A new approach to assemble a three-dimensional (3D) computer model of the T-x-y diagram is demonstrated on the example of the Ag-Au-Sb system. It is based on the assembling of phase diagram from the surfaces and the phase regions. Its first variant (template) permits to design the 3D model even in the absence of some important data. Further, the template becomes the precise model, when new data are discovered. As a result, the obtained 3D computer model makes it possible to construct any iso- or polythermal section, to calculate mass balances for the arbitrarily taken compositions and even to find errors in the interpretation of experimental data. T-x-y diagram Ag-Au-Sb consists of 78 surfaces (5 liquidus, 5 solidus, 36 ruled surfaces, 16 solvus, 16 horizontal simplexes of the 4 complexes in accordance with the invariant reactions) and 40 phase regions (5 L+I, 5 I, 7 L+I+J, 8 I+J, 5 I+J+K, where L – liquid and I, J, K – solid solution Ag(Au), Sb, compound AuSb2 and two phases of variable concentration in the Ag-Sb system).
This work has been performed under the program of fundamental research SB RAS (project 0336-2014-0003) and was partially supported by the Russian Foundation for Basic Research (projects 14-08-00453, 15-43-04304).

Mercury emission from non-ferrous smelting plants has attracted worldwide attention. To realize the goal of mercury removal from high SO2 concentration flue gas, a new method, using acidic thiourea solution, was proposed. It was found that it displayed significantly higher removal efficiency for elemental mercury from high SO2 flue gas, up to above 89% at the optimal condition. Low solution pH and temperature contributed to Hg0 removal due to the high stability of thiourea. Adding oxidants, such as FeCl3 and H2O2, could promote the oxidation of mercury, especially in the initial reaction period. After the mercury removal from flue gas, the CuCl2 modified activated carbon was added to acidic thiourea solution to absorb mercury. Almost 92% of mercury in solution was removed and the thiourea solution after absorption process could be reused to absorb gaseous mercury. In summary, the noval technology is environmentally sustainable for the recovery of mercury from non-ferrous smelting flue gas.

Industrial silicon slag is a kind of metallurgical slag during ladle secondary refining process. In this study, the following methods were used: X-ray fluorescence (XRF), scanning electron microscopy (SEM), the energy dispersive spectrometer (EDS), and the X-ray diffraction (XRD) to determine the chemical composition, morphology, and phase of silicon slag and silicon inclusions in slag. The results showed that O, Si and Ca concentrations in silicon slag were very high, and the silicon content was as high as 22.19%. The purity of metallic silicon wrapped by slag reached 94.07%. Compared with the normal metallic silicon product, the concentrations of Ca and Al in silicon inclusions obviously increased while the concentrations of other impurities changed little. In addition, the separation between silicon and slag was not complete. After cooling, the impurity phases in silicon inclusions enriched at the grain boundaries and produced a significant dendritic segregation phenomenon. The silicon slag was mainly composed of Si, SiC and oxides of Si, Fe, Al and Ca. The impurity phases in silicon inclusions were FeSi2, Ca3Al2Si2, and CaSi2.

The optical process control system consists of an optical telescope which focuses on the light emitted by the high temperature off-gas. An optical fiber guides the light into a server, where it is analyzed by a spectrometer. The composition of some particular off-gas components are displayed in the form of process trend curves. By using the trends of these curves some information is obtained about the status of the process. This work makes a detailed analysis of the application of this technique in Pierce Smith Converters and concludes on the positive aspects as well as on the limitations of this technique.

Boron is an obstinate impurity to be removed from metallurgical grade silicon (MG-Si) by metallurgical route. In this paper, boron removal from MG-Si was carried out by a united blowing-slagging secondary refining technique. The gases O2 and H2O-O2 were blown into MG-Si melt in an electrical resistance furnace. Simultaneously, the slagging reagents SiO2-CaO-CaCl2, SiO2-CaCl2 and CaO-CaCl2 were also added. The effects of gas composition, slag composition, gas flow rate, ratio of slag to MG-Si, refining time and refining temperature on the efficiency of boron removal were investigated. The results indicated that the boron removal efficiency of 40% and 97% can be obtained, respectively, when a single O2 or H2O-O2 gas was blown with a refining time of 120 min at 1450 oC. The distribution coefficient of boron (LB) increased from 0.93 to 2.85 with a slag/MG-Si ratio of 2:1, a refining temperature of 1550 oC and refining time of 120 min, respectively. An optimal result can be gotten by a united blowing-slagging refining method.

