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By D. J. Goodwill

BHP Copper operates a 3,400 tpd dry concentrate, single burner, Outokumpu flash smelting furnace (FSF) at their San Manuel copper smelter in Arizona. The very fine (-325 mesh), dry concentrate is fed to the burner from a 550 metric ton (nominal) capacity furnace feed bin via two drag chain feeders. During the 10-year history of the furnace, operations have been plagued by serious flooding problems. The fine concentrate sometimes becomes aerated during discharge from the bin and flows like a fluid at very high uncontrollable rates to the burner. This results in upset conditions at the concentrate burner leading to poor furnace metallurgy. This paper will examine the problems of uncontrolled feed from the furnace bin (i.e. flooding), and' instantaneously feeding a flash smelting burner. It will show that a drag chain is a poor choice of feeder when high rates are needed, and that drag chains always produce a funnel flow pattern in a bin. BHP's drag chains cause narrow diameter, high velocity flow channels within the stored material. Consequently, there is insufficient residence: time for the concentrate to fully de-aerate before discharge, hence flooding occurs. In addition to the flooding problem, drag chains create a pulsating flow to the concentrate burner due to the tendency for material to slough off in discrete chunks at the discharge end of the slow moving chain conveyor. During the scheduled FSF rebuild in May 1999, BHP intends to remove the drag chains, modify the bin to a mass flow design and to use STAMET® multi-disc feeders to accurately and instantaneously control the rate of discharge from the bins. Air slides will be used' to convey the concentrate to the burner.

Jan 1, 1999

By Taner Kavas

The refractory bricks of a rotary cement furnace containing of alumina and magnesium chromite were studied in order to determine whether they could be used in the concrete production as aggregates. Three mortars were prepared by mixing 1 part cement, 3 part aggregate materials, 0.5 part water by weight and mechanical, chemical, thermomechanical and microstructural characteristics were evaluated. The compressive and bending strength of samples were determined after 2 and 28 days curing. Resistance to chemicals were established by calculating the weight gain of mortars stored in 2 % HCl solution for 1 h and 24 h. Thermomechanical characteristics were determined by measuring the compressive strength of heat treated specimens at temperatures of 400 °C, 600 °C and 800 °C. Consequently, magnesium chromite containing waste brick aggregates have given the best results.

Jan 1, 2006

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 Mariola Saternus

The quality of the liquid metal has the biggest influence on the quality of the final products. In the metallurgical industry, and especially in aluminium production the refining process is the important technological stage. Today the most popular are refining reactors with impellers like URO ? 200, which can generate small gas bubbles. A rotary impeller also makes the metal bath to be stirred well. There are two basic hydrodynamic parameters: the flow rate of refining gas and the mixing of refining gas (impeller rotation) that influence metal stirring and generating small gas bubbles. The paper presents the influence of the flow rate of refining gas on the hydrogen removal process from aluminium (final hydrogen concentration), taking into consideration the refining process of AlSi7Mg alloy and using URO - 200. The mathematical model of this process is also presented. The equation needed for calculation of the final hydrogen concentration as a function of the equivalent bubble diameter is shown. Basing on this equation the calculations of bubble diameter and optimal refining time are done. This paper presents the physical model (the water one) of aluminium refining process and the gas dispersion taking into account the fact that the gas flow rate is changing from 2,5 to 17,5 l/min and the impeller speed is changing from 0 to 400 rpm. Schemes of gas dispersion in liquid metal in comparison with the model data are shown and the optimal values of the gas flow rate and the impeller speed are chosen.

Jan 1, 2006

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 Zviad Kovziridze

The problems related to the production and research of SiC-Si3N4 composite are presented. The technology of producing the protective casings for tips and thermocouples is developed. Optimum composition charge and technological parameters are defined. The results of casing testing at production plants are presented.

Jan 1, 2006

By Milorad Cirkovic, Mile Bugarin, Vlastimir Trujic

"Industrial scale testing was performed in the plant-site of Bor Company. Charging sample was from 4-5 tons for each particular test. All operations in industrial scale investigations were carried out in one furnace. For the aim of successful realization of experiments, and primarily for safety and prevention the risk of toxic contamination the working environment, a plant was designed and constructed for cooling and wet dedusting of gases formed during smelting process, zinc removal and flame refinement of molten metal. For the requirements of industrial investigations a complete plant for cooling and wet dedusting of gases has been constructed for brass scrap processing. In this plant, the original ultra-sonic water spraying devices have been installed. The efficiency of such simplified system for gas treatment has been 98,6%. Introduction Permanent development of techniques and technology causes formation the considerable quantities of secondary raw materials that are much more relevant as the raw material base for many metals. Due to a fact that large quantities of metal, are concentrated in the waste materials, large consideration is given to this topic, and numerous technologies for this waste recycling are developed in the world nowadays. High energz price and permanent increase of metal price on the world market have made that secondary raw material tretament, for the aim of various metals production, becomes more and more relevant in the world. In comparison of metal production using enrichment and metallurgical treatment of primary raw materials, the non-ferrous metals production from secondary raw materials has a range of advantages, as well as: - Low level of capital investments, - High technological recovery of qualitative secondary raw materils, - Considerably low consumption of energetic resources regarding to the treatment of primary raw materials (ore and concentrate), - Reduced consumption of unrecoverable mineral resources, - Reduced enviroment pollution [1,6]."

