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By R. G. Robins

The effective removal of arsenic(V) from process streams and waste waters by precipitation with excess iron(II1) is sometimes attributed to the formation of basic ferric arsenates. The authors have investigated this system extensively using a variety of techniques and conclude that the solid phase produced is iron(II1) oxyhydroxide (ferrihydrite) with arsenic(V) adsorptively bound to the 2-3 nm particles.

Jan 1, 1992

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 J. L. Jambor

Sulfide-rich tailings accumulated in a 4l-hectare impoundment at the Waite Amulet minesite near Noranda, Quebec, have undergone partial oxidation and destruction of the principal sulfides (pyrite and pyrrhotite) in the vadose zone. Mineralogical studies and whole-rock chemical analyses of 18 samples from 3 boreholes along a cross-section of the tailings pile indicate that the principal chemical manifestations of the alteration are a pronounced depletion in sulfide-sulfur, and an enrichment in total Fe as Fe203' Other elements such as Al, Mn, Mg, Ca, Na, and K in the solids show erratic or inconsistent variations, but a trend to Si enrichment in the oxidation zone is clear. The trend is interpreted to be a relative enrichment whereby the proportion of the stable silicate minerals has increased as a consequence of the consumption of pyrite and pyrrhotite in the oxide zone.

Jan 1, 1989

By Alexey T. Kovalev, Irina A. Khabarova, Valentine A. Chanturiya, Igor Zh. Bunin, Elizaveta V. Koporulina

"The paper presents new theoretical and experimental results about mechanisms of disintegration of mineral complexes and structural transformations of the sulfide surface under high-power nanosecond electromagnetic pulses (HPEMP). The heated gas outflow from nanosecond breakdown channels of sulfide minerals under HPEMP is considered. It is shown that the gas outflow from channels can be an additional destructive factor in the processes of the electric pulse discharge disintegration of mineral complexes. It is shown that the effect of HPEMP changes chemical surface composition and, respectively, technological properties of pyrrhotite and pentlandite. Morphology and elementary composition of new micro- and nanoformations on mineral surface of pentlandite and pyrrhotite have been investigated using up-to-date methods of SEM/EDX and Scanning Probe Microscopy. Preliminary electropulse effect on mineral products before flotation allows producing optimal conditions for flotation separation of pentlandite and pyrrhotite owing to forming the new nanophases and defects on the surface of sulfides.IntroductionThe effectiveness of High-Power Nanosecond Pulses in the disintegration and liberation of fine disseminated mineral complexes and the recovery of micro- and nanoparticles of precious metals from refractory ores was demonstrated in [1, 2]. Possible mechanisms of selective disintegration were considered in [1-3]. It has been shown both theoretically and experimentally that electric breakdowns can play an important role in the nanosecond pulsed treatment of milled minerals (e.g., semiconductor sulfides and quartz with particle sizes of 100 µm to 2-3 mm) that are carriers of finely disseminated gold and other valuable components. Electric discharges in such minerals are accompanied by a destruction of integrity in the form of breakdown channels and the formation of a system of cracks around these channels [3]. The development of the domains of induced cracks around the channels is determined by the pressure of evaporated material in the breakdown channel. Upon an instantaneous energy release in a channel (nanosecond discharges), the change in its transverse size and in the gas density and pressure in the channel is determined by (i) the radial motion of the evaporation wave, (ii) the radial expansion of the channel, and (iii) the heated gas outflow from the channel. The evaporation wave moves with a speed on the same order of magnitude as the speed of sound (or greater) and travels a distance of around the initial channel radius, i.e., a much smaller distance than the breakdown channel length."

Jan 1, 2011

By C. Pichler, A. Ressler, D. Gregurek, A. Spanring

In order to improve the refractory lining life at one of the RHI key customer test procedures were developed within a two years collaboration project. In the first year of cooperation detailed refractory corrosion work in the rotary kiln with Ca-ferritic slag was performed. The main results of the second year of cooperation, reported in this article, involve a detailed testing work with nickel matte and pre-selected refractory brands which was performed in TBRC. A first part of this work was a complete chemical and mineralogical characterization as well as FactSage calculations carried out on provided matte samples. According to these results testing in the TBRC was realized at different process temperatures with several magnesia-chromite bricks. Based on the mineralogical investigation a high chemothermal load caused by sulfidic matte resulted in a deep reaching infiltration of the brick microstructure and partly corrosion of main brick components.

