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By Moto Goto

PT Smelting, located in Gresik, East Java, is the first copper smelter and refinery in Indonesia. Since the first charging concentrate in December 1998, many equipment troubles have been systematically eliminated, and the present operation is smooth and has accomplished the design capacity of 200,000 tonnes per year of LME, grade-A copper cathode. This paper describes troubles and countermeasures, which were experienced until now.

Jan 1, 2002

By Cameron Hams

Noranda's Process Reactor and Codelco's Teniente Converter are physically similar vessels, which leads to the commonly held misconception that the two processes are the .same. However, notable differences in chemistry, operating philosophy, and construction make them quite dissimilar. This paper compares and contrasts the Noranda Reactor and the Teniente Converter, and attempts to explain some of the apparent differences in behaviour and performance. The results of a worldwide survey of most operating Noranda Reactors and Teniente Converters, along with those processes that have ceased operation or are planning to be started-up in the future, are presented.

Jan 1, 1999

By Alejandro R. Alonso, Lizet Alvarado, Gretchen T. Lapidus

"Cobalt and lithium recovery from spent Li-ion secondary batteries has been increasingly studied in recent years due to the high value of both metals and the low proven reserves for lithium. The standard method employed until now has been the deactivation and crushing of the batteries, followed by leaching of the L1C0O2 spinel from the battery cathode using acid solutions, such as 1.5 to 2.0 M HC1 or H2SO4, in a temperature range from 120°C to 250°C. Once leached, the cobalt is separated by electrodeposition and the lithium by precipitation, using large amounts of carbonate to bring the solution to alkaline pH values. In the present work, citric-thiosulfate solutions are used for the spinel leach at room temperature, favoring a reductive environment at room temperature, which stabilizes the cobalt(II) as cobalt citrate and lithium(I) at pH 5, and recovers approximately 99% of both metals.IntroductionThe Li-ion batteries industry has become an important economic sector in recent years. This type of battery is the most promising system for energy storage, because of its high efficiency in charge-discharge cycles, and its adaptability to many configurations. The demand will probably increase because of the need for mobile energy sources in many types of devices ranging from cell phones, tablets, and laptops to medical, navigation and sophisticated communication equipment and even in automobiles.One major problem related to the use of these batteries is the method employed for recycling the components, mostly cobalt and lithium. Currently, there are two processes employed on an industrial scale: the Sony/Sumimoto process, used since 1990 [1] and the Toxco Process [2]. In the first case, incineration is used to open the batteries and at same time volatilize the organic solvents. After that, the metals (copper, iron and aluminum) are physically separated. The cobalt and lithium are recovered as oxides and then thermally treated in order to recycle them for new batteries manufacture."

Jan 1, 2012

By P. R. Khangaonkar

The variety of intermediates, middlings, complex materials and wastes produced in the conventional processing of tin ores as experienced in the tin industry in South East Asia is reviewed. The problems associated with the treatment of these materials so as to produce useful products by hydrometallurgical or pyro-cum-bydrometallurgical approaches are discussed. Results of treatment of amang middlings consisting of cassiterite, struverite, ilmenite, zircon, monazite etc by chlorination with carbon tetra chloride are presented. The efforts to leach tin without letting iron coming in, by alkali leaching of certain wastes of tin processing are also briefly indicated. It is felt that pyro-cum-hydrometallurgical approach can help a viable treatment of these materials so as to obtain usable or value added products.

Jan 1, 1994

By W. J. Guay

Scrubbing of simulated copper reverberatory furnace gases containing 1.0 percent sulfur dioxide with the minus 74 ~m fraction of the San Manuel tailings has shown sulfur dioxide removals of almost 100 percent over an effluent pH range of 3.1 to 4.6 and a wide range of liquid to gas ratios with absorptions of 11 to 17 Kg of sulfur dioxide per tonne of minus 74 um slimes. The high reactivity of the tailings slimes with S02 indicates that the reaction rate is not controlled by the slow dissolution of calcium carbonate in sulfurous acid which characterizes scrubbers using ground limestone. The interpretation of these results has been considerably enhanced by wet chemical analysis and emission spectrographic analysis which show that calcium and iron account for about 90 percent of the SO2 absorption with the rest being accounted for by aluminum, magnesium, potassium, and sodium. Mineralogic examination confirms the, chemical and spectrographic analyses showing that the major constituent removed from the slimes is calcium carbonate, with lesser amounts of chlorite and montmorillonite (silicates containing iron, magnesium, aluminum, and calcium) being removed.

