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By Rolando Campos

The CODELCO-CHILE Teniente Converter Technology, is presently being applied in four Chilean smelters (Caletones, Chuquicamata, Potrerillos and ENAMI-Ventanas). A Teniente Converter is due to be used at ENAMI-Hernan Videla Lira (Paipote) smelter in the near future. Also, a Teniente Converter is to be installed as part of a retrofit project for Nkana smelter of Zambia Consolidated Copper Mines Ltd. (ZCCM). The charge to be treated through this smelter will consist of a blend of concentrate arisings from the various concentrators within the ZCCM group. The present status on the application of the Teniente Converter Technology at Caletones smelter as well as its projected performance when used at Nkana smelter, are presented in this paper. The design operational basis, autogenous smelting throughputs, concentrate to matte ratios and benefits due to the use of technical oxygen, are presented and analysed.

Jan 1, 1992

By John W. Cash

The mineralogy and textures of cyclone dust, sludge, and occasional build-ups in the American Iron and Steel Institute (AISI) direct ironmaking pilot plant at Universal, Pennsylvania have been studied by reflected light, transmitted light, and cathodoluminescence microscopy, and phase compositions have been determined by SEM-EDS. The cyclone dust consists of particles of carbon, metallic iron, sulfur-bearing iron, and wustite. Measurements of particles in the sludge indicates that 69% are less than 2.5 um across, 21 % are 2.5-5 um, and 10% are larger than 5 um. Mineralogically the sludge particles are mainly carbon and metallic iron, with minor wustite and sulfur-bearing iron. Build-ups that sporadically develop in the furnace consist of olivine, hercynite spinel, metallic iron, wustite, pyrrhotite, pseudobrookite, akermanite-ferroakermanite and gehlenite. The microtextures shown by the build-ups indicate that much of that material has precipitated at the build-up loci. This study has been supported by AISI and the U.S. Department of Energy.

Jan 1, 1995

By V. A. Luganav

The behavior of arsenopyrite under heating has been studied by many scientists. It has been already established that under heating at more than 650°c and without air access the arsenopyrite dissociates with the formation of one atom arsenic. Under vacuum the dissociation process begins at 5500C with the formation of elemental arsenic. The residue of dissociation process contains pyrrhotite and throilite. In the presence of pyrite, arsenopyrite dissociates under lower temperature and with a higher velocity than without it. The industrial realization of fool scale processing of arsenic bearing raw materials is possible only by the use of standard equipment and oxygen containing blast. In this view the paper presents the results of the study on the effect of oxygen in the gaseous phase and its addition into the charge of pyrite in the process of arsenopyrite decomposition. Thermodynamic analyses showed that under thermal processing of arsenopyrite in the presence of pyrite and limited quantities of oxygen in the gaseous phase the formation of arsenic sulfides is possible according to the following reactions:

Jan 1, 2003

By P. Myllykoski, J. Nylander

"A commercial program package called Crownoff for the simulation of temper rolling in four high mills has been verified against measured data. The agreement between measured and calculated transversal strain distributions of the strip was found to be good. Effects of the strip crown and work roll bending force on the strain distribution were simulated. The results showed that when a single ground camber of work rolls is used for all strip widths; the strip crown should be parabolic, excluding the edge drop. An increase or decrease of the strip crown by 30 % during a coil can be compensated by a 2 to 5 t change in the work roll bending force. The ability to control the strip crown by work roll bending was insensitive to strip width. IntroductionCold rolled steel strips are usually temper rolled after recrystallization annealing, which follows cold rolling. The purpose of temper rolling is to suppress the yield point, finish the strip surface and correct possible flatness errors. The presence of a yield point might otherwise cause problems during subsequent forming processes. The in homogenous yielding in non-temper rolled steels leads to the formation of Lüders bands in the strip surface.The rolling force is influenced by the rolling speed and changes in frictional conditions in the roll bite. Therefore it is very important to plan carefully the mill settings and control algorithms during rolling. The purpose of mill control algorithms is to ensure constant reduction and the best possible strip flatness during the entire coil.Correctly predicting the rolling force is important for determining the mill presettings. Torque, forward slip and power requirements are not usually critical, if the reductions are small. However, the large elastic deformations occurring in the roll bite make the physical description of the process difficult. Physical rolling models developed for cold rolling contain assumptions that lose their validity as the reductions decrease to the level of one per cent."

