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By Richard B. Stein

Bechtel's BEMSIM computer program is a useful tool for solvent extraction-electrowinning plant design optimization. Its power (up to 90 stream components, 240 process streams, 180 process steps) has been applied to investigate floweheet configurations in order to perform basic engineering, sizing of plant equipment and to optimize performance of commercial-size copper plants. Flowsheet variations presented include series, parallel and series-parallel extraction stages, while heat balances simulate operations in summer and extreme winter conditions. The BEMSIM program has also been applied to nickel-cobalt, gold and manganese extraction.

Jan 1, 1993

By Zhenfeng Zhou, Qingguo Xue, Jingsong Wang, Yingli Liu, Yuanyuan Zhang, Hailong Huo

Coal burnout strongly depends on the residence time and dispersion of coal particles in the raceway region of a blast furnace. The residence time and dispersion of coal particles are directly related to the lance arrangement. In this work, a three dimensional model was developed to simulate the lance-blowpipe-tuyère-raceway region of a blast furnace. Double lance and eccentric configurations were considered. For the double lance, the double-lance and eccentric double-lance were considered. For the eccentric double lance, the effect of intersection angle of the two lances was investigated.

Mar 1, 2017

By Kazutaka Kunii

It is invariably certain that after punching for IC Leadframes, scrap metal were generated. These seraps were re-dissolved and in order to use as raw material for leadframes, it is necessary to remove the Ni plating. In this study a simple method was developed for the removal of Ni plating by surface oxidation of Ni plating. For this purpose a fundamental study was carried out on the oxidation behavior of Ni plating. Results showed that by controlling the oxidation condition, a considerably high rate of Ni could be removed.

Jan 1, 1996

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

Rapidly solidified TiAl-Cr-xNb-Y(x=2,4,6, at.%) alloys have been produced using a single roller melt spinning method. The microstructure of alloy ribbon was refined and component became more homogeneously by rapid solidification technology. There were two phases in alloy ribbons, including -TiAl and 2-Ti3Al phases, yet the amount of 2-Ti3Al phase in matrix obviously increased by rapid solidification than cast alloys. The micro-hardness testing also carried out. Compared to the cast alloys, the alloy ribbons have much higher hardness.

Jan 1, 2009

By E. Gutierrez-Miravete

Hot pressing processes are widely used to shape metallic, ceramic, and glass components. The process is an essential step in manufacturing ceramic fibre-glass matrix composites. The paper describes the use of computer simulation by the particle method, to the analysis of the deformation and flow of glass during hot pressing. The hot glass is represented by an assembly of interacting particles which deform in response to the applied pressure. The results, which should be regarded as complementary to continuum-based studies, provide useful insight about the hot pressing process.

Jan 1, 1990

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 Sergio N. Monteiro

Polymeric matrix composites with dispersed hard particles are being as wear resistant tools in industrial polishing operations. In the present work, the microstructure of epoxy composites with different amounts of embedded diamond particles, up to 30 wt.%, was investigated for the effect on fracture characteristics. It was found that the introduction of diamond particles promoted an increase the porosity of the epoxy matrix. Moreover, the particle morphology associated with a non-uniform distribution within the matrix was responsible for the nucleation of cracks that caused rupture of the composites.

Jan 1, 2006

By Sergio Neves Monteiro

In the present work, a ceramic foam elaborated with illitic clays was characterized. Properties related to density and compression strength were determined in samples fired at 1300oC, a temperature that permits the clay structure to generate and retain gases that will produce the foamy structure. The microstructure of the ceramic foam was studied by X-ray diffraction, scanning electron microscopy and mercury porosimetry. The results showed that the ceramic foam presents a bulk density of 0.38 g/cm3. The microstructure is formed by large open pores, quartz particles and vitreous phase.

Jan 1, 2006

By D. P. Briand

Falconbridge Limited operates a smelter in Sudbury, consisting of fluid bed roasters, acid plant, electric furnaces and Peirce-Smith converters, to treat local concentrate and other custom materials. The products are a low iron, nickel- copper-cobalt matte and sulphuric acid. This paper describes the operation and highlights some of the recent efforts to improve human resource effectiveness, to reduce sulphur dioxide emissions and ground level concentration excursions, to develop and expand the custom feed business, to improve productivity and performance in safety and hygiene, and to improve furnace integrity and process control.

Jan 1, 1993

By V. V. Geikhman

The paper updates the Plant experience in the development and implementation of an advanced environmentally friendly zinc production technology complying with the technological and economic level of producers in the world and the standards of maximum permissible gas emissions stipulated by the Russian legislation. General water recycling engineering allowed to ensure 95.6% water rotation level. All solid wastes formed during treating zinc concentrate are processed into marketable products or semiproducts and sold. As a result of implementing innovation techniques production at the Chelyabinsk Zinc Plant is non-waste.

Jan 1, 2006

By Keri Ledford, Stephanie Lin, Jason Nadler

Novel processes are being developed to fabricate thin copper thermal wick samples of a targeted porous microstructure. Structures of desired porosity, thisckness and pore size and distribution are achieved by tayloring the incorporation of sacrificial polymer beads in to slurry precursors. The thickness of the final structure is dictated by precisely controllable slurry application methods, such as spin coating. Ina subsequent heat treatment, th epolymer components thermally decompose and the remaining copper particles sinter to form a reticulated foam. The resulting microstructures are characterized in terms of porosity, permeability and specific surface area.

