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By Marco A. S. Aguiar, Luis G. S. Sobral, Vânia Mori, Paulo A. Medeiros da Silva

"Copper occurs in the crust of the earth, predominantly, as sulphides. Among the copper sulphide minerals, the chalcopyrite is the most abundant and the most refractory to the conventional oxidative processes. This work aims at developing an electrolytic process for treating a copper sulphides flotation concentrate, more precisely chalcopyrite (CuFeS2) and bornite (Cu5FeS4) in the percentages of 70 and 30%, respectively.This paper presents a low-cost operational electroleaching process for treating copper sulphides flotation concentrates, with a high chalcopyrite content. This research practical work aims at improving the copper extraction from that sulphide mineral, in a relatively short time with low-operating cost taking into consideration the influence of a cationic surfactant. The electrolyte of the electrolytic reaction system was a 2,0 mol.L-1 NaCl solution containing CTAB, a cationic surfactant. The electroleaching system contains one DSATM (dimensionally stable anode) anode and two nickel or copper foams (threedimension electrodes. During the electroleaching process the chloride ions are oxidized to chlorine at the anode surface, which in contact with the aqueous phase generate enough hypochlorite ions to oxidize chalcopyrite.The copper ions released from the chemical oxidation process are reduced at the cathode surface as metallic copper."

Jan 1, 2008

By Paulo von Krüger

This paper deals with the cell design and operation of a tin electrorefining 1:5 pilot plant. The purpose of the work was the fitting of the basic parameters to be used in a full-scale tankhouse from a major Brazilian tin producer. The main specific difference was the use of permanent stainless steel cathodes instead of conventional tin starting sheets. The results of both product quality and operating parameters are discussed.

Jan 1, 2003

By Lary L. Speakman

Typical heavy metal removal system generate a great deal of waste that must then be discharged somewhere. Using Bio-Fix Beads developed by the Bureau of Mines in combination with other waste stream minimization processes, Harrison Western Environmental Services has developed a "zero" discharge operation. Data from current on-site operations will demonstrate the effectiveness of the Harrison Western approach. For 1992 Annual TMS meeting,: "Future Trends and Innovations" Material category Key words: Residues and Effluents Technical category Key words: Extraction and Processing.

Jan 1, 1992

By Kai Tang, Casper van der Eijk

Natural gas has been used as reductant in the production of iron for several decades. Recently, the use of natural gas as reductant for other metals has been drawing attention because of the low price of natural gas, as well as the reduction of CO2 emissions compared to the use of coke and coal. In this work, the reduction of a mixture of Ti- and Ni-oxides by natural gas has been studied. Within the Ni-Ti system, the intermetallic compound Ni3Ti is thermodynamically the most stable one. Therefore, powders of Ni-oxide and Ti-oxides were mixed in an atomic ratio of three to one and subsequently pelletized. Reduction was performed in a TGA furnace at constant temperature with varying reducing gas atmospheres. In a natural gas containing atmosphere, the Ni-oxide was easily reduced to metallic nickel while the Ti was reduced to Ti-oxycarbides or Ti-oxynitride when nitrogen was present. Depending on the process parameters, several percent of Ti was dissolved in the nickel-based solid phase.

Jan 1, 2014

By N. A. McKay, J. G. Davison

"Heap leachable ore deposits from many countries have been submitted for process mineralogical evaluation and laboratory testwork. Numerous factors must be addressed and integrated by the mineralogist, geologist, metallurgist and engineer. Projects encompass grass roots exploration, preliminary petrographic analysis, predictive and process mineralogy, dye penetration analysis of rocks and thin sections, metallurgical beneficiation testwork and plant optimization studies. The significance of mineralogical factors, such as geological controls, degree of oxidation, dye amenability, liberation, deleterious minerals, refractoriness, and the impact of mineralogy on gold recovery and process considerations, will be presented.ABSTRACT ONLY"

Jan 1, 1997

By M. Benavides

An experimental study is carried out With sulphide ore obtained from Bailadores-Venezuela as well as artificial concentrates. Concentrates of the minerals from froth flotation are fused to study equilibrium between the matte and slag phases. The first part of the work deals with obtaining a concentrate by flotation experiments with collective and selective reagents, with acceptable metallurgical recovery, studying the influence of different parameters in the process. The second part gives the results of the experimental investigation. on thermodynamic equilibrium in smelting which facilitates knowledge of the elemental processes, giving bases for the possibilities of reducing the loss of metal in slag.