Jan 1, 1994

By Onuralp Yiicel, Ozlem Okur, Murat Alkan

"In this study, Co-Cr-Mo alloys were produced using a mixture of Co304, Cr203 and Mo03 powders with Al powders by a Self-propagating high temperature synthesis process. SHS is a process of material synthesis that has revealed a number of reactants combinations capable of much higher energy release than conventional explosives. Al203 is added to the mixture to decrease the adiabatic temperature of the system. The thermodynamic simulations and the calculations of adiabatic temperature were examined with FactSage 6.2. In the SHS experiments, different Co304/ Cr203/Mo03 ratios were examined, and their effects on the metal recovery and alloy compositions were carried out. The samples were characterized by using chemical analysis, XRD, XRF and SEM/EDS techniques.IntroductionSelf Propagating High Temperature Synthesis (SHS) has significant advantages compared to the high technology furnace applications, such as very short processing time, simple operation, low energy requirement and low cost [l, 2]. In a SHS process, the ignition starts the combustion and propagates throughout the reactant mixture yielding the desired product. However, the disadvantages of the process such as inhomogeneous or unreacted products due to undesirable reaction rates needs to be overcome by changing some parameters such as ignition temperature, particle size, additive, atmosphere etc. [3, 4]. This work aims to establish a scientific and engineering background in the production of some cast Co-Cr-Mo master alloys via SHS (Self Propagating High Temperature Synthesis) metallurgy which is attractive process technique regarding fast and low-cost production ability of cast alloys."

Jan 1, 2013

By Don Ibana

Supported by the Minerals Council of Australia (MCA) through the Minerals Tertiary Education Council (MTEC), three Australian universities–Curtin University, Murdoch University and the University of Queensland–have formed the Metallurgical Education Partnership (MEP) to jointly develop and deliver an engineering design capstone unit–Metallurgical Process and Plant Design–in their respective undergraduate programs in extractive metallurgy, in order to enhance the students’ educational experience. A unique feature of the program is the close interaction of the students in all three universities and a significant involvement of industry professionals. Now in its sixth year, it is clear that this unit is achieving its objectives

Jan 1, 2014

By T. DebRoy

In recent years rapid technological advances have been achieved in the application of high energy density heat sources such as lasers and electron beams in diverse metals processing operations such as metal refining, fabrication, coating, surface modification and alloying. However, our phenomenological understanding of these new and emerging processes has not kept pace with the technological achievements. Inadequate understanding of plasma-metal interactions, the complexity of the component physical processes, and the scarcity of thermophysical data at temperatures much higher than the melting points of metals are the main difficulties in the comprehensive analysis of these processes. Several unique contemporary issues related to metals processing with high energy density beams such as rapid evaporation of alloying elements during processing and the role of plasma in influencing vaporization rate interfacial tension and species solubility in metals are discussed in this paper.

Jan 1, 1993

By I. A. Ibrahim, A. K. Ismail, A. A. I. Afifi

"Synthetic rutile for paints industry is conventionally produced by a combined smelting and leaching process. Smelting process is an energy intensive step and represents economic burden in view of the increasing energy costs. Egyptian ilmenite ore containing 40% TiO2 and 38% total Fe was thus directly leached with sulphuric acid to produce eventually synthetic rutile. The process-involves digestion of the ore with sulphuric acid whereby both TiO2 and Fe are dissolved. The solution was then treated with iron powder to convert Fe3+ to Fe2+ to avoid co-precipitation of iron during the hydrolysis step. After solid/liquid separation and clarification, Fe was crystallized as ferrous sulphate hydrate by chilling. The titanium pregnant liquor was concentrated by evaporation and then hydrolyzed to precipitate hydrated titanium dioxide which was then calcined to produce synthetic rutile containing 98.6 TiO2 and 0.58% Fe2O 3. The optimum conditions of all the processing stages were determined.IntroductionSynthetic rutile for paints, welding rods and other industries could be produced from ilmenite ore by sulfuric acid leaching process. This process is a batch process and nearly 80% of all TiO2 produced in the world is made by this process [1]. Figure l shows simple block flowsheet of the process. The process involves the following stages.Digestion: In this stage, ilmenite ore is treated with concentrated sulfuric acid where both iron and titanium are converted to their respective sulfates according to the following equations:"

