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By Ronald J. Roman

The shrinking core model for coarse particle leaching has been generally accepted as describing the leaching of a copper oxide or sulfide ore. However, when a mixed oxide/sulfide ore-is leached this model can not be used in its simple form because at least two and possibly three separate leaching processes are occurring simultaneously (dissolution of oxide copper minerals, secondary copper minerals and primarily copper minerals). It has been impossible to isolate their individual leaching curves from the recovery/time curve generated by the column leach test. This paper describes a tests program carried out at the Groupo Mexico, Mexicana de Cobre's La Caridad operation in which the individual recovery/time curves for the leaching of copper oxide mineral, secondary copper mineral and primary copper minerals were developed from standard column leach tests. Once the individual recovery/time curves were developed scale-up of the column leach test results to the commercial heap leaching operation is possible by using the shrinking core model.

Jan 1, 1999

By K. Kashiwaya, N. Hiroyoshi, H. Furuya, N. Sumiya, M. Tsunekawa, M. Ito

"The number of hybrid vehicles is increasing and this is causeing an increase in waste nickelmetal hydride batteries. The cathode activating agent of batteries is made of nickel hydroxide and the anode activating agent is an alloy of nickel and rare earth elements. Conventional rotary kiln methods cannot recover the rare earth elements, and hydrometallurgical treatment of crushed product consumes large volumes of agent. The physical separation of the anode alloy from the cathode hydroxide would make it possible to reuse the alloy. The authors have reported separation of anode and cathode components in the large size fractions using a newly developed dry magnetic separation method. Wet magnetic separation has been applied to the powder fraction and about 90% anode purity was achieved. This paper reviews experimental results from previous publications and proposes an integrated treatment process for crushed nickel-metal hydride batteries.IntroductionEnvironmentally-conscious clean energy vehicles have attracted much attention in developed countries and particularly hybrid vehicles are increasingly mass-produced as low emission vehicles. Hybrid vehicles have both a gasoline engine and an electric motor to save on gasoline usage and a nickel-metal hydride battery is used to store electric energy. The battery contains Nihydroxide and Co as the cathode activating agent and an alloy of Ni and mischmetal (mM), a rare-earth element mixture consisting of La, Ce, and Nd, as the anode hydrogen adsorption component. In conventional recycling, the Ni and Fe are recovered with a rotary kiln-electric melting process and the Co and mM go to the slag component [1] and hydrometallurgical treatment of crushed product consumes large volumes of agent. Japan Oil, Gas and Metals National Corporation have proposed a low energy and low cost recycling treatment process combining the physical and chemical treatments and the authors are investigating the physical treatment process."

Jan 1, 2008

By Takahiko Okura

"It is said that the energy and resources crisis will come before long because the lifetime of known deposits of crude oil and common metals such as Pb, Zn, Cu is estimated to be less than 50 years. Establishing the sustainable society by means of resources-recycling has become an absolute necessity.The non-ferrous metals industry in Japan has been involved in the resource- recycling business for many years, along with the introduction and enforcement of various legislations to preserve the environment and natural resources. Including process-linkage during various manufacturing activities, the non-ferrous metals industry, the iron-making and cement industries are treating considerable amounts of recycled materials and wastes, in an environmentally-sound and economic manner.The Mining and Materials Processing Institute of Japan has submitted “The present and issues in Japanese non-ferrous metals and recycling industries.”The topic of the paper is to highlight the actual conditions within the resources-recycling structures and the present issues.IntroductionGlobalization has been changing the world, introducing the spike of energy and metals price. In addition, the preservation of the environment has also been strongly facing the crisis and many people have been aggrieved by both shortage and the increment in the price of the meals.In the world of metals, even though their reserves are coming depleted, the production rates are increasing, and then the industry has to enhance their productivity under stricter environmental regulations. The Japanese industry experimented the same scenario some 40 years ago, facing big pollution problems, but concurred them and enhanced the technology to overcome the more severe regulations. It will be fruitful to present the current situation in the Japanese industry for the world. The present issues are also presented."

