P. Klut, D. Groult, R. Marechalle, B. T. H. Bonnema

In the past 5 years, Compagnie Europeenne de Dezingage (CED) has developed a successful dezincing process and the St. Saulve pilot plant has evolved into a commercially successful production plant. Currently the plant meets all the required standards for scrap and zinc quality, output capacity, availability, and meets the prescribed environmental emissions standards. The initial process problems relating to zinc recovery, uncontrollable explosions and sodium hydroxide aerosol emissions have all been solved. Presntly, the yearly production of dezinced scrap is around 50.000 tonnes/year; this capacity is enough to supply the local market. This capacity can be increased easily to 65.000 tonnes/year or more. The market for dezinced material is growing due to the increased consumption of galvanized material on one hand and on the other hand the higher demand for high quality scrap. The proven technology of CED is currently patented worldwide, but CED is inviting licensees to implement the dezincing technology in other parts of the world.

Jan 1, 2000

By W. F. Drinkard

Many in the environmental movement have focused on this element. But, nothing they or anyone does will change the amount of arsenic in the world. This report is on actual commercial plants that we developed and operated to recover or stabilize arsenic values from metallurgical dusts from gold and copper pyro operations and arsenical gold bearing ores. When they were available gold and copper values were recovered. Our experience in arsenic extends over thirty years. My first corporation, Mineral Research & Development Corporation was the first in North America to manufacture the then new CCA (copper-chrome-arsenic) wood preservatives. This class of wood preservatives proved to be so effective that it made wood into an entirely new material of construction. It is not uncommon for wood properly treated with arsenical CCA preservatives to last for thirty; forty, and sixty years. Over a hundred years have been projected in some field tests. Hundreds of thousands of trees have been saved. Millions more trees would have been saved had environmentalists not decided that their arsenic phobia was more important than trees. There are several variations of CCA. The most popular is CCA-C. Its formula is: CrO3 . . . . . . . . . . . . . . . . . . . 47.5% CuO . . . . . . . . . . . . . . . . . . . 18.5% As2O5 . . . . . . . . . . . . . . . . . 34.0% Until recent restrictions were placed on the consumption of arsenical wood preservatives, annual consumption in North America was about 150,000,000 lbs./yr. About 64,500,000 of arsenic as the pentoxide was safely consumed this way. World CCA consumption has been about double the above figures or 300,000,000 lbs. as 100% CCA and 129,000,000 lbs/yr as As2O5. Close to 100% of all the arsenic used in wood preservatives is derived from gold or copper processing. The valence of arsenic required for CCA wood preservatives and many other markets is the same valence that is required for stabilization. The economic challenge is how to get there. We have built and operated eleven plants to oxidize arsenic trioxide to its pentavalent form. Most of these have been classic in that they used a common oxidants such as hydrogen peroxide or nitric acid to achieve this.

Jan 1, 2005

By B. Willit, J. Martin

"Continued emphasis on water and energy conservation with less operator attention has created a need for more sophisticated cooling tower controls. A joint Betz/ASARCO project has produced a computerized water parameter controller and automated pumpless feed unit. Interfacing the unit via radio modem to the operator control room computer allows real time system status monitoring. Incorporating SPC principles to monitor and regulate all pertinent parameters yielded enhanced water control. This paper described the system design and present the results of a six month trial.BackgroundReducing operating costs and better manpower utilization are two of the largest concerns confronting maintenance managers today. At the ASARCO plant in Amarillo, a trial has been initiated to prove that it is possible to accomplish both of these objectives by using automated cooling tower control. The system is being adapted from a unit that was designed for continuously operating cooling towers in refineries and power plants by Betz Equipment Systems Division, a subsidiary of Betz Laboratories, Inc. The System l3000™ is designed to continually monitor conditions in the cooling system and to provide adjustments to the chemical balance for corrosion and deposition control. At Asarco, the unit was installed on the Rodline cooling system which operates on an intermittent basis.The primary justification for this project is to reduce costs of the five cooling systems in the plant. Current procedures require an operator to make visual checks every two hours on the five cooling towers as well as run lab tests on the water to insure proper treatment levels. This manpower can be better utilized by controlling the towers and collecting all the data available at one central location, in this case, the boiler house."

