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By F. E. Pawlek

Copper concentrates can be comminuted in an attritor within a very short time to a particle size of 1 - 0.1 um. Addition of sodium hydroxide enhances commninution. The concentrates, suspended only in water, can be completely dissolved under oxygen over pressure and temperatures ranging from 120 - 180°C (248 - 356°F), because the surface area of the concentrate has been significantly increased by the ultra fine grinding. Addi¬tion of a small amount of silver ions to leach liquor containing sulfuric acid acted as a catalyst for the dissolution of chalcopyrite, because of the formation of local elements on the surface. The addition of C1- ions was also catalytically very effective. With this method it is possible to completely dissolve the copper contained in chalcopyrite concentrates after ultra fine grinding within 30 min at 110°C (230°F) under an oxygen partial pressure of 1 atm (14 psig). Several flowsheets demonstrate the industrial feasibility.

Jan 1, 1976

By R. R. Odle

A laboratory and pilot-scale investigation of direct smelting of copper concentrates was conducted to determine the effect of concentrate analysis and the degree of roasting on the yield and quality of copper produced in a subsequent smelting step. A stoichiometric :mOdel of direct smelting is presented which predicts the? quantity of copper; slag, and white metal' prOduced'and the distribution of copper in these phases as a function? of the concentrate '(calcine) analysis.

Jan 1, 1983

By A. E. M. Warner

In co Limited has long and extensive experience in converting nickel-copper primary smelting mattes over a broad range of nickel/copper weight ratios and combined nickel-copper-cobalt contents. At the Copper Cliff Smelter, the composition of the converter product matte has to meet the requirements of the matte separation process; at the Thompson Smelter, converter matte of a different composition is cast into anodes for nickel electrorefining; and in Soroako, Indonesia, a very low copper product matte is granulated for the Japanese market. Recently, Inco has conducted pilot plant testing of three possible nickel-copper matte continuous converting routes, namely flash converting, oxygen top blowing-nitrogen bottom stirring, and tuyere blowing. This test work has generated substantial new information on nickel-copper matte converting chemistry. This overview paper reviews the metallurgy of nickel-copper matte converting, in particular the behaviour of cobalt and the operating conditions required to meet the iron and sulfur specifications of the product matte. The relevant thermodynamic information is used to discuss the industrial data.

Jan 1, 2003

By Chao Li, Shuai Wang, Hongxu Li, Lifeng Zhang, Xie Yang

The method of chloride-hypochlorite leaching has the advantages of short process, low pollution and higher in reaction rate compared with the traditional leaching method. In this research, NaCl - NaClO solution is used to leaching gold from a refractory gold concentrate, and the influence of NaCl and NaClO concentration, reaction time to the leaching rate were investigated in this experiment. The raw materials and the leaching residue were characterized by a series of analysis methods such as XRD, XRF, SEM and EDS. Results indicate that the leaching rate and the desulfurization rate can be achieved at 96.26% and 98% with most optimum conditions as follows: NaCl concentration 50g/L, NaClO concentration 200g/L, Liquid-solid ratio 10:1, the best reaction time was 150 mins. And these conditions should be guaranteed pH<8.0, ORP>900mV.

Jan 1, 2015

By Jie Li

Series of carbon compounds as anode materials were prepared for super lithium ion capacitor using graphite and active carbon (AC) as raw materials. Their electrochemical properties were investigated by constant current charge-discharge test. The results showed that the compound anode had good capacitive performance as well as Li-ion battery performance. The potential of the capacitor could be as high as 3.5V vs Li/Li+ when compared with 2.5V vs Li/Li+ in the AC-AC capacitor, accordingly, the energy density increased from 21.7Wh/kg to 40.3Wh/kg. The compound anode also had excellent rate performance that as the current density increasing from 0.1A/g to 1A/g,the capacitance decreased only 1.3F/g, and good cycle performance that the capacitance holding remained 96.7% after 10 times cycles even at the highest potential of 3.5 V vs Li/Li+.

