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By J. N. Hryn

This paper describes some of the work done in Phase 1 of a multi-year, five-phase program aimed at demonstrating the economic feasibility of producing commercial-scale quantities of commodity materials derived from salt cake residue-oxide. The amount of salt cake generated annually in the U. S. is estimated to be 510,000 tons, including 340,000 tons of residue-oxide. Used beverage can (UBC) processing accounts for the majority of residue-oxiae that could be made available for further processing into commercial products. To characterize the composition of residue-oxide. eight residue-oxide samples from various secondary processors were obtained and analyzed. Surprisingly, the composition of residue-oxide was found to be independent of source or alloy family being processed, with? the exception of slightly elevated silicon levels in 3XXand UBC residue-oxide samples. Major phases detected in the residue- oxide were? alumina, spinel, and aluminum hydroxides. Preliminary economic analyses indicated that the refractory market appears to be the best choice for high value-added products produced from residue-oxide with minimum processing. Bench-scale tests indicated that low silicon containing residue-oxide is ready to enter this market, but the elevated silicon content of UBC and 3XX residue-oxide preclude this possibility. A separation technology should 'be developed to remove silicon-containing . species from the alumina and spinel values Present in residue-oxide. This technology would then allow UBC and 3XX residue-oxides to be converted to significantly higher value-added products.

Jan 1, 1995

By Michael Heximer, Dominic Verfielst, Timothy Moore

"Teck's Trail Operations recently installed new pressure filters in the cold stage purification step in the zinc leaching plant. Alloy 2205 duplex stainless steel was chosen as the material of construction as it was in use in the hot stage purification operation. Within a year of commissioning, an unacceptably high rate (greater than 1 mm/y) of corrosion was observed on the weld heat affected zone (HAZ). Laboratory and field tests were conducted to establish the conditions under which the corrosion was occurring. The tests isolated the aggressive conditions to a unique combination of materials present during the filter regeneration stage. Furthermore, the change of the duplex grain structure of the alloy during welding resulted in the HAZ being more susceptible to the corrosive environment. A new material of construction was recommended as a result of the investigation.IntroductionThe sulphide leaching plant uses four horizontal tank pressure leaf filters to remove solids precipitated in the cold stage electrolyte purification process. The current filters were installed in 2007, and replaced a bank of filter presses. The material of construction for the filters - alloy 2205 duplex stainless steel - was selected based on its successful use in similar service areas of the leaching plant. However, within the first year, unexpected and rapid corrosion of the filter tank material was observed. Although moderate general corrosion was noted throughout the filters, the attack was particularly aggressive in the areas where intense heat was applied during fabrication, observed at the HAZs caused by welding, and on the exposed edge grain of the duplex plates. On the inaugural annual inspection of the filters in the first year of operation, a corrosion penetration rate of 1.0 to 1.5 mm/y was observed at the HAZs. The parent plate of the pressure tank was a minimum of 6 mm, with a minimum allowable thickness of 3 mm under the ASME pressure tank design rules. Therefore, the projected useful life of the filters could then be roughly calculated to be two to three years. Urgent action was required to understand and correct this problem."

Jan 1, 2012

By Guo Xueyi

The reaction mechanism for the manganese dioxide reductive dissolution in acidic chloride media in the presence of ferrous/ferric ions are based on theoretical delineation and dual cell experiments. In terms of the Buttler-Volmer equation and chemical kinetic principles, a electrochemical kinetic equation was deduced, which successfully provided a theoretical basis for describing the role of Cl-, Fe2+, Fe3+ and H+ in solution, as well as their interrelationship in manganese dioxide reductive dissolution. Dual cell experimental studies indicate that the increases of Cl- and Fe2 in solution are helpful to accelerate the couple process; while, Fe3and Mn2+ hinder the coupled reaction to some degree. Higher acidity in solution is beneficial to the dissolution of MnO2. All the dual cell experimental results are consistent with the theoretical deduction. This study will be useful to understand the mechanism for the leaching of manganese nodules from the deep ocean, as well as the leaching of manganese dioxide ore from land.

Jan 1, 2003

By Corby Anderson

The efficient separation of palladium from the transition metals copper, nickel and iron can be effected by passing a leach solution of these metals through a column of the silica polyamine composite material, WP-1, patented by Purity Systems Inc (PSI), Assignee, University of Montana with exclusive license to PSI. The separation can be done at the intrinsic pH of a nitrogen species catalyzed (NSC) oxidative pressure leach solution (~0) and stripping of the palladium from the composite can be effected with hydrochloric acid/ammonium chloride solutions at 50oC. Batch capacities of the composite for palladium are ~ 1.8 mmol/g resin. The possibilities for isolating the metal from the strip are discussed. Given the proven longevity and rapid capture kinetics of the polyamine composites, this new approach should prove to be an economically viable alternative to the multi-step concentration processes practiced in the PGM industry to date.

