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By John A. Vallomy

"The CONSTEEL Process introduces a new concept in electric steelmaking by continuously feeding-preheating-melting and refining ferrous scrap or direct reduced iron. The process uses the furnace off-gas and fuel to preheat the scrap in a specially designed preheater. Thermal incineration of the flue gas reduces the carbon monoxide level to the more stringent requirements. Hot water or steam production from heat of flue gas is optional. The tap-to-tap time is set to match the cycle of the caster. The steel is treated via ladle metallurgy. The environment inside and outside of the steelplant is improved by decreasing levels of noise and hazardous emissions. Energy consumption decreases and disturbance to the electric network is eliminated. A CONSTEEL prototype was tested at Nucor Steel, Darlington, SC. A greenfield project is in the completion stage at the Florida Steel plant of Charlotte, NC, USA. The Process PhilosophyThe philosophy of the CONSTEEL Process is not solely to enhance efficiency; this was just a natural result of the change from a batch to a continuous practice. The primary objective in development was four-fold:1) 100% process control2) Rational use of available energy3) Improved environment inside and outside the plant4) Stability of energy input from the power systemIt was to make electric steelmaking more a science than an art and amenable to modern automation.The Basic Concept of CONSTEELThe concept of the process is shown in figure and includes basically a continuous feeding system, a preheater and a melting - refining furnace. A pre-established amount of heat is introduced into the scrap while traveling through the preheater using the sensible and chemical heat contained in the furnace off-gas and additional fuel. Melting-refining is carried out in the electric furnace. Slag formers, slag foaming additions and oxygen are injected to refine the melted steel continuously, to minimize the refractory erosion, to shield the arc, thus optimizing the transfer to the metal bath of the heat generated in the arc, to keep the bath homogeneous in composition and temperature and to produce carbon monoxide (CO) which is fuel for the preheater."

Jan 1, 1988

By Pekka Hanniala

The Outokumpu Flash Smelting process today is the most feasible method for copper matte smelting. The economic feasibility of the process has always been one of the main decision making criteria in smelter projects. Thus, today about 50 % of the world primary copper production utilizes Outokumpu Flash Smelting Technology. However, in the future, environmental criteria will have stronger and stronger impact on decision making. Flash Smelting technology offers the best pollution control features of any process. today. It is foreseen that, in the near future, the global trend will be that all the smelters must decrease their emissions at an accelerating rate, compelling the smelters to make increasingly larger investments on environmental protection. In most of smelters ?today, Peirce-Smith converting and transfer of the molten material in ladles are the number one pollution source. The key today for copper converting and minimizing emissions is the Kennecott-Outokumpu Flash Converting process, which has proven to be the most effective converting method in terms of pollution control and, production efficiency including capital and operational costs. Outokumpu Flash Smelting technology is applicable also for small to medium scale smelters but the most interesting area is the upper capacity limit for smelting in one line, which has not yet been reached. We predict that by the year 2000 to 2005, there will be at least one smelter which produces 500,000 tonnes of Cu per year based on one Flash Smelting and Flash. Converting unit. The current state-of-the-art of the Outokumpu Flash Smelting - Flash Converting process is presented in this paper as well as some new options for copper production to be utilized in the near future but which are available already today.

Jan 1, 1998

By M. M. Swan

A stratiform gold occurrence of Precambrian age located 20 miles southeast of Prescott, Arizona, within the Agua Fria Mining District, displays chemical, mineralogical, structural and lithological patterns indicative of a distal, exhalative volcanogenic environment. Metavolcanic and metasedimentary rocks of the Proterozoic Yavapai Series (1775-1820 m.y.) host the mineralization and are'characterized by greenschist grade metamorphism, steeply-plunging penetrative folds and steeply-dipping schistosity. Mineralization is confined to a 100m thick stratigraphic section that is comprised of a series of thin auriferous massive sulfide beds and intercalated schist .containing disseminated sulfides. The mineralization extends more than 4km along strike. Coincident with, and largely confined to the mineralized strata, are anomalous amounts of As, Sb, Cu, Pb, Zn and Ag and associated silicification, sericitization and carbonatization. This exhalative mineralized system is interpreted to have been deposited in a paleo topographic low on the distal flank of a submarine rhyolite dome and to represent the final episode of a Precambrian volcanic cycle.

Jan 1, 1981

By A. J. van der Zeeuw

The use of SME 529 in the extraction of copper from acidic liquors and of copper and nickel from ammoniacal solutions, is illustrated with results of laboratory and bench scale mixer/settler experiments. Special features of SME 529 are its high loading capacity and the ability to keep the complexes dissolved in the organic phase up to quite high concentrations.