Jan 1, 2009

By Hongfa Hu, Stavros A. Argyropoulos, Stephan Ferenczy

"Physical as well as mathematical modeling was carried out to investigate the exothermic mass transfer in liquid metal systems. In these systems, the exothermicity induces unique heat, mass and momentum transfer phenomena. Moreover, these phenomena are deeply coupled and they are further complicated by the presence of a moving boundary.In the physical model used, ice cylinders were immersed into sulfuric acid solutions, because the intermixing of ice with sulfuric acid is very exothermic. In this low temperature system, velocity and temperature measurements in the sulfuric acid were made as well as measurements of the ice melting in the sulfuric acid.The mathematical model developed solved simultaneously the heat, mass and momentum equations numerically, utilizing the control-volume finite difference approach. The enthalpy method was adopted to track the moving boundary. Predictions made by the mathematical model were in close agreement with the results obtained by the physical model.The results from the mathematical model were further validated with experiments involving high temperature liquid metals. Specifically, data were obtained in an experimental setup involving (a) dipping silicon cylinders into high carbon liquid iron and (b) dipping nickel cylinders into liquid aluminum. Results from these experimental studies supported the predictions of the mathematical model."

Jan 1, 1999

By Musa Karakus

The sedimentary iron ores of Alsace-Lorraine, France have very high phosphorous contents that average 0.7% and are as much as 2.19% P. Ores from the Tucquegnieux and Joeuf mines have been studied by cathodoluminescence microscopy, X-ray diffraction, scanning electron microscopy, and electron microprobe analysis in order to fully characterize the mineralogy, size, shape, and distribution of the deleterious phosphate grains. The phosphorous occurs as collophane, a carbonate fluorapatite, in ten morphological forms, most abundantly as microcoprolites, but also as intraclasts, concentric layers, and cortices in ooids, phosphate replaced ooids and bioclasts, phosphatiC shells, fossil infillings and internal molds, fish teeth, phosphatiC laminae, and cements between the goethite ooids. About 95% of the phosphate grains are sufficiently large that relatively fine grinding fol&apos;lowed by reverse flotation would be expected to be effective in significantly diminishing the phosphorous content of the concentrates.

Jan 1, 1989

By A. González

Arsenic is one of the main contaminants present in Chilean copper concentrates and its abatement represents a challenge for the process metallurgy, particularly under the strong environmental requirements in the global community. The possibility to form ferric arsenate directly from a gas phase by means of a heterogeneous reaction between an arsenic gas bearing and iron oxide was studied at laboratory scale. A thermodynamical analysis for the system Fe-As-O-S has been initially made, in order to obtain the stability conditions for the ferric arsenate or other FexAs2O2 type compounds. Experiments were made using an hematite sample suspended in a thermogravimetric device. AS4O6 gas generated from solid AS203 that was passed through the iron oxide sample and its instantaneous weight change was recorded directly. A kinetic study for the AS4O6 volatilization was made to control the gas composition. A chemical control between 300 and 600°C with an apparent activation energy of around 14 Kcal/mol As2O3 was determined. The samples after the reactions were chemically and XRD analysed. Arsenates detected corresponds to complex compounds. Results shows a dependence on temperature and oxygen content in the gas phase. The kinetics for iron arsenates formation is slow, reaching an arsenic capture of 6% after 80 minutes of reaction when an oxygen content of 50% is fed continuously at 800°C and 3,56% As in the gas. Experiences made at the same temperature but under higher oxygen content in a closed reactor, allowed arsenic capture close to 60%. For higher temperatures the capture is considerably lower.

Jan 1, 2003

By D. M. Wyslouzil

The fundamentals of dissolving silver and silver minerals are discussed in the following sections: 1) Basic chemical reactions in the silver system 2) Leaching of pure silver minerals 3) Leaching of silver-bearing ores 4) Description of processes The basic chemical reactions of silver are an important guide to the mineral processor or the extractive metallurgist, particularly for systems in which complex formations are balanced against solubilities. The competition of other cations for free ligands can shift the equilibrium to the detriment of silver. Solubilities of pure silver minerals in specific solvents may not be a good indication of the solubility of silver minerals in ores. The abundance of silver minerals which usually appear in a typical ore precludes the selection of a single method that would result in the best extraction of silver from all minerals in the ore. Frequently, the recovery of silver from host minerals requires a destructive pretreatment such as intensive leaching, oxidation with or without elevated temperature and oxygen pressure, or roasting. The transformation of the host or the silver minerals does not always result in a leachable species? and this requires additional treatment before the precious metal can be recovered.