Jan 1, 2000

By Lztok Peruš, Goran Kugler, Matevz Fazarinc, Milan Tercel

"Hot deformability of M42 tool steel additionally alloyed with cobalt and molybdenum was investigated. Hot-compression tests were carried out in the temperature range 850 °C -1200 °C, at strain rates range 0.001--6s-l up to strain of0.9. Field-emission scanning electron microscope and optical microscopy were used for characterization of microstructure of deformed samples, which revealed a very complex precipitation of carbides that strongly depends on the soaking temperature, the soaking time, the stress state, the deformation temperature as well as on the strain rate. Gathered data was used to calculate the processing parameters such as process maps, apparent activation energies and strain hardening exponents. For better understanding of thermodynamical properties of the studied steel a simultaneous thermal analysis was conducted. Furthermore the analysis of phase equilibrium was calculated using Thermo-Cale software. On the basis of these studies the optimal soaking temperature and process windows were determined.IntroductionHot workability ofledeburitic tool steels is important economic factor. This means that for each tool steel individuallysafe range of hot working parameters should be revealed. Publications in the literature with regard to the hot workability of tool steels are rare and therefore more information from this research area is desired.The relatively low hot workability of ledeburitic tool steels, i.e. steels in which the solidification is completed by a eutectic transformation of the residual interdendritic liquid to austenite and various alloy carbides (ledeburitic carbides), is usually characterized by the production of surface and internal cracks during the hot deformation."

Jan 1, 2013

By Shuai Wang, Gang-hua Fu, Lu Yang, Yu-feng Guo, Tao Jiang

The fluorine-bearing iron concentrate is one of the refractory raw materials for pelletization, which is mainly used in Baotou iron and steel company with lots of problems, such as narrow roasting temperature range and low compressive strength of products. According to its specific character, the effects of roasting temperature, time on the compressive strength and microstructure of pellets were researched. The results show that low melting substances formed during the roasting was the dominant reason of those problems. High melting substances were added in the roasting to investigate their effects on the roasting properties of fluorine-bearing iron concentrate pellets. Low melting substances were reduced when chromite was added. The compressive strength of products was 3100N/P when the 2% chromite was added at the roasting temperature of 1150 ºC, which was increased 700 N/P compared with the pellets without chromite, and the roasting temperature range was expanded by 170 ºC.

Jan 1, 2016

By Sung-Joo Lee, Gi-Chon Han, Nam-Il Um, Hee-Chan Cho

"In Korea, almost all of bottom ash produced by coal power plants is disposed of in ash ponds. Ash storage areas comprise more than 80% of most coal power plant sites. This disposal method is causing environmental problems and a managerial burden for plant operators. In this study, investigations to develop a beneficiation process for separating coal pond ash into various products were undertaken. To improve efficiency of the separation, coal ash was separated by sizes and each size fraction was subject to various beneficiation processes. The separation process used were flotation (-200 mesh size), hindered settling (16x200) and tabling (16x200 and 8x16 mesh). The results showed that various marketable products, such as lightweight aggregate, sand, high-carbon fuel, could be recovered from coal pond ash using simple physical separation techniques.IntroductionDue to the increased use of coals every year, about fifty million ton of coals were used in 2007 alone. As a result, about 6 million tons of coal ash were generated. In Korea, the coal bottom ash is classified as a general industrial waste and is usually disposed of in ash ponds. The costs for this disposal method continue to increase due to rising costs of site management and development and more strict environmental regulation. Therefore, utilities are constantly looking for ways to increase utilization of coal ash. In this study, various beneficiation processes were evaluated to examine the possibility of separating coal pond ash into various products which can be used as aggregates and high-carbon fuel."

