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By Malti Goel

"The cost-effective capture of carbon dioxide (CO2) from the point sources for its reduction the atmosphere offers many challenges in materials science. Novel CO2 capturing approaches using chemical, physical and biological methods are in the research stage and are aimed to minimize the cost. Appropriate materials development , which can withstand required temperature or pressure as the case may be for CO2 emanating from coal gas or industrial waste gases form the minimum condition. Other requirements are reclyclability of material and cost of separation. Nano-material composites can be more effective in selective capture of CO2 and can offer solutions for large-scale separation process. Nano-porous material catalysis can enhance the reaction rate of CO2 with other chemicals and thus help in capture of CO2 and convert it into value added products. This paper reviews recent industrial scale developments. In the Indian context, R&D priority areas in CO2 capture process development with a focus on energy industry are presented.IntroductionScience of Climate Change is growing at an enormous pace. With the ultimate goal of stabilization of greenhouse gases in the atmosphere, new scientific approaches are being researched worldwide. A shift in policies from low carbon and no carbon energy sources to fossil fuel sources with capture of carbon and its permanent storage is taking place. The process of carbon capture is both energy and materials intensive and the cost of power generation may increase up to 40% when carbon capture and storage (CCS) technology is implemented. Development of cost effective R&D technology therefore remains the greatest challenge before the scientific community."

Jan 1, 2009

By R. D. Brittain

In order to analyze and control the transport of harmful trace-element impurities in various smelting processes, it is necessary to have fundamental information about the chemical thermodynamic properties of the pertinent condensed and vapor phases. This paper describes recent thermodynamic studies of the gaseous arsenic sulfides and of the activity of arsenic in a copper-iron sulfide matte phase. These studies were carried out by high temperature mass spectrometry and by effusion vaporization techniques, which permitted clear identification of the molecular species involved, a decided advantage in such complex systems. The nature of the results obtained and comparisons with previous interpretations will be described.

Jan 1, 1983

By Ruiling DU, Jiazhi Zhang, Yong Zhao, Keng Wu

Reaction kinetics of metallurgical physical chemistry which was successfully applied in metallurgy (as ferrous metallurgy, non-ferrous metallurgy) became an important theoretical foundation for subject system of traditional metallurgy. Not only the research methods were very perfect, but also the independent structures and systems of it had been formed. One of the important tasks of metallurgical reaction engineering was the simulation of metallurgical process. And then, the mechanism of reaction process and the conversion time points of different control links should be obtained accurately. Therefore, the research methods and results of reaction kinetics in metallurgical physical chemistry were not very suitable for metallurgical reaction engineering. In order to provide the definite conditions of transmission, reaction kinetics parameters and the conversion time points of different control links for solving the transmission and reaction equations in metallurgical reaction engineering, a new method for researching kinetics mechanisms in metallurgical reaction engineering was proposed ,which was named stepwise attempt method. Then the comparison of results between the two methods and the further development of stepwise attempt method were discussed in this paper. As a new research method for reaction kinetics in metallurgical reaction engineering, stepwise attempt method could not only satisfy the development of metallurgical reaction engineering, but also provide necessary guarantees for establishing its independent subject system.

Jan 1, 2015

By Guan-Yong SHI, Cong Wang, Zhi-he DOU, Ting-an ZHANG, Shi-gang FAN

Based on the pre-works, this paper proposed a new short stage process of the intensify aluminothermy reduction by the stage to prepare high titanium ferroalloy with low O and Al contents. We investigated the effects of Al and Ca and Si combination reduction agent, slag type and step-up reduction conditions on the Al content and distribution in the alloy. The results show that the step-up reduction can not only reduce effectively the oxygen content in the alloy, but also reduce effectively Al content. For instance, the oxygen content in high titanium ferroalloy is within 1%~4%, and the Al content is within 1%~5%. Its quality reaches the requirement of high titanium ferroalloy prepared by remelting process.

