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By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world's smelters, However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty, Ltd. in Australia.

Jan 1, 2003

By I. H. Gundiler

Sandia National Laboratories (SNL) is tasked to support The Department of Energy in the dismantlement and disposal of SNL designed weapon components. These components are sealed in a potting compound, and contain heavy metals, explosive, radioactive, and toxic materials. SNL developed a process to identify and remove the hazardous sub-components utilizing real-time radiography and abrasive water-jet cutting. The components were then crushed, granulated, screened, and separated into an aluminum and a precious-and-base-metals fraction using air-tables. Plastics were further cleaned for disposal as non-hazardous waste. New Mexico Bureau of Mines & Mineral Resources assisted SNL in investigation of size- reduction and separation technologies.

Jan 1, 1995

By Deming Wang, R. A. Overfelt

"The oscillating cup viscometer has become a dominant technique to measure the viscosities of high temperature molten metals. Unfortunately, the viscosity estimation model from the observed logarithmic decrement and period of the oscillation is very complicated. There are still large discrepancies of viscosity estimation values between using different measurement facilities and using different viscosity estimation models for a same molten metal. The purpose of the paper is to evaluate the accuracy of an oscillating cup viscometer in Auburn University. Two well known viscosity estimation models, Roscoe's and Torklep's equations, are compared and discussed. The theoretical literature for the fluid flow inside an oscillating cup is reviewed and a more accurate working equation for the Auburn oscillating cup viscometer is developed. Some design parameters of the oscillating cup viscometer, which directly affect the accuracy of viscosity estimation by using the working equation, are discussed. In addition, applications and experimental measuring data are presented in the paper for several different commercial alloys, such as aluminum alloys: A319, A356 and A201, nickel-base super alloys: In713 and In718, and casting irons, C40 Gray Iron and Ductile Iron.1 IntroductionThe oscillating cup viscometer is the most important and has been most frequently used in viscosity measurement for high temperature liquids [1-4]. The principal advantages of this technique over others are its mechanical simplicity and the ability to measure the time period and amplitude decay with great precision. In the viscometer, a high temperature liquid (such as a molten metal) is contained within a crucible suspended by a wire to form a torsional pendulum, which induces torsional oscillation motion. This motion is damped primarily by viscous dissipation within the viscous liquid inside the cup. The viscosity of the liquid can be calculated by an analytical or numerical solution ofthe equations of motion of the oscillating cup system."

Jan 1, 2001

By Patrick R. Taylor

Keywords: Thermal Plasma, Electroreduction, Electrolysis, Transition metals, Waste treatment, Molten oxides, Chromium oxide. An innovative process to treat transition metal oxide waste materials from diverse sources is presented. This technology involves using reverse-polarity DC plasma driven electrolysis in molten oxides. The process results in the recovery of the transition metal and other heavy metals from waste. By-products generated throughout the processing was converted to environmentally acceptable slag. The significance of this technology is that the treatment of the waste is accomplished in one step which in turn lowers the cost of remediation. Moreover, this process uses high temperature properties of thermal plasmas, which makes it possible to use molten oxides instead of halides as electrolytes. Chromium was successfully reduced from chromium oxide through the plasma driven electro-reduction process. It was shown that the selection of the appropriate ionic conducting oxides was critical for the formation of a slag that would enhance the reduction of chromium oxide.

Jan 1, 2004

By Kumar M. Lyer

The channel reactor for ferrous and nonferrous processing has been modeled as a combination of ideal reactors. Cold model studies simulated the counter-current flow of slag and matte (or metal) with high-strength submerged gas injection. A composite model has been developed which describes the mass transfer between the two liquid phases, including the transfer of minor elements. The residence time for the matte droplets in the matte/slag emulsion is compared with the settling rates for the matte droplets in the slag to determine their relative importance in the mass transfer between matte and slag. The governing equations for mass transfer have been developed using correlations for the mass-transfer coefficients in the continuous and dispersed phases. An application of this scheme to a typical copper smelting system is presented.

Jan 1, 1993

By Douglas K. Modrow

In the fall of 1993, construction was completed on a state of the art industrial waste water treatment plant at Asarco's East Helena Lead Smelter. Purpose of the plant was to remove arsenic and metals using hydroxide precipitation. Completing of the plant culminated a lengthy process of laboratory bench-scale test work, engineering, construction, and Environmental Protection Agency (EPA) oversight. Unfortunately, the effiuent requirements for the plant were made significantly more stringent as construction was rearing completion. As a result, optimization activities were initiated to determine and implement measures to substantially improve effiuent quality so the new discharge limits could be met. These activities consisted of acquiring a thorough understanding of process chemistry and plant operations, and developing simple, practical methods of automating unit operations associated with the treatment plant. Implementation of these modifications in the second half of 1996 will not only significantly improve the constancy and reliability of treatment plant operations, but also result in operating cost savings and reduced need for increased operator attention at capacity flows, plus allow the treatment plant to meet the new discharge limits.

