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By I. Barin, G. Eriksson, F. Sauert

Computer-aided calculations using data bases and program systems are more and more needed for the rational development and optirnization of high-temperature processes. The calculation of mass and energy fluxes between different process steps as well as the determination of the chemical equilibria will be discussed, giving examples from nonferrous metallurgy. The simulation of a waste-material treatment process including high-temperature combustion and gas-cleaning systems will also be demonstrated.

Jan 1, 1988

By E. Morrice

Solubility of yttrium oxide (Y203) in fluoride melts was experimentally measured in the temperature range of 998 to 1273 K and, YF3 composition in LiF.YF3 melts varying from 20 to 50 mole pct using a graphite crucible in an argon atmosphere. Solubility of oxide in the melt was found to increase with increasing temperature and YF3 composition in the melt. An expression for in XY2O3 as a function of temperature for several melts was deduced. The calculated activity coefficients of Y2O3 in the melts exhibited a negative deviation from Raoult's law.

Jan 1, 1989

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 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 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 Tong Deng

Clean processing of copper converter slags for reclaiming cobalt and copper could be a challenge. An innovative and environmentally benign approach for recovering metal values from such a slag was developed in the present work. Curing the slag with sulfuric acid, without re-smelting or roasting as currently practiced in the industry, made it amenable to leaching, and more than 95% of the cobalt and up to 90% of the copper was extracted, together with iron, by water leaching, leaving silica behind in a residue. Copper in the leach liquor was recovered by cementation with iron, and the dissolved iron crystallized as ferrous sulfate monohydrate. Cobalt in the pregnant solution rich in iron was recovered by either cementation or sulfide precipitation. Chemical and mineralogical characterization of the slag and its products were examined and compared to determine the nature of the changes occurring during curing and leaching. Operating variables were also investigated and optimized.

Jan 1, 2003

By Florian Kongoli

The overall productivity and efficiency of sulfide smelting plants depends considerably on the productivity and efficiency of each unit furnace operations. Furthermore, the efficiency and productivity of each furnace affects and dictates to a certain degree the process of managing the flow of materials from one unit to another. A furnace with low productivity, several technical problems or high frequency of accidental shut downs can easily become a temporary or a permanent bottle neck in the entire flowsheet and can be the cause for a low productivity and efficiency of the entire plant. As a result, controlling, optimizing and automating the individual furnace operations in order to assure a stable process but at the same time to increase productivity is an indispensable need. In this paper, the authors discuss their recent work in effectively controlling acute industrial furnace problems such as magnetite build-up and accretions, eliminating unnecessary slag foaming, decreasing slag losses etc. as well as the intensification, optimization and automation of a series of furnaces in sulfide smelting through a unique physical process modeling that correctly simulate the industrial furnace operations and avoid guessing and uncertainties. The advantages of this new approach have been discussed.

Jan 1, 2006

By Edgar Vidal

Beryllium metal and alloys have been crucial in the advancement of technologies in space exploration, transportation, national defense, communications, energy, safety and medicine, to name a few. Beryllium is one-third lighter than aluminum and six times stiffer than steel, with unique thermal properties. Demand for this metal is expected to continue to increase as new technologies emerge, hence its efficient and safe extraction needs to be addressed. Current extraction technologies are very complex and energy intensive, but at the same time yield excellent quality metal. In order to develop new or improve current extraction methods, a detailed analysis of current and past extraction technologies must be made. This work intends to compile and interpret most of the research, development and industrial practices used in the production of beryllium, and open the field for innovative extraction methods.

Jan 1, 2006

By John M. Rapkoch

In the continuing search for copper matte converting methods, commercially available and feasible choices remain Peirce-Smith Converters, Hoboken Converters, Mitsubishi Converting, Ausmelt converting, and Outokumpu/Kennecott Solid Matte Oxygen Converting (?Flash Converting?). While each alternative improves on Peirce-Smith Converters? limited fugitive gas capturing capability, the Peirce-Smith Converter is relatively easy and economic to operate and has an unmatched ability to accept valuable but difficult-to-handle material such as scrap anodes and purchased scrap copper. Recent experience with designing, building, and starting up an ISASMELT facility, applied in primary smelting of copper concentrates, has led the authors to speculate on how suitable the ISASMELT process would be for copper converting, given its low fugitive gas release and its ability to accept a variety of feed types. This paper reviews the potential metallurgical challenges posed by converting copper matte in an ISASMELT vessel and considers possible engineering and design challenges posed by the inclusion of this technology into a new or refurbished copper smelter.