Jan 1, 2008

"Silver is traditionally recovered in base metal smelters (lead and copper), or as a by-product of other precious metals (gold and/or PGM's). This paper presents the results of non-conventional techniques to recover silver from complex materials. The PLATSOL® process has been developed to recover, in one step and without the use of cyanide, base metals (copper, cobalt, nickel) and precious metals (gold, PGM's) from sulphide concentrates too low in grade to enter the mainstream extraction processes. Silver is only partially recovered in solution with gold and the PGM's during the PLATSOL® process. However, the silver minerals are transformed into silver chloride, which can then be recovered from the PLATSOL® residue using conventional techniques. Some South American silver concentrates contain levels of impurity (mostly arsenic) so elevated that the penalties incurred significantly affect the process economics. The present results have shown that a low temperature calcination process transforms the concentrate into a product well suited for traditional recovery treatments. Metallurgical details will be provided, as well as the results of mineralogical studies that helped clarify the process mechanisms.IntroductionSilver occurrences in nature are very diversified, and, therefore, primary silver is produced as a by-product of many base metal and precious metal operations [1], as well as a co-product of most gold ores. However, difficulties can arise when high temperature processes are used for refractory gold ores or copper concentrates, or when the silver concentrate contains impurity elements such as arsenic that trigger high penalties."

Jan 1, 2012

By M. A. Halim, V. I. Lakshmanan, T. Sheikhzeinoddin, R. Roy

"Chloride metallurgy is emerging as an alternative process for the production of base metals. Process Research ORTECH Inc. (PRO) has been at the forefront of technological development of chloride metallurgy. PRO has developed an innovative technology for the production of high purity titanium dioxide, iron oxide and vanadium pentoxide from ilmenite ores and concentrates. PRO is also developing its proprietary mixed chloride technology for the extraction of vanadium from other sources such as oil shales. In this paper, results from the test work conducted at PRO for the extraction of Ti and V using a mixed chloride lixiviant are presented.IntroductionTitanium and vanadium alloys and compounds have numerous industrial applications. Titanium dioxide is used in paints, plastics, rubber, paper, inks, textiles and a number of other miscellaneous applications. Currently nanosize T1O2 is being investigated for application in the cosmetics industry. Inorganic sunscreens mainly use T1O2 or ZnO particles, which reflect and scatter ultra-violet light. T1O2 nanomaterial is also finding application in smart construction materials and coatings, as a photo-catalytic converter. Nano TiO2 can catalyze the dissociation of NOX gases and other automotive emissions, thereby reducing the smog in urban centers. After the construction material is exposed to sunlight or ultra-violet light, the T1O2 is photo-activated and degrades the pollutants.Titanium metal and titanium dioxide are produced from ilmenite (FeTiOs) or rutile (naturally occurring T1O2) ore. Only about 6% of the titanium resources are used to produce titanium metal and the rest is used to produce T1O2. Many of the titanium ore deposits currently have unacceptable levels of transition metals which limits their processing by conventional routes."

Jan 1, 2012

By John A. S. Green, J. Gilbert Kaufman, Subodh K. Das

"The aluminum industry is a leading proponent of global sustainability and strongly advocates the use of recycled metal. As the North American primary aluminum industry continues to move offshore to other geographic areas, such as Iceland and the Middle East, where energy is more readily available at lower cost, the importance of the secondary (i.e., recycled metal) market in the U.S. will continue to increase. In the past, the recycling industry had been synonymous with the collection of aluminum beverage cans. However, as the opportunities for aluminum recycling have multiplied in motor vehicles, building and construction, and aerospace, these market are getting additional scrutiny for optimization of recycling strategies.Accordingly, the secondary industry can now draw upon a much wider range of product forms and alloys for its raw material, but this in turn brings issues of alloy sorting, impurity content, and control as the material is remelted and recycled into new product forms. The purpose of this paper is to take an integrated, industry-wide approach to look at the recovery of material from demolished buildings, shredded automobiles, and aging aircraft, as well as from traditional cans and other rigid containers. Attempts will be made to assess how the different alloys used in these separate markets can be recycled in the most energy efficient manner.IntroductionIn his recent book “Aluminum Recycling”[1], Mark Schlesinger points out that in traditional extractive metallurgy, the raw material used to produce a metal is mined from the earth and then is separated from other gangue minerals and impurities. In aluminum recycling, however, the ore body consists of scrap metal found on the ground, rather than in it. He further notes that scrap comes with its own variety of gangue and impurities such as painted coatings, other metal attachments, and even dirt and other contaminants. So, while the recycling process still requires some refinement and expenditure of energy, the effort and energy involved is much less than traditional mining."