Jan 1, 1990

By Patrick R. Taylor

A non-transferred arc thermal plasma assisted cyclone reactor has been designed, built and operated to evaluate its use in vitrification of wastes. Simulated waste (liquid, slurry or fine particulate) is injected near the plasma flame, where nearly instantaneous dehydration and calcination reactions happen. A non-transferred arc plasma torch was attached tangentially to the cyclone and is utilized as both an enthalpy source and to provide the gas velocities required to generate the cyclonic gas flow patterns. The closed top cyclone flow sends the solid particulates to the wall, where they are captured by a thin film of molten glass that is injected as a powder at a position lower in the reactor. The molten glass is then collected in a crucible. The feasibility of simulant injection directly into the flame zone and its effect on electrode lifetimes has been studied. Several candidate refractory systems have been evaluated for their suitability for extended use under the demanding conditions present in the cyclone reactor.

Jan 1, 2002

By R. Shimpo

Equilibrium calculations by a computer may sometimes fail in giving solutions when the system includes a large number of components and more than three phases, and especially when no definite information about stable phases is given. An improved method of calculation is presented in which the number of phases need not to be initially fixed, phases can appear or disappear in the course of&apos; calculation and a new method is combined with the Newton-Raphson method to obtain solutions easily. The improved method is applied to the copper smelting operation and all the successive stages of the operation are successfully simulated.

Jan 1, 1983

By B. C. Blakey

Unlike most hydrometallurgical slurries, those containing significant concentrations of goethite are typically highly viscous and shear-thinning, even at solid volume fractions below 5%. The viscosity may also depend upon time. These characteristics must be taken into consideration in slurry transport and heating. The technical literature is replete with apparent contradictions regarding the viscous behavior of these slurries, which may be due, in part, to variations in viscosity-measuring techniques. We present techniques that yield consistent results suitable for use in process design. A striking degree of time-dependent behavior is demonstrated for a laterite slurry. Reliable methods to design and analyze tubular transport and heating systems for time-independent slurries are summarized. Rules of thumb are then offered to account for the effects of time-dependency.

Jan 1, 2000

By G. S. Victorovich

Technical progress in primary smelting has changed the face of the copper industry in the years since the Second World War. Much of this change has resulted from a wide acceptance of flash smelting technology. In addition, research has been directed toward devising converting processes to replace conventional Peirce-Smith converting technology. One major thrust has involved a revival of the old " ", idea of oxygen flash converting of comminuted mattes. This paper reviews the 60-year history of flash converting. Particular attention is paid to Inco&apos;s investigations into the processing of white metal containing significant amounts of nickel and, in some cases, iron. Thermodynamic analysis and laboratory experimental results are presented which throw light on the behaviour of nickel and other salient features of flash converting. The possible role of oxygen flash converting in the copper pyrometallurgy of the future is briefly discussed vis-a-vis direct production of copper.

Jan 1, 1993

By Ben Hogg

Since the development of the top-submerged lance (TSL) technology for copper and lead smelting by the cooperation of Mount Isa Mines (MIM), now owned by Glencore, and the Commonwealth Scientific Industrial Research Organisation (CSIRO) the core of the ISASMELT™technology has always resided in the lance system. Through continuous innovation and operation of our own smelters, first at MIM, subsequently at Mopani, and also at both the Kazzinc Copper and Kazzinc Lead smelters, Glencore Technology have expanded the core equipment supply to enhance the plant operability. The success of Glencore Technology’s expertise can be directly measured by the success of the Kansanshi Copper Smelter plant, which achieved 100% nameplate capacity within three months of start-up. This paper describes the ISASMELT™ core equipment and how it is applied to smelt sulfide materials. It highlights the strength of the ISASMELT™: continuous innovation to facilitate the versatility and continued increased capacity with every plant implementation.