Because of distinctive properties, such as dendritic structure, high green strength, and low oxygen content, the electrolytic copper powder has been widely used in aviation, aerospace, national defense industry and other domains. But at present, energy consumption of the electrolysis process in copper powder production is high, and the current efficiency is only about 90%. Therefore£¬the decrease in energy consumption in the electrolysis process has become the major bottlenecks to the development of the enterprises. In this paper, a new electrolysis cell with different liquid inlet arranged on the sides (inlets was paralleled with the plate electrode) and ends (inlets was vertical with the plate electrode) of the cell was manufactured. Then, the effect of flow changes in a different liquid inlet on the current efficiency, energy consumption and properties of copper powder was studied. The experimental results showed that the electrolytic process had the highest current efficiency and lowest energy consumption when the flow rate is 1.5l/min in the paralleled inlet and 0.5 l/min in the vertical inlet. Under the optimal conditions, the current efficiency, energy consumption and copper powder size were 96.68%, 733.7186 kw∙h/t and 76.831um respectively. This means an obvious rise in current efficiency and decrease in energy consumption compared to traditional feeding method.

SiO2 is used in various smelting reactors as a major constituent of refractories and as a chemical flux. Its mechanical properties are affected by numerous impurities such as Na2O, K2O, MgO, CaO, Fe2O3 and Al2O3. As part of a wider project, this work studies the effect of various network modifiers in SiO2 linear and volumetric expansion. The experiments were carried out using solid cylindrical pressed samples of various mineralogical compositions but identical in size, weight, volume and area. These samples were held inside an electric furnace in laboratory at different temperature within the 1200°C-1260°C range interval keeping the time constant for all heats. After the tests the linear expansion was quantified using the variation of the diameter of the circular surface of the cylindrical sample and volumetric expansion was quantified using the difference of total volume of the cylindrical samples after heating. The results were analyzed, a model was created and various conclusions on the individual effect of each impurity as well as various ratios between them and SiO2 were drawn.

During the electrodeposition of manganese, the anode has the problems of high oxygen evolution potential, high density and loose surface film, which is the main reason for the high energy consumption of the electrowinning process. By means of experiment and simulation, the effect of the different opening method on the anode plate on electrodeposited manganese were investigated. Under the premise of the same porosity and electrolysis condition, through comparative analysis of the quality and microstructure of electrolytic manganese and anode slime, electric manganese deposition current efficiency and the electric field distribution in the electrolytic cell to characterize different anode plate performance. The experimental results show that the anode plate with different openings has great influence on the process of manganese electrowinning, and the performance of the anode plate with the circle opening is better.

Bubble formation is extensively studied by various operating conditions mostly investigated on single-hole nozzle or porous nozzle. However, few investigation is focused on bubble formation process generated from multi-hole nozzles. In present work, bubble formation was originally studied by injecting nitrogen with different gas flow rates through multi-hole nozzles submerged in quiescent water. Different nozzles with different number of holes were employed to investigate the influence of holes on bubble formation. The process of bubble formation was captured by a high speed camera and analyzed by a digital image processing algorithm. The bubbling regimes, bubble diameter and circularity were applied to quantitatively analyze the bubble formation. Drawing from the results, the bubble regimes were categorized into single bubbling with delayed release, double bubbling with delayed release and double bubbling without delayed release. Simultaneously, different stages of the formation process were divided to describe the bubble formation. Afterwards, bubble diameter and circularity were quantitatively analyzed to investigate bubble characteristics. An appropriate equation for prediction of bubble diameter was proposed by combining the opening ratio, inner diameter of nozzle and Reynold number. It was found that the bubble formation process from multi-hole nozzles was pretty regular and noticeably stable. As a result, the present work can not only benefit the research on bubble formation generated from multi-hole nozzles but also guide the application of multi-hole nozzles in practice.