Jan 1, 2012

By J. Peter, S. E. James, J. L. Watson

A survey of operating zinc smelters and refineries throughout the world has been done in conjunction with the Lead-Zinc 2000 Symposium. This survey follows the examples set by the Japanese Mining Industry Association in 1985 and 1995. Questionnaires were sent to operating zinc plants that covered feed materials, process details, energy consumption and labor requirements. The voluntary responses to the survey were tabulated. Key operating parameters including feed grade, production capacity, quality of the intermediate products and quality of the final products have been compared for both hydrometallurgical and pyrometallurgical processes.

Jan 1, 2000

By W. Marnette

Norddeutsche Affinerie is the largest West European copper producer with an annual output of more than 350,000 tonnes of refined copper, about half of which is produced from copper concentrates. However, in addition to concentrates, Norddeutsche Affinerie processes secondary raw materials and recycling materials which contain a combination of copper and lead. These materials were previously treated in blast furnaces, a technology which has meanwhile been superseded at NA by the electric furnace process, primarily owing to the necessity of complying with the increasingly stringent requirements for environmental protection.

Jan 1, 1994

By R. J. Batterham

This paper sets the scene for the Australian-Asian Pacific Course and Conference on Pyrometallurgy for complex materials and wastes. The relentless presence of competitiveness is rehearsed as the source of the current trends towards continuous improvement and benchmarking. While this might be expected to lead to more spending on pyrometallurgy, the opposite appears to be the case. The paper examines the reasons and suggests that we face an increasing challenge for selective developments that can lead to sustainable competitive advantage - both in mineral and in waste processing.

Jan 1, 1994

By C. K. Gupta

The paper reports on the experimental work and results obtained in processing a xenotime concentrate. The rare earth resource concentrate has been treated by three different methods namely, hydrothermal leaching, alkali roasting and alkali pugging or baking. The recovery in hydrothermal leaching with caustic soda at 150-160°C has been 89%. En comparison, processes involving alkali roastings with soda ash at 850°C and with caustic soda at 500°C, and alkali pugging or baking with caustic soda at 200°C have given recovery values close to 100%

Jan 1, 1992

By K. Suseelan Nair

Magnesium alloys containing rare earths are finding increasing applications in space programmes. A number of alloys have been developed and e good data base an the mechanical properties of these alloys is available. However details on metallurgical aspects are found to be sparse in, literature. This paper, at first, briefly reviews the available data on these alloys and subsequently presents the microstructural investigations conducted on quatenary fig-4.9% Zn-1% Rare earth-0.5% Zr cast alley, using optical metallic-graphy, electron probe micro-analysis and X-ray diffraction techniques.

Jan 1, 1989

By David B. George

In spite of the many well-known problems inherent in Pierce-Smith converting, it remains the dominant copper converting process. Continuous copper converting and direct concentrate to blister smelting have been commercially available for over 25 years and now produce approximately 15% of copper smelter production. The two fully commercialized continuous converting processes, Mitsubishi MI Process and Kennecott-Outokumpu Flash Converting, and several emerging converting processes are reviewed with view of their potential, limitations, and environmental performance. Some myths regarding these technologies and Peirce-Smith converting are also challenged.

Jan 1, 2002

By M. Rosales

Using the k-e turbulence model, a mathematical fluid dynamics simulation of the flow characteristics in a Teniente converter has been conducted. Two cases were studied: - Transversal sections in the smelting-converting zone; and - A three-dimensional simulation that includes the walls of the reactor The calculations give the velocities field, the gravity waves amplitude, the splashing behaviour, the phase distribution and the shear stress distribution. The latter helps to explain the pattern of refractory lining wear. The calculation includes the approximate shape and dimensions, and the eventual coalescence of bubbles.

Jan 1, 1999

By Luis W. Pommier

Large quantities of sea sludge containing halogenated organic compounds, such as PCB, oils and metals like arsenic and lead have accumulated throughout the years at the bottom of sea channels and harbors and are obstructing navigation and creating environmental problems which need to be resolved. A sludge from a California port would be dredged by suction pumps, it would be processed in a plant which would be built either on firm soil or on floating platforms. The sludge shows contents of up to 1 ppm of PCB, 15 % oil and 10 ppm of arsenic, which generates a very fetid odor. Bench scale work indicates that most of the contamination concentrates on the solid phase, in fact, only minor amounts of oil report to the sea water and can be readily removed by physical means. After separation of the sea water from the solids of the sludge by decantation, it is possible to solubilize the PCB, the oil and the metals into an organic solvent leaving a non-hazardous soil for disposal near the harbor. The PCB is dehalogenated during the solubilization process leaving a liquor solution containing the oil and metals. The oil is extracted leaving an aqueous solution containing the arsenic. Further process extracts the arsenic from this solution rendering the liquid non-hazardous. Transportation and disposal of the sludge is impractical. There are hundreds of thousands of tons of hazardous soils accumulated in each harbor, which would fill the hazardous waste disposal sites available and it would be, prohibitively expensive to do so. It is not possible to compare the costs of decontamination with a competitive method. If it were, the proposed process would be less expensive than transportation and disposal and it has the advantage of removing the liabilities from the Responsible party. After a full scale continuous pilot project is run to decontaminate a small, 500 cubic yards accumulation of this type of sludge in a California harbor, a full scale environmental project would be initiated. The decontamination of one million tons of sludge would be completed in five years.

Jan 1, 1995