Jan 1, 2015

By Miguel Barron

Recently, a new lance design for BOF steelmaking has been proposed in the literature. This lance, in addition to six peripheral inclined supersonic nozzles, contains a vertical centered nozzle whose oxygen flow is independent from the main oxygen supply. The above authors affirm that their lance maximizes the droplet generation without causing spitting. In this work, the performance of a lance with four peripheral nozzles and one vertical centered nozzle is numerically modeled by means of Computational Fluid Dynamics software. Transient two dimensional computer simulations were carried out considering two phases, namely molten steel and gaseous oxygen. Numerical results confirm that bath agitation and droplet generation are enhanced as a result of the vertical centered nozzle, however a proper performance of this lance, related to a conventional one, strongly depends on the Mach number of the oxygen jets and the lance height.

Jan 1, 2008

By R. Steven Izatt

Green chemistry principles will be discussed, and examples will be given of the use of Molecular Recognition Technology (MRT) to selectively separate specialty metals such as cobalt, nickel, bismuth, rhenium, molybdenum, indium and germanium from various primary and secondary feed streams. Recovery of these metals has numerous advantages including (i) conservation of valuable resources, (ii) prevention of environmental damage, and (iii) elimination of capital and operating expenses due to re-processing or disposal of metal-bearing streams.

By Theo Lehner

"During my first contact with industrial metallurgy as a summer vacation worker at the Steelplant at Luleå, Sweden, I came during a visit to MEFOS into contact with works of Prof. Worner caried out during the piloting of the Worcra continuous steelmaking process. These tests are still today remarkable as an innovative step in the art of metalmaking. By that they involved the necessary ingredients for the development of our art: seeing, knowing and doing. Industrial injection as applied during slag fuming will be discussed below.Phenomena of injection metallurgyPhenomenon according to Collins dictionary is"" anything that can be perceived as an occurrence or facts by the senses"". To open the senses for the interesting phenomena in pyrometallurgy must be the main task of any educator. The investigations by Engh et al. around the mixing phenomena of the WORCRA process are an early example of combining senses with knowledge. To see what you model must be a crucial part in any development. This can also involve to see and control that one is subject to the same conditions as in published models. Below the need ""to see"" will be illustrated by some recent investigations around slag fuming. In the literature various models for reactions occuring during the fuming of slags are presented. Two recent models hint ·ata) the occurrence and importance of iron for the fuming processb) the occurrence and importance of lead droplets during respectively."

Jan 1, 1996

By Stein Tore Johansen

Some ferro-silicon furnaces have heat-recovery equipment. Here, the recovery of electric energy from the off-gases can be increased by increasing the off-gas temperature. This is easily done by reducing the amount of air which usually is mixed into the?off?gas to cool the gas mixture. If the off-gas becomes too hot problems with severe fouling or clogging of the gas channels close to the furnace is observed. The result is irregular stops to clean the off-gas channels. The paper focuses on the nature of the clogging phenomena and some of the ways to avoid clogging. A detailed experimental study was carried out at the Elkem Thamshavn Plant. Theoretical studies were performed to understand the particle deposition, turbulent multiphase fluid flow and off gas combustion in the off-gas channels. The study has resulted in reduced clogging.

Jan 1, 1992

By Carla Lupi

NiMH sealed cells (portable cells) are today widely used in all consumer applications replacing primary alkaline batteries: wireless mobile communication, portable computers and camcorders, are the largest application segments. The Italian market. of NiMH cells is steadily growing, following the impressive penetration rate of the cellular phones. The organization of a national collecting system and correct recycling process are the key factors to prevent environmental impact associated to these wastes, while the metal values recovery can improve the feasibility of the recycling process The University of Rome, Texeco Engineering S.d, and MO.SMO.DE. S.a.s. have developed a combination of mechanical and hydrometallurgical processing to recover Nickel, and Cobalt salable products and rare earths intermediate products. A new plant located in South Italy, designed after this technology, is able to recycle waste Ni-MH batteries collected in the Italian territory, together with other industrial and portable batteries based on different chemistries. The process is able to treat both individual cells and plastic power packs and includes as basic steps an original crushing and elutriation treatment to separate plastic, metallics, and active mass components that are subsequently treated by a hydrometallurgical process to recover Ni, Co, and RE. The hydro metallurgical main steps are: acidic leaching, RE separation, multistage precipitation of Ni, Co and Fe and final solvent extraction on dissolved Ni and Co salts. For each operation the operative condition have been determined.