Jan 1, 1976

By Keiji Toyabe

Several purifying techniques have been developed for controlling the impurity levels in the copper electrolyte at Niihama Copper Refinery. These have been carried out as follows; i ) the study of the reaction in liberation made it possible to raise the current efficiency for arsenic removal by more than 50% and to decrease generation of arsine sharply. By applying this method, a good performance was attained at commercial operation. li) the antimony in the electrolyte can be successfully removed by contacting it with activated carbon. This procedure is applicable particularly when there is a large amount of antimony in the copper anode. lli) for the nickel sulphate recovery from the electrolyte, an electric evaporating system was developed. The characteristics of this process are, capability of continuous operation with less manpower, the high recovery ratio of nickel sulphate (more than 85% as nickel) and no black acid formation in the treated solution.

Jan 1, 1987

By T. J. A. Smith

This paper provides an overview of some of the key issues in design of smelter gas handling systems, with particular reference to sulphide smelting plants. In both primary smelting and converting. gas handling and treatment systems often represent the major capital cost component. There is also ample evidence that poor system design can be a major cause of smelter down time, lost production and unforeseen high maintenance costs. The paper discusses these issues and offers guidance for improved design.

Jan 1, 1992

By Claudio Toro, Alex Moyano, Jonkion Font, Carlos Caballero, Pedro Morales

"Codelco-Chile in the last decade has carried out industrially-oriented research as an alternative to the traditional batch-type converting process. In a first stage carried out preliminary evaluations in a rearranged Peirce Smith (PS) converter, and then an exploratory test in a “Convertidor Teniente” (Teniente converter, TC) for the Codelco-Chile Continuous Converting Process. However, the validation test for this process in the TC was delayed up to the second quarter of 2007 where the validation studies were done satisfactorily.Thus, the objective of this paper is to present the results of the campaign tests validating the Codelco-Chile Continuous Converting Process in the TC1 of the Codelco Norte smelter.The results of charging the solid or liquid matte or high grade matte (“white metal”) by Garrgun, or by mouth of the 22 m x 5 m TC1 are presented. Some features of the industrially validated process are discussed, and the pilot test results of the matte injection are also presented."

Jan 1, 2009

A novel pressure leaching process for platinum group metal (PGM) feedstocks is described. The process is particularly well suited for treatment of ores or concentrates that are too low grade for economic processing by the conventional smelting/leaching process. Operating conditions have been identified under which gold, the PGM's and the base metals dissolve simultaneously in a pressure leaching autoclave. The product of this leaching process can then be treated by one of several flowsheets, of which the preferred will likely involve solid/liquid separation, followed by precipitation (or adsorption on activated carbon) of gold and the PGM's, followed by copper solvent extraction/electrowinning. Depending on the concentrations of nickel and cobalt, the copper raffinate would either be partially recycled to the autoclave to allow NilCo concentrations to build up, or it would proceed directly to a Ni/Co refinery. This paper deals with the pressure leaching process and the recovery of gold and the PGM's from the pressure leach product.

Jan 1, 2000

By Junzo Hino

Most of the waste that contains a small portion of copper is landfilled. The recycling process of copper from the waste, such as shredder residue, should be developed in order to save mineral resources and prevent environmental pollution. Shredder residue, generated from disposed automobiles and electric appliances, consists of many types of plastics, glasses and metals. The combustion heat of plastics is efficiently used for smelting in the recycling process that consists of melting and reduction. Because the waste contains numerous components the knowledge of the distribution behaviors of the main components is necessary to develop the recycling process. The distribution behaviors in the recycling process are evaluated by using the thermodynamic calculation program, HSC Chemistry. The calculation results are compared with the practical operation data of the recycling process and discussed.

Jan 1, 2003

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 Tanm Engin, Ali Riza Tarakcilar, Derya Dispinar

"Nowadays, the casting industry is developing parallel with the information technologies (IT). Particularly the casting simulation software is being frequently used in foundry floors for casting quality control and optimisation. In this study, the filling and solidification analysis of a rolling roll manufactured by spherical graphite cast iron were carried out by Vulcan casting simulation software. The appropriate defect relieving suggestions were presented by anticipation of defects that may form during the casting process.IntroductionThe optimisation of a casting process has long been the most focused area in manufacturing plants. Many of the work involve not only the process itself but the cost as well. When it comes to the process, it is important to be able to control the defects that may form during casting.The casting process begins with the melting of a charge; followed by pouring into the mould cavity. One of the most important factors is the difference in the liquid/solid density which may lead to porosity. On the other hand, turbulence during filling is another significant factor in casting operations [1].During solidification, due to the density difference between liquid and solid, porosity might form which leads to crack-like defects. There are several other factors that may determine the quality of a casting such as segregation, inclusions, grain size and etc. However, porosity is one of the first parameters that can be easily determine and controlled by the help of simulation software. Simulation is a cost-effective tool in the optimization of process parameters and castings can be visually observed. Time loss and economic expenses could be minimized [2]."