Jan 1, 2008

By Steve Johnston, Mowafak Al-Jassim, Fei Yan, Omar Sidelkheir, Alain Blosse, Katherine Zaunbrecher

"Imaging techniques are applied to multi-crystalline silicon wafers and solar cells throughout the production process. Photoluminescence imaging, both band-to-band and defect-band, is used to characterize defects and wafer quality at all process steps. These steps include bricks sawn from ingots, wafer sawing, cleaning and texturing, emitter diffusion, edge isolation and glass removal, anti-reflective coating/passivation, and metallization of finished cells. Bricks, wafers, and cells can be imaged at a rate commensurate with in-line measurement, giving spatial information to characterize quality and defect content. Photoluminescence images on silicon bricks can be correlated to lifetime measured by photoconductive decay and could be used for high-resolution characterization of material before wafers are cut. The defect areas in as-cut wafers are compared to imaging results from electroluminescence and lock-in thermography, and cell parameters of near-neighbor finished cells, showing correlations to efficiency, open-circuit voltage, and short-circuit current.IntroductionImaging techniques can rapidly characterize material quality and defect density. Photoluminescence (PL) imaging can be applied to silicon from the brick level to all wafer process steps [1-8]. At the brick level, material thickness allows for measurement and correlation to lifetime where surface recombination effects are minimized [6, 7]. At the as-cut wafer level where thin unpassivated wafers prevent accurate lifetime assessment due to surfaces, defects can still be categorized and quantified to predict finished cell performance [3-5]. Defect regions can be identified by recombination-limited band-to-band PL or by defect-band emission [9-12]."

Jan 1, 2012

By G. G. Krishna Murthy

Several experiments were conducted to determine the rates of heat transfer coefficients of CaO-SiO2-A1203-FeO slags at temperatures in the range 1623-1823 K The experimental technique involved measuring heating rates of a solid specimen, sub¬merged in slag phase, using a temperature probe made of Pt\ 10%Rh-Pt. Effect of %FeO (3-10%), %FeS (0.1-0.68%), %P205 (0.2-3.0%), %MgO(5-6%), and %MnO (0.96-3.84%) present in the slag on overall heat transfer coefficient, U, of slags was investigated. Simple first order heat balance equation in combination with experimental plots rising temperature of solid specimen versus time were employed to determine the values of U. The values of U determined in the present investigation were present in the range of 70-260 cal/Ks.m2. The value of U increased with increasing the slag temperature. The values of U were not effected by increased amounts of sulfur in the slag phase. The increased concentrations of MgO, FeO, MnO, and P205 in the slag phase decreased the values of U. On the other hand, the increased amounts of Fe2O3 in the slag phase increased the value of U. Comparison of the results, obtained using the slag bath stirred by argon injection, with those determined without any stirring indicated that both radiative and conductive heat transfer mechanisms are important even at high temperatures.

Jan 1, 1993

By Hiroshi Maeta, Takao Kino, Hirota Osono, Kikuo Matsusaka, Azusa Shida

"Prior to refine an ultra-high purity material, it is necessary to estimate the surface cleanness of a base material. In this report, the cleaning method of a surface for refining of an ultra-high purity aluminum has been studied. Aluminum sample of 99.999% purity was p9lished mechanically and electrically and washed with various solvents. Surface composition and a depth profile near the surface were examined. Based on the experimental results, surface structure of an ultra-high purity aluminum was discussed.IntroductionRecently, studies on high purity metals have become of interest, and we have reported .various properties of an ultra- high purity aluminum1- 2)In order to purify a metal, it is necessary to clean a work area and to make vacuous as possible. So, we are studying the purification of aluminum by an ultra-high vacuum refining system and a zone refining system set up in a clean room with cleanliness class of 1000.Now, in order to avoid a mixing of impurities into the refining metal, a surface cleanness of a base metal is very important factor. The purity of the base aluminum used our work is 99.999%, but the surface state of the base aluminum is not clear. Aims in this work .are to investigate the surface state and to obtain the cleaning method of the base aluminum.Experimental procedureSamples used in this work were 99.9% (3N), 99.99%(4N) and 99.999% (SN) aluminum produced industrially and 99.9999% (6N) aluminum purified by us."