Jan 1, 2000

By A. R. G. Azevedo, G. C. Xavier

"The search for technological innovations in the Civil Construction takes as an objective the reduction of costs and increase of the productivity. However, these technologies demand analysis and studies of parameters of control that provide the quality of the products. With the intention of improve the knowledge on industrialized mortars used in mechanized projection machines, a characterization was done in the state anidro, fresh and hardening of three mortars, being each one of a State, Rio de Janeiro, Sao Paulo and Bahia. The tenors of water/ mortar was obtained through tests done in built environment, it varied from 0,17 to 0,26. From these results, the mortars were projected by his respective consistency, analyzing its compressive strength, and traction adherence resistance, in this way, the good performance of the revetments was provided.IntroductionThe market competitiveness of Construction has led companies to invest in construction processes and techniques in order to rationalize and optimize the buildings. Thus, changes emerged in coating system providing improvements in conventional materials and novel construction techniques, such as mortar industrialized and mechanized projection.Adopting projection equipment mortar is flagged as one of the solutions to reduce the interference of hand labor in construction, optimizing the performance of internal and external coatings, as well as streamline the production process and transportation, reducing lossesMaterials and deadline for execution of the casing(l)The process has been used due to its benefits, however, studies are necessary parameters for quality control of these mortars used in the projection to greater knowledge of mixing and market acceptance. It is therefore quite relevant information processing techniques available on the subject, as necessary to carry out research aiming at defining specific indicators of quality."

Jan 1, 2013

By Jochen Petersen

Design and operation of heap leach processes are still largely based on,operator experience and rule of thumb. Although considered a low-cost, low-tech route for mineral extraction, the underlying physical, chemical and biological processes are actually rather complex. Numerous heap leach models have been devised over time, but the majority of these tend to simplify the true process and are of limited use in practise. The modelling approach presented here combines the more conventional reaction-diffusion model with models accounting for equilibrium reactions in solution, bacterial growth kinetics, complex reactions schemes, gas flow, heat conservation, etc. One particular model application is discussed in the context of developing a novel high temperature heap leach processes using thermophile micro-organisms. The complexity of processes such as this can only be appreciated with the aid of a systematic model. For the designing engineer an accessible, personal computer based model should be an indispensable tool for the design and optimisation of efficient heap leach operations.

Jan 1, 2002

By Stein Tore Johansen

Some ferro-silicon fumaces have heat-recovery equipment. Here, the recovery of electric energy from the off-gases can be increased by increasing the off-gas temperature. This is easily done by reducing the amount of air which usually is mixed into the off-gas to cool the gas mixture. If the off-gas becomes too hot problems with severe fouling or clogging of the gas channels? close to the fumace is observed~ The result is irregular stops to clean the off-gas channels. The paper focuses on the nature? of the clogging phenomena and some of the ways to avoid clogging. A detailed experimental study was carried out at the Elkem Thamshavn Plant. Theoretical studies were performed to understand the particle deposition, turbulent multiphase fluid flow and off gas combustion in the off-gas channels. The study has resulted in reduced clogging.

Jan 1, 1992

By Albert F. S. Seboukens

A 5;6 MVA pyrometallurgical demonstration-scale pilot plant was commissioned at Mintek, South Africa, in 1994, using lead blast-furnace slag and coke as raw materials. The plant included a.d.c. power. supply, two plasma-arc furnaces' and an ISP lead-splash condenser. Slags containing typically 12 per cent zinc oxide and 3 per cent lead oxide are produced as a waste during the smelting of lead in a blast furnace. These slags are a potential: resource for the recovery of lead and zinc. During 1994, about 600 t of lead blast-furnace, slag was proceced through the pilot plant using the Enviroplas process. Zinc and lead oxides were reduced to their respective metals, volatilized, and collected in an. ISP lead splash condenser. Prime Western grade zinc and slags disposable in accordance with current US legislation, were produced. Zinc condensation efficiencies of about 80 per cent were achieved.