Jan 1, 2015

By Fathi Habashi

"Davy, Faraday, and Bunsen laid the foundation of electrometallurgy which had a· great impact on other areas of metallurgy. Electrometallurgy is presently dominated by the production of aluminum, the electrorefining of copper, and the electrowinning of zinc. It has also been successful in the electrowinning of copper from solutions obtained by leaching-solvent extraction. Electrowinning processes, however, are capital intensive. Improvement of the present technology should be intensely investigated especially when it is expected that such processes will increase greatly as a result of a shift from certain pyrometallurgical processes to pressure hydro metallurgy.INTRODUCTIONPyrometallurgy was used for thousands of years to produce copper and iron from their oxide ores!). Today it is still the only route to produce iron and steel and it is certain that it will remain so for many decades to come because pyrometallurgy is most suitable for the treatment of high grade oxide ores. Even when high grade iron ores are exhausted, it is possible to beneficiate the low-grade ores and produce pellets suitable for reduction in the blast furnace, which is a very efficient reactor, being a heat exchanger as well. Hydrometallurgy on the other hand can be traced to the time of alchemists in the Middle Ages when they were seeking to transmute base metals into gold, and thus were able to prepare many acids and bases which are the essential leaching agents."

Jan 1, 1997

By Luis W. Pommier

The developed processes, the subject of this paper, extract the hydrocarbons, halogenated organic compounds and metal contaminants from hazardous soils, rendering them non-hazardous and ready to be placed back on the ground. The processes first segregate a non-contaminated fraction from the contaminated soil. This initial task is performed using available minerals processing technology: sizing, gravity separation, magnetic separation, froth flotation, etc. The remaining contaminated fraction, is submitted to two leaching operations for the removal of organic and metal contaminants, whenever both are present or to a single leaching operation if only one type of contaminant is present. The decontaminated soil fraction is mixed with the non-contaminated fraction and is placed back on the ground. The leaching liquors, used at neutral pH, are non- hazardous. After decontamination the liquids are processed to extract the contaminants, now valuable materials, for commercialization. Organic contaminants are removed by distillation of the solvents. The metal contaminants are precipitated in their oxide form. In both cases the regenerated solvents are recycled. The decontamination processes are economically competitive with transportation and disposal of the soils to permitted facilities for hazardous materials, and most importantly the developed processes remove the liabilities from the Responsible Parties. The law establishes that these liabilities do not disappear with either fixation nor with transportation and disposal since the environmental liabilities are of the ? cradle to grave? type.

Jan 1, 1994

By P. Peczak

A Monte Carlo simulation technique has been used to study dynamic recrystallization in polycrystals. A continuum microstructure of the polycrystal is modeled employing a discrete lattice. The response of the material to hot deformation is simulated by adding stored energy and recrystallization nuclei continuously with time. The experimentally observed nonuniform character of deformation substructures is modeled by employing a phenomenological expression for inhomogeneous distribution of the stored energy. All simulations were performed on HP-Apollo 9000 Series 700 workstations. A program written in FORTRAN with use of PHIGS graphics library calls was used to interactively monitor the current state of the matrix and all relevant parameters: deformation stress, average grain size and effective nucleation rate. Visual analysis of the simulated microstructure allows a better understanding of the data developed by averaging over a number of very long Monte Carlo runs. Since the essential features of dynamic recrystallization are accurately reproduced by the model, it is used to discuss the role of the controlling mechanisms of the dynamic recrystallization in real polycrystal.