Jan 1, 1981

By Liu Chunpeng

The new technological process developed is by means of thermal plasma arc smelting to obtain high grade Ni matte directly from Ni-Cu concentrates containing 6-7% nickel and 3-8% sulfur. In comparising with conventional smelting and converting processes the plasma arc smelting process has many advantages over conventional processes, such as lower energy consumption, lower capital investment and free from SO, pollution by transforming the sulfides into elemental sulfur with microwave irradiation under controlled oxygen potential, moreover, the process is simple and easily controlled due to less magnetite troubles in the operation. Therefore, this new technological process can be used as an alternative way to conventional process for Ni-Cu concentrate smelting. The main economical technical index is summarized in Tabal 1. Table 1 Main Ecnomic-technical Index

Jan 1, 1993

By Manfred Schmidt

Realizing an invention of Professors Queneau and Schuhmann, Lurgi GmbH has developed a radically new lead smelting technology, which was demonstrated on a ?30,000 tpy scale at Berzelius Metallhiltten GmbH between 1981 and 1986. Designed to treat all grades? of lead concentrates as well as complex secondaries, the novel QSL-Process applied one bottom-blown, refractory-lined long reactor and comprises two basic steps: Continuous oxygen smelting of the green charge is followed by continuous carbothermic slag reduction. Four firm orders and a number of serious inquiries from major lead producers confirm that the QSL-technology has convinced the industry of inherent process advantages. These include low investment and operating costs, flexibility and environmental acceptance. In the fall of 1986 Cominco Ltd. decided to erect a 120,000 tpy QSL plant at the site of the Trail lead smelter. Feed materials will consist of lead concentrates and zinc leach residues. The designed QSL reactor has a total length of approx. 41 m, and working diameters of 3.74 m for the oxidation section and 3. 24 m for the reduction section .. Separate gas offtakes on both sections will enable to? reduce the sulfur dioxide gas volume, and to recover a mixed zinc-lead oxide fume. Operation of the QSL reactor will start end of September 1989. First results will be presented.

Jan 1, 1990

By S LeClair

Intelligent manufacturing involves intelligent, product-directed systems that facilitate the on-line, real-time generation of an improving product process cycle. A first step in the journey relates to self-directed systems which have the ability to reason and create their own processing paths in response to varying product and process conditions encountered during the process. This paper discusses an application of self-directed process control in the manufacture of graphite-epoxy laminated composites. An Air Force team involving researchers and production personnel have caused the development of a system now in use at the Air Force Logistic Center at McClellan Air Force Base in Sacramento CA. The paper discusses results and lessons learned in the process of trying to speed the implementation of research efforts which show significant potential of improving the product quality in less time and at less cost

Jan 1, 1992

By Emil H. Geus

A process has been developed to recover aluminum from dross which does not require the use of salt flux as commonly employed, This results in a salt-free residue which has potential industrial uses or alternatively can be safely land-filled. The dross is first heated by an air-fuel or oxy-fuel burner in a sealable rotary furnace. At a suitable temperature the burner is turned off and the temperature of the dross thereafter controlled by means of an atmosphere of oxidative and inert gases. When the free metal has agglomerated it is first discharged from the furnace, followed by the residues.

