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By Thomas P. Battle

Modern-day direct reduction of iron first developed as a small-scale, low capital and operating cost alternative to the blast furnace. Since commercialization of continuous DR technology in the late 1960s, the market for the products of direct reduction has grown to more than 74 million tonnes in 2012. The initial advantages of DR plants over BF facilities have grown over the years, for several reasons, including the increased size of DR modules, lower energy and emissions (particularly CO2), along with the flexibility to use a number of different reductants. The development of DR technology over the past forty years will be emphasized in this presentation, including recent developments that allow for even more direct sustainability comparisons with the iron blast furnace – and even combine the two technologies for improved synergies. Also briefly discussed will be the possibilities of using direct reduction for non-ferrous ores.

Jan 1, 2014

By Tapio Ahokainen, Asmo Vartiainen

"Outotec's portfolio contains a wide variety of smelting solutions for non-ferrous metals. Some of these include flash smelting for primary copper and nickel, flash converting for copper, Ausmelt technology for primary and secondary copper, nickel, tin, lead, and zinc residues and waste, Kaldo technology for secondary copper, lead, and precious metals recovery. Outotec also offers slag cleaning technologies and much more.Company provides complete process solutions tailored to each customer's individual needs. Decades of experience have resulted in extensive metallurgical know-how that ensures the most profitable process choice and optimal performance. Outotec's life cycle technology partnership with their customers spans from the early stages of process solution design through the supply and commissioning of the entire process chain. They include integrated process control and holistic service and support concepts. Continuous research and development ensures that the customer is provided with the latest advancements in process and equipment solutions.IntroductionOutotec develops and provides technology solutions for the sustainable use of the Earth's natural resources. Solutions are ranging from various processes and special equipment needed for metallurgical extraction and mineral processing of ores to the production of refined metals and minerals. The processes include not only the grinding and physical separation of ores but also the smelting and leaching of base metals and precious metals. The company provides engineering services for whole projects as well as life cycle services on the equipment and products that they supply."

Jan 1, 2012

By B. L. Chulu

In the carbothermic reduction of lead sulfate to produce lead, the inclusion of soda ash (Na,CO,) in the charge provides for the control of sulfur dioxide in the effluent gas. An important mechanism in the process appears to be the carbothermic reduction of the sodium carbonate whereby sodium gas and carbon monoxide are produced. These intermediates then participate in the reduction of the lead sulfate to produce lead metal and stable sulfur species in the molten slag phase. In addition, there is some evidence that the presence of lead metal in the charge may also serve to increase the lead recovery in the process. These aspects were investigated by conducting laboratory-scale smelting tests with small charges (;3g), at 1173°K(9000C). Recovery did not exceed 74w% and the role of incipient lead metal in the charge could not be clearly assessed.

Jan 1, 1993

By Albaharna O. T., Argyropoulos S. A.

"This paper describes the development and the implementation of process control in a variety of instruments used in metallurgical laboratories. These instruments are used for different research projects in extractive metallurgy. Hardware and software aspects for this implementation are described and analyzed. Extractive metallurgy applications where process control was .used are presented. IntroductionMicroprocessors are invading almost every area of our lives and are turning up in unexpected applications. A great deal of new equipment which is coming into the market have built- in microprocessor systems. Nevertheless, the area of upgrading existing processes has been slow to develop. There are a variety of reasons for this, and many of these are economic. One of the principal reasons, however, is the general reluctance on the part of many organizations to commit a strong effort to put this new technology into their existing processes.Microprocessor systems developed ""in lab"" are capable of not only measuring thermophysical events which are taking place in metallurgical furnaces, but simultaneously controlling these furnaces. In this paper software and hardware aspects in the implementation of microprocessor control for resistance and for induction furnaces are presented. In addition to this, metallurgical results are given from experiments where this furnace control was applied."

