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By Józef Czernecki

Chalcocite-bornite concentrates of KGHM contain, similarly to chalcopyrite concentrates, 20-30 wt.% Cu but several times less iron (2-7 wt.%) and sulphur (9-12 wt.%). Another useful characteristic of KGHM concentrates is the presence of organic carbon (5.5-8.5 wt.%) in them, which serves as fuel in the flash smelting process. The main contaminants of the concentrates are lead (1.3-2.5 wt.%) and arsenic (0.05-0.4 wt.%) which require appropriate technological treatment in order to remove them from the copper pro-duct. Chalcocite-bornite concentrates are processed in KGHM by two different processes: ? a flash smelting process (Glogow 2 Smelter) ? a shaft smelting process (Glogow 1 Smelter, Legnica Smelter) The shaft smelting process used in the Glogow 1 Smelter and in the Legnica Smelter has higher production costs than the flash smelting process of HM Glogow 2. Additionally, the shaft smelting process employs several concurrently running installations (six dryers, seven briquetting lines, six shaft furnaces, nine converters), the operation of which, including maintenance, requires significant financial expenditure. Therefore, the Company is currently considering the substitution of the shaft furnace process in the Glogow 1 Smelter and in the Legnica Smelter by the one stage flash smelting process located in the Glogow Smelter, with output equaling the copper production capacity of both smelters, i.e. 320 000 ? 350 000 t/a. There are two technological options being considered which differ from each other in their man-ner of flash slag cleaning. In the first, the slag cleaning would be the same as in the existing Glogow 2 Smelter, i.e. the slag would be cleaned by pyrometallurgical reduction of the oxide copper and other metal compounds in the electric furnace in order to produce waste slag containing below 0.6 wt.% Cu. However, the other option of the flash slag cleaning would be carried out in two stages. After preliminary slag reduction in the electric furnace to 3-5 wt.% Cu, there would be flotation of the partially reduced slag.

Jan 1, 2006

By M. F. Hochella

Transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) analysis have been used to study the mode of occurrence and mineral associations of gold in partially oxidized high grade gold ore from the Carlin sediment-hosted deposit. Rounded.gold particles have been observed that range in size from 0.03 to 0.1 p.m (300 to 1000 A) in diameter. The gold is associated with maghemite h-Fep3l and a K-Al-Si-bearing phase that is suspected to be illite. Detailed descriptions of gold and its mineral associations in 'Carlin-type' gold deposits are critical not only to understanding the mechanism of fluid transport and precipitation of gold, but also to developing improved metallurgical techniques for the recovery of gold from refractory ore. Direct observation of gold in unoxidized ore is rare due to its relatively high degree of dissemination and low average bulk concentration which averages 9 ppm according to Radtke (1). Hausen and Kerr (2) observed 1 to 5 p.m grains of gold directly in oxidized ore but these microscopically visible particles account for only a small percentage of gold present in the ore. The samples used in this study were selected from individual beds of high grade, partially oxidized ore (4.55 oz/ton or 156 ppm gold) that were collected in the Main pit of the Carlin mine. The samples were collected from several thinly laminated carbonate micrite beds within the top 50 meters of the Roberts Mountains Formation. The carbonate micrite has been altered by hydrothermal fluids to a calcite-absent, moderately silicified rock referred to as alteration zone #3 by Bakken and Einaudi (3). Based on petrographic and SEM studies, the samples contain carbonaceous matter, and both pyrite and iron oxide pseudomorphs after pyrite. The oxidation of pyrite may be a pro-duct of deep weathering, in which case limited remobilization of gold may have occurred. TEM sections of the rock were prepared by first embedding small chips in low viscosity epoxy. The epoxy blocks were cut with a Reichert Ultracut E ultramicrotome, producing thin sections less than 0.1 p.m thick. The sections were examined with a Phil-lips 400ST TEM at 120 keV in both imaging and selected area diffraction modes. Native golci*was easily detected in TEM bright field images due to the large electron density contrast between gold and all other phases that are present (Figs. 1 and 2), Gold was positively identified with high spatial resolution EDX analysis in the transmission electron microscope, although selected area diffraction of individual grains was not successful EDX analyses of the platy and massive minerals immediately surrounding the gold particles typically indicate the presence of Si, AI, K, and Fe, However, the d-spacings derived from selected area diffraction of these polycrystalline masses (as, for example, in Fig. 2) give an exact match for maghemite. As a result, there is no diffraction information to identify the K-AI-Si-bearing phase(s). The lack of a diffraction pattern could be due to either electron beam damage or to a poorly crystalline phase(s).