Jan 1, 2012

By M. A. Gimenes

The utilization of chlorination in extractive metallurgy and advanced ceramics areas has been widely investigated as a preparative route in order to obtain intermetallic compounds, which are used as precursors in the development of new materials and process. The major processes of decomposition of rare-earth ores use sulfuric acid and sodium hydroxide at high temperatures, however there is not much work concerning chlorination. In this work, a systematic study of the reaction between xenotime (REPO4), chlorine and carbon has been performed. Particular emphasis was on kinetic studies to establish optimized conditions for the reaction. The kinetics of chlorination of xenotime raw material by rare-earth elements/compounds has been studied over a temperature range from 600°C to 950°C. The influence on the rate of conversion of xenotime to RECl3 on temperature, partial pressure of chlorine, carbon content, and particle size were investigated. A global rate equation that includes these parameters has been developed. The results show that the process follows the unreacted core-shrinking model with a formation of a porous product layer. The powder X ray-diffraction technique corroborated this model showing clearly the patterns related to the formation of yttrium oxychloride (YOCl), indicating that the reaction mechanism involves the presence ofan intermediate step before the formation of lanthanide chloride.

Jan 1, 2000

By Susumu Okabe, Etsuji Kimura

"The Mitsubishi Continuous Copper Smelting and Converting Process is the typical applications of injection metallurgy to nonferrous metallurgical operation, where the top blowing multiple lance system is employed for the continuous feeding of the raw materials and reaction gases into the molten bath. This results in an effective dispersion of the reactants into a strongly agitated bath. These are considered as the major advantage of the process with respect to the high production efficiency. On the other hand, however, the strong agitation may cause a considerable amount of refractory wear, and the melt splash generated by the lancing may also have negative effects on the productivity, i.e. the increase in the refractory wear, the metal loss, the heat loss, and the accretion growth, etc. Therefore, the optimization of the blowing condition as wen as furnace design is very important to achieve a stable and efficient operation, and fundamental understanding of the injection, agitation, and splashing is badly needed.In this paper, fundamental aspects of the Mitsubishi Process regarding injection, especially splashing phenomena, are discussed. The splashing on a vertical plane caused by the top blowing gas injection onto liquid surface was investigated through physical model study. As a result of the study, the splashing rate on the furnace wan was wen correlated with the physical properties of the bath materials, gas velocity, cavity shape, lance/wall distance and ceiling position. Obtained equations were compiled in a computer program and have been successfully applied to the evaluation of the furnace design. IntroductionInjection metallurgy is an application of gas/solid-in-liquid dispersing operation to the metallurgical processing, and has been widely adopted in various fields in order to improve their efficiency or productivity. The dispersed small particles of gas or solid materials in the liquid phase result in increased interface area, and injected momentum causes an agitation and enhanced heat and materiel transfer. Typical examples of injection metallurgy are LD converter for steel making, PS converter, Noranda process, Isasme1t for copper making, and Mitsubishi Material's continuous copper smelting and converting process, and so on."

Jan 1, 1996

By C. Burton Clark

The important role of the petrographic microscope in the petrology of refractories is discussed, based on 45 years of industrial experience by the author. Highlights of his career are used to illustrate improvements in equipment and techniques during the period. Two specific investigations are described which emphasize the interrelated use of the petrographic microscope with other instruments such as the x-ray diffractometer and scanning electron microscope. Emphasis is placed on the use of phase equilibrium diagrams for guidance in predicting and interpreting reactions that occur under non-equilibrium conditions in the manufacture and use of refractories.

Jan 1, 1982

By E. Oshilna

The Mitsubishi process has many advantages pertaining to economical and environmental matters. These advantages have led to the installations of the Mitsubishi process in constructing new smelters: The Mitsubishi process utilizes highly oxygen enriched blast air and uses a special lime slag in the C?furnace. These characteristics change the . distribution of Impurities from other processes which use P.S. converters, Recently an Increased amount of secondary materials which contain impurities Is being treated at Naoshima Smelter. In order to cope with an Increment of the Impurities load and maintain the cathode quality, many Improvements have been Implemented. This paper discusses the impurities behavior In the Mitsubishi process and describes the measures taken to treat an Increased ?amount of secondary materials:

Jan 1, 1998

By W. D. Cho

The slag chemistry in steel processing plays an important role in terms of the removal of impurities including alumina particles. In the present study, the dissolution of solid alumina particles in CaO-based fluxes at the temperatures between 1450 and 1550 °C has been investigated to determine dissolution kinetics and mechanism. Alumina particles were added directly in the slags and the size of alumina particles was measured as a function of time using optical and scaru;ling electron microscopes. The dissolution rate has also been obtained as a function of Si02, CaF2, MgO and MnO contents in the slags. The diffusion boundary layer between alumina and bulk slag phase has been observed and analyzed using SEM and EDX. In addition, some experiments have been performed for the dissolution of alumina in BaO-based fluxes.