Jan 1, 1996

By Moto Goto

Today, Pierce-Smith converters, coupled together with various types of smelting units, are used in most of the world's smelters. However, due to the "batch" processing nature, and problems associated with fugitive emissions during the transfer of melt and blowing stages, this arrangement will unlikely be adopted in future smelters. Modern day alternative processes include the Mitsubishi Process, Outokumpu Flash Smelting and Flash Converting Process, the Noranda Process, and the Ausmelt Process, but only the Mitsubishi Process is a "truly continuous" smelting and converting operation, producing a constant flow of blister without tapping, and is economically proven by long term commercial operations. This paper reviews recent advances in modern continuous converting technologies, with a special section devoted to operation of the "first standalone Mitsubishi C-furnace" coupled together with a Noranda Reactor, at Port Kembla Copper Pty. Ltd. in Australia.

Jan 1, 2003

By J. Rajek

The novel multi-component, multi-particle, multi-phase precipitation model developed recently is used to predict the precipitation kinetics in complex 9-12% Cr steels investigated within the European COST 522 project. These steels are used for tubes, pipes, casings and rotors in USC (ultra super critical) steam power plants for the 21st century. In the computer simulations, the evolution of the precipitate microstructure is monitored over the entire production heat treatment starting with the casting process, including austenizing, several annealing treatments and in-service conditions. The main interest lies on the concurrent growth and coarsening interaction of different types of precipitates. Keywords: Precipitation kinetics, heat treatment, power plant steels, simulation

Jan 1, 2003

By J. Etay, S. Daugan, Y. Fautrelle

"New type of electromagnetic parametric instabilities arising at the free surface of liquid metal in the presence of a low frequency magnetic field are presented. First, the mechanism of the instability is analysed in an idealised case. Then, the experimental device working with mercury is described. Various shapes, both regular and irregular, of free surface are found. A experimental stability diagram is obtained. Measurements of the deformation performed on photographs are compared with physical orders of magnitude.IntroductionWhen a liquid metal pool of electroconductivity a is submitted to an A.C. magnetic field B = B0 cos mt, electrical currents j are induced in the liquid metal and interact with the applied magnetic field to create electromagnetic body forces F = j x B. Those Lorentz forces comprise both a mean value (time average) and an oscillating part. Those forces are widely used in many metallurgical processes to stirr a liquid metal or to control its free surface, e. g., in aluminium continuous casting or electromagnetic levitation problems (1-3). When liquid metal free surfaces are submitted to AC. magnetic fields, the shape of those interfaces may interact with the applied field and leads to a various instabilities. A review of these instabilities may be found in Fautrelle (4). That instabilities may be a problem for the control of processing as electromagnetic levitation or quasi-levitation."

Jan 1, 1999

By J. Pesl, U. Kemey, F. Sauert

"The CONTOP® smelting cyclone is a water-cooled, upright, high-intensity smelting reactor. The technology for the reactor was initially developed and brought into industrial-scale operation in the area of non-ferrous metallurgy. The two largest smelting cyclones were built with a capacity of 32 tons per hour of copper concentrate mix.The newest industrial CONTOP® plant treats up to five tons per hour of zinc-bearing residues including EAF dust. The highly concentrated zinc-lead oxide produced is sold to the zinc industry. The slag fulfills the leaching criteria and is used in waterway construction. The heat transferred to the cyclone cooling system and the off-gas boiler produces steam from which power is generated in a turbine.V AI has erected a new CONTOP® demonstration plant at MEFOS, Lulea, Sweden. A zinc volatilization rate of 90% was achieved during hot commissioning with Swedish EAF dust.Treatment costs in the range of 85 to 100 EUR per ton were estimated in a feasibility study on the treatment of 73,000 and 57 ,000 tons EAF dust for a group of steelmaking mills in Southern Europe."