Jan 1, 1989

By C. Díaz

Roast-reduction smelting (RRS) of nickel concentrate, combined with flash smelting of copper concentrate, was one of the process options that Inco considered as a means of meeting its 1994 sulfur dioxide abatement target at its Copper Cliff operations. RRS involves deep roasting the nickel concentrate in fluid bed roasters. The roaster off-gas is heated in a sulfuric acid plant, and the low sulfur calcine is reduction smelted with coke in an electric furnace to yield a sulfur-deficient matte. The latter material is converted to Bessemer matte in Peirce-Smith converters, with minimal evolution of sulfur dioxide, and the converter slag is reverted to the electric furnace. Excellent nickel and cobalt recoveries are obtained. This paper discusses the development of RRS, including extensive commercial scale testing at Inco's Thompson Smelter, and its key operating parameters.

Jan 1, 1993

By J. R. Sarazin

Density driven convection during solidification has been recognized for some time to result in macrosegregation particularly when lower density alloying elements are rejected into the interdendritic liquid. The resulting segregates are commonly referred to as channels, freckles or A-segregates. Buoyancy driven convection leading to channel formation has been examined in three model systems possessing somewhat different materials parameters. They are the Pb-Sn eutectic system, the transparent aqueous-salt NH C1-H 0 4 2 eutectic system and the transparent organic succinonitrile-ethanol monotectic system. Convection in these systems is controlled by a balance of buoyant and viscous forces, which are strong functions of composition and temperature. Composition, temperature and flow velocity were measured and elimination of channels through heavier ternary additions is discussed.

Jan 1, 1991

By Stavros A. Argyropoulos

Exothermic mass transfer takes place in various areas involving metallic systems, ranging from liquid metal processing operations to the growth of thin films in microelectronics. The formation of intermetallic compounds plays an important role in the exothermic mass transfer of metallic systems. Two types of exothermicity are identified , namely , Microexothermicity and Macroexothermicity. The former is encountered when small amounts of metals are mixed, while the latter is exhibited when a solid metal in a lump form is added into liquid metal. In this paper two types of exothermic mass transfer in metallic systems will be presented and reviewed. Mathematical modelling work for these types of exothermic mass transfer will be analyzed.

Jan 1, 1993

By Zhendong Tao, Wei Huang, Zhongxi Yang, Hang Guo, Haoran Geng, Jingxiang Yao

"CaSO3.0.5H2O typed Flue Gas Desulfurization (FGD) gypsum is a by-product formed in flue gas desulfuration by double-cycle fluid bed method, its composition is different remarkably from that of gypsum yield by normal desulfuration methods, and few studies using it as cement retarder have been carried out. In this paper, the experimental study using CaSO3•0.5H2O typed FGD gypsum as cement retarder was carried out. The experimental results indicate that, when FGD gypsum is added solely into cement, the retarding action is not satisfactory because of its slow dissolution rate; The composite retarder composed of FGD gypsum and natural gypsum can regulate efficiently setting time of cement over a wide range of addition and rate of both each other, and the mechanical property of cement can be improved significantly.Fire-power plants have discharged a lot of harmful gases such as SO2 etc., which has resulted in serious pollution on the environment. To reduce harmful gas containing sulfur in the flue gas, various flue gas desulfuration (FGD) techniques have been developed. At present, the FGD method used widely is to add desulfuration agents such as limestone powder or other calcareous-contained materials during the coal burning or in the flue gas so that the components containing sulfur react with them to form solid sulfate or sulfite and to be separated from the flue gas by collectors. CaSO3•0.5H2O and CaSO4•2H2O typed FGDgypsum can be obtained respectively by dry and wet FGD process[1,2]. As a by-product of fire-power plant, features of of FGD gypsum and its applications have been paid great attention. Pavel Tesa'rek et al [3] presented in full the characters and properties of FGD gypsum; Zofia Konik et al[4] prepared expansive additive used to cemnent industry by using FGD gypsum and aluminate clinker; A. K. Alva et al [5] investigated the effects of FGD gypsum and fly ash on soil properties and found the growth of seedlings of either rootstock improved significantly in soils amended with FGD gypsum and fly ash. FGD gypsum also can be used in gypsum binders, plasters and plasterboard manufacture [2.6]. C. S. Poon et al [7] investigated the effects of FGD sludge on the pozzolanic reaction of reject-fly-ash-blended cement pastes. Many studies using CaSO4•2H2O typed FGD gypsum as cement retarder has been reported[2,8-12]. Howevere, few studies using FGDG as retarder were reported so far. In present study, the chemical compositon, phase composition, structure and features of CaSO3•0.5H2O typed FGD gypsum have been analyzed, and its application characters used as cement retarder have been investigated experimentally."