Jan 1, 1995

By Shigehito Deki

"A new wet process has been developed for the synthesis of various kinds of oxide thin films on various kinds of substrates, even which have complex surface morphology, from aqueous solution. The process was named as the LPD, Liquid Phase Deposition, method, which has some advantages over the conventional dry processes. This process can be applied to an on-site synthesis of advanced materials in the thin film technology. In this paper, some current topics on the synthesis of the composite thin oxide films by the LPD method, are presented.IntroductionGenerally, metal oxide thin films have been made by different preparative processes such as r.f. sputtering, chemical vapor depositon, CVD, laser ablation and sol-gel method, etc [1-3]. Each method has it own advantages and disadvantage. In some cases, the process is not suitable for the preparation of thin film on substrate with large surface area or complex surface morphology, and makes the deposition apparatus complicated and expenisve. By using Liquid Phase Deposition, LPD, method which overcomes some of those problems, metal oxide or hydroxide thin film can be formed on the substrate with large surface area and complex surface morphology, which are immersed into the aqueous solution only at ambient temperature and under atmosphere without any special equipments and high energy. And also, multicomponent oxide thin films can be formed readily by mixing solutions containing the objective metal ions, because it is performed in the aqueous solution which is typically a homogeneous mixing system. This process utilizes ligand-exchange, hydrolysis, equlibrium reaction of metal-fluoro complex species, MF x (x-2n>-, and F consumptive reaction. In the aqueous solution, MFx<x-2n>-is hydrolyzed with water to release F ions by a ligand exchange equilibrium reaction as following;"

Jan 1, 2000

By P. M. Tyroler

Inco operates a hydrometallurgical plant to treat the residue from the pressure carbonylation process. The main constituent in the residue is cop¬per. The residue is leached under pressure in an acid sulphate solution in two stages and the copper is recovered via electrowinning. The electrowinning tankhouse is fully integrated into the overall plant flowsheet as spent elect¬rolyte is required in upstream leaching steps. In recent years, the amount of residue had increased and copper removal capacity became the rate limiting factor for the entire plant. Consequently, a major program was undertaken to upgrade the tankhouse with regards to capacity, efficiency, cathode quality, working environment and structual integrity and appearance. This paper will describe current facilities and operation, and detail progress in our up¬grading efforts.

Jan 1, 1987

By Sang Han Son

The vapor pressures of FeCI2 and ZnC12 in the FeCl2-ZnCl2 system were measured by the transpiration method at 873K and 917K. The vapor pressure data were interpreted to indicate the formation of complex ions in the FeCl2-ZnCl2 melts. It is presumed that the complex molecule FeZnCl4 as well as FeCI2 and ZnCI2 exists in the vapors in equilibrium with molten FeCl2-ZnCl2 mixtures. The activities in the FeCl2-ZnCI2 system are shown a negative deviation from Raoult&apos;s law. These results suggest the formation of complex ions such as ZnCl42- in molten FeCI2-ZnCI2 mixtures.

Jan 1, 2003

By Jiang Feng, Li Chuanhua, Zhang Libo, Peng Jinhui, Ju Shaohua

Solvent extraction of Cu2+ from the leaching liquor contain Cu and Fe use a microfluidic technology. Currently, the conventional copper extraction process has many problems such as long distance and small driving force of mass transfer. In order to solve the problems, studies are carried out on the extraction process of low grade copper leaching liquid using Lix984N as an extractant with a new microfluidic solvent extraction technology. The effects of flow rate on the separation and extraction efficiency between Cu and Fe are studied, and the results show that a steady liquid-liquid interface of laminar flow is form in the micro-extractor, and extraction efficiency is 78 % and 2.5 % for Cu and Fe at the contact times of 0.84s respectively. Besides, the separation coefficient between Cu and Fe is as high as 140.04. The studied microfluidic technology has the advantages like improving extraction efficiency and reducing reaction time and providing the potential application in the hydrometallurgy extraction of Cu.