Jan 1, 2008

By F. Nava-Alonso, O. Alonso-González, A. Uribe-Salas, R. Pérez-Garibay

"Cyanidation is the most used method to recover gold and silver from their ores. In this process, other metals besides gold and silver may sometimes dissolve and interfere with the efficiency of extraction. Copper is one of those metals, reaching concentrations as high as 1000 mg/L in some cyanidation plants, making difficult the extraction and purification processes, and increasing the operating costs.This preliminary work was intended to study the feasibility of using amines to form a precipitate and to eliminate copper from a synthetic solution containing high copper and cyanide concentrations, as is the case of some cyanidation effluents. The solid formed is removed from the solution using conventional filtration techniques. Seven amines were evaluated at different pH values and amine additions. Up to 90% of copper present may be removed at the natural pH of the effluent (alkaline). The remaining copper would permit to recycle the solution back to the cyanidation process. IntroductionCopper is generally considered the most problematic metal in gold leaching due to the rapid formation of copper cyanide complexes when some readily-soluble minerals are processed (e.g., azurite, malaquite, cuprite, chalcocite and bornite). The copper solubilization as cuprous cyanide complexes leads to a significant economic penalty in terms of excessive cyanide consumption and high cost for cyanide elimination. When activated carbon is used to recover gold and silver, the copper-cyanide complexes decrease the efficiency of the process because of the competition of the cuprocyanides with the aurocyanide for the adsorptive sites on the activated carbon (Rees and Deventer, 1999).Several techniques have been developed to attempt to overcome the problems caused by the copper presence in cyanidation solutions, notably: acidification-volatilization-regeneration (AVR), ion exchange-electrolysis or solvent extraction-electrowinning (Lu et al., 2002). In this work the use of some amines is proposed to remove the copper-cyanide complexes by precipitation of a copper-cyanide-amine solid. The process was evaluated for different amine additions and pH values, using copper-cyanide synthetic solutions of composition similar to that presented by some cyanidation plants with high copper."

Jan 1, 2008

By Georgeta Rata, Cornelia Petroman, Ioan Petroman

"Proper training and education in the field of recycling and waste treatment are inconceivable without the proper teaching of the terminology specific to both recycling (aerospace products recycling, automotive recycling, general recycling, recycling behaviour, recycling schemes, recycling systems, and waste recycling) and waste (characterization of waste, electronic waste, heavy-metal containing waste, monitoring of waste, radioactive waste, solid waste, waste collection, waste conversion, waste recycling, waste reutilization, waste stabilization, waste storage, and waste treatment) in both the students’ mother tongue and in English for Special Purposes (ESP) as a second language (with focus on the structuring of the specific terminology). Including linguistic approaches among the possible approaches of environmental protection and material sustainability means including linguistics among the various disciplines addressing energy supply, cement and building materials, metallurgy, chemistry, glassware, pulp and paper industry, machinery, automobile and electronic industries, collection, and sorting, further treatment and final disposal of post-consumer material.IntroductionCultural and technical changes have produced more novel artefacts than novel activities or novel properties, generating new vocabulary needs that are readily answered by new words (nouns).The purpose of this research is to show that ‘waste words’ – phrasal words (items that have the internal structure of phrases but function syntactically as words, e.g., cattle waste) and particularly compound nouns (words formed by combining roots, that tend to have a meaning that is more or less idiosyncratic or unpredictable, e.g., wastepaper ‘discarded paper’) – used in the study of the English of recycling, waste treatment, and clean technologies can be misleading for both native and non-native students and/or users of English because their structure alone does not allow instant, proper understanding of their meaning.Our hypothesis is that this inconvenient can be overcome by getting to reach the proper meaning of these new words. Or, arriving at the precise meanings of the ‘waste words’ depends on our knowledge of the world (for example, wastepaper indicates that some used paper is discarded and not wasted) rather than on purely linguistic knowledge."