Jan 1, 1993

By Tam Tran

Over the last decade, halide (chloride, bromide and iodide) systems have been evaluated as alternative lixiviants for the processing of gold to replace cyanidation which has been widely used in commercial practice. This paper first reviews the development of processes promoted by Kaljas Ltd / Lachlan Resources (Australia) and Great Lakes Corp (USA) using different bromide/bromine systems in the early 1990's. Several research groups subsequently evaluated the use of iodide/iodine and chloride/chlorine for gold extraction, showing similar characteristics of gold/silver dissolution and recovery. A critique is :given on the advantages and the ,shortfalls of halide systems as alternative lixiviants. The stability of gold? halide complexes is discussed, based on practical experience and thermodynamic modelling of their speciation, The iodide system provides the most stable gold / silver complex for easier handling. However, the cost of iodide inhibits its application for are processing. In this critique, emphasis is given on the cheapest system, which involves the use of chloride for leaching (in conjunction with an appropriate oxidant). However the chloride-base leachant has a major drawback which is related to the unstable nature of gold chloride in a reducing environment.

Jan 1, 1998

By Ann M. Hagni

Microscopic and sub-microscopic gold commonly occurs in the sulfides pyrite (FeS2) and arsenopyrite (FeAsS). To recover refractory gold from pyrite and arsenopyrite, these sulfides are roasted to create porosity and permeability prior to cyanide leaching. A new technique of adding Ca(OH)2 and roasting, lime roasting, is being tested fro retention of contaminant sulfur and arsenic and effectiveness of gold extraction. The lime roasting of pyrite at 500°C contains anhydrite (CaS04), oldhamite (CaS), calcium sulfite (CaS03), hematite (FenOs), magnetite (Fe304), and minor amoupts of pyrrhotite (Fel.,S) and pyrite. At 600°C, 650°C and 700°C the main constituents are anhydrite, oldhamite, and hematite. At 750°C, 800°C, and 850°C anhydrite and hematite are the predominant phases with minor oldhamite. The roasted arsenopyrite at 450°C contains arsenic sulfides, calcium sulfite, hematite, and minor oldhamite, magnetite, and pyrrhotite. At 650°C 700°C 750°C and 800°C, anhydrite, oldhamite, arsenic sulfides, and hematite are present. At 850°C, the same minerals are present with only minor oldhamite. The textures indicate excellent porosity and permeability at high temperatures. At lower temperatures, rims of low porosity and permeability surround many of the pyrite and arsenopyrite particles, and the complete oxidation process from pyrite to pyrrhotite to magnetite to hematite can be observed in individual particles. Additional process mineralogy techniques employed in this study are electron spectroscopy for chemical analysis (ESCA) and cathodoluminescence microscopy (CLM) in the determination of the calcium-sulfur- oxygen phases. Automated scanning electron microscopy-energy dispersive spectroscopy was utilized to analyze particles for gold content. Reflected light microscopy (RLM) revealed arsenopyrite and pyrite encapsulated in quartz particles of the gold-bearing concentrate, gold roast calcine, and cyanide leach residue.

Jan 1, 1993

By Anja Pfennig, Axel Kranzmann, Phillip Zastrow

"Properties of pipe steels for CCS technology require resistance against the geothermal corrosive environment (heat, pressure, salinity of the aquifer, CO2-partial pressure). To predict the reliability of two different injection pipe steels with 13% chromium and 0.46% carbon (1.4034, X46Cr13) as well as 0.20% carbon (1.4021, X20Cr13) steel coupons were heat treated by comparable routines prior to long term corrosion experiment (60°C, 100 bar, artificial brine close to a CCS-site in the Northern German Basin, Germany). In general higher carbon content exhibits better corrosion resistance with respect to corrosion rate, amount of pits and maximum intrusion depth in the case of local corrosion. At 100 bar hardened steels with martensitic microstructure have the lowest corrosion rates with an average of 0.003 mm/a after 2000 h exposure time. At ambient pressure normalized steels show the lowest corrosion rates, indicating that the corrosion is driven by grain boundaries.IntroductionEngineering a geological on-shore saline aquifer CCS-site (CCS Carbon Capture and Storage [1-3]) corrosion of injection pipe steels may become an issue when emission gasses, e.g. from combustion processes of power plants, are compressed into deep geological layers [4-8]. Typically 42CrMo4 (1.7225, AISI 4140) is used for casing, and for injection pipe the steel X46Cr13 (1.4034, AISI 420 C) or X20Cr13 (1.4021, AISI 420 J) is used. Saline formations are the most favorable storage sites in Germany [9], because of their large potential storage volume and their common occurrence. Leakage of CO2 back into the atmosphere may be a problem in saline aquifer storage, especially around the water level within the borehole. Carbon dioxide corrosion may cause failure of pipelines and wells as known from the oil and gas industry [4,6,10,11, 12].From thermal energy production it is known, that the CO2-corrosion is sensitively dependent on alloy composition, contamination of alloy and media, environmental conditions like temperature, CO2 partial pressure, flow conditions and protective corrosion scales [6-8,13- 20]. Considering different environments, aquifer waters and pressures, the analyzed temperature regime between 40 °C to 60 °C is a critical temperature region well known for corrosion processes as shown by Pfennig et al. [21-23] and various other authors [10,24-28] (figure 1). Here a maximum around 4.7 mm/year was found for the pit intrusion depth of 13% Cr steel X46Cr13. Still this may be predicted by the rather conservative Norsok-Model used in the oil and gas industry to calculate surface corrosion rates of carbon steels [29]."