Jan 1, 1995

By J. W. Matousek

Copper losses in smelter slags are :typically normalized with some form of the distribution coefficient, written as the ratio of the weight percent assays of metal in slag to the metal in matte or its inverse: L(s/m) = %(Cu)/%[Cu] or L(m/s) = %[Cu]/%(Cu) However, this simple approach ignores the dynamics of the smelting process. It overlooks the effect of the chemical work done in producing a given matte grade from concentrates of different grades -- or from a single concentrate blended with varying quantities of copper bearing precipitates or reverts. This paper examines the combined influences of matte grade and the work done in smelting on the copper content of smelting furnace slags. A simple model for the relationship is proposed.

Jan 1, 1999

By René Bustamante

The subject of this paper is a comparative evaluation of different copper smelting gas cooling techniques, using "productivity and quality" criteria. The first section presents a brief description of the operation of the radiant and the evaporative cooling systems, focusing on the differences between each other, in particular regarding. a) mass and energy balances; b) gas flow, temperature and composition; c) dust concentration and recovery. This section includes a brief discussion of the "client-server chain", i.e. the links between the cooling equipment and the down-and up-stream operations. More in particular, the up-stream server relationship impacts on the operating stability of the furnace, and in turn on furnace down-time and Cu production losses; and the down-stream client relationship affects the operation of the electrostatic precipitators, in terms of workload and cost of handling larger quantities of dust of a given dust size The second section deals with the development of indexes to measure and compare value added through the "utilization, productivity and quality" that can be expected of both cooling methods at the physical and economic levels, and the impact on the overall smelter productivity and the final cost composition of copper. The final section presents the results and includes a discussion of the comparative advantages and disadvantages of both cooling systems.

Jan 1, 1999

By Toshihide Takenaka, Takashi Matsui, Nao Murakami, Masahiro Kawakami

"Electrowinning of Ti have been investigated in a LiF-NaF-KF melt including K2TiF6 at 773-923K by applying electrochemical oxidation ofH2 gas as an anodic reaction. The cathodic behavior of titanium and the anodic behavior of H2 gas were studied by voltammetry in detail to clarify the electrolytic condition for the process. The electrowinning of Ti was carried out by potentiostatic _electrolysis. Steady electrolysis was achieved under the suitable electrolytic condition without breaking out the anode effect. Titanium metal was electrodeposited on a Ti cathode though the deposits were usually powdery. It is concluded that this process is potential if the morphology of the deposit can be improved.IntroductionTitanium has such good properties as high specific strength and high corrosion resistance. However, the availability of Ti has been limited because the price of Ti is much higher than those of other common metals, such as Fe and Al. The production process of Ti ingot from its ore is rather intricate so that the production cost is high. If the simpler process is developed, the production cost should be retrenched. Titanium metal is usually produced by the Kroll process, which consists of the electrowinning of Mg metal in molten salt and the chemical reduction of TiCl.i by Mg metal. The Kroll process is very elabrate, but not simple. Because the chemical reduction ofTiCl4 by Mg metal is highly exothermic, a considerable amount of energy is wasted.Titanium metal can be electrowon in molten salt bath in principle. A simpler and more effective process than the Kroll process may be realized by the direct electrowinning so that the electrowinning of Ti metal has been studied widely[ 1]. Some researchs progressed to a pilot plant stages [2], but the electrowinning of Ti has not been industrialized yet."

Jan 1, 2000

By Varadajan Seshadri

Kambara Reactor (KR) consists of a ladle where pig iron is stirred by an impeller during addition of a flux powder. The objective is to improve agitation leading to dispersion, of the flux powder, in the molten pig iron in order to improve desulfurization of the liquid melt by improving solid liquid interaction. The life of the impeller is limited as it is subjected to abrasion at high temperatures. The shape and design of the impeller also has an effect on the performance of this reactor. A 1:7 scale cold model of a KR unit of the Companhia Siderurgica de Tuberao ,one of the integrated steel plants in Brazil was constructed in order to evaluate the mixing and mass transfer conditions. Mixing efficiency was investigated by tracer additions and subsequent measurement of conductivity. Mass transfer in the reactor was assessed through iodine transfer between water and kerosene and employing a macroscopic model. Mixing depends on impeller shape and depth of immersion The role of dispersion is highlighted by faster kinetics when impeller velocity is increased. The results enable assessment of design aspects of the impeller on the process.