Jan 1, 2003

By Dan Wang, Qian Xu, Guangshi Li, Xionggang Lu, Xingli Zou, Zhongfu Zhou, Hongwei Cheng, Changyuan Lu

The preoxidation of the ore has a profound significance to the concentration, separation and purification of nickel and copper from the lean complex ore. In this paper, the natural Ni-Cu sulfide mineral samples under the elevated temperature condition in air were investigated, as well as under isothermal condition at 600 oC in air. The mineralogical characterization was studied using XRF, ICP and the Rietveld method. The oxidation behavior and the element migration of the Ni-Cu sulfide ore were studied by XRD, SEM-EDS and TG. The XRD Rietveld method was successfully developed in the phase identification and quantification of this complex ore powder sample. The oxidative intermediates (Cu/Ni-ferrite) were detected by XRD, and the process of the element migration was obviously revealed by the line scans using SEM-EDS. It is the preoxidation of this mineral that provides guidance for the extraction of valuable metals from low-grade Ni-Cu sulfide ores in the future.

Jan 1, 2015

By W. G. Davenport

Chapter 6 examined autotherrnal smelting of pure chalcopyrite concentrate with 50 mass% O2-50 mass% N2 blast. It showed that production of 1500 K products with this blast requires: 181 kg of pure oxygen 337 kg of air per tonne, of concentrate. It also showed that the grade of matte produced with this blast is 58% Cu. This chapter re-examines autotherrnal smelting by asking: (A) WHAT COMPOSITION BLAST (MASS% 02 -MASS% N2), 298 K, WILL AUTOTHERMALL Y PRODUCE 65% Cu MATTE 1500 K FROM PURE CHALCOPYRITE CONCENTRATE? (B) HOW MUCH PURE OXYGEN AND AIR WILL BE NEEDED? These are important questions for flash? smelting because furnace operators usually want to send specific composition matte to converting. This chapter shows how a specified matte can be produced autotherrnally with 298 K oxygen-air blast. Later chapters show how it can be done with hot blast, hydrocarbon combustion, different concentrates etc.

Jan 1, 2001

By Elli Nurminen

Sulphate decomposition was studied in the conditions of a typical copper flash smelting heat recovery boiler. The aim was to determine the kinetics of the copper sulphate decomposition reactions and to find out if they are likely to take place in the process conditions prevailing in an industrial HRB. The information is essential in CFD-modelling of the reactions taking place in the boiler and for optimising the process. Thermal decomposition of sulphates was studied by thermogravimetry. The experiments were conducted with a commercial copper sulphate, a partially sulphated copper oxide and an actual process flue dust. The main variables studied were temperature and gas composition of a N2-O2-SO2-mixture. The samples were characterized with SEM, optical microscope and XRD. Temperature affected the decomposition rate strongly but the gas composition had a minor effect on the kinetics. The decomposition was fastest in the partly sulphated oxide and slowest in commercial copper sulphate. Keywords: Sulphate decomposition, flash smelting, heat recovery boiler, flue dust

Jan 1, 2004

By E. Açma

In this study, the production of Cu, Co, and magnetic iron oxide from the ancient copper, slags, located in Küre-Turkey, is investigated. In the process under development, fayalitic slags containing 1% Cu, 0.43% Co are reduced in a D.C. arc furnace with coke or graphite additions. A metallic alloy, consisting of 3.8% Cu, 3.3% Co, 2.1% S, and the rest being Ice, is produced by granulation of the liquid metal. About 85% recoveries of Cu and C:o are achieved by hot sulfuric acid leaching of these granules followed by H2S precipitation. The, production of magnetic iron oxide is possible from the discarded leach solution, loaded v:ith FeS04, by using a method with geothite precipitation, dehydration, controlled reduction, and re-oxidation steps. The magnetic oxides produced have 20 m2Jg surface area, 1:8.3 aspect ratio, and the coercivity of 330-380 Oersted.