The feasibility of using emulsion liquid membranes (ELMs) with the guanidine extractant LIX 7950 as the mobile carrier for detoxifying copper-containing waste cyanide solutions has been determined. Various parameters affecting the extraction efficiency of copper and cyanide by ELMs have been examined. Under moderate stirring speed and suitable stirring time, mixing of ELMs and the external feed solution exhibits an insignificant effect on the ELM stability. Effective extraction of copper cyanides by ELMs only occurs at pH below 11. High copper concentration in the external phase and high volume ratio of the external phase to ELMs result in high transport of copper and cyanide. The high molar ratio of cyanide to copper tends to suppress copper extraction by ELMs. The presence of thiocyanate ion significantly depresses the transport of copper and cyanide through the membrane while the thiosulfate ion produced less impact on copper removal by ELMs. Zinc and nickel cyanides can also be effectively extracted by ELMs and a selectivity order of Zn>Ni>Cu>Fe with ELMs has been confirmed.

Hydrogen peroxide catalyze reduce selenic acid by sulfur dioxide was discovered in this paper. The experimental conditions such as reaction temperature and acidity of solution have less influence on the catalytic reduction, and the reduction rates of selenate are all above 99.8%. This new method offered a solution of recovering selenate. Further research revealed the formation mechanism of selenium elementary substance under different reaction temperature. The analyses of solution concentration and characterizations of solid particles indicated that, under 25 oC, selenic can be directly catalytic reduced into red selenium, while reaction temperature is above 60 oC, the trigonal crystal selenium was formed by reaction between Se2- and Se4+, where the Se2- was produced by further reduction of red selenium, not a simple crystal form transformation as a result of temperature change.

The reaction mechanism of the oxygen-enriched direct smelting process of jamesonite concentrate was studied. With the assistance of FactSage software, the predominance diagram for the Sb-Pb-S-O system at different temperature was drawn. The products of the oxidation reaction for sulphide and the phase stability zone were affected by temperature. The increase of temperature is in favor of the formation of lead-antimony alloy. The phase changes that occurred in the particles of a typical jamesonite concentrate and the reaction products during direct smelting in a laboratory small-scale top blown furnace at 1523K were investigated by X-ray diffraction, scanning electron microscopy with energy-dispersive X-ray spectroscopy, optical microscopy and electron probe microanalysis. In the oxygen-enriched smelting of jamesonite, it was shown from the observation results that the oxidation reaction proceeded by three stages. During the initial step of smelting, the oxidation products were lead-antimony alloy and iron-enriched gudmundite. Then the selective oxidation of sulphides of lead and antimony continued. At the last stage, the ferrous sulphide oxidized and slagged. The formation of the gudmundite inhibited the volatilization of antimony, which led to more antimony in starting material into the alloy phase. The composition of lead-antimony alloy was investigated. It found that there was a small amount of copper and iron in the alloy besides lead and antimony. Copper and iron precipitated in the form of antimony-copper and antimony-iron alloy respectively during cooling of liquid alloy.

The alkaline fusion process is a useful pretreatment for rare earth elements (REEs) recycling from the blue phosphor (CeMgAl11O19:Tb3+, CMAT). But the lack of basic theory affects the further development of alkaline fusion process. In our previous work, Free Oxoanion Theory (FOAT) has been summarized to elucidate the structure decomposition process of blue phosphor (BaMgAl10O17:Eu2+, BAM). In this paper, alkaline fusion experiments were performed to describe the CMAT structure decomposition mechanism. Different substances (KOH, NaOH, Ca(OH)2, NaCl, Na2CO3, and Na2O2) were chosen to react with CMAT to explain alkaline fusion process, only KOH, NaOH, Na2CO3, and Na2O2 can damage the CMAT structure. Cerium, terbium and magnesium ions were bonded with free oxoanion (OH-, CO32-, O22-) preferentially to escape from the CMAT structure. The remaining structure of aluminate eventually decomposed into aluminate in air. Cations (Na+, K+) were introduced to bond with the aluminate ions to maintain the charge balance of reaction system. It¡¯s clear that FOAT can be used to elucidate the structure decomposition process of aluminate phosphors (both BAM and CMAT) during the alkaline fusion process. Furthermore, the activation energy of CMAT reaction with NaOH was determined by three model-free methods. The calculated activation energy variation tendency versus conversion factor agrees with the proposed mechanism.