Jan 1, 2008

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 Philippe Charlier

Recycling of aluminium contained in used aseptic beverage cartons is a difficult task which has nevertheless to be tackled by our modern societies. Techniques have earlier been developed by the paper and pulp industry for the recycling of the board fibres from collected post-consumer beverage cartons. A joint technical feasibility study by Granges and a leading beverage carton producer has dealt with different techniques for handling residues from repulping facilities. The aluminium obtained can be used as raw material for the production of thin gauge foil, thus closing the recycling loop.

Jan 1, 1995

By Peter Schwartz

This paper presents GBN's "Global Scenarios" for the first decade of the 21st century. We describe a set of key scenario actors and develop 6 driving forces in demography, technology, climate change, macroeconomic change, globalization, and geopolitics. We argue that a set of majorchallenges to world systems of commerce and politics will coalesce in the next several years. We develop four scenarios which differ according to how these challenges are handled, and which scenario actors play the key roles in managing the transition.

Jan 1, 1999

By Jason Eric Sallee

Ongoing operations at the Cyprus Miami Smelter involve the use of an electric furnace for settling of copper matte from discard slag. Proper operation of the electric settling furnace is a major factor in minimizing losses of copper to the discard slag. Recent test work at the smelter has shown improvement in the operation of the electric furnace with a subsequent improvement with regard to the copper losses. This paper presents a general discussion of the Cyprus Miami Smelter operation, past results with respect to copper losses, recent operational changes and test work, and the subsequent results.

Jan 1, 1999

By Yang Wang, Xiancong Zhao, Hao Bai, Qi Shi, Zhancheng Guo

Linz-Donawitz converter gas (LDG) or basic oxygen steelmaking gas (BOSG) is one of the most important secondary energy sources in iron and steel industry, whose effective use plays a vital role in energy saving and emission reduction. However, the generation of LDG suffers from great fluctuation with respect to the production status of steel making. Therefore, a long term prediction model of LDG generation would be essential in gas system balancing and optimization. In this paper, a long term prediction model for the generation volume of LDG was proposed based on the steelmaking production estimation from Gantt chart and k-means clustering algorithm. Compared with the previous model, this model considered the influence of different steel type on LDG generation. The experimental results of a steel plant demonstrate that the proposed model exhibits high accuracy and can provide an effective guidance for balancing and scheduling of byproduct gases.

Jan 1, 2016

By M. A. Llavona

The study of the formation and components of copper patina and its conservation has assumed great importance. The changing environment has accelerated the processes of patinas degradation; thus, the exhaustive study of factors capable of affecting the patina formation, growth and durability has assumed great importance for the industrial activity of copper. The main components of the patina, oxides, chlorides, nitrates and sulfates, have been determined; the effect of physical, chemical and microbiological factors on patina formation, particularly the influence of acid rain, natural organic matter, particles and microorganisms have been defined. The effect of different electrolytic solutions that accelerate the formation of copper patinas has been determined, and a review of the state of knowledge of the formation and evolution of metal patinas has been made.

Jan 1, 1999

By Du Sichen

The present paper presents the modeling of gas-solid reactions in the case of the decomposition of CaCO3, describing the reaction kinetics on the basis of heat-transfer concepts which could be compared with thermogravimetric results. In the case of solid-solid reactions, the present paper describes the model developed for describing solid-solid reactions from dynamic X-ray diffraction technique, developed by the present team. The model has been successful in explaining the formation of spinel from MgO and Al2O3.

Jan 1, 2006

By Byung-Su Kim

Most electric arc furnace dust (EAFD) treatment processes employ carbon as a reducing agent for the zinc oxide in the EAFD. In the present work, the reduction reaction of zinc oxide with carbon in the present of various additives was studied. The effects of temperature and the additives of calcium carbonate, magnetite, and mill scale on the kinetics of the reduction reaction were measured in the temperature range of 1173 K - 1373 K under nitrogen atmosphere using a weight-loss technique. The mill scale is one of byproducts generated from the steel rolling process. From the experimental results, it was concluded that all three additives accelerates the reaction rate of zinc oxide with carbon, but the effect of addition of calcium carbonate is the highest. It was also found that magnetite, mill scale, and calcium carbonate in the reduction reaction of zinc oxide with carbon promotes the carbon gasification reaction.