Jan 1, 1983

By Mark C. Bronson

The feasibility of several pyrochemical approaches-for separating non-radioactive constituents from ICPP HLW calcine were examined. The removal of aluminum as AICI3 from aluminia calcine was successfully demonstrated. The examination of pyrochemical processes to remove non-radioactive constituents, primarily aluminium, zirconium, calcium and fluorine, from zirconia calcine showed that fluorine removal was required in order to chlorinate the calcine. A molten calcium chloride wash, a calcium reduction, and. a sulfuric acid treatment were examined as possible zirconia calcine pretreatment options for fluorine removal. Fluorine removal from simulated ICPP zirconia calcine was demonstrated by both a CaCl2 wash method and a sulfuric acid treatment method. X-ray fluorescence analysis indicated that greater than 97% of the fluorine can be removed by either method. Fluorine removal by a calcium reduction using an alloying agent, zinc, or a calcium reduction using, a filtration separation were also demonstrated, but the efficiencies of fluorine removal were considerably less ranging from 50 to 90%. Regeneration of CaCl2 from the salt and oxide residues of the CaCl2 wash experiments was also demonstrated 'by an aqueous dissolution method. From the salt residue, 85% or more of the CaCl2 was recovered and contained little if any CaF2 or CaO. From the oxide residue close to 100% of the CaC12 was recovered. Because of the overall success of the CaCI2 wash, it was determined to be the preferred fluorine removal process. The sulfuric acid treatment to remove fluorine is effective, but the proposed overall flowsheet has not' been adequately demonstrated.

Jan 1, 1995

By J. W. Perez

In the treatment of process effluents containing metal ions, it is sometimes desired to remove all of the heave metal ions while at other time it is, desired to remove one heavy metal ion from another, selectively. Ion and precipitate flotation processes were evaluated to perform these functions using the copper-iron aqueous system as a model. Because preliminary foam fractionation experiments proved to be relatively inefficient, most of this work has focused on precipitate flotation using both hydroxide and sulfide precipitation. Test results indicate that by proper control of reagents and operating conditions, it is possible to substantially reduce the froth volume over that achieved with foam fractionation and to separate copper from iron selectively. Mechanisms for collector attachment to precipitates were studied.

Jan 1, 1992

Sodium is added to aluminum-silicon eutectic alloys to modify the structure. The ideal amount is about 100 ppm but due to the fact that sodium is lighter than aluminum and can float to the surface where it bums, oxidizes ad volatilizes, a far greater amount is usually added. Furthermore, as the sodium is continually lost from the alloy the optimum amount is only present for a limited time. The net result is a process which is hard to control, produces fumes and a considerable amount of dross. It is shown that by electrochemically titrating sodium through a tube of sodium beta alumina electrolyte that the sodium can be added continuously in a controlled way. As the sodium is added to the bulk of the aluminum, there is no sodium on the surface of the alloy so that little surface oxidation occurs, and no fumes and dross are produced. This leads to an improved product and working conditions.

Jan 1, 1995

By Dorothée Proffit

Characterization of solids containing cyanides is carried out according to recommendations and standard guidelines. Most of these procedures are based on the analysis of leachates collected either on site or after leaching in the laboratory of samples. Unfortunately, these sole results are often insufficient to identify the source of the pollution. To provide 'a more complete characterization of polluted solids, optical and electron microscopy, XRD, Mossbauer spectroscopy, and transmission infrared spectroscopy were combined to analyze leachates and raw or ground samples. This combination of techniques allows the determination of the kind of cyanoferrate complexes are present in the solid state, different from insoluble Prussian Blue, since they do not have the same extraction' behavior. The use of all these techniques to characterize solid samples combined ,to the usual analysis of solutions gives a better understanding of ' the cyanide behavior.

Jan 1, 1998

By Jorge Alberto Soares Tenório

Electronic components have precious metals like Au and Ag. These metals have a high performance in electric conductance. The recycling of the scrap, however is too difficult because of the presence of other metals like Fe, Al, Zn, Sn, ceramics and plastics, all together in electronic components. The aim of the present work was to define one way for physical separation to have metallic non-ferrous concentrates. It was used three kinds of scrap. I was used conventional equipment for mineral processing like hammer mill; screens, electrostatic and magnetic separation.