Jan 1, 2003

By Michael E. Stout

M.A. Industries, Inc. has developed and is now offering on a commercially available basis, complete systems to recover and recycle lead from spent SLI batteries. The system begins with the breaking and separation of the component parts of the batteries and subsequent treatment of the effluent water produced by this operation. The recyclable materials recovered from this process are metallic lead, lead paste and polypropylene. The lead paste is introduced into a process to convert it from a lead sulfate to a lead carbonate. The process also regenerates the salt solutions into reusable carbonate. The lead carbonate is then leached into an acid bath where it is later recovered by a proprietary electrolytic process. The metallic lead is recovered in a short rotary furnace producing metal for further refining and alloying. The polypropylene is further washed and then introduced to a reclaim extruder along with the proper modifiers and additives. The resulting resin can then be sold on the open market to injection molding processors. This complete system greatly reduces the amount of waste to be disposed of and completely complies with all applicable EPA guidelines.

Jan 1, 1993

By L. A. Neumeier

The Bureau of Mines, U.S. Department of the Interior, is investigating the feasibility of partitioning complex sulfide minerals to simpler sulfide .phases by sulfldation reactions. Such partitioning can afford opportunity to improve selective extraction of mineral constituents of value. This report describes initial research involving sulfidation partitioning of chalcopyrite concentrates. Small chalcopyrite samples were sulfidized with elemental sulfur in glass capsules sealed after evacuating and backfilling with helium, by heating for 1 to 24 h at specific temperatures in the range of 250° to 500° C. which extends from below to above the boiling point of sulfur (-445° C). Above the boiling point of sulfur, the overall reaction with adequate sulfur (13.9 wt pct of CuFeS2) is 5CuFeS2 + 4S g ? Cu5FeS6 + 4FeS2.

Jan 1, 1989

By J. Fogarty, J. Sofra

The mobile telecommunications sector is one of the fastest growing industries worldwide. However, increasingly stringent environmental regulations are placing pressure on manufacturers to accept responsibility for end of life products. The companies are therefore exploring avenues to recover the valuable components contained within the mobile telecommunications devices thus reducing the quantities of toxic components going to landfill. Batteries used to power the devices, are typically based on either nickel-cadmium, nickel metal hydride, or lithium ion cells. They contain toxic metals including nickel, cadmium, lithium, potassium, lead, and cobalt in a complicated arrangement of battery cells surrounded by a metals then plastic casing. The Ausmelt Catalytic Waste Converter (CWC) for waste treatment and recycling is well suited to processing all three mobile phone battery types for the recovery of valuable metals in marketable products that can be recycled to industry without turning out harmful levels of toxic emissions. Ausmelt recently demonstrated the capabilities of its CWC by continuously processing 4.5 tonnes of nickel-cadmium batteries. Using Ausmelt's pilot plant facility in Australia, the nickel-cadmium batteries were processed to produce a nickel iron sulphide (matte), a cadmium fume and a final slag which satisfied CS toxicity leach test criteria and was safe f<~r disposal to landfill. This paper explores the commercial development of the Ausmelt CWC for treating each of the three battery types in light of (a) the outcomes of the recent demonstration, and (b) the current and expected future availability of batteries for processing.

Jan 1, 2000

By Nicole de Jager, Michael J. Nicol

"In order to liberate gold from refractory gold ores and concentrates it is generally necessary to oxidise the surrounding sulphide minerals, typically pyrite and arsenopyrite. Traditional methods of oxidation include pressure leaching, roasting and bacterial oxidation. In recent years, bacterial and pressure oxidation have found increasing favour, although these methods are by no means completely satisfactory and each is subject to particular disadvantages.A novel process has been developed as an alternative to the traditional methods whereby electro-generated ferrate(VI) ions in alkaline solution are used to oxidise a pyrite concentrate. This process has been observed to proceed fairly rapidly and could prove to be a more economically viable process, as well as being more environmentally acceptable. As an added benefit, operating in an alkaline environment is advantageous for downstream cyanidation processes.Ferrate(VI) is a relatively unknown species, due mainly to its instability in acidic solutions. However, in alkaline solution it has been observed to be sufficiently stable for use as an oxidant when used under favourable conditions. Ferrate(VI) is most conveniently manufactured electrolytically via the dissolution of high-carbon anodes in strongly alkaline solutions. Some literature has been published on the electrolytic generation of ferrate(VI) and relatively high efficiencies have been observed by both the authors and other researchers.This study utilises both electrochemical techniques and leaching experiments to examine the kinetics of the oxidation of pyrite by ferrate(VI), which is produced electrolytically. Cyclic voltammetry, rotating disk voltammetry and potential step experiments have been used to investigate the kinetics and mechanism of the oxidation process."

Jan 1, 1997