Jan 1, 2000

By S. K. Kawatra, T. C. Eisele

"Recent advances in microbiology have made the application of biotechnology to metallurgical processes possible. Hydrometallurgy stands to gain the cost from the use of microorganisms, as they are useful for both dissolution aids and for removing metals from solution. The development of genetic engineering techniques promises to greatly increase the importance of bioprocessing of metals and minerals by the year 2000.In this paper, the basic effects of microorganisms on metallurgical processes are reviewed, and the applications which are currently either in use or near being used are presented. Representative data collected at Michigan Technological University is also given.IntroductionMany hydrometallurgical operations exist which are thermodynamically possible, but which are industrially impractical due to slow kinetics, high reagent costs, or the need for a highly corrosive environment. However, recent discoveries in microbiology indicate that in many cases these difficulties can be reduced greatly by the action of bacteria and other microorganisms (1-8).A major advantage of using living organisms in hydrometallurgy is that once the culture is established the microorganisms produce their own reagents either from the material being processed or from low-cost nutrient supplements. They thus allow extremely complex chemical reactions to be carried out at reasonable cost. The major drawback of using microorganisms is their inability to tolerate extremely high temperatures, excessive concentrations of toxic metals, or very highly acidic, alkaline, or corrosive conditions. However, the complex reactions which bacteria make possible frequently eliminate the need for such extreme conditions. Also, in recent years a number of organisms have been isolated from such exotic environments as hot springs and deep-ocean vents which can tolerate temperatures higher than was previously thought possible for any organism, and can catalyze a number of metallurgically important reactions (8)."

Jan 1, 1988

By Bradford C. Wesstrom

The extraction of metals from Copper Refinery Slimes may involve many different processes. This paper describes the use of pressure leaching for decopperizing of copper refinery slimes at the El Paso Refinery. Process equipment will be described, along with the process chemistry, unit operations and unit processes associated with the decopperizing process. Copper contained in the raw slimes ranges from 15-35%. After autoclaving less than 1 % copper remains.

Jan 1, 2000

By G. S. Gupta

To predict the iron oxide concentration a mass transfer model has been developed for an Induction Smelting Process (ISP) in which self-fluxed composite pellets (made of iron ore, brown coal and lime) are melted in a single phase induction furnace in conjunction with top blown oxygen. Transient mass balance equation with complex boundary conditions has been worked out by adopting a relatively new approach known as the cell model approach. These equations have been solved numerically using finite difference technique to obtain the iron oxide concentration profile in the ISP. Numerical and experimental results obtained for iron oxide concentration show a reasonable agreement with each other.

Jan 1, 1991

By Tengfei Qi, Liqiang Fan, Huiqing Tang

A new method to process the oolitic high phosphorus iron ore for phosphorus removal has been proposed in this research. It is an integration of direct reduction and melting separation with carbon-containing pellets prepared using biomass char. Experiments of direct reduction were preceded using a tubular furnace and three parameters were investigated and they were reduction temperature, biomass char adding ratio(molar ratio of carbon to oxygen） and atmosphere. Results show that the optimum condition is of reduction temperature is 1373 K, biomass adding ratio 0.9, PCO2/PCO 1.0 and reduction time 15~25 min. Under this condition, the reduced briquettes with a metallization of 75.0~80.0 % and a residual carbon content of 0.69~0.11 wt% could be obtained. Subsequent melting separation experiments were conducted using a Si-Mo high temperature furnace. Results show metal with phosphorus content of about 0.4 mass% could be obtained from the reduced sample.

Jan 1, 2015

By Katsunori Yamaguchi

A new technique for the removal of tramp-elements from steel scrap has been required from the viewpoint of saving energy and protection of environment. In order to obtain fundamental information on the removal of copper, tin and zinc from molten iron, the extraction method by using of phase separation in the liquid Fe-Pb-C system was investigated at 1453K. A mixture of iron, lead and carbon melted in a carbon crucible separates into two phases of lead and iron containing carbon. The compositions on the miscibility gap in the Fe-Pb-C system are 95.4%Fe-4.5%C-0.1 %Pb and 99.9%Pb-0.I%Fe. The distribution ratios of copper, tin and zinc between the lead and the iron phases, Lx [mass%X in molten Pb]/(mass%X in molten Fe), are 2.2, 2.2 and 1.4, respectively. Seventy percent of copper and tin from iron scrap can be eliminated with comparable lead addition. Gold, silver and palladium are enriched in the lead rich phase, on the contrary platinum and rhodium are more distributed to the iron rich phase than to the lead phase.

Jan 1, 2003

By Tom Lewis

This report discusses the evaluation of the ENVIRO-CLEAN PROCESS, a technology developed by Lewis Environmental Services, Inc. for the recovery of metals such as chromium, mercury, copper, cadmium, lead, and zinc from surface and groundwater streams. This new heavy metal removal process (patent-pending) utilizes granular activated carbon with a proprietary conditioning pretreatment to enhance heavy metal adsorption combined with electrolytic metal recovery to produce a saleable metallic product. The process generates no sludge or hazardous waste and the effluent meets EPA limits. A 50 gpm system was installed for recovering hexavalent chromium from a ground water stream at a site located in Fresno, California. The effluent from the activated carbon system was reinjected into the ground water table with the hexavalent chromium concentration < 10 ppb. The system simultaniously removed trichloroethylene (TCE) to concentrations levels < 0.5 ppb. The activated carbon is regenerated off-site and the chromium electrolytically recovered. The full scale system has treated over 5 million gallons of ground water since installation.