Mechanism model of copper oxygen-enriched bottom blowing smelting (SKS) was constructed by analyzing smelting process deeply, combined with related theories of a copper metallurgical process. Model¡¯s cross section includes seven functional layers, i.e. gas layer, mineral decomposition transition layer, slag layer, slag formation transition layer, matte formation transition layer, the weak oxide layer and the strong oxide layer. Longitudinal section is divided into three functional regions, including reaction region, separation transition region, and liquid phase clarification region. The layers or regions play different roles and constitute an organic unit. Ploycomponent, such as CuFeS2, FeS2, Cu2S, FeS, 2FeO•SiO2, Cu2O, FeO, Fe3O4, SO2, H2O, N2 and S2, transfers quickly through the interface between different layers and regions, with the effect of character differentiation and fluid flow. SKS is at the state of dynamic non-steady multiphase equilibrium, and the value of oxygen and sulfur potential changes gradually in longitudinal and cross direction, and the capacity of SKS could rise by reasonably controlling the potential value in different layers and regions.

FLOGEN CONTOP offline and online control expert system was commissioned in Paranapanema smelter at Dias D’Avila in order to control and optimize the Hoboken Converters operations. The results indicate the possibility to decrease the amount of silica used as a flux, minimize the slag and copper blowing time, maximize the use of reverts, minimize slag volume and decrease copper losses in the slag. The system finds the optimum of the charge among various scenarios while the main process parameters (such as bath temperature, sulfur content in the blister and copper in the slag) are calculated during the operation, providing a clearer overview of the process and supporting the determination of slag and copper blowing end point. The presentation will describe some of these achievements.

Phosphorus from high-phosphorus rhodochrosite affects electrolysis efficiency, leads to excess phosphorus in manganese metal during electrolytic manganese metal, and affects the steel productions performance and quality. Chemical precipitation technology in the presence of removing reagents was studied to remove phosphorus from acidic leach liquor that is produced by sulfuric acid leaching of high-phosphorus rhodochrosite ore. Factors associated with the removal efficiency, including various phosphorus removal reagents, pH, Fe/P molar ratio, and H2O2/Fe molar ratio, were also investigated. Experimental results showed that the removal efficiency of Fenton reagent (Fe2+/H2O2) was higher than Fe2(SO4)3, FeSO4¡¤7H2O and H2O2 under the same conditions. Phosphorus removal efficiency over 99.81% was obtained at pH 3~5, Fe/P molar ratio of 2, H2O2/Fe molar ratio of 0.5~1. Phosphorus concentration in mother liquor was changed from 6834 mg¡¤L¨C1 to 13.32 mg¡¤L¨C1. The mechanism of phosphorus removal by using Fenton reagent is the formation of iron-hydroxy-phosphate and the adsorption of the ferric hydroxyl complexes during precipitating processes.

There have been investigated the issues of associated recovery of rare metals and trace elements at different stages of processing of the ores mined at the non-ferrous deposits of Kazakhstan. It has been shown that the recovery of associated components to these or other flotation concentrates varies quite widely, which is primarily connected with a variety of minerals-carriers. There has also been presented the information about the recovery of associated components at the stage of flotation concentrates metallurgical processing. The recovery is not higher than: selenium to grade selenium ~ 45%; tellurium - 46%, cadmium - 75%, thallium - 6%; germanium - 18%; indium - 90%; gallium - 12%; mercury - 12; bismuth to lead bismuthide - 83%; rhenium to ammonium perrhenate - 42%. It has been shown that the maximum complexity of the raw materials use is achieved with the presence of integrated production.