Jan 1, 2006

By Russell James Hewertson

Since 1989 Air Products and Chemicals, Inc. has converted over 40 air fuel fired furnaces to oxy-fuel and air-oxy-fuel. Advances in burner design, flow control technology and operating experience have lead to improved performance with quicker melt times and lower costs. Metal recoveries are improved by faster melting and better furnace atmosphere control, allowing lower grade materials to be processed economically. The presentation will discuss the improvements made in recent years and review data from state of the art installations.

Jan 1, 2000

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 Ken-ichiro Uemura

"The DIOS process has been developed for eight years since 1988. The research project was started with the element studies carried out by each of the five integrated steel making companies in Japan, the final two and half years were spent for the pilot plant studies. Operation were conducted in the entirely closed and pressurized system successfully as planned. From the result, the DIOS process was proved to be viable as a future iron-making process substitutable for the conventional blast furnace. In addition, a lot of findings were obtained. Hot metal productivity was primarily determined by a oxygen flow rate, and a coal consumption varied depending on the productivity. The post combustion ratio was a little lower than expected from the result of the element study. It was supposed to relate the gas-reforming with coal or volatile matter in the free space of the furnace. Hot metal carbon content seemed to depend on the char content in slag.INTRODUCTIONThe JISF's DIOS pilot plant (DIOS=Direct Iron Ore Smelting Reduction Process) has finished its last campaign of the operations in January 1996. The project was started in 1988 as a joint research of the Center for Coal Utilization, Japan and the Japan Iron and Steel Federation (JISF) with a subsidy for promoting coal productions and utilization technologies from the Agency of National Resources and Energy, the Ministry of International Trade and Industry(MITI). Throughout the pilot plant test, a total of over 20,000 tons of hot metal was produced for more than 2,000 hours of the operation. Recorded production rate was 538 ton/day for 3 days at a specific coal consumption of approx. 1,000kg/hmt. Long-term operation was carried out in the fifth campaign for 18 days, which has proved that the entirely closed and pressurized DIOS process works well as planned. In Figure 1 is shown the representative operational performance obtained in the first five campaigns. The project is going to be finished by the end of March this year after investigating the technical viability and economic potential of the process, and completing the conceptual design of the DIOS commercial plant. In this paper, the system and facilities of the DIOS process are first introduced and some of the results of the pilot plant test are detailed later."

Jan 1, 1996

By C. Camurri

Results from the Metallurgical Department of Universidad de Conception showed that fire-refined copper could be rolled without previous remelting for deoxidation. The goal of this work is to determine the rheology of fire-refined copper from tensile tests at different temperatures and strain rates, and Ford plane compression tests. All that in order to simulate and calculate rolling process variables. For rheology hardness coefficients, n variables between 0.28 at 600°C and 0.46 at ambient temperature are obtained. The sensibility coefficient for strain rate m varies between 0.056 at 600°C and 0.006 at ambient temperature. The activation energy for plastic flow Q in the considered temperature range is 1436 cal/mol.

Jan 1, 1999

By Leonard A. Duval

This concept employs a viable energy saving method that uses a solvent to separate oil from particle matter; it can be used in metal forming industries to deoil sludges, oxides, and particle matter that is presently committed to landfill. If oily particles are used in their oily state, severe consequences to environmental control systems such as explosions or filter blinding, occur in the air handling equipment. This is due to the presence of hydrocarbons in the stack gases resulting from the oily particles. After deoiling, the particles can be recycled and the separated oil can be used as a fuel. The process does not produce a waste of it's own and does not harm air or water. It demonstrates the dual benefits of being commercially viable and in the national interest of conserving resources.

Jan 1, 1994

By Padmavathy Mahadevan, Samir Chefai, Eduard Guerra

"Electrocoagulation is a technique for treating wastewater streams from metallurgical plants whereby electrodes are corroded to generate gases (most notably oxygen at the anode and hydrogen at the cathode) and solid particulates which acts as substrates for coprecipitation of impurities. The performance of electrocoagulation reactors, in terms of their efficiency for removing a particular impurity, is highly dependent on several factors, most notably: the nature of the electrodes, the spacing between electrodes, the current density, the height of the electrodes, the solution flow rate, and application of periodic current reversal. Because these variables have complex interactions, in order to ensure reliable scale-up of laboratory results, experiments should be conducted under conditions that closely match those that would be employed at an industrial scale. To that end, this article describes the design and commissioning of a versatile laboratory scale electrocoagulation reactor that allows for the control of all the aforementioned variables along with the ability to measure the instantaneous spatial distribution of current within the reactor.IntroductionArsenic is often removed from metallurgical waste streams in stirred tank reactors by coprecipitating it with ferric ions as an arsenical ferrihydrite [ 1]. Electrocoagulation is an electrolytic technology that can accomplish the same task, but has not yet been widely adopted to treat metallurgical waste streams [2]. The electrocoagulation process involves the use of an external DC power supply to drive the dissolution of a relatively non-toxic metal into the wastewater stream, usually either iron or aluminum, which then largely precipitates as oxyhydroxide phases that adsorb undesired impurities [l]. At the anode, the metal is dissolved and oxygen is often evolved, lowering the local pH and enhancing metal ion solubility."