Jan 1, 2008

By Robert L. Stephens

"It can be argued that one of the most important property of any material is cost, since this property detennines the applications for which a material can be considered. Despite growing demand and production for commodity metals such as copper, nickel, zinc, lead, and tin, the cost of these metals has been steadily decreasing in real terms. The only way that metal miners and producers can remain financially viable in the long term is by continuing to lower their cost curve through the implementation of new metals production technologies. This paper reviews technological developments in the production of copper, nickel, zinc, lead, and tin that have or threaten to redefine the cost curves for these metals.DisclaimerThe opinions expressed in this paper the author's, and are not necessarily those held by the author's employer, Cominco Ltd.IntroductionThis meeting will discuss many novel technologies and processes for producing metals and materials with specific properties that will enhance the applications ranges for the material or will allow entirely new applications to be developed. However, in every real-world case, the cost of the new material or process is an important property that determines which applications the material or process can be used in. Other properties that are important depend on the applications.A recent press report (1) discussing the potential replacement of aluminum radiators with copper radiators in pickup trucks and sport utility vehicles provides an interesting example to reinforce the importance of cost in materials selection. In this case, the displacement of aluminum by copper is being considered because of the more favorable heat dissipation characteristics of copper. Heat dissipation has become more important due to the development of hotter-burning V-8 and V-6 engines. For this application, engineers also consider cost, weight, size, durability, and manufacturing process. The report stated that the development by the International Copper Association (ICA) of the ""CuproBraze"" manufacturing process for heat transfer products was an important development. This technology produces 845 radiators that weigh less, are more uniform in quality, and are potentially more compact. They are also expected to cost less in high production quantities than copper units produced in the past, last three to four times longer than soldered copper radiators, and the process also eliminates the use of lead solder from the manufacturing process."

Jan 1, 2000

By Kiyoshi Shibata

A new assessment model has been proposed for metal production and its recycling system. The model consists of three processes, smelting of ore, cascading and upgrading of metal scrap. The present approach is to assess the total energy consumption of the system, by introducing two equations for describing the relationships between critical impurity content and the mass of production or scrap recycling. The total energy consumption in the system can be described as a function of recycling rate and performance of the upgrading process. The present model suggests that the impurity removal efficiency and yield in the upgrading process are essential to reduce the energy consumption in the systems. Especially, such points should be explicitly controlled in recycling of aluminum. The potential capability of this model was also discussed by obtaining several quantitative information required for the process design and the operational control of beneficial recycling of metals.

Jan 1, 1998

By Sasa Djokic

In developed countries, the difference between demanded and produced quantities of non-ferrous and rare metals are compensated by secondary raw materials recycling and reprocessing of by-products from both ferrous and non-ferrous extractive metallurgy. Utilization of non-ferrous and rare metals from the metallic secondary raw materials is very significant, both for recovery of the metal value and contribution to the environment protection. Similar to all non-developed countries, the extractive metallurgy in Serbia was based on available natural resources and not so strict environment protection regulations, which was either insufficient or completely absent. Today, Serbia is at the beginning of development of efficient and economical technical and technological solutions in order to ?ecologize? technogenic systems by waste materials, secondary raw materials and degraded soils regeneration (by recycling and revitalization). Several metallurgical technogenic systems in Serbia, together with secondary raw materials classification according to their potentiality for metal extraction by using the existing technologies and expected economical and ecological effects of recycling, are discussed in this paper.