Jan 1, 1989

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 Luis W. Pommier

The wastes of the plating industry are generated in the process of rinsing the plated objects and during the cleaning of the plating shops. High volumes of hazardous waters are neutralized on site producing recyclable water, generating a metal rich, hazardous, filter cake. Occasionally, a complete plating bath has to be discarded which increases the metal content of the filter cakes. These filter cakes are discarded as hazardous at a cost of over $ 250 per ton. The metals found in the cakes are generally copper, nickel and chromium or zinc, lead and cadmium, assaying from 2% to 15% or even higher content of each metal The metals and their contents are highly variable. Some plating shops discard their products directly to hazardous waste sites, others, have them collected by companies which consolidate wastes from several producers prior to discarding. These wastes, richer in metal content than mine ores, need neither mining nor crushing and grinding for concentration. The commonly found impurities in the mine ores, i.e.: pyrites, arsenic, and valuable metals which are present in minute quantities, are absent in the filter cakes. The processes available to selectively recover the metals from the filter cakes, are discussed based on their technical and economic merits. The flow-sheets include leaching, solvent extraction when required, and electrolytic refining. Examples, showing the separation of copper, nickel and chromium and also of zinc and lead in pilot plants, show the technical and economic viability of the processes.

Jan 1, 1996

By Akira Nishikawa

During the twentieth century the copper smelting industry achieved dramatic expansion corresponding to the vast growth of global economy. This was largely due to innovations in pyro-metallurgical processes, such as autogenous smelting and continuous smelting and converting technologies. However, as copper production capacity increased, its impact on the environment also could not be ignored, and thus with increasing global environmental awareness, many smelting operations either had to renew or rebuild their facilities. In addition to these changes, in places like Japan and Europe, with scarce primary resources, the treatment and recovery of metals from a variety of items such as car shredder dust, used electrical appliances and electronic devices, on top of scraps traditionally treated, is having a profound effect on the reduction of waste and the preservation of primary resources. Thus compared to the days when copper smelting focused on the environmental control in order to break with "Smoke Stack Industry", copper smelting today is making an important contribution to the sustainable development of human society.

Jan 1, 2003

By Patrick R. Atkins

Energy issues will have increasing impacts on decision making in all facets of society over the next few decades. Industrial users of energy and producers of products that affect energy use must be fully aware of the implications of their processes and products on the energy situation. This paper describes a model that has been developed for the aluminum industry that allows scenarios to be evaluated to gain improved understanding of possible implications for our businesses. A brief overview of the model is provided.

Jan 1, 2006

By R. J. Wesely

Non-ferrous smelters traditionally have a hot gas handling system. In these systems, the dust is captured as a dry material which is often recycled to the process. Some smelters use wet gas cleaning methods with the recovery of the dust as a wet sludge. Although this sludge can be recycled to the process, in some cases it is preferable to dispose of the sludge. This paper will discuss the disposal methods available and specifically will deal with one type of sludge which has a high arsenic and high lead content. Problems with this sludge were investigated and methods were tested with the aim of stabilizing the sludge so that it passes the EPA TCLP test. Results of the laboratory tests are given.

Jan 1, 2000

By Yoshiaki Suzuki

In 1996, Saganoseki smelter & refinery successfully shifted to a single flash smelting furnace operation and increased the copper production capacity to 450,000mtpy in 1998. As the next step, Saganoseki planned to further increase the productivity in the smelting process. Applying the latest technology and carrying out technological innovations the throughput of the flash smelting furnace has been increased to 195 tons per hour and the matte grade has been raised to 68%. In 2005, six PS converters have been successfully consolidated into four by maintaining the production capacity. This paper introduces recent operation conditions and results of implementation of technological improvements.

Jan 1, 2006

By Uday Pal

In direct reduction processes for iron and steel making, significant amounts of Fe-C alloy droplets are generated and these remain suspended in relatively low FeO (around 5%) containing slags. Earlier workers have found that when the FeO content in the slag is <5%, the decarburization reaction becomes extremely slow (virtually ceases to occur) even though the alloy droplet contains a significant amount of carbons (2-3%). Understanding this rate controlling kinetic phenomena is crucial to designing an&apos; optimum direct steel making process. We studied decarburization of Fe-C particles by low FeO (<5%) containing CaO-SiO2A12O3 slags and found that by putting both the droplet and the slag in direct contact with an inert electronically conductive member that extends deep inside the slag bulk were able to quickly and completely decarburize the droplets. A detailed description and an explanation of the process will be presented.