Jan 1, 2012

By Etsuro Shibata

For the treatment of huge amounts of the sulfur which is from the earth by both natural and man-made activities, a harmonized sulfur cycle was presented. The man-made sulfur cycle which includes sulfur circulation from oil, coal and ore was analyzed in detail based on the recent world sulfur trend. Then the man-made cycle was compared with the natural sulfur evolution such as volcano. Finally, the harmony in both natural and man-made sulfur cycles was discussed.

Jan 1, 2006

By Joel F. Flurnerfelt

Molten Al and Al alloys containing si, Mn, Ti, and y have been lanced with nitrogen-bearing gases. These lancing experiments provided the means for observing what phases form during exposure to nitrogen-bearing gases for finite periods of time, <2 minutes, at high temperatures, >1290oC. The experiments were conducted in sn induction heated drop tube furnace apparatus. The overall premise of these experiments was to select those Al alloys and gas compositions that show promise of forming secondary dispersoid phases, particularly AIN, in the Al matrix. The alloys selected will be atomized using gas atomization reaction synthesis (GARS) using the most favorable conditions. In this case, the chosen Al alloy will be atomized with a nitrogen-bearing gas, such that the Al and gaseous nitrogen species react to form a dispersoid phase within each powder particle. The powder particles that result from this "aggressive" GARS-process would be essentially Al metal-matrix composites within a uniform distribution of dispersoids. To date, only high-purity Al has been atomized using a mild GARS reaction. This work is funded by the Materials Science Division of DOE-BES under contract number W-7405-Eng-82.

Jan 1, 1996

By Huang Rui

The coal asphalt is combusted at different temperature in a heating cabinet with the temperature limit by 1200°C. By comparing the mass of the remainder of each experiment, the completely combusting temperature of asphalt smoke can be determined. Based on the experimental process of asphalt smoke, a discrete mathematical model of the asphalt smoke combustion is set by theoretic analysis. Through computer programming, the dynamic combustion process of asphalt smoke is calculated to simulate the experimental model. The result of experiment shows that coal asphalt can mostly react upon 500°C and the mass of remainder is 49.41% to initial mass of sample in the condition. The computing result shows that the temperature and the concentration of asphalt smoke influence its burning temperature approximating linearity. The consumed quantity of fuel to ignite the asphalt smoke needs be considered with the two factors.

Jan 1, 2006

By Laurentiu Nastac

"The importance of investigating solute redistribution during the unidirectional solidification of multi-component alloys is broadly discussed in the literature. A previously developed analytical model that was experimentally validated for Al-Cu, Sn- Bi and Fe-Si dilute binary alloy systems is used in this article to study in detail the solute redistribution, the liquid/solid interface stability based on an extended transient constitutional undercooling criterion and the size of the initial transient region during the unidirectional solidification of Ti-6-4 and Ti-17 alloys. A comparison between Ti-6-4 and Ti-17 alloy systems with respect to interface stability and the size of the initial transient region is also provided. The effective partition coefficients of the alloying elements in these alloys were determined based on specially designed experimental measurements.IntroductionThe importance of investigating solute redistribution during alloy solidification is broadly discussed in the literature [1-5]. One of the relevant applications of this study would be the mathematical modeling of equiaxed and columnar solidification of multicomponent alloys. This includes the instability of the solid/liquid interface. There are several mass and heat transfer processes that involve the calculation of solute redistribution during directional solidification such as industrial directional solidification processes, continuous casting, remelting processes, Czochralski crystal growth technique, floating zone techniques, etc."

Jan 1, 2012

By Paul-Dominique Oudenne

This paper reviews the experience gained by CMI NESA over the last thirty years for the treatment of arsenical and antimonical bearing concentrates and other complex metallurgical by-products. The importance of preliminary mineralogical characterization is emphasized as a preliminary step for the success of the roasting. Stage selective roasting appears as an attractive and efficient route for the treatment of complex concentrates. Numerous examples will be given for confirmation of such thermal treatment.

Jan 1, 2006