Jan 1, 2006

By Peter Forschner

Classical Mixing Theory is based on applying many fundamental correlations to standard baffled dished bottomed vertical cylindrical vessels with high degrees of symmetry. Horizontal autoclaves operating at elevated temperatures and pressures have been used for more than two decades. All compartments and especially the first and last compartments are asymmetrical. To date no comparison of the effects of the asymmetric geometry on mixing system design and scale-up has been published. The results of investigating solids suspension, mixing time, momentum transfer from the impeller to feed slurry and feed inlet location in the first autoclave compartment are presented as influences on residence time distribution. CFD modeling was developed and verified with the test apparatus.

Jan 1, 2003

By Xu Weihong

After being pre-treated, composite electro-deposits of semi-bright nickel/nano-SiO2 with bright nickel or with amorphous Ni-P alloy, and Composite electro-deposits of Zinc were prepared on Nd-Fe-B magnetic material. The effect of cathodic current density, nano-SiO2 concentration, stirring strength and surfactants on the corrosion resistance of electro-deposits were studied. In addition surface appearance and structure of the composite coatings were analyzed by SEM. The present investigation shows that the corrosion resistance of composite electro-deposits of semi-bright nickel/nano-SiO2 with amorphous Ni-P alloy was the best, the solution system of semi-bright nickel/nano-SiO2 with bright nickel was stable and its electro-deposits also had an excellent corrosion resistance, composite electro-deposits of Zinc not only had good corrosion resistance, but also low cost, thus making it an excellent electro-deposit for medium or low-class Nd-Fe-B magnetic material.

Jan 1, 2006

By V. B. Telles, D. C. R. Espinosa, J. A. S. Tenório

"The purpose of this work was to study the reutilization of the steelmaking dust, derived from steel production in the electric arc furnace (EAF), in iron ore sintering process aiming zinc elimination. In each sintering process were collected sintered samples, these materials were analyzed by chemical analysis using atomic absorption spectrophotometry in order to determine the zinc content. Samples of not sintered mixtures were also characterized by chemical analysis aiming to determine the initial amounts of zinc, i.e. in order to check the zinc amounts present in the mixture before the sintering process. The comparation among the zinc contents of samples sintered and not sintered allowed to determine the elimination of zinc during the experiments. Results showed that the zinc elimination in the process is proportional to the ratio reducer/waste. The zinc removal was lower when the reducer/waste ratio was decreased.IntroductionThe electric arc furnace dust (EAFD) is a residue generated in the steelmaking process using electric arc furnace. Aproximately 30% of all steel produced (in the year 2009) was obtained through electric arc furance (EAF). In the United States of America the percentage of this process in the total crude steel production was about 62% in 2009, while in 2000 this percentage was only 47% [1].The iron ore sintering is a process that reuses wastes generated in metallurgical industries. However, the materials used must be physical and chemical characteristics compatible with the blast furnaces.The quantity of zinc, cadmium, chrome and other metals present in the EAFD depends on the quality of the scrap used to feed the EAF and the type of steel that it is been made [2,3]. The reuse of EAFD waste is interesting to steelmaking processes because of its iron content. However the presence of zinc inside a blast furnace is undesirable since the zinc oxide can be deposited on the blast furnace walls and in the drivers of gas output, interrupting the flow. Another part of the zinc oxide can form deposits on the refractory lining of the blast furnace [4,5]."

Jan 1, 2012

By K. Abe

Onahama Smelter has two green-charge reverberatory furnaces and the annual smelting capacity is 600 thousand tons copper concentrate. In addition to the concentrate, various kind of industrial wastes has been processed and utilized. First, the brick waste from converter is ground and used as raw material of castable for repairing the copper melt launders. Second, the slag containing calcium-sulfide from other foundry is fed to the reverberatory furnaces. Calcium sulfide is oxidized to CaO. The melting rate of concentrate is accelenlled and the slag loss is decreased. Third, the tip tire made of waste car tire is charged into the reverberatory furnaces as fuel. The steam of waste heat boiler for turbine generators has been increased so as to decrease the electricity cost. Fourth, the sulfur accretion from other chemical plant is blended into the copper concentrate and the sulfur is recovered as the gypsum for sale. Fifth, the processed waste oil has been utilized in the copper concentrate dryer by which the smelting capacity was increased effectively. Consequently, Onahama smelter contributes to the society by processing the wastes to the harmless slag and utilizing them as fuel through the copper smelting.

Jan 1, 1996

By Xiyun Yang

Magnetite was prepared by hydrogen reduction method. For a conversion to cobalt-modified magnetite, magnetite particles were suspended into a solution containing Co2+ and Fe2+ to precipitate a cobalt ferrite layer on the surface. pH value influences the particle composition directly, the desirable CoFe2O4 is obtained when pH value is 12. The coercivity increases with the increase of cobalt content, cobalt efficiency reaches a maximum value at cobalt content of 2.71wt%. With cobalt modification, magnetite particles have similar lattice constant and squareness ratio to that without cobalt modification. TEM and XPS analyses indicate that acicular morphology is retained during the coating process, the epitaxial growth layer consists of CoFe2O4and 0.3Co2O3CoFe2O4 at cobalt content of 2.71wt% and 5.03wt%, respectively.

Jan 1, 2006