Jan 1, 2008

By Christian Ludwig, Virginie Silberstein, Rizlan Bernier-Latmani, Simona Regenspurg

"Residues from waste incineration (bottom ashes) form large amounts of heavy metal-rich waste. Theoretically, heating and the addition of chloride to the ashes could remove these metals by formation of volatile metal chlorides. The remaining heavy metal-poor ashes could be used, for example, as cement additives. In the proposed process of our study we used bypass dust from the cement industry as chloride additives to the bottom ashes. We aim to determine experimentally the optimal conditions to remove heavy metals from ashes and to simulate this process by thermo- chemical modeling. In our experiment we investigate heavy metal flows by heating of differently composed mixtures of bottoms ash and bypass dust in dependence of different furnace temperatures (500-1200 °C). Furthermore, we investigate the reactivity (leaching characteristic) of the resulting product in order to predict if secondary residues can be landfilled in agreement to Swiss regulations for inert materials.IntroductionThe incineration of garbage is generally considered as the most environmentally friendly method for the reduction of municipal solid waste. This is because, compared to traditional storage of waste on landfills, incineration produces less greenhouse gases and destroys toxic organic compounds. The released exothermic energy can be recuperated and the residues from the combustion chamber (bottom ash) are strongly reduced in volume. However, they still form about 600 kt of waste per year in Switzerland, which needs to be landfilled. However, these residues could be potentially used as construction materials after mechanically recovering ferrous and non-ferrous metals. However, the resulting ashes (discharged dry or wet) still contain increased amount of heavy metals (exceeding state regulation) requiring them to be finally deposed on a hazardous waste site. A thermal treatment of these ashes could enable both, to separate and recuperate the remaining heavy metals and an inorganic heavy-metal poor material. The evaporation of metals depends on temperature and can be lowered by addition of chlorides, which would lower the boiling point of most metals by formation of metal chlorides (table 1). 745"

Jan 1, 2008

By Florian Kongoli

While calcium ferrite slags have been successfully used in continuous copper converting for the last 30 years, ferrous calcium silicate slag was proposed about 8 years ago as an additional alternative for copper smelting. Although both slags are normal extensions of each other their phase relations have not been completely clarified. In this paper the liquidus relations of both slags have been quantified at various areas that cover both of them. The existing experimental data have been first reviewed and discussed in relation to the solidification procedure. An original physical model is then used to predict various diagrams of the liquidus surface of both slags. It is shown that the ternary liquidus diagrams normally used for FeOx-SiO2-CaO system are not suitable for industrial slags. The new model diagrams of Fe/CaO versus SiO2 and Fe/SiO2 versus CaO as well as Fe/CaO versus Temperature and Fe/SiO2 versus temperature are proven to be much more convenient for ferrite and ferrous calcium silicate slags. Based on these diagrams the effect of SiO2 and CaO on the melting temperature is quantified. The effect of Cu2O is also quantified through the model. Some Fe/CaO versus Cu2O and Fe/SiO2versus CaO at various copper contents are predicted and the results show good agreement with the experimental data. It is also shown that in the presence of liquid copper, Cu2O is dissolved in the slag depending on the oxidation degree of the system and might lower the liquidus temperature. Some discussions are also presented taking into account plant observations and important conclusions are drawn for copper smelting and converting

Jan 1, 2006

By Nicola Baldo, Marco Pasetto

"The paper presents the results of a laboratory study, conducted at the Experimental Road Laboratory of the University of Padova, in order to verify the possibility to use different types of electric arc furnace (EAF) steel slags – in substitution of the natural aggregates – in the composition of both dense graded and porous asphalt mixes for flexible road pavements. The research has been articulated in a preliminary study of the chemical, physical, and mechanical properties of the EAF steel slags, and in the following mix design and performance characterization of the bituminous concretes, through stiffness modulus tests at various temperatures and permanent deformation (creep) tests. All the mixtures with EAF slags have satisfied the requisites for acceptance standardized for the road sector, thus resulting as suitable for use in the construction of infrastructures, moreover presenting higher mechanical characteristics than those of the corresponding asphalts with full natural aggregate. IntroductionSteel is produced industrially employing two main technologies: the integral cycle, which starts from mineral iron, and the electric cycle, which uses scrap metal. A consistent amount of the steel produced in Italy (approx. 55%) comes from Electric Arc Furnaces (EAF), which every year, alongside the steel, produce approximately 2 million tons of slag. The recycling of this waste product to produce new high-quality raw materials would reduce both the exploitation of limited natural resources and the amounts of refuse. In the European Union, 60% of slag from EAF is still today disposed of in dumps. The extremely diverse origins of scrap metal (waste from mechanical manufacturing, industrial and civil demolition, car bodywork, etc.) means that the by-products generated by the smelting, slags and ashes, contain different elements, in varying composition, also depending on the type of steel to be produced and the consequent adding of binding and melting elements during the production process. For this reason, iron and steel industry electric furnace slag - unlike the blast furnace dross utilised in cement works, which has a more uniform composition as it comes from a more standardised cycle – has been viewed in the past with some diffidence and so, at least in Italy, the possibilities of its re-use have never been fully developed."