Jan 1, 2014

By Kenji Sasaki

Tamano Smelter started its operation in January, 1972 adopting FSFE ( Flash Smelting Furnace with Furnace Electrodes ) type smelting furnace at a production capacity of 101,00Ot/y of anode copper and 285,00Ot/y of sulfuric acid. Since then, it had experienced several production expansion program, it had twice as production capacity as start. 196,000t/y of anode copper and 436.000t/y of sulfuric acid. This time, we have completed the plan for increasing production capacity up to 226,000t/y of anode copper and 510,000t/y of sulfuric acid, by the oxygen enriched operation. We carried out several improvements and modifications, changing of cooling system ill FSFE, enlargement of converter and anode furnace, and some progresses in sulfuric acid plant and environmental facilities.

Jan 1, 1993

By R Bartlett

Process engineering-science originally developed for percolation leaching of ore in heaps is extended to the decontamination of unsaturated soil, either in situ or after excavation and emplacement as a soil heap on an impervious pad. Phenomena considered include: soil matrix porosity and permeability; percolating solution retention, capillarity and flow; washing sweep efficiency; optimum solution application rates during leaching; soil agglomeration to improve soil permeability and soluble contaminant transport by diffusion in soil agglomerates. Practical aspects briefly discussed include leach pad construction, solution distribution and recovery from the soil, and solution containment.

Jan 1, 1994

By David T. Bunney

In .December of 1987, International Mill Service, Inc. signed an exclusive licensing agreement with Tetronics Research & Development Co. Limited of Faringdon, Oxfordshire., England to commercialize plasma technology which had been demonstrated in an EAF dust processing application. The intent of the process is to reduce and volatize the zinc, lead and cadmium oxides inherent in EAF dust and collect these elements as metals in an ISP (Imperial Smelting Process) zinc splash condenser, and to render the resultant slag an inert, non-hazardous material. With these objectives in mind, IMS started commissioning facilities in 1989 at Florida Steel in Jackson, Tennessee and Nucor-Yamato Steel in Armorel, Arkansas. This paper will address the commercial development and progress of the technology at these two installations. Process Description In the EAF steelmaking process typically the off gas stream is cleaned by some form of baghouse. The particulate collected is known as Electric Arc Furnace dust and has been designated by the U.S. EPA as hazardous waste number K061, once it leaves the collection system. This designation was given to the material due to the high toxic concentrations of lead and cadmium (nickel and chromium for stainless EAF dusts) inherent in the dust. IMS' method of operation is to locate the facilities on the client mill's property adjacent to the baghouse. The dust is transported directly to IMS via a closed conveyance system. This method enables the technology to be an additional processing step in the steelmaking process. Once the dust has been transported to the IMS facility, it is fed, metered and mixed mechanically in the feed conveyance system with a carbon reductant (typically coke breeze). The carbon reductant is approximately 10% of the dust feed rate. This mixture passes through the feed system and enters the furnace