Jan 1, 1995

By Huang Rui

The coal asphalt is combusted at different temperature in a heating cabinet with the temperature limit by 1200°C. By comparing the mass of the remainder of each experiment, the completely combusting temperature of asphalt smoke can be determined. Based on the experimental process of asphalt smoke, a discrete mathematical model of the asphalt smoke combustion is set by theoretic analysis. Through computer programming, the dynamic combustion process of asphalt smoke is calculated to simulate the experimental model. The result of experiment shows that coal asphalt can mostly react upon 500°C and the mass of remainder is 49.41% to initial mass of sample in the condition. The computing result shows that the temperature and the concentration of asphalt smoke influence its burning temperature approximating linearity. The consumed quantity of fuel to ignite the asphalt smoke needs be considered with the two factors.

Jan 1, 2006

By R. M. Luna-Sánchez

Electrochemical studies, particularly Evans? diagrams, have been employed in hydrometallurgy to simulate and explain the redox phenomena that take place at mineral and metal surfaces during operations such as leaching and cementation. However, despite their utility, in some cases, the combination of the cathodic and anodic branches, determined separately, does not reproduce the chemical environment present when both processes occur simultaneously on a specific surface. In the present paper, limitations of Evans? diagrams are analyzed through two examples: silver sulfide cyanidation and gold cementation on zinc. In both cases, the surface kinetics are sensitive to the local pH and cyanide levels. When the electrochemical oxidation of silver sulfide or the reduction of gold are performed in the absence of its corresponding redox reaction, the local pH obtained does not simulate the real situation and the combined reaction kinetics may be very different from those determined from the Evans? diagrams.

Jan 1, 2003

By R. W. Lee

The first prototype plant using the Imperial Smelting Process commenced operation in 1950. It is timely therefore to review the developments that have occurred with the process over the past half-century. A major advantage claimed initially for the process was its ability simultaneously to recover zinc and lead from bulk concentrates. This has remained a fundamental advantage, but it has been extended by the increasing treatment of secondary materials containing zinc and lead. This has been facilitated by the development of hot briquetting and tuyere injection. These techniques and their impact on the technology of the operation will be described. The other major advantage claimed for the process was its potential to achieve new levels of productivity in the pyrometallurgical smelting of zinc. This has been realised with operating furnaces producing up to 400 t/d of zinc. The technical developments that have enabled this scale of operation will be reviewed.

Jan 1, 2000

By P. M. Rosário

The extraction performances exhibited by a phosphoric (D2EHPA), a phosphonic (Ionquest 801), a phosphinic (Cyanex 272) and a dithiophosphinic (Cyanex 301) acid derivative towards indium recovery from a diluted sulfuric solution are evaluated and compared. Equilibrium extraction isotherms were obtained. The chemical reactions involved and the approximate stoichiometry of the In(III) extracted species by the four ligands are presented and discussed. Stripping of In(III) from loaded D2EHPA and Ionquest 801 has been accomplished successfully, but has not been so effective from loaded Cyanex 301. Plots of %E vs. pH were established for D2EHPA, Ionquest 801 and Cyanex 301, denoting their behavior towards the extraction of similar mass concentrations of In(III), Fe(III), Fe(II) and Zn(II). Cyanex 301 is the least selective towards In(III), whereas D2EHPA and Ionquest 801, both for a pH = 0.5, do not extract Zn(II) at all.

Jan 1, 2003

By S. Kurama

Incorporation of de-watering sieve waste of borax (TSW) from Etibor Kirka Borax Company (Turkey) on the mechanical and physical properties of a commercial floor tile composition was investigated. In order to achieve this aim, TSW was partially employed in place of feldspar in the standard composition up to 20 wt %. The formulated compositions were wet milled, dried, shaped and then fired at 1190C for a total firing time of 38 minutes (from cold to cold) under industrial conditions. It was found that using of TSW up to 15 wt % improved the physical and mechanical properties of final product. The results indicated a good prospect for TSW as a co-flux in floor tile formulations.

Jan 1, 2006

By M. D. Street

Lead and zinc production commenced in 1966 at Brunswick Smelting using the Imperial Smelting Process. In 1972 the blast furnace was modified to produce lead bullion only which was refined to corroding grade lead using conventional kettle refining techniques. Since 1972 consumption of lead concentrate and production of refined lead has doubled and this paper describes changes to operating and maintenance techniques which have contributed to this improvement. Reference is also made to improved environmental, health and hygiene practices at the smelter.

Jan 1, 1983