Jan 1, 1987

By Guodong Lai, Shixing Wang, Lijuan Chu, Jinhui Peng, Zebiao Zhang

"The beneficiation of poor manganese ores containing phosphate gangue is very difficult by conventional processes, because of the similarities in the physico-chemical properties of the constituent minerals. The shaking table gravity concentration process and concentrated strong acid selective intensified leaching process were used for dephosphorisation of Yunnan manganese ore. The leaching process was effective. The effects of intensified leaching time, solid-liquid ratio and particle size were investigated. The relevant leaching factors were optimized as -0.125+0.088 mm particle size with 68% nitric acid for 24 h when using a solid-liquid ratio of 1:1 at room temperature and atmospheric pressure. Under these conditions, the P/Mn ratio was reduced from 0.0107 to 0.0056, and the grade of manganese was increased from 12.32% to 42.76%. The dissolution of manganese during leaching was negligible.IntroductionManganese and its compounds are widely used in the iron and steel industry as deoxidation and desulfurization agents and as alloying additives [1-2]. Because of the increase in demand, low grade refractory manganese ores are becoming a new source. Many Chinese manganese ores are high in phosphorus, which cannot be used directly for metallurgical purposes. This occurs because phosphorus enters into the metal phase during smelting and its presence sharply deteriorates the mechanical properties of the metal [3-4].Kanungo and Sant [3] investigated the dephosphorization of phosphorus-rich manganese ores by selective leaching with dilute hydrochloric acid. They observed that leaching with dilute hydrochloric acid (0.1-0.6M) could reduce the phosphorus contents to the specified limit of 0.12%. Ye [5] investigated dephosphorization of high-phosphorus manganese ore of the Huayuan type. Using high intensity magnetic separation, roasting and leaching with acid for dephosphorization, as used in the industry, a 40.15% manganese concentrate with a P/Mn ratio of 0.0037 was obtained. Yimin [6] investigated magnetic separation followed by inverse flotation of high-phosphorus manganese ore, and found that the P/Mn ratio could be reduced from 0.046 to 0.002."

Jan 1, 2012

By Dan Wang, Qian Li, Yong-bin Yang, Tao Jiang

"Thiosulfate is one of the most promising non-cyanide lixiviants for gold leaching. However, the undesirable reaction between thiosulfate and copper (II) gives rise to increased reagent consumption, which results in high cost and huge limit to its development. This paper presents study on the effect of ammonia, copper (II) and Cu(NH3)l+ ions on the oxidative decomposition of thioulfate. It shows that the presence of copper (II) and Cu(NH3)l+ can significantly increase the thiosulfate oxidation, while ammonia is relatively unaffected. The oxidation of thiosulfate by copper(II) in the absence of ammonia is fast at first and then decreases as time increased within a certain time, which can postulate that an intermediate product is responsible for the decreased consumption. The effect of ammonia is depended on the interaction with copper (II), which was found to significantly affect the consumption of thiosulfate.IntroductionFor over one century cyanidation is widely used in industrial production of gold, due to its simplity of process and low cost of production. However, cyanide is a highly toxic chemical reagent used dangerously and brings serious environmental pollution. What's more, cyanidation has slow speed of leaching gold and poorly leaching effective for refractory ores. With the exhausting of free-milling gold ores and promoted environmental protection requests, the disadvantage of cyanidation becomes a growing problem. In recent years, more and more research activities have been focused on alternative processes using non-cyanide lixiviants. Among the non-cyanide lixiviants, thiosulfate is considered as the most promising one[l-5].Compared to cyanide, thiosulfate is an inexpensive, nontoxic and less-pollution reagent, which can form complexes with many metal ions. Thiosulfate leaching of gold has an acceptable leaching rate and is insensitivity to impurities. Moreover it presents advantage on the treatment of refractory gold ores such as carbonaceous gold ores, copper gold ores, complex arsenic and sulfur gold ores, and so on[6]."

Jan 1, 2013

By A. Lackner

Using the CFD software package FIRE, the smelting process inside a cyclone reactor is modelled. The fluid flow is calculated 3 dim., using different turbulence models. The effects of design parameters (length and diameter of the cyclone, concentrate feeding tangentially or from the top,..) and operating conditions are investigated. Single particle traces illustrate how to increase particle retention time before the particles reach the liquid film flowing down the cyclone wall. Moreover a two phase flow approach is developed, based on the "Discrete Droplet Model". The position, velocity, diameter and temperature of each reacting particle is described. The results show the advantages of top concentrate feeding, large height/width ratio of the tuyeres and increasing number of tangentially gas inlets.