By G. Van Weert

Refractory gold ores and auriferous concentrates containing silver tend to form refractory silver jarosites during pressure oxidation. Earlier work with pure Ag2S has shown that the addition of iodine species to the autoclave feed yields cyanide soluble iodargyrite (Agl) instead. Near complete silver extractions from the autoclave product were obtained at a I-/Ag+ ratio of 5 or more. This paper reports on the pressure oxidation and cyanide leaching of two industrial refractory (arseno) pyritic silver-bearing concentrates: 1. from Peru (sulphosalts) and 2. from the USA (pyrite, with acanthite occlusions). While using a I-/Ag+ mol ratio of only 1 in the feed, it has been possible to obtain 98 and 97% Ag extraction from the two autoclave products by cyanide leaching, respectively. This compares to 11 and 54% Ag extraction from the as-received concentrates and 4 and 15% Ag extraction, respectively, after pressure oxidation without KI present. The results of the testwork are discussed in terms of concentrate mineralogy and pressure oxidation conditions.

Jan 1, 1994

By Jared Ball, Darren Snashall, Paul Telford, Pengfu Tan, Ben Hogg

"The foamed converter charges were up to 3 8 per month in Xstrata Copper Smelter at Mount Isa. The issue of high converter foamover frequency had remained unsolved for many decades in Mount Isa. A thermodynamic model of copper P-S converter and a viscosity model of converter slag have been developed to simulate the slag blow and copper blow, in order to understand the mechanism of converter foamover. The model predicts the chemistry and viscosity of slag during slag blow and copper blow. The effects of oxygen potential, charge of dirty reverts, slag carryover, under-blowing, over-blowing, and temperature on the foamover and viscosity of slag in copper blow have been discussed. A theory has been developed to understand the mechanism of converter foamover. The practical solutions have also been developed and implemented in Mount Isa Copper Smelter. Some improvements of the industrial operations have been presented. After a series of improvements, the number of foamed charges per month in the converter operations has been decreased significantly from 35 in Aug 2008 to only one per month in 2009/2010.1. IntroductionThe Copper Smelter in Mount Isa receives the concentrate containing about 25% copper and produces anode copper that contains about 99% copper. There are several stages in the process. The first stage carries out in the ISASMELT™ furnace. The ISASMELT™ process produces a molten copper matte containing about 60% copper. An iron-silica slag and a sulfur dioxidebearing off-gas are the by-products of the process. The slag is taken to the slag dams for cooling before it is recycled through the Mount Isa Copper Concentrator.The matte is sent to Peirce-Smith converters. The converters further remove iron and sulphur to produce blister copper which contains about 97% copper. The anode furnaces remove any remaining sulphur and oxygen to produce anode copper that is about 99. 7% pure. This is cast into anodes and sent to the Xstrata Copper Refinery in Townsville for final refining.In the copper pyrometallurgical industrials, slag foaming is an important phenomena which occurs when the gas bubbles have stability and not rupture. Foaming greatly increases the interfacial area between matte, slag and gas and is essential for the operation of high intensity smelting processes. However, foaming or foamover is undesirable in P-S converter since it can damage the equipment and injure the operators. Figure 1 shows that the whole process of a foamover development in a converter."

Jan 1, 2011

By Arthur E. Morris

Fifty years ago when Professor Yazawa began his career, the field of process simulation and modeling was in its infancy. Since then, tremendous progress has been made in our ability to model metal production flowsheets from mine to refined metal. This progress has come about by parallel developments in basic understanding of process chemistry and in computational techniques. This paper will review the progress made in process understanding and modeling in lead, zinc, and copper metallurgy from its inception to the present, and the role of Professor Yazawa&apos;s work in furthering this progress. Specific examples wi1\ be given for the sintering of lead concentrates, slag fuming, zinc concentrate roasting, flash smelting of copper, and pyro-extraction of zinc. Factors limiting further progress will be described.

Jan 1, 2003

By Kymberley Worrell

The Cripple Creek and Victor Gold Mine was acquired by Newmont in August 2015. The high grade flotation mill project was commissioned in February 2014. The mill to date has been throughput limited due to mechanical and design issues. In order to create the most value from a throughput limited plant a campaign to provide timely ore characterization was undertaken. A diagnostic leach methodology was developed to determine gold associations by ore type. The resulting associations were then used to characterize feed blend; gold losses and optimize gold production. The diagnostic methodology is presented along with discussion on flotation implications.