Jan 1, 2015

An EAF dust generated in a Swedish steel mill has been leached in hydrochloric acid at The solution obtained has been subjected to purification by cementation followed by precipitation of zinc with sodium carbonate. The thermal decomposition of the precipitate was studied using thermal analysis and X-ray diffraction. The results show that during the calcination of the precipitate three different reactions occur. The decomposition of the solid phases Zn5(CO3) (OH)6, CaZn(CO3)2 and CaCO3 occur completely at 370°C, 560°C and 940°C respectively, yielding a final product containing 61.9% ZnO and 38.1% CaO. Methods to minimize calcium and manganese in the final product are discussed.

Jan 1, 2003

By Yuanbo Zhang, Zhixiong You, Daoxian Duan, Guanghui Li, Tao Jiang

"Manganese is mainly consumed by steel and battery industries. In recent years, it is essential to utilize the low-grade manganese oxide ores with total manganese grade below 25%, as the high quality manganese ore resources are becoming scarce with the rapid development of the steel industry. Conventional pyro-metallurgical processes for utilizing manganese oxide ores are characterized by high production cost and energy consumption, low productivity, serious environmental pollution, etc. In this study, reduction thermodynamic of MnO2 reduced by sulfur was firstly carried out. Then, a novel process of reduction roasting with sulfur followed by acid leaching was developed to recover manganese from the very low-grade manganese oxide ores. Effects of main factors, including temperature, reduction time and S/Mn mole ratio, were investigated, and a high leaching efficiency of Mn above 95% was obtained under optimal conditions.IntroductionHigh/middle-grade manganese oxide ores are generally used in the metallurgical industries, particularly in steel plants and ferro-alloy units. The consumption of metal manganese in the ferro-alloy industry accounts for 85- 90% of the total Mn demanded [1]. Therefore, high quality manganese ore resources are becoming scarce with the rapid development of steel industry. It is essential to make good use of large quantity of low-grade manganese ores (TMn < 25%) presently available."

Jan 1, 2012

By O. Norman Lotter

There are many scales of innovation in the pursuit of concentrator performance improvement, including paradigm change, inventive change and incremental change. All are important, but the last is low risk, low cost and has a relatively high probability of success, given the right metallurgical skills. Seeking continuous improvement is also essential to ensure that performance does not decline over time due to ore type changes, personnel changes, equipment wear and other factors. When properly implemented, these small gains offer a very high rate of return for the project cost because they are made from marginal, not total, operating costs of the plant. To be effective this approach requires plant trials that use designed structure and appropriate statistics to test the observed differences arising from the old and new process treatments, be they a change in flotation reagent, in grind, pulp density, etc. However the pursuit of small but financially significant performance gains is often regarded as fruitless because of the range of variance in plant data, and the consequent difficulty of ‘proving’ that a benefit has been achieved. Opportunity for improvement is thus sometimes relegated to the realm of the impossible, or at best, treated with skepticism. Operations managers prefer to look for the larger gains, which are easier to demonstrate and prove. Unfortunately, these are seldom to be found; rather, a large gain can be more easily made by executing a series of small recovery improvements that are together equivalent to the ephemeral single large gain. In this paper we advocate a policy of continuing improvement driven by rigorous performance testing protocols and a formal ‘risk analysis’ approach to judging the efficacy of changes implemented in the plant. Following these simple procedures allows rational decisions to be made on the basis of quantifying risk and reward. In particular we consider the choice of hurdle rate for decision-making which best balances risk and reward. It is shown through case studies from actual industrial practice that this approach is practical and delivers significant financial value to the operation.