Jan 1, 2005

By Qinmeng Wang

The oxygen bottom blown copper smelting process is a new technology which has been widely applied to the copper production in China. In this work, a computational thermodynamics model for this technology has been established, based on smelting mechanism and theory of Gibbs free energy minimization. The calculated results from the model agree well with the actual industrial data, indicating that the model can be used for the predictions under different operating conditions. The tendencies of the key parameters (such as Cu losses and Fe3O4 content in slag) and the distribution ratios of the minor elements (such as Pb, Zn, As, Sb and Bi) can be predicted by adjusting the oxygen/ore ratio charged into the bottom blown copper smelting furnace. The model can be used to monitor and optimize the industrial operations of the oxygen bottom blown copper smelting process.

By I. Peerawattuk

Growing demand for Li-based battery technologies is leading to an unprecedented growth in the lithium industry. Although innovation in battery technologies has pushed lithium into the spotlight, lithium was not always known for its application in batteries. The primary use of lithium—prior to the introduction of commercial lithium-ion batteries in the early 2000s—was in the ceramics, glass, grease, and the medical industry. Before being converted into usable forms, lithium products must be upgraded from the raw material. Processes for recovering lithium may involve: thermal treatment, water leaching, solar evaporation, ion exchange, carbonation, and electrodialysis. Presented, is a historical review of lithium applications and the different techniques of converting lithium-rich minerals and brines into usable products with additional discussion on future lithium extraction processes.

By Guo Xueyi

The morphological characteristics of the nickel particles electrodeposited from chloride dominant aqueous solution was investigated. The effects of the electrolyte constituents, the parameters for the electro-deposition on the morphology of the nickel particles were addressed. It is evidenced that not only the particle size but also the morphology of the deposited nickel particles strongly depend on the electrolyte constituents and technical operation conditions. The electro-crystallization mechanism of the metallic nickel particles deposited at high current density was elucidated. The ultra-fine nickel particles with flake, nodular or dendrite shape may be produced by controlling the duration for electro-deposition.

Jan 1, 2003

By Peter C. Hayes

"The high temperature reduction of solids through the use of reactive gas atmospheres has application in a wide range of industrially important processes. Whilst significant advances have been made in understanding and describing these processes, some key aspects of the chemical reactions and reaction mechanisms operating in these systems, for example, the transformation from metal oxide to metal, remain poorly understood. A number of different product morphologies have been identified in these reaction systems and the reaction rates have been shown to be critically dependent on the product structure.Theoretical examination of the elementary process steps taking place in the region of the gas/metal/metal oxide interface, combined with electron microscope studies of the resultant product microstructures, have enabled the key process and material variables responsible for the development of the various product morphologies to be identified. By considering i) established criteria for the stability of moving interfaces in a thermodynamic potential gradient, ii) the relative rates of chemical reactions on the oxide and metal surfaces, and iii) key process phenomena and physico-chemical properties of the solid phases, the mechanisms and conditions for the formation of various product morphologies are identified. Interestingly the analysis points to direct analogies between these phase transformations and, the phenomena and microstructures observed in metal solidification, and the potential to develop generic models of these fluid/solid reaction systems."

Jan 1, 2013

By C. A. Silva

Ladle change-over, during continuous casting of steel, initiates transient flow in the tundish which influences the inclusion content and degree of mixing between two consecutive batches of steel. The mixing behavior in the tundish during this period is determined by the casting rate and the ratios of: inflow to outflow during the refilling period; and, the low liquid level relative to the nominal level in the tundish during the transiency. A 3:10 scale water-model of a typical one strand slab caster was operated in conjunction with a tracer technique to characterize the velocity fields for several combinations of these parameters. Steady operation, a limiting case of the transiency, provided a basis for comparison. High-order moments -- skewness and kurtosis -- of the residence time density function have been utilized as signature elements associated with a particular residence-time distribution for the system. A simple mathematical model incorporating the above parameters as well as a characteristic Peclet Number was successful in simulating the features of the transient period.