Integrated utilization of natural resources using energy-saving and waste-free technologies is relevant around the world. This applies to such type of raw material as titanium-magnetite ore. Shortage of ilmenite raw materials in the Republic of Kazakhstan for titanium slag melting challenges the search of alternative titanium-containing raw materials, titanomagnetites in particular. At the same time, there are deposits of indigenous titanomagnetite ores (Velikovskoe, Tymlay, Masalskoe, etc.) of huge reserves, which can become the complex raw material for production of iron, titanium and vanadium. Tymlay field in the South-Eastern part of Chu-Ili watershed is of particular interest, within the Karasay ore unit with iron content of 30,4 and titanium dioxide - 10%, and after beneficiation titano-magnetite concentrate contains Fe-52,4; TiO2-of 16,06%. Technology of titanium-magnetite concentrate ore-thermal melting was developed at Tymlay deposit producing hot metal and low titanium slag that can become the raw material for titanium production using chloride method. Slag produced in course of titanomagnetite ore-smelting consists mainly of alumosilicates and sodium silico titanates, magnesium and calcium titanates, titanium dioxide and lower titanium oxides. In this regard, chemical beneficiation is the main task of researchers handling the problem of low titanium slag processing. Following operations were carried out to improve titanium slag quality: slag sintering with sodium hydroxide; cake leaching with water to remove water-soluble impurities; to reduce the number of operations impurities leaching with hydrochloric acid was combined with pyrohydrolysis of titanic acid; rutile concentrate production (85% TiO2, 7,66% SiO2), silica removal by means of sodium hydroxide solution treatment, finally sellable rutile concentrate was produced with titanium dioxide 91-92% and silica 1,7 to 2,0% content. Based on research results technological scheme of titano-magnetite concentrate processing at Tymlay deposit was proposed producing hot metal and certified rutile concentrate, suitable for chlorination.

Low-temperature alkaline smelting method was applied to treat Copper smelting tailings to separate iron and silicon from tailings and obtain-high economic value iron oxide red. The effects of the alkaline mineral ratio, solid-liquid ratio, smelting temperature and time, leaching temperature and time on the separation of Fe and Si were studied by single factor experiments. The optimum conditions were obtained as: an alkaline mineral ratio of 1.5:1, solid-liquid ratio of 1:5, smelting temperature of 823k, smelting time 1.5 hour, leaching temperature of 313K and leaching time 20 min. Under these optimum conditions, the content of Fe increased from 47.00% to 62.15%, the content of Si decreased from 17.44% to 1.74%, Si/Fe decreased from 0.371 to 0.03. The results indicated that low-temperature alkaline smelting-leaching method can effectively and enrich of Fe and Si from bottom blowing smelting copper tailings. The prepared iron oxide red has the iron oxide percentage composition for 80.75 %, which corresponds to the H102 in the GBT 1863-2008 standards.

Trepca Company, as per design capacity, can produce about 90,000 t/year zinc sulfate solutions as a by-product of neutral leaching of zinc calcine. Besides zinc, these sulfate solutions contain impurities such as Cu, Cd, Co, Ni, As, Ge, Sb, Se, Te and Ag with the following average concentrations: Cu and Cd = 0.2-1.2 mg/l; Co=1.0-10mg/l; Ni =20-50 mg/l; As, Ge, Sb, Se, Te and Ag = 0.1-0.5 mg/l. Based on the above data, it is evident that the selective recovery of these metals from these solutions represent a significant economic added value. In this point of view, in order to revive and improve operation practices as per design capacity in the Trepca Company, a project is undertaken in cooperation with FLOGEN Technologies Inc. in order to increase efficiency of the process through proper control and optimization. In this paper the existing refining process within the entire flowsheet is described as per design parameters. The recovery of metals by separation and cementation in metallic forms is overviewed based on the fact that these metals have higher electro-chemical potentials than zinc. The operation factors that have the most profound effect on the process such as impurity concentration, temperature, time, etc. are described. The improvement aspects of this process through proper control and automation will be subject of a subsequent paper in the future.