Jan 1, 2008

By B. Boryczko, J. Norwisz, Jose Escobedo Bocardo, Z. Kolenda, A. Holda

"Classical thermodynamic analysis of any thermal and chemical process is usually based on the first law of thermodynamics. Such an approach is not sufficient when deeper understanding of the nature of each elementary process is required. The use of the first and second law of thermodynamics together is necessary to solve practical process more effectively. Enthalpy and exergy balances allow to enhance our understanding of thermal processes especially when cumulative consumption of energy and exergy is calculated. To ensure reliability of such an analysis the least squares method for adjustment of mass balances of principal chemical elements has been applied and described in detail. Numerical analysis has been carried out to compare two different processes of copper production – shaft furnace and flash smelting.IntroductionClassical thermodynamic analysis of any technological process is usually based on the First Law of Thermodynamics in the form of energy (enthalpy) balances. Such an approach is useful in engineering practice as it makes analysis easier in the global scale neglecting modeling of the elementary processes, allows calculation of the thermal efficiency and makes possible to control quality of the measurement results. Additionally, graphical presentation of the energy balance is simple in the form of Sankey diagram.In the case of aluminum electrolysis process, design of the new electrolyzer or its modernization is always based on the enthalpy balance.However, deeper thermodynamic analysis leads to the conclusion that such an approach is not sufficient. The First Law of Thermodynamics guarantees the exact equivalence of the various forms of energy (allowing all forms to be measured in the common unit such as joules) but it does not guarantee interconversibility. Thermal energy (heat) is in a peculiar and unique position, for whereas all other forms can be completely converted into thermal energy, the reverse process id impossible, only a portion of the heat can be converted into mechanical energy. Explanation comes from application of exergy balances. As we know exergy expresses the amount of mechanical work necessary to produce a material in its specified state from components common in the natural environment, in a reversible way, heat being exchanged only with environment [1]. Consumption of exergy connected with the fabrication of some considered product appears not only in the plant manufacturing the product, but also in all plants delivering raw materials for the final production process"

Jan 1, 2008

By A. F. Sidorov

A method of improving mineral recoveries from ores by modifying the physical and chemical properties of minerals using radioisotope radiation was tested. It was observed that irradiation modifies mineral cell sizes, changes the crystal structure of some minerals, reduces the sulfur content 1 to 1.5 % in sulfides, changes the zeta potential, alters the surface properties of mineral grains I and produces other changes. Preliminary tests indicate that accelerated electron treatment of ores in connection with mineral processing has a potential for improving mineral recoveries by flotation and by magnetic separations.

Jan 1, 1989

By Yuuki Hagio, Hiroyuki Tobo, Michihiro Kuwayama, Yasutaka Ta

"Reduction of CO2 emission is necessary to remedy global warming, however, promising approaches of CO2 separation require a large amount of energy. Molten slag, which is generated as by-product of steel production, has high temperature, but its energy has not been harnessed. To recover the thermal energy from the slag and to apply to separation of CO2 are economical and environmental conscious ways. We propose a new heat recovery system, in which, molten slag is solidified continuously on water-cooled roll and the solidified slag plates are charged into counter-current heat recovery equipment. In laboratory scale experiments, heat recovery ratio of more than 30% was acchived by controlling the thickness of slag.IntroductionThe steel industry in Japan has been working on the projects of ""Environmentally Harmonized Steelmaking Process Technology Development (COURSE50)"". COURSE50 aims at developing technologies to reduce CO2 emissions by approximately 30%. One of the main technologies is to capture and recover CO2 from blast furnace gas using chemical absorbents to regenerate CO2-laden chemical absorbents by separating CO2 from the absorbents. As one of the solutions, JFE Steel Corporation has been developing sensible heat recovery process from steelmaking slag. It is effective to recover and use unutilized high temperature waste heat within a steel plant as the thermal energy required."