Jan 1, 2000

By Ivanildo Hespanhol

"DALYs are a measure of the health of a population or burden of disease due to a specific disease or risk factor. It evaluates the time lost because of disability or death from diseases compared with a long life free of disability in the absence of disease. DALYs are calculated as the sum of years of life lost by premature mortality (YLL) and years of healthy life lost in states of less than fully health, i.e., years lived with a disability (YDL), which are standardized by means of severity weights, thus: DALY=YLL+YLD.WHO has established for wastewater use in irrigation (1) the same reference level of health protection as established for drinking water quality (2), i.e., the additional burden of disease from consuming water irrigated food should not exceed 10-6 DALY(Disability-Adjusted Life Years) loss per person per year (pppy). This level of risk means that a single additional case of disease may occur in a population of 1 million, during a life time (70 years). In a individual basis is equivalent to the occurrence of a mild disease during about 31,5 seconds.Such a restrictive risk is almost impossible to be attained in most developing countries which may not be able to afford the cost of wastewater treatment and of other protective measures, even for restrict irrigation.This paper presents proposals to adapt the reference level of risk to local technical, cultural, economical and social conditions of developing countries on the basis of a risk benefit approach."

Jan 1, 2008

By Tapani Järvinen

Non-ferrous metals and metals in general are considered as being non-renewable natural resources. Metals are needed because of their excellent and irreplaceable properties. The consumption of metals, with the exception of carbon steel, is steadily growing by 1-3 % annually, and that of stainless steel as much as 3-6 %. This is a general trend, which is periodically disturbed by cyclical variations. In recent years so-called "New Economy" has become prominent in the public media and the market value of the traditional industry has been well below its real value and importance. Nevertheless, the modem society requires metals today and also in the future, and the companies using the most modem technology in a responsible way and innovative solutions not only in technology, but also in everything they do will survive. This paper describes the role of Europe as a producer of primary base metals and as a supplier of technologies in the base metals industry. It concentrates on the development and commercialization of technologies and project implementation in the metallurgical industry. As one example of a European approach to these matters the paper presents Outokumpu' s response to the future challenges in the base metals industry. Outokumpu Oyj is one of the leading metals and technology companies in the world of stainless steel, copper, zinc, and sales of technology in metals and minerals businesses. Outokumpu applies its knowledge of metals and processing to generate value for its customers and shareholder. Everything we do, we do in an economically, environmentally and socially responsible way.

Jan 1, 2003

By Tapani Järvinen

Non-ferrous metals and metals in general are considered as being non-renewable natural resources. Metals are needed because of their excellent and irreplaceable properties. The consumption of metals, with the exception of carbon steel, is steadily growing by 1-3 % annually, and that of stainless steel as much as 3-6 %. This is a general trend, which is periodically disturbed by cyclical variations. In recent years so-called "New Economy" has become prominent in the public media and the market value of the traditional industry has been well below its real value and importance. Nevertheless, the modem society requires metals today and also in the future, and the companies using the most modern technology in a responsible way and innovative solutions not only in technology, but also in everything they do will survive. This paper describes the role of Europe as a producer of primary base metals and as a supplier of technologies in the base metals industry. It concentrates on the development and commercialization of technologies and project implementation in the metallurgical industry. As one example ofa European approach to these matters the paper presents Outokumpu's response to the future challenges in the base metals industry. Outokumpu Oyj is one of the leading metals and technology companies in the world of stainless steel, copper, zinc, and sales of technology in metals and minerals businesses. Outokumpu applies its knowledge of metals and processing to generate value for its customers and shareholder. Everything we do, we do in an economically, environmentally and socially responsible way.