Jan 1, 1995

By Yong Xian, Zhaohui Sun, Honggang Zhong, Qijie Zhai, Jie Sun

Vacuum refining is admitted as an effective means to remove impurities in the process of alloy smelting. In this paper, Orthogonal and single factor experiments were carried out to investigate effects of multiple factors, such as superheat degree of the melt, degassing time and vacuum degree, on the vacuum refining process. The results showed that the best removal rate of oxygen and nitrogen is up to 82.71% and 61.3%, respectively, due to high vacuum degassing efficiency. It is found that the superheat degree is minimal impact on the deoxidization rate, in addition, nitrogen removal is controlled by the degassing time. The inclusions exist in the AlV55 alloy are mainly composed of oxides and vanadium-nitrogen compounds.

Jan 1, 2015

By John Snowberger III, J. Brent Hiskey

The electrochemical dissolution of super alloys containing different amounts of rhenium was investigated. The initial part of the investigation focused on the anodic dissolution of rhenium from second-generation (3% Re) and third-generation (6% Re) nickel based alloys. Exploratory electrochemical tests were conducted to evaluate solution chemistries and to establish fundamental dissolution behavior of the alloys. These included rotating disc electrode (RDE) cyclic voltammetry, linear sweep voltammetry, and chronoamperometry tests. Electrolytes comprising sulfuric acid, hydrochloric acid, and ammonium sulfate were examined. Of these, a 0.1 M HCl solution proved to be extremely effective for electrochemical dissolution of samples of CMSX-4, CMSX-10, and SC-180 alloys. This paper discusses in detail the electrochemical behavior of these alloys.

Jan 1, 2014

By Jiao Li, WenhuiMa, KuixianWei, YongnianDai, Cong Zhang

The paper studied the diffusion process of nitrogen and characteristic distribution of iron impurities in the bottom of cast crystalline silicon ingot along the direction of crystal growth. According to the dynamics analysis of the decomposition of Si3N4 coating, the diffusion process of nitrogen into multicrystalline silicon ingot during casting process should be divided into three steps. The diffusion length of nitrogen in multicrystalline silicon ingot is 700 μm. The results of EDS analysis indicate that the distribution characteristic of iron in multicrystalline silicon ingot is concerned with the diffusion process of nitrogen in this length. Based on the above research results, the distribution model of iron in casting multicrystalline silicon ingot was established and verified by the experimental results.

Jan 1, 2015

By Richard D. Hagni

Ore microscopy is a useful technique to detect and study the ore minerals that are associated with sediment-hosted and volcanic-hosted deposits of finely disseminated gold and silver. Ore microscopy can be used to determine the: 1) precious metal-bearing minerals in some ores, 2) associated ore minerals that may form geochemical exploration halos, 3) character of iron sulfide grains, 4) extent of sulfide oxidation, 5) character of oxidized iron minerals, 6) character of original sulfide grains from a study of the hypogene and supergene oxidized ores, 7) relative time of oxidation, 8) character of organic matter, 9) minerals that may consume excessive amounts of cyanide solution, 10) extent of silicification and silica encapsulation, and 11) possibility of salting.

Jan 1, 1987

By Ying-Chu Hoh

The extraction of cerium(IV) by valence change with two-phase electrolysis was studied experimentally. The results show that the electro-oxidation extraction depends mainly on the distribution of the solute between the two phases, the reaction on the electrode surface and the diffusion of the reactant and product between the electrode and aqueous interphases. The effects of various parameters on cerium extraction were also studied. The selected parameters were background current, catholyte acidity, agitation speed, operation current and voltage and surfactant addition. The electro-oxidation extraction mechanism can be divided into eight steps. In addition, Wee the rate of extraction is quite fast, the percentage extraction Ce+4 can be taken as an index to show the conversion rate of Ce+3 J to Ce+4.

Jan 1, 1989

By Jeff M. Kuhn

A new solvent extraction process for the removal of halides from zinc sulphate solution was tested in pilot plants at both a 0.1-L/min scale and at a 3-L/min scale. Teck Cominco?s process is called the HalogonTM process, for which patents are pending. Mixer-settlers were used for the 0.1-L/min pilot scale and two BATEMAN pulsed columns for the higher rates. Pilot testing was performed with commercial zinc sulphate solutions containing variable amounts of chloride and fluoride. Sulphate extraction was also controlled and deleterious halides were loaded and stripped into a form suitable for disposal. The engineering aspects and economics of this solvent extraction process for halide removal are also reported.