Jan 1, 1993

By Lin Yang, Yuanbo Zhang, Zhuoxuan Li, Guanghui Li, Jinghua Zeng, Tao Jiang

A technique has been proposed for recovering iron from hematite-rich diasporic-type bauxite ore in this study. Direct reduction roasting followed by low intensity wet magnetic separation process was carried out. The parameters including reduction temperature and time, sodium salts, grinding conditions and magnetic field intensity for separation of iron were determined. The optimum process parameters as follows: roasting temperature of 1050 oC, time of 60 min, sodium salts involving sodium sulfate, borax, sodium carbonate with dosages of 10 wt%, 2 wt%, 35 wt% respectively, and magnetic field intensity of 1000 Gs with fineness of pulp reached 92.75% passing -0.074mm. Under the optimal conditions, an iron concentrate containing 88.17% total iron grade and iron recovery of 92.51% was obtained, 4.55% total iron grade in tailings. This novel technique provide a potential route for utilizing hematiterich diasporic bauxite ore, recovering iron resource firstly, and extracting alumina from magnetic separation tailings further.

Jan 1, 2015

By Mao Chen, Baojun Zhao, Zhixiang Cui

Bottom blown oxygen copper smelting process, operated at high grade matte (up to 75 wt% Cu) with relatively low (2-3 wt%) Cu in slag, has been commercialized for more than five years at Dongying Fangyuan Nonferrous Metals CO., Ltd. Quenched slag and matte samples have been collected at different operating conditions while the slag temperature was measured by thermocouple. The samples were analysed by X-ray Fluorescence and Electron Probe X-ray Microanalysis. FactSage computational software was used to explain the observations of the industrial samples. The analyses show that the copper loss was closely related to the operation parameters. The Fe/SiO2 in slag and temperature determine the solid proportion, which significantly affects the physical entrained and also chemically dissolved copper in the slag. The present study will be useful in understanding the slag chemistry of bottom blown copper smelting furnace and in optimization of the operating conditions to lower Cu loss in the slag.

Jan 1, 2015

By Mike Dry

While McCabe-Thiele plots are useful for designing single-component solvent extraction systems, not least because of their simplicity, they are less useful for multi-component solvent extraction. This paper presents a relatively simple method, compared to other approaches, for modelling solvent extraction as chemical equilibrium reactions between the various aqueous and organic species. The essence of this approach is how values for the equilibrium constants can be extracted from standard laboratory data. Synergistic solvent extraction of nickel is used to illustrate the method.

By A. Navarra

Within conventional copper and nickel-copper sulfide smelters, ladles of molten matte are fed into converters. These converters blast oxygen-enriched air into the matte, thereby eliminating iron and sulfur. The converting reactions are exothermic and, indeed, the converter heat balance is often a limiting consideration on the smelter throughput. If a portion of the matte were fed in solidified (granulated) form, this would support higher oxygen enrichment, and lower volumes of converter offgas, allowing higher throughput. This approach is not applied in conventional smelters, partly because of the copious amounts of water that must be evaporated in typical granulators, as in the Kennecott-Outotec process. The current paper recalls a waterless matte granulator that had been pioneered in the 1990’s, and is applicable to conventional smelters. A mathematical formulation is presented that can be used in the context of simulation-based optimization, to estimate the size and impact of waterless matte granulation.

By A. J. Rigby

Current practices employing porous plugs to inject nitrogen into molten copper during primary smelting are described. Nitrogen stirring increases heat transfer to the bath, eliminates temperature stratifications, and improves efficiency during the steps of desulfurization and deoxidation. The opportunity to use porous plugs as the means to introduce reducing gases to deoxidize copper is also discussed. Previously reported laboratory results using porous plugs, which point to very high utilization efficiencies of hydrogen when used as the reducing gas, are again reviewed. Advances in the design of the porous plug, and the introduction of a system enabling external replacement of plugs is also discussed.

Jan 1, 1999

By Jun Li

Several metal sulfides were examined in-situ by Raman spectroscopy before and after anodic oxidation. Results obtained for chalcocite, chalcopyrite, covellite, galena, pyrrhotite and pyrite electrodes are presented. Under appropriate conditions, sulfur was detected after a potential was applied to the mineral electrodes for a threshold period of time. For all the minerals, application of a negative potential on the oxidized mineral reduced the surface product and the sulfur peaks disappeared from the observed spectra. For those minerals containing sulfur as S< in the crystal lattice, polysulfides were identified as oxidation intennediates.

Jan 1, 1993

By Seung-Chul Lee

Transparent conducting tin(1V) oxide thin films have been studies and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process condition and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.18-cm and the transmittance is higher than 90% in a visible range.