Jan 1, 2006

By P. G. McCormick

The refining of rare earth metals by the direct solid state reduction of their respective chlorides during mechanical alloying has been studied. Erbium and gadolinium were synthesised by milling their respective chlorides with calcium. The mechanical alloying of SmC13 with calcium resulted in partial reduction of SmC12. Examination of the milled powders using X- ray diffraction and analytical electron microscopy has enabled characterisation of product structure and morphology. The synthesis of Fe17Nd2 by the mechanical alloying of NdC13 and Fe with calcium has also been studied. The Fe17Nd2 phase forms during heat treatment of the mechanically alloyed powder.

Jan 1, 1992

By Haotian Xue

A new process to extracted antimony directly from stibnite concentrate by reductive sulfur-fixation smelting in sodium molten salt has been presented. The influences of sodium salt content and composition, ferric oxide addition, temperature and time was investigated, respectively. The optimum conditions was determined as follows: W????: ??concentrate=40%, W??alt: ????concentrate =88.75%, WFe2O3 :Wconcentrate =55.13%, W??aCl: ????alt=40%, 1123K, 1h. Under above-mentioned optimum conditions, the average direct recovery ratio of antimony can reach 91.48%, and the main chemical composition of obtained crude antimony is Sb 94.31%, Fe 4.436%, Pb 0.502%, Au 0.0236%. In comparison to traditional antimony pyrometallurgical process, the smelting temperature of present process is reduced from 1423~1473K to 1123~1173K. During the smelting operation, SO2 emision can be avoided completely due to sulfur-fixation as FeS. Furthermore , S0 can be obtained when the molten slag is handled by water leaching with conditions of 323K, L/S=5/1, 2h.

Jan 1, 2014

By Isabel Lázaro

A detailed study has been undertaken into the electrochemistry of the leaching of chalcopyrite in acidic solutions containing ferric ions. Mixed potential measurements have shown that the maximum potential achievable on a chalcopyrite disk in a ferric sulfate medium lies within the so-called passive or prewave region in the anodic behavior of chalcopyrite. The very low current densities due to the anodic oxidation of chalcopyrite at potentials in the region of the mixed potential has made studies of the initial stages of dissolution difficult. However a careful rotating ring-disk electrode (RRDE) study has enabled data to be obtained for the stoichiometry of the initial dissolution reaction to be obtained. Thus, in addition to the detection of soluble iron and copper as products in this potential region, a soluble sulfur species has also been detected. A comparison of the experimental with the expected collection efficiencies of the products on the ring has revealed that this soluble sulfur species is likely to be thiosulfate. The characteristic transient anodic behaviour of chalcopyrite in this potential region has been interpreted in terms of a rate limiting solid-state diffusion process. Thus, extrapolated rates based on reported measured solid-state diffusion coefficients for the mineral at elevated temperatures have been shown to be consistent with the potentiostatic current-time transients. Furthermore, comparative studies of the anodic characteristics of the copper sulfide minerals covellite and bornite has confirmed their greater reactivity in this potential region. The results of this investigation have been combined with a parallel study of the non-oxidative behaviour of chalcopyrite in order to derive a model for the dissolution process which is consistent with other published studies of the electrochemistry and dissolution of the mineral.