Jan 1, 1997

By K. H. Ho

This paper describes a simplified numerical model which is used to study the skull formation of liquid metal on a rapidly rotating disc in centrifugal atomisation. The skull formation is one of the problems limiting the wide use of centrifugal atomisation. The enlarging skull on the atomising disc reduces the yield of metal powder produced and produces a resistance to the centrifugal force which worsens the quality of the powder. It is costly and often difficult to study the flow behaviour by experiments due to the complex heat transfer and phase transformation during the processing. Computer modelling is therefore a powerful tool for mechanistic understanding of centrifugal atomisation. This paper investigates the flow pattern of the melt on the rotating disc as a function of initial temperature, melt flow rate and disc rotation speed as well as the physical properties of the melt, such as density, surface tension and viscosity using the commercial package Flow-3D. Keywords: Solidification, Rotating disk, Centrifugal Atomization

Jan 1, 2003

By Jiu-ju Cai, Wen-caho Liu, Fei Liu

"With the northern cities of China as study objects, and to confirm Ground-source heat pump system of the environmental benefit and the developing direction. In this paper LCA was applied to the environmental benefit Ground-source heat pump System from raw materials acquisition to system production, utilization and disposal. The conclusion shows that Ground-source heat pump system of the environmental benefit in the northern cities of China. The result showed that Ground-source heat pump system had remarkable environmental benefit. 1. Introduction Life cycle assessment Originate in the sixties of last century, what it paid close attention to is to obtain processing from products raw materials, the processing of products produces, products transportation, products use and maintain to the influence to environment of course. It is a products -oriented environmental management style, it is the environmental management mode of meeting the needs of sustainable development strategy [1]. The research object was in the city and lie in the North of China, would undertake Beijing Olympic Games some football matches in the second half of 08, in order to improve the local environment, adjust the energy structure, reduce the heating consumption of urban coal in the centre, eliminate the coal-burning boiler under 10 tons, since 2005, the local government promotes and utilizes actively the heat pump technology in the source substitute the heating of coal-burning boiler. At present, this area is adopted the technological heating area of heat pump of source reach 20 million square meters, account for this area heat 11.2% of area always, it is estimated, by 2010, adopt the technological heating area of heat pump of source will reach 65 million square meters, the proportion of the area rises to about 30% to account for this area and always heat [2 ]. Study to the whole lifespan of heating system of heat pump of ground source of this area on the basis of LCA method, obtain the products impact on environment of different stages and environmental benefit, find out and reduce or dispel the measure of the influence, improve the environmental benefit of the ground source heat pump heating system.2. MethodologyThe research approach used in this research is the Life cycle assessment, the frame of the research approach is goal and scope definition, the inventory analysis, impact assessment, interpretation.[3][4][5]"

Jan 1, 2008

By Kunihiko Takeda, Kimio Imaizumi, Tsuyoshi Arai

"The study on the preparation of mono-dispersed liquid droplet was performed using ultrasonic as one of the steps of producing the perfectly mono-dispersed particle. The ultrasonic system was a 33.6kHz ultrasonic generator, an amplifier, an electric distortion element, and a bolted Langevin type horn installed in .a cell. For the first time, a liquid pillar under a nozzle of the cell ·was stably formed. Then, dense and coarse parts were alternatively constructed by oscillating the wavelength of the ultrasonic.· The diameter of those liquid droplets were found to be· perfectly uniform, therefore, it was measured by ""multiplex photography"" using a synchronized stroboscope with the ultrasonic.- From the results, more than 30,000 of perfectly uniform liquid droplets in 1 second were observed by this method.IntroductionRecently, research on the control of physical form is done in various fields of industry. Some examples are the processing technology of the minute compound material of micro-machines and integrated circuits, and the form control of molecule size like catalysts. There is a need for such material to take on various forms in correspondence to its use. ""Form control"" as used in this study will indicate ""research on physical chemistry factors which determine the size of the material"" and will refer to the contour uniformity of comparatively little particles. A well-known method of preparing particles is to spout a mist of liquid and slurry from a nozzle l) 2). Particles for metals, catalysts and food have been prepared by this method. In this case, although an approximate particle diameter can be decided by controlling the nozzle diameter and the violent outflow velocity, it is not easy to completely control ·the contour and to prepare a particle with uniform diameter. ·However, the preparation of perfectly uniform particles is necessary for solders for the adhesion of electronic wiring 3), ion exchange resins4), catalysts and so on. Large quantities of fine particles and super-fine particles are generated when manufactured in the usual way. Large quantities of these fine· particles and super-fine particles have polluted the internal and external' environments of factories. The products yield' ·decreases, also. From such a background, this study examines the preparation of perfectly uniform particles that could be· collected -100% as products. Recently, NASA has succeeded in the preparation of perfectly uniform particles in zero gravity 5). But the preparation of 'perfectly uniform particles by this method is difficult, and it can not be used in general industry"

Jan 1, 2000

By Bart Blanpain, Tom Peter Jones, Muxing Guo, Liugang Chen, Huayue Shi

Fayalite based slag is formed during the smelting process of secondary copper resources. It was found that with the presence of high ZnO, the slag became viscous, causing a slag tapping problem. In the present paper, the phase relations of the slag system ZnO-“FeO”-SiO2-Al2O3- CaO (ZnO = 0-12 wt%, Al2O3% = 0-15 wt%, CaO = 0-1.5 wt%, with iron saturation) at 1150 °C is studied by using quenching technique followed by phase identification and compositional analysis of equilibrated samples. The dependence of FeO and Al2O3 solubility in the liquid slag on the chemical composition of slag is characterized. Based on the experimental data, the solid fraction of the slag, which may considerably, influences the slag viscosity, at the tapping temperature can be reasonably estimated and, therefore an appropriate modification of the slag composition can be made.