Jan 1, 1999

By Jörg Wallner

In order to limit SO2 emissions, the Montanwerke Brixlegg AG has installed a desulphurisation plant with the primary aim of reducing the peak emissions from the copper converter that are of particular ecological concern. The author discusses the process requirements, the desulphurisation process selected and the results achieved.

Jan 1, 1996

By K.H. Song, H.T. Son, H.S. Kim, W.Y. Kim

In order to evaluate the grain refining and mechanical properties due to severe plastic deformation (SPD), this wrok was carried out. Convential rolling (CR) and cross roll rolling (CRR) as a SPD method were introduced, and NI-20Cr alloy as an experimental material was chosen. The materials were cold rolledto 90% in thickness reduction ans subsequently annealed at 700oC for 30 min to obtain the fully recrystallized microstructure. For annealed materials after cold rolling, electron back-scattered diffraction (EBSD) analysis was carried out to investigate the grain boundary characteristic distributions (GBCDs). CRR process was more effective to develope the grain refinement relative to CR process, as a result, grain size was refined from 70 um in initial material to 4.2 um (CR) and 2.4 um (CRR), respectively. These grain refinements directly affect the mechanical properties improvement, in which microhardness and yield and tensile strengths were significantly increased than those of initial meterial.

Jan 1, 2012

By James R. Myers

A source of clean gas containing sulfur dioxide and sufficient oxygen for convers.ion to sulfur trioxide ?is essential to the production of sulfuric acid. S02 containing gases obtained from roasting sulfide ores are heavily contaminated with inorganic dust and volatile impurities. If not removed, these contaminants will reduce product acid quality, foul the catalyst beds and mist eliminators, and accelerate equipment corrosion. This paper reviews conventional gas cleaning systems for metallurgical acid plants, followed by a discussion of modern systems utilizing DynaWave Scrubber technology. This technology is based on a unique approach to? gas scrubbing that can concurrently accomplish several gas cleaning/processing tasks scrubbing liquid is injected into the gas stream to create. a "Froth Zone". This is a region of extreme turbulence, with a very high rate of liquid .surface renewal. It efficiently removes both particulate matter and gas contaminants, and is also a cost effective quenching device for gases as hot as 1250º C. Smelter

Jan 1, 1992

By Donald I. Bleiwas

World primary nickel production in 1987 is projected to be 770,000 mt, slightly higher than that in 1986. Market economy country (MEC) production in 1987 is projected to be about 524,000 mt, an increase of almost 5 pct over 1986 production. Production cutbacks and closures at Japanese ferronickel plants in 1987 resulted primarily from the strong yen and higher energy prices. Cutbacks also caused reductions in ore production from Indonesia, New Caledonia, and the Philippines. Technical problems affected production, to varying degrees, in Botswana, Indonesia, and Yugoslavia. World primary nickel production for 1988 is projected to be 787,000 mt, of which 536,000 mt will be produced in MECs. Increased production is projected from Botswana, Canada, Cuba, and possibly Greece and Yugoslavia, while slight production decreases are projected for Indonesia, New Caledonia, the Philippines, and Zimbabwe. .. South African nickel production in 1988 could be severly curtailed by social strife. In the early 1990&apos;s Brazil and China could be major economic competitors to Western nickel producers.

Jan 1, 1988

By P. A. Botha

The coal seams in the Waterberg basin occur in correlates of the Vryheid and Volksrust Formations as developed in the main Karoo basin. In the Vryheid Formation, five thick seams of predominantly dull coal are present, whereas a multitude of thin, lenticular seams (a few millimetres to 2 metres}, predominantly of bright coal, are developed in the overlying Grootegeluk Formation. During exploration, the coal seams were divided into 11 zones. Analytical data on float and middlings fractions (RD less than 1.40 and between 140 and 1.80, respectively} were used mainly for stratigraphic correlation of the zones in the Grootegeluk Formation. The affinities of the major and trace elements for different mineral phases and/or organic material are discussed on the basis of correlation matrices and vertical variation diagrams. Titanium and vanadium clearly show some degree of organic affinity. P 205&apos; AI203 and alkaline-earth elements are also positively correlated by the presence of goyazite in the coal. This type of investigation gives an indication of the degree to which undesirable elements like P and S can be removed during coal beneficiation, of which coal zones are unsuitable for the production of metallurgical coal on account of a high content of these elements, and to what extent the blending of different coal zones is required to keep the concentration of these elements within acceptable limits.

Jan 1, 1991