Jan 1, 2003

By Qin Hua, Xiangru Chen, Qijie Zhai, Yongsheng Yan, Liang Chang

"In this paper, pure bainite ductile iron and their alloying form of 0.2wt% niobium were prepared by a controlled cooling heat-treatment. The effect of niobium alloying on the microstructure, hardness and impact toughness of bainite ductile iron was studied. The results show that adding niobium effectively improves the hardness and toughness of bainite ductile iron. The hardness and the impact toughness of niobium-alloyed bainite ductile iron were investigated by varying the temperature at which samples were fed to the incubator.IntroductionThere are two essential methods to prepare the bainite ductile iron: isothermal quenching [I-31, and alloying [4• 51• Isothermal quenching process is very time and energy consumable, concerned as a high cost technique for mass production. Besides, there are certain limitations on the size and shape of castings in this process. In addition, it potentially harms the environment. As for the alloying, Ni, Mo, and Cu have to be utilized to obtain bainite. However, the large demand and high cost of Ni makes it not feasible in practice.It is well known that niobium can promote the formation of carbon compound, and improves the stability ofundercooled austenite, which is preferred to the increase of the hardenability. Previous studies showed that niobium could refine the grain and improve the mechanical properties of gray cast iron [6-81 • Therefore, in the present work, the effects of niobium and the temperature at which samples were fed to the incubator on the microstructures and properties of niobium alloyed bainite ductile iron were investigated."

Jan 1, 2014

By M. A. Aziz

The electrochemical performance of a series of carbon materials produced from coconut shells, which are very cheap and readily available in Bangladesh was investigated for their viability as anode materials in rechargeable lithium-ion batteries. X-ray diffraction technique was used to measure the interlayer spacing (d002) of the produced carbon materials. A number of half-cells were prepared with the produced carbon materials from coconut shell as working electrode and metallic lithium as counter electrode with 1MLiPF6 electrolyte in a mixture of ethylene carbonate and dimethyl carbonate. The discharge-charge profiles were measured for the different half-cells by using Arbin 24-channel Cyler. The value of interlayer spacing of the coconut-based carbon material was found to be 0.397 nm at 900°C, which is most suitable for lithium-ion insertion into the carbon structure without any expansion. The specific discharge capacity of carbon material from coconut shell heat treated to 900°C was found to be 1015.65 mAh/g. The coconut carbon material heat treated to 900°C delivered 335.22 mAh/g reversible capacity, which is comparable to the commercial carbon/graphite presently used in lithium-ion battery systems. The irreversible capacity loss and coulombic efficiency in 25th cycle of half-cell made with coconut carbon material were found to be 0.16% and 99.83% respectively. The carbon material produced from coconut shell can, therefore, be used as a potential anode for rechargeable lithium-ion batteries.

Jan 1, 2006

Steel Ladle in Bhilai Steel Plant, SAIL, India, passes through VAD & LF-RH route and this exposes refractory lining to a severe operating conditions. Ladles are lined with in-house manufactured MgO-C refractories. Lining life used to be 35 heats, out of which 18-20 heats were through VAD/LF-RH, hence, ladle availability had become a constraint. Laboratory studies were carried-out to optimize granulometry and composition. Granulometry was developed by adopting Andearssen packing model. A suitable plasiticiser was identified to eliminate inconsistency caused due to variation in resin quality and weather condition. It reduced variation in green bulk density from 6 to 1.3%. Abrasion and slag erosion studies were conducted, which shows that with increase of carbon, abrasion resistance decreases and corrosion resistance improves. Based on these studies, graphite in slag zone was increased from 10 to 12.5% and in metal zone it was reduced to 7.5%. Different process parameters of brick making were optimized to make MgO-C bricks of maximum bulk density with reduced coke porosity. Modified bricks have bulk density of 2.99-3.02 g/cc and coke porosity of 9.5-10.5%. Further, shape of the bricks were changed from side arch to mini keys and thickness was increased from 80 to 100 mm. Mini key bricks are pressed from sides, thus eliminating variation in thickness which is critical dimension for dry joints. These modifications improved average lining life of steel ladles to 64 heats, which includes 37-40 secondary heats. Maximum life obtained is 87 heats.

Jan 1, 2006