Jan 1, 2016

By Dale T. Peters

In the United States, the United Kingdom and numerous other countries, copper has long been the plumbing material of choice. This has been the case since the late 1920s in the United States and since World War II in the United Kingdom. However, in recent years the plumbing tube market has caught the eye of the chemical industry, and several plastic resins have been introduced to the marketplace as substitutes for copper in household plumbing systems. One of these, polybutylene tube, had so many failures in the United States that a class action law suit was filed, and the manufactures of this product were forced to create a trust fund of nearly one billion dollars to repair damages caused by their product. Chlorinated polyvinylchloride (CPVC), in rigid pipe form, on the other hand, has been mechanically acceptable albeit its recent introduction precludes the test of time enjoyed by copper tube in this application. This paper reviews the State of California's portrayal of copper's environmental effects and will be largely based on the data and information assembled by the Copper Development Association Inc. in its presentation to the State of California in August, 1998 in response to the State's Draft Environmental Impact Report for Chlorinated Polyvinyl Chloride (CVPC) Pipe for Use for Potable Water Piping in Residential Buildings. The paper is intended for use as a model for the use of other copper organizations and individuals in responding to similar situations.

Jan 1, 1999

By Biserka Lucheva, Tzonio Tzonev

"A unique DC electric arc rotary furnace with capacity 150 kg has been designed and constructed for the recycling of low-quality scrap and aluminum dross. The main constructive feature of this furnace is that the axially positioned graphite electrodes (cathode and anode) are placed 100 mm away from the rotation axis of the furnace. A specific characteristic of the construction is the possibility one of the electrodes (the anode) apart from moving axially (parallel to the furnace axis) to move at 90° outside the working space. High recovery rate of metal aluminum from aluminum dross (92%) was realized in this furnace. This is the reason for construction of industrial DC electric arc furnace.IntroductionThe consumption of aluminum waste has been rising continuously on a world scale, which is a great stimulus for the development of the technology for aluminum recycling.To recover the aluminum in dross, the conventional recycling process uses salt rotary furnaces heated with a fuel or a gas burner. This treatment process produces a secondary dross containing alumina, salts, impurities and a small amount of aluminum. Molten aluminum is tapped from the furnace and the residue is then dumped from the furnace. It has been the practice to dispose the residue in a landfill. Improvement of this technology, known as the oxy-fuel process, uses a gas burner enriched with oxygen to increase the thermal efficiency [1]. Recent studies show that the most efficient aggregate for recycling of aluminum scrap has turned out to be the rotary tilting furnaces, heated by plasma or electric arc, for which the use of flux is not necessary [2,3].Accordingly, there is a substantial need in the industry for an improved process for recovering free aluminium. It is particularly desirable that such process be cost effective and ecologically safe."

Jan 1, 2008

By Jitka Jandová

A laboratory process based on simple and environmental friendly operation, aimed at recycling of spent Li/MnO2 batteries, is described in this study. This process involves roasting Li/MnO2 batteries in a vacuum furnace at 650°C, followed by selective leaching Li2CO3 from calcined electrode material in distilled water at ambient temperature and controlled crystallization of pure Li2CO3.

Jan 1, 2006

By Seyed Mohammad Taghavi

In this report, the efficacy of different factors such as temperature of reaction, time of reaction and depth of bed are investigated in a process of recovery of zinc oxide from zinc ore concentration residues in a fluidized bed furnace. Under optimum conditions, there was more than 93.5% zinc oxide in products.

Jan 1, 2006

By Magdalena Regel-Rosocka

Extraction of zinc(II) from hydrochloric acid solutions is discussed. The literature on the extraction of zinc(II) in the presence of iron(III) and iron(II) with various basic and solvating reagents has been reviewed. It was found that tributyl phosphate (TBP) is the best compromise, and permits both effective extraction of zinc(II) and its stripping with water. The process was confirmed in a continuous laboratory mixer-settler circuit.

Jan 1, 2003