Jan 1, 1992

By R. Padilla

The reaction of chalcopyrite with gaseous sulfur has been investigated in the range 350-450 °C in order to transform this mineral into a more acid soluble copper sulfide and insoluble iron sulfide. The results of thermodynamic analysis of this system as well as the X-ray diffraction analysis of the reaction products showed that in the temperature range 350 400°C the sulfidation reaction proceeded without formation of intermediate copper-iron sulfides according to: The effects of temperature and time on the conversion of chalcopyrite were studied. Conversion of chalcopyrite reached about 80% very rapidly with increase in temperature up to about 400°C. The recovery of copper from the sulfidized samples was determined by leaching in oxygenated 1.2M H2S04, 2M NaCI solution. Copper recoveries over 90 % were obtained from samples sulfidized for 30 min at temperatures lower than 400°C.

Jan 1, 2001

By S. B. Bortnikova

This paper presents the results of an investigation of the gold-silver oxidized ores at the Salair mine. West Siberia. High losses of precious metals during primary ore processing are the result of outdated technology that is not suited to treat the present ore compositions. The main mineralogical forms of gold and silver and their confinement to different grain size fractions have been determined. About 50% of gold in the slime fraction and 60% of the silver in the form of acanthite that are scattered from the secondary minerals are lost to the waste. The results of these investigations have provided the basis for the recommendation of a new technological process to upgrade the current practice of the gold extraction plant and for methods to reprocess the concentrates.

Jan 1, 1995

By Cynthia Belt

"Energy management is critical to aluminum processing given the high energy requirements of melting and processing aluminum. Energy costs have always been a high percentage of the total production costs within this industry. Energy management at many plants relied on better technology that many times required high capital. As carbon management has grown in importance and project payback becomes more critical, a larger view of a plant's process is required. This paper looks at the energy requirement due to current typical practices in overall product recovery, metal loss, utilization, and technology to understand potential methods of reducing overall energy within a plant and within the aluminum processing industry.IntroductionFor many companies that process aluminum, energy is a major portion of their costs that can surpass the cost oflabor. Aluminum processing can include secondary processing of scrap and prime aluminum into sows and/or molten aluminum or casting aluminum by various methods such as direct chill, continuous casting, low or high pressure casting, mold casting, and extrusions. In the case of this paper, we are considering only plants that include the melting process as a portion of their process. The process of melting aluminum takes energy. In most cases, the aluminum must then be heat treated one or more times. Post processing of the aluminum includes rolling mills used for making sheet, extrusion lines, and machining such as saw cuts, drilling, or surface finishes that all take additional energy.While these high energy costs directly affect the profits of the company, energy management within the metals industry is still not widespread. A co=on misconception is that the solution to high energy costs is high cost capital equipment. While state-of-the-art equipment can certainly improve energy efficiency, it is not the only solution. To obtain a truly energy efficient plant, several directions needs to be addressed through an energy management thought process with a wider scope. Impact on potential savings is possible through: product recovery, metal loss, utilization, and new technologies. An understanding of the potential costs and savings from these means is important. Several of these methods provide low cost approaches to saving energy.The background data used in this paper is not a random sample within aluminum processing but yearly averages from various plants in different aluminum processing industries. As is normal in this industry, the plants have been under different corporate management over the years with different strategies for energy management. This data is not meant to be accurate for the entire industry but to suggest areas for energy efficiency work."

Jan 1, 2012

By Kumar Ganesan

Elevated mercury levels are expected in aged gold mine tailings due to residual mercury from the amalgamation process, The fate of mercury in tailings is not well understood, Its potential health risk depends mainly on the degree to which mercury is mobile in soil. Mercury is re-moved from soil by evaporation, plant uptake, microbial activities, leaching, and other physico-chemical processes. In this research the amount of mercury lost by evaporation was evaluated. Several aged gold mine tailings in Montana were sampled for total mercury and its flux into the atmosphere. Mercury levels in tailings were higher than the general background levels in most sites. The mercury levels in some cases were as high as 10,000 ug/g. The field measurements using flux chambers indicated a wide range of mercury flux from aged gold mine tailings. The mercury flux ranged from 0-11,000 ng/m2/hr. The mercury loss by evaporation helps rid the soil of mercury but the mercury vapor then will participate in the atmospheric mercury cycle, The low solubility of elemental mercury in water helps to minimize mercury leaching from tailings, however, conversion of elemental mercury to more soluble forms by bio-geo-chemical processes can enhance its mobility posing increased health risk.