By Tabbetha A. Dobbins

We report studies concerning the time frame for catalytic reactions between NaAlH4 (sodium alanate) and TiCl3 during high energy milling. Spectral features in x-ray absorption spectra were analyzed for samples milled for various times (0 minutes, 1 minute, 5 minutes, 25 minutes, and 125 minutes). A structural transition from Ti3+ to Ti0 is observed within the first 5 minutes of milling. The Ti0 structure persists for samples milled for times longer than 5 minutes?even after those samples underwent a subsequent single hydrogen desorption/absorption cycle. Samples milled for less than 5 minutes retain Ti3+. For samples milled for 1 minute, the Ti-K edge position shifts from Ti3+ to Ti0 after a single desorption/absorption cycle. However, the first coordination sphere around the Ti0 absorber occurs at longer distances for 1 minute milled sample. These results hint at the formation of Ti0 pure metallic clusters upon desorption/adsorption cycling of 1 minute milled sample. Previously reported x-ray absorption spectroscopy studies have demonstrated the structural transition from Ti3+ (in TiCl3) to Ti0(determined to be TiAl3 found at the surface of the alanate powder). Aluminum deficiency on the NaAlH4 lattice is responsible for controlling hydrogen absorption capacity. These time-resolved spectroscopy studies suggest the possibility for controlling aluminum deficiency, while still maintaining titanium activation of the alanate powder, by manipulating the coordination environment of the titanium dopant during the first five minutes of high energy milling. Specifically, a possible approach to mitigating aluminum deficiency during doping would be to introduce an alternative species to which the to Ti3+ catalyst would form a metallic bond after the TiCl3 has attached at the surface of the sodium alanate powder and before the Ti3+ forms the TiAl3 intermetallic species.

Jan 1, 2006

By Ryszard Prajsnar

During copper production in shaft and flash smelting processes at KGHM Polska Miedz S.A., lead bearing material of sulfide, sulfate, and oxide character is generated in forms such as slime from shaft furnace gas handling systems, converter dusts, and dusts from an electric furnace for copper removal from flash smelting slag. These materials are polymetallic concentrates of Pb, Zn, and Cu, with As, Cl, and Cd as impurities. Shaft furnace slime, containing. about 50% PbS and 15% bituminous substances, is the main lead-bearing material. At the Glogów copper mill, a new plant was commissioned in June 2001 to process 80,000 tonnes per year of lead bearing materials to produce 26,000 tonnes per year of crude lead. The plant consists of a feed conditioning system, three (3) rotary rocking furnaces with a capacity of sixteen (16) tonnes of lead feed fired with natural gas and oxygen-enriched air containing up to 45 vol% O2, and a gas handling system. The gas handling system includes a post-combustion chamber, a gas cooling chamber with Cl neutralization, gas mixing chamber, bag filter, and dry limestone scrubbing system for SO2 removal. The lead-bearing feed is smelted with five (5) wt% Na2CO3 and thirteen (13) wt% iron scrap at a temperature of 950 to 1050°C for three (3) hours. The smelting process consists of four (4) stages; feed drying, firing of gaseous hydrocarbons and solid coal from the feed, lead reduction from slag, and separation of molten products. The flow rates of natural gas and oxygen to the burners are controlled to ensure combustion of the bituminous material in the furnace. The process produces crude lead bullion containing (wt%) 0.1 to 0.5% Cu, 0.02 to 0.5% As, 0.05 to 0.07% Bi, 0.1 to 0.5% Sb, and 0.1 to 0.6%Sn. The process also produces a mixture of sodium silicate slag, Fe-Zn-Pb-Cu-S matte, and Fe-As speiss containing (wt%) 5 to 10% Pb, 2 to 6% Cu, 10 to 15% Zn, 1 to 3% As, 10 to 15% S, 0.5 to 3.0% Cl, 2 to 4% K, 4 to 7% Na, 20 to 30% Fe, and 5 to 10% SiO2. The dust is made up of PbO, ZnO, PbSO4, and PbCI2, KCI, and NaCI with a chemical composition (wt%) of 35 to 50% Pb, 5 to 15% Zn, 3 to 6% As, 4 to 8% Cl, 2 to 5% K, and 2 to 5% Na. The construction of the new lead production plant at the Glogów copper mill will process both current lead-bearing materials as well as lead-bearing material that have been stockpiled over the last fifteen (15) years to give a significant improvement in protection of the natural environment.

Jan 1, 2002