Jan 1, 2003

By J. Shibata

The recovery process of valuable metals, such as Ll, Mn, Ni and Cr from a waste lithium battery was developed n this study. Lithium and Mn are selectively leached from the battery by using dilute mineral acid. Main part of the battery comprises stainless steel, and Fe, Ni and Cr are easily leached by the mixture of dilute HCl and HNO3 Lithium and Mn are precipitated as metal carbonates from the? individual leached solution with sodium carbonate solution. The solution containing Fe,Ni and Cr Is treated by solvent extraction to separate NI and Cr from the leached solution. The experiments are carried out for leaching and separation steps. According to the experimental results, the flow. sheet for a recovery process of valuable metals from a waste lithium battery has been established.

Jan 1, 1995

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 Saskia Duyvesteyn

Ion flotation is a technique applicable to the removal of metal ions from dilute solutions, using ionic surfactants.- While there are a number of physical and chemical parameters that influence the ion flotation process, this paper focuses on two of the important chemical ones, namely frother concentration and ionic strength. The effect of several frothers, including ethanol, iso-propanol and MIBC at concentrations ranging from 0% to 0.4%, was studied for the model Cd-dodecylsulfate and Cu-dodecylsulfate systems. The ionic strength, as well as the effect of monovalent and multivalent counter ions, was also studied in the range of 1@3 - 1 M, at constant pH. The results are discussed in terms of applicability to a range of effluents from minerals and materials processing operations.

Jan 1, 1994

By F. G. Prado

The technology for the extraction of zinc from zinc residues, such as zinc ashes, drosses and metallurgical flue dusts, by way of ammonium chloride solutions is well established, at least at the laboratory and bench scale levels. (3, 4) Zinc is soluble in ammonium chloride solutions in the form of zinc diammine chloride. Its solubility depends upon the concentrations and temperatures employed. The procedure and the equipment required are simple, and they can be applied either to small or large operations. As a by-product, zinc diammine chloride is produced with extremely low impurities in quantities which are stoichiometrically proportional to the zinc removed. The technology has been applied experimentally to galvanized steel residues. The dezincing results, including removal performance, energy and reagents required, and by-products are summarily presented in this paper.

Jan 1, 1992

By Metehan Erdogan, Furkan Özdemir, Ishak Karakaya, Mustafa Elmadaglı

Tungsten is mainly produced by H2 reduction of WO3 which makes its production difficult and costly. A promising method was recently reported for direct electrochemical production of tungsten from CaWO4 (scheelite) which is estimated as the seventy percent of the all tungsten reserves of the world. This paper investigates the application of pulse current in the electrochemical reduction of CaWO4 pellets attached to a current collector. The electrolyte was composed of calcium chloride and sodium chloride salts at eutectic composition (48 pct mol NaCl at 873 K). The reduced samples were cleaned with dilute hydrochloric acid solutions and characterized by X-ray diffraction and scanning electron microscopy. Examination of the results revealed that metallic tungsten was obtained by pulse current reduction.

Jan 1, 2016

By O. Kitamura, H. Kubota

The Harima Works started its ISP operation in 1966 and been expanding its production capacity from 3,000 tonne Zn/month and 1,500 tonne Pb/month to 7,500 tonne Zn/month and 2,500 tonne Pb/month. It is not only treating zinc, lead and bulk concentrates but also secondary materials like Waelz kiln oxide from the Shisaka Works of Sumitomo Metal Mining, waste treatment sludges, industrial wastes and others. Its final products cover Prime Western Grade (PWG) zinc, Special High Grade (SHG) zinc, continuous galvanizing grade zinc, electrolytic lead, cadmium, indium, thallium and sulfuric acid. This paper briefly describes the smelter's historical and present operations. The key data for the current impurity control management and for the distribution of impurities such as copper, iron and arsenic are presented.