Jan 1, 1993

By K. Fagerlund

Methods for simulation of settler reactions, matte-slag separation and matte settling in copper flash smelting have been examined. The reaction, separation and settling phenomena of slightly oxidized chalcopyrite samples and cuprous sulfide-magnetite mixtures in fayalite type slags were examined at about 1300°C under inert atmosphere. Two methods based on introduction of molten samples of oxidized chalcopyrite concentrates or synthetic matte-magnetite mixtures onto the surface of molten iron silicate slag were tested. In the first method the samples were water quenched and polished specimens were studied and analysed using light optical microscope, scanning electron microscope, energy dispersive spectrometer. In the second method processes taking place after the introduction of samples onto the slag are followed "in situ" using X-ray transmission image monitoring. Great differences were observed in separation and settling behaviour of low and high grade copper mattes produced as a results of interaction of initial samples and slag.

Jan 1, 1997

By Dale T. Peters

Conductivity, both electrical and thermal, are attributes accounting for about 70% of the applications of copper and its alloys. This paper presents results of on-going research into two new applications that depend on copper's excellent conductivity. The Copper Development Association (CDA), together with materials and motor company partners, is working toward a solution to the key problem preventing pressure die casting copper for the conductor bar/end ring structure of the induction motor rotor, i.e., lack of a durable high-temperature mold material. Work is showing that a combination of high- temperature materials and elevated temperature processing gives much improved mold life compared to die steels. Substitution of copper for aluminum in the rotor can result in a 20% decrease in electrical losses in motors consuming 35% of electrical power generated in the U.S. The second development uses the excellent thermal conductivity of several high-strength high-copper alloys to simultaneously improve productivity and part quality in the injection molding of plastic parts.

Jan 1, 1999

By T. Shibasaki

Purification of copper electrolyte at Naoshima is carried out by two stage liberation to completely depress copper and impurity ions followed by concentration of the solution to produce crude nikel sulfate as by-product. A new nickel recovering process has been developed and pilot tested recently. It consists of the following process steps.; neutralization of spent electrolyte from liberation section to remove free acid and most part of remaining impurity ions, refining and nickel concentration by solvent extraction, and crystallization of pure nickel sulfate from concentrated strip solution. This paper describes the results of laboratory and pilot plant tests, then briefly discusses feasibility of the proposed process.

Jan 1, 1987

By H. Deveci

Bioleaching/biooxidation is essentially a dissolution process with the involvement of acidophilic bacteria acting as the "catalyst" to accelerate the dissolution of metals from sulfide minerals. The contribution of bacteria to the metal dissolution is closely controlled by the growth of bacteria, which is itself affected by the physico-chemical conditions within the bioleaching environment. There are a number of operating parameters controlling bioleaching processes, which are required to be maintained within a certain range in the leaching environment whereby the activity of bacteria with the resultant oxidation of sulfide minerals can be optimized. In this regard temperature, acidity, oxidizing conditions, availability of nutrients, oxygen and carbon dioxide, surface area and presence of toxic ions are of prime importance for control and optimization of bioleaching of sulfide ores/concentrates. Bioleaching processes are temperature and pH dependent with optimum metal dissolution occurring in a particular range where the bacterial strain is most active e.g. mesophiles at 35-40°C and pH 1.6-2.0. Provision of nutrient salts is required to maintain the optimnm growth and hence metal dissolution with the quantity of nutrients apparently being dependent on the availability of substrate i.e. head grade/pulp density of an ore/concentrate. Oxygen transfer is one of the most critical factors since the oxygen levels below 1-2 mgll may adversely affect the oxidizing activity of bacteria. Bioleaching rate tends to improve with increasing the surface area at low pulp densities but, in practice. the pulp density is limited to -20010 w/v. Increasing concentrations of ions such as cr may also adversely affect the oxidative activity of bacteria. Keywords: Bioleaching, Biooxidation, Acidophilic bacteria

Jan 1, 2003