Jan 1, 2012

By Erwin Flender, Preben N. Hansen, Peter R. Sahm

"Until now FDM-Techniques have been widely used for Modeling Solidification Processes in Castings. Often a rigid, regular type of enmeshment (cubes, , --) have been used. This has the advantage of low CPU-costs, but the disadvantage of a zig-zag presentation of the interface between the casting and the mold. The last point is the reason why FEM-Techniques, giving the possibility of a true presentation of the shape in the enmeshment, are increasingly used. The disadvantage is the high CPU-costs. In this paper, a technique is presented, which uses the FDM-Mesh with the zig-zag presentation of shape and ADI-Algorithms to calculate temperatures and gradients. The new idea is that the calculated parameters are not presented related to the mesh in which they are calculated, but displayed using the true shape of the casting. Such an advantage of both low CPU-costs and shape correct presentation of the calculated results are achieved. IntroductionThe main reason for using a regular type of enmeshment is that it gives the possibility, via ADI-Algorithms, of obtaining a very fast FDM-Technique. The technique presented by P.R. Sahm and P. N. Hansen (1984), and also used by E. Flender (1985), is numerically so stable that average time steps, at least 200 times larger than the limit given by the explicit FDM-Technique, can be applied. To obtain reasonably good results, average time steps in the range of 20 to 50 times the explicit limit seems to be applicable. It should be pointed out,however, that FDM-Techniques can be used on arbitrary nets, the disadvantages being the same as for the FEM-Techniques. This has, among others, been discussed by P.R. Sahm and P.N. Hansen (1984)."

Jan 1, 1986

By E. L. Frueh

AMAX Base Metals Research & Development, Inc. has developed a process for treating copper-nickel mattes to produce copper cathodes and a pure nickel sulfate solution. In this process, the input matte is preleached in a copper sulfate electrolyte bleed solution so as to dissolve nickel from the matte and cement copper from solution. The preleach leaves a substantially pure nickel sulfate solution. The residue from the preleach is roasted to less than about one percent sulfur. A portion of the calcine is leached with sulfuric acid to make a copper sulfate solution for input to the tank house. The residue from this leach and the remaining calcine are smelted to form a bimetallic (copper/nickel.) anode. The anodes are electrolytically refined and copper is preferentially deposited on the cathode while the nickel reports to the electrolyte, A bleed stream is taken from the electrolyte and used in the preleaching of the input matte. This process produces high purity metal streams while consuming less energy and smaller amounts of reagents as compared with other matte processes.

Jan 1, 1983

By Melvin A. Jennings

Ion-exchange technology for precious metals recovery is at a turning point. Some very exciting technology has been developed in the past five years which should lead to commercialization of the process. Ion-exchange will allow not only for the recovery of gold and silver, but also will allow for the recovery of cyanide form plant tailings. This process may soon be competitive with Merrill-Crowe for silver and once this occurs, it will become the process of choice.

Jan 1, 1991

By Marcelo Jimenez Bustos

The Chagres Smelter was the first in Chile to follow environmental regulations to control sulfur dioxide emissions. Because of this, the operation and development plans have had to incorporate environmental planning as part of its policies for almost three decades. The present article shows the development of the environmental standards applied to its operations, investments and operational improvements carried out to meet the regulations and improve competitiveness. Results to-date and future plans are outlined, as well as their impact on operations and the environment.

Jan 1, 1993

By James D. Navratil

Ferrites have been used to separate a wide range of substances such as dissolved metal species, particulate matter, and organic and biological materials; they have been used almost exclusively for metal waste treatment applications. The versatility of the ferrite waste treatment technique is evident in the wide variety of application methods. Furthermore, ferrites can be used to remove selected impurities in feed solutions containing metal products requiring purification. A brief overview of ferrite properties and recent applications for metal recovery and waste processing will be presented.

Jan 1, 1990

By D. A. Horne, V. R. Daiga

Certain steel mill wastes contain significant amounts of zinc oxide due to the use of galvanized scrap during the steel making process. Typically electric arc furnace (EAF), and basic oxygen process (BOP) flue dusts contain 20 to 30% zinc oxide and 40 to 50% iron oxides, along with smaller quantities of lead and cadmium. These materials can be recovered from the flue dusts by using a proven rotary hearth furnace (RHF) process. By-products of the recycling operation include a crude zinc oxide fume, which is captured in a baghouse filtering system, and sponge iron that may be recycled into the steel making operation. Crude zinc oxide properties plus the operating experience from two commercial RHF installations utilizing MR&E's DRyIron™ Process will be presented.

Jan 1, 2000