Jan 1, 2000

By K. Gao, R. Dry

"Carbon boil, which results in excessive spitting and even complete destruction of a metal drop, could significantly influence the efficiency of direct smelting processes. Carbon boil has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure, and melt area/volume ratio. The time of carbon boil was determined using a CCO camera coupled with a time/date generator connected in parallel to a video recorder and a computer. The time of carbon boil was in the range ~5 - 15 seconds under the conditions in this study. A mechanism for carbon boil has been proposed.IntroductionThe occurrence of carbon boil in molten iron drops can result in excessive spitting and sometimes even complete destruction of a metal drop. In direct iron smelting processes, this could significantly influence the decarburisation of liquid metal and the post combustion and hence may influence the efficiency of smelting processes. The generation and consequent ejection of metal droplets into the gas phase occurs due to the intense turbulence in the bath which results from the injection of gases and coal. The aim of this investigation is to understand the fundamentals governing the carbon boil phenomenon under direct iron smelting conditions to assist control of process efficiency.Carbon boil phenomenon has been studied as a function of some key parameters such as melt sulfur content, oxygen partial pressure and melt area/volume ratio. The time for the occurrence of carbon boil has been determined in this study at 1440 °C using a novel approach which includes utilisation of a CCD camera coupled with a time/date generator connected in parallel to a video recorder and a computer. This arrangement permits the capture of the entire sequence of events leading up to carbon boil and therefore the determination of time of boil which is in the range -5 - 15 seconds under the conditions in this study."

Jan 1, 1996

By Munyaradzi Kwatara, Ron Schonewille, Edgar Peek, Juzer Tayabally

"The potential recovery of nickel from a South-American saprolitic laterite ore using the segregation roasting technique was investigated. The ore was heated to temperatures that ranged between 900 and 1 000°C in a rotary kiln. In all the tests, the laterite ore was first mixed with a predetermined amount of calcium chloride and either coal or coke. By varying the temperature, calcium chloride and reductant in the different tests, a preliminary set of optimal conditions was established for the specific laterite ore that was tested. A combination of chemical analysis and electron-probe-micro-analysis (EPMA) were used to determine and evaluate the effectiveness of segregation roasting on the recovery of nickel. The present paper describes the test procedure and the results that were obtained.IntroductionIt is known that laterite ore resources account for an estimated 72% of the world's nickel resources, with sulfide sources accounting for the remaining 28%. Yet sulfide resources account for 58% of the world's primary nickel production while laterite resources account for the remaining 42% [I]. There are numerous reasons for this discrepancy, but the most important one is the mineralogical and compositional complexity that is associated with laterite ore deposits. For example, this complexity currently offers only limited opportunities for upgrading, thereby creating capital intensive whole ore processing facilities. It then follows logically that the identification and application of a low-cost processing option for the treatment of laterites could potentially open up an opportunity for exploiting these vast untapped laterite resources.To this end, a preliminary screening investigation was initiated by Xstrata Process Support to evaluate the potential application of the so-called (nickel) segregation process as a unit operation that could potentially be integrated into a laterite processing flow sheet. Laboratory bench tests were performed on this segregation process and this paper details some of the findings from this preliminary investigation."

Jan 1, 2011

By Larry M. Southwick

Pneumatic converting (Bessemerizing) of iron revolutionized the steel industry. Bessemerizing of copper (conversion of copper sulfide matte to copper metal) was proposed at almost the same time, but it was slow in being accepted. The differences between iron and copper converting were great and technical problems were substantial. It took 25 years for the process to become viable and another 25 years before a truly economical solution was found. A major economical and productivity problem was the short life for converter refractory linings. The first converters had acid (silica) linings, which were quickly consumed since silica was a flux for the process. Converters had to be relined at least once per day, a laboriously expensive manual process with only the most rudimentary mechanical aids available to assist. The industry was revolutionized almost overnight when finally a viable basic (magnesite) lining was developed. This lasted 100's of days versus less than one, leading to converters that were easier to operate and which handled larger charges. This change occurred after W.H. Peirce and E.A.C. Smith, with support from the Guggenheim interests, successfully operated a basic lined converter in a copper refinery in Baltimore. While Peirce and Smith are generally given credit for the development and explosive acceptance of this idea, a Pittsburgh industrialist, Ralph M. Baggaley, working in an independent smelter in Butte, Montana, successfully built and operated a basic lined converter four years before they did. In fact, the early support for Peirce and Smith likely occurred because Guggenheim's staff were encouraged after thoroughly examining Baggaley on his earlier successes. The questions of technology primacy between Baggaley and Peirce/Smith are ironically similar to those between Wm. Kelly and Bessemer in converting iron to steel. This paper will review what Baggaley (and other early researchers) accomplished, examine why he (or they) did not receive credit equal to Peirce and Smith and explore what his (their) place should be in the development of successful basic linings. More suspects than a Victorian Whodunit.

Jan 1, 1999