Jan 1, 2003

By Daowu Yang, Zhuo Ren, Hui Liu

"In this paper, the photochemical catalysis degradation effect of photocatalyst obtained by charcoal-supported nano TiO2 (nano TiO2 / charcoal) on the formaldehyde in the air was studied. The influences of the nano-TiO2 loading and the photoreactor structure on the efficiency of photochemical catalysis degradation of formaldehyde was reviewed.The nano - TiO2 / bamboo charcoal adsorption of formaldehyde, as well as the influences of a certain amount of formaldehyde after adsorption on its photochemical catalysis effect were discussed. The sol preparation process of Ce-doped nano-TiO2 was described. Experimental results indicated that: the surface of bamboo Charcoal still has a strong formaldehyde adsorption capacity after Supported by Nano TiO2.After adsorbing formaldehyde, the photochemical catalysis degradation efficiency of formaldehyde of the catalyst at a steady state is basically the same with new prepared catalysts’. When the thickness of the catalyst layer of the multi-ladder-type structure photoreactor is 2mm, the interval is 20mm, the absorption efficiency of formaldehyde of Nano- TiO2 / bamboo charcoal is the best . Nano-TiO2 undoped Ce responded with no degradation of formaldehyde after 2 hours, while the degradation rate of formaldehyde of the Ce-doped nano- TiO2 reached 15% 2 hours late, and the formaldehyde decontamination of the equipment reached 94%.IntroductionEmerging out of home decoration in the distribution of formaldehyde, benzene, ammonia and other indoor pollutants have been proved to be very harmful to the human body. Photocatalysis can eliminate air pollutants, in particular, can effectively degrade the air volatile organic compounds, it is a new method of air purification developed in recent years. the biggest advantage of photochemical catalysis degradation is green, this method can be available at normal temperature and pressure to degrade formaldehyde and other organic matter into carbon dioxide and water without secondary pollution.Nano-TiO2 have become the most studied photocatalyst due to its stable, non-toxic harmless, superior photochemical catalysis properties [1]. Initially nano-TiO2 powder was used as a photocatalyst, but it’s difficult to recover and easy to wear and tear [2,3]. Later, the TiO2 was used in the form of film loaded on some carriers, such as glass beads [4]. As the photochemical catalysis reaction occurred on the catalyst surface, only the organic matter adsorbed on the catalyst surface can be degraded, so the catalyst was requested that must have a strong adsorption. Combined the adsorption properties of bamboo charcoal and the photochemical catalysis activity of nano-TiO2 together. Made the photocatalyst by loading the nano-TiO2 on bamboo charcoal to degrade organic matter in the air. Nano-TiO2 semiconductor photocatalyst has a strong catalytic oxidation due to the photo generated hole of the surface [5,6],and has a potential application. Some studies have shown that nano-TiO2 photocatalysis activity can be increased by doping certain metal ions [7,8].The aim of our work in this study was to use bamboo charcoal load Ce-doped nano-TiO2 photochemical catalysis oxidation to degrade formaldehyde,and design a multi-ladder structure photoreactor, also prove the availability of the device from the theoretical and experimental."

Jan 1, 2011

By R. G. Reddy

Industrial copper reverberatory furnace slags were treated by high temperature techniques (sulfide and carbothermic reduction) to recover copper in alloy or matte phase at 1473K. Recovery was investigated for the condi¬tions of varying amounts of metallic sulfide, carbon and CaO additions. The results showed that recovery of copper increased with increasing amounts of carbon addition, and also is strongly dependent on the initial concentration of copper in the slags. Copper recovery for both carbothermic reduction and sulfide treatment were modeled with linear relationships as follows: for carbothermic reduction (%Cu recovery) = 9.0 (%Cu in slag)initial 73.8 and for sulfide (%Cu recovery) = 7.1 (%Cu in slag)initial 82.2 Higher copper recovery was obtained with sulfide treatment than with carbothermic reduction of slags.

Jan 1, 1983