Jan 1, 1996

By Antti Roine

Sulfidic zinc concentrates are usually roasted in a fluidized bed furnace into sulfur-free oxide form. Metallic zinc is produced from this oxidic calcine using hydrometallurgical leaching, solution purification and electrowinning stages. The roasting step is necessary because zinc oxides are easier to dissolve using traditional leaching methods than zinc sulfides. The Kokkola Zinc smelter uses various types of zinc concentrates and secondary materials as feed mixture. This makes it difficult to find optimum process parameters for the roaster when the composition and particle size distribution of the feed mixture varies even on a daily basis. Certain conditions may even cause difficult accretion problems or increase the amount of calcine in the process off-gas line excessively. A thermochemical heat and material balance model was developed for process advisor, in order to estimate the effects of different process parameters (temperature, process air coefficient, concentrate feed, oxygen enrichment, water feed, etc.) on the heat balance, roasting temperature and calcine composition. This model was constructed using the heat balance module of HSC Chemistry 4.0 software. The prevailing chemical compounds in the concentrate and calcine were verified using mineralogical analyses and equilibrium calculations. The roasting process seems to operate near chemical equilibrium conditions, if the behavior of the main components is considered. This paper describes briefly the basic principles of the calculation model and outlines the results with several diagrams and discussion. The calculated results were in reasonable agreement with the recent process air oxygen enrichment and water feed test campaigns carried out at Kokkola in 1999.

Jan 1, 2000

By Dinesh Goyal

Industrial fly ash from (electro static precipitator) was mixed with soil at different levels on v/v basis for raising of pulpwood tree species. In field trials conducted on degraded soils increase in the plant growth of Eucalyptus tereticornis, Acacia auriculiformis and Casuarina equisetifolia by 10 %, was observed during the initial six months after plantation at 18-24% (v/v) fly ash concentration which was at par with chemical fertilizer treatment. Level of As, Se and Mo in flyash was 6.2, 3.6 and 4.0 ppm respectively. The radioactivity analyses 40K, soil and 28 fly ash showed that the activity levels of gamma emitting radionuclides K, Ra, Ac were within the permissible limits and mixing of fly ash with soil at tested concentration would have no deleterious effects. Available Co, Cr, Ni and Cd in rhizospheric soils were below detection limit. Fly ash at 10-20 % level (v/v) was also found to be a good potting mix material in forestry nurseries in terms of improving biomass production by 20 %, when tested in nursery seedlings of Eucalyptus tereticornis. Nursery addition of fly ash in soil decreased soil dehydrogenase activity and the soil bacterial population was negatively affected. These results indicate that use of fly ash in forestry sector involving nursery and plantations as a soil amendment agent upto 10-20 % v/v is a gainful utilisation of fly ash.

Jan 1, 2002

By E G. Prado

We have confirmed on bench scale the removal of chlorides and alkalies (+95%) and over 2/3 of the zinc, lead and cadmium from EAF dusts. This has been achieved with arrononium acetate solutions alone, or with combinations of water wash, amonia-ammonium carbonate and ammonium acetate solutions. Also confirmed are the process routes for the recovery of the aforementioned elements into marketable products. The technology involves the complete recycling of the reagents. The FAF residue is returned to the electric furnace without risk of impurities buildup. Commercial scale testing with the recycled dust was satisfactory, including quality of the slag and its behavior during the melting stage. A cursory feasibility evaluation is presented.

Jan 1, 1994

By P. G. Mason

The Getchell property was mined for oxidized gold ore by underground and open pit methods from 1936 to 194.5, by which time known oxide ores were mined out. From 1945 until 1967 sulfide ores were mined and roasted to improve gold recovery with varying degrees of success. In J 983 FRM Minerals, Inc. purchased the property. Since then they have carried out extensive geological exploration to define the size and character of the orebody. The sulfide ore is refractory to direct cyanidation, thus considerable metallurgical testing has been necessary to develop a suitable, cost effective process for its treatment. Wright Engineercs Limited have designed and engineered a gold extraction plant, which incorporates pressure oxidation to liberate the gold and? is scheduled to be commissioned early in 1989.

Jan 1, 1989