Jan 1, 2003

By K. S. Raja, M. Misra, S. K. Mohapatra

"Ordered arrays of TiO2 nanotubular photocatalysts were prepared by a simple anodization process. Band gap states of the TiO2 were altered by controlling the anodization electrolyte composition and thermal annealing conditions that resulted in enhanced photo activity. These nanotubes were used for reducing CO2 to methanol either by photochemical or photo electrochemical routes. Pd nano-particle loaded TiO2 nanotubes were employed for photochemical reduction of CO2 to methanol that showed a conversion rate of 12 x 10-3 mol m- 2h-1. Carbon modified TiO2-xCx type nanotubes were used as photo anode and Ti as cathode for photo electrochemical reduction of CO2. The potential of Ti cathode was maintained at -0.5 V SCE. The formation rate of methanol was determined as 13 x 10-3 mol.m-2h-1.1. IntroductionGlobal warming due to emission of carbon dioxide is a serious environmental concern. The atmospheric concentration of CO2 is about 384 ppm by volume and about 3 x 1012 tonnes by weight. Burning of fossil fuels and deforestation are the leading causes for increase in the anthropogenic CO2. More than 32 x 109 tonnes of CO2 are released per year (based on 2006 data) worldwide from the fossil fuel. Pumping CO2 from the fossil fuel power plants into deep ocean basin is one of the most discussed disposal options. The other potential option is converting this green house gas into valuable fuels.Carbon dioxide feed stock can be converted into fuels of solid, liquid or gas phase by chemical, electrolytic, photocatalytic and photo-electrocatalytic methods. Reduction of CO2 to fuel form of any phase requires energy. The reduction process should be energy efficient so that we do not spend more energy and emit more (indirect) CO2 in the process of converting CO2. From this point of view, conversion processes occurring at room temperature look attractive.Electrolytic conversion of CO2 into various forms such as methane1, ethane2, ethylene3, methanol4,5, ethanol6, n-propanol, formic acid7, and formaldehyde has been widely reported. The standard equilibrium potential (at pH: 0) for reduction of CO2 to methanol is 0.14 VSHE and to methane is 0.2 VSHE which is thermodynamically more favorable than hydrogen reduction. However, the gas phase reduction is kinetically complex requiring effective electrocatalyst. The major issues with electrolytic conversion of CO2 to useful products are:"

Jan 1, 2010

By Hua-qing Li

Electromagnetic stirring process effectively improves the casting quality of metals. In this paper, the physical simulation experiment, in which the molten copper is displaced by mercury, was designed. The factory test parameters were determined according the simulated data. The flow behavior of the mercury to be stirred as well as the relations between the microstructure of plate blanks and the current parameters were analyzed. With an appropriate electromagnetic stirring, the inverse segregation of tin for C51900 alloy plant blank reduces from 15 % ~ 30 % to about 5 %, and the proportion of equiaxed grain rises to larger than 30%.

Jan 1, 2009

By Pan Gu, Zhen Zhang, Wen-Feng Tan, Jiang Diao, Bing Xie, Wang Zhou

In order to recover the chromium resource in chromium-containing vanadium extraction residue, a promising method is to prepare ferrochromium with the residue. The synthetic residue has been reduced under 1300, 1350 and 1400 °C at the reduction time of 1, 2 and 3 h respectively. The reduced samples have been smelted and separated by an induction furnace. The contents of chromium and iron in metallic phase have been determined by an inductively-coupled plasma spectrometer. The results indicate that chromium iron carbide (Cr, Fe)3C7 is the intermediate phase and titanium oxides have been reduced during the reduction process. While the sample has been reduced under 1400 °C for 3 h, metallic phase becomes the dominate phase and reduction reactions almost complete. Moreover, the chromium content in the metal phase reaches 10.19%.

Mar 1, 2017

By Buket Tunçer, Mehmet Buğdaycı, Onuralp Yücel

ZrB2 and TiB2 are one of the most significant metal borides. They are being used in various industrial areas from space technology to nuclear industry owing to their physical properties such as high melting point, high thermal/electrical conductivity and low density. Present study was conducted in two main stages: Self-propagating high-temperature synthesis (SHS) reactions and leaching. ZrO2, TiO2, B2O3 were used as starting material and Mg used as a reductant to produce ZrB2-TiB2 powders via SHS. Therefore, it was aimed to determine production parameters, leaching conditions and comprehensive examination of final product features. The samples were characterized by using chemical analysis (AAS), XRD, XRF and SEM/EDS techniques

Jan 1, 2015