A residue containing 18.80 wt. % Cr and 3.11 wt. % V was obtained from a wastewater treatment plant. Experiments on vanadium and chromium leaching from the residue were carried out by sulfuric acid, sodium hydroxide. The best leaching performance was showed by the acidic leaching, in which process, the residue was leached with sulfuric acid at 90 ¡aC for 120 min with the liquid¨Csolid ratio of 4:1 ml.g-1. The leaching efficiency of vanadium and chromium could reach a maximum value of 90.32% and 99.31%, respectively. While in alkaline leaching process, the high selectivity for vanadium was observed. The leaching efficiency increased from 62.64% to 91.71% enhanced by an electric field. Hydrogen peroxide was also introduced to enhance the leaching process of vanadium and chromium, the leaching efficiency of vanadium and chromium could reach up to 86.49% and 98.60%, respectively.

Silver separated residue (SSR), a hydrometallurgical product derived from copper anode slime, which is abundant in valuable metals like Pb, Bi, Sb, Sn, Au, Ag and PGMs. In this paper, a novel method namely reductive alkali-fusion was employed to treat the SSR for the effective separation and enrichment of valuable metals. In the fused system of NaOH and Na2S, Pb and Bi sulfates were reduced to noble lead which also contains Au, Ag and PGMs, while the Sb and Sn were transformed into sodium oxysalts dissolved in fused salt. The results show that in the semi-industrialized experiment, the direct recovery of Pb reaches 87% and almost all Bi, Au, Ag and PGMs are enriched in noble lead under the suitable conditions as follows: 1:0.6:0.3 of SSR-NaOH-Na2S mass ratio, 700 oC of fusion temperature and 4 h of fusion time. For downstream treatments, the noble lead is favorable for vacuum distillation to separate valuable metals, and the molten salt can be treated by water leaching followed by H2O2 oxidation and Ca(OH)2 precipitation to recover Sb and Sn respectively.

Chelyabinsk Zinc Plant developed the technology of processing of zinc-, lead- and tin-containing copper industry dusts, including the following stages:<br />-pyrometallurgical stage – calcinations with an addition of sulphidizer, flux and reducing agent to the product, where lead is removed from the product with a transfer in processed sublimates, while zinc and tin stay in cinder;<br />- hydrometallurgical stage – high-temperature leaching of cinder, where zinc, iron, copper etc. are extracted in solution with obtaining of tin-concentrating solid residue. <br />There is considered the hydrometallurgical stage of obtaining of tin-containing concentrate from cinder with low content of lead (less than 1%). <br />There is shown the low extraction of zinc in solution and absence of selective separation of tin and lead with acid sulfuric-acid dust leaching without application of pyrometallurgical stage. <br />Three-stage leaching (similar to the technology of hydrometallurgical processing of Waelz-oxides, existing in Chelyabinsk Zinc Plant) and one-stage high-temperature leaching were researched for obtained cinder. Three-stage product leaching is low-efficient, because it requires a lot of equipment and does not provide the required concentration of tin in solid residue. <br />About 98% of zinc, contained in cinder, more than 95% or copper and iron is transferred in solution during the high-temperature product leaching by waste zinc electrolyte with addition of sulfuric acid (t= 80-900C, the concentration of H2SO4 is 160-170g/dm3). Obtained solution is required for application in a technological cycle of the zinc plant. The solid residue contains 14-21% of tin, which allows to use it at tin enterprises. <br />Keywords: copper industry dusts, cinder, pulp, hydrometallurgical processing, selective leaching, zinc, tin, lead.

The technology of preparation of ferric oxide from zinc hydrometallurgy high iron slag by hydrothermal method, which realized the separation of zinc-iron and utilization of iron associated effectively, was proposed and investigated. The effects of iron precipitation ratio, the constitution and morphology of the product were studied with respect to variables such as temperature, reaction time, pH values of the solution as well as stirring speed. The experimental results showed that the influence was obvious, in which the reaction temperature was the most important factor. The iron precipitation ratio could reach 95%, and the spherical nanometer hematite could be obtained under the optimum conditions, it were determined as follows, when the stirring rate was fixed at 800r/min, oxygen pressure was fixed at 2.0MPa: the minimum reaction temperature is 180¡æ, pH¡Ý1.0, 1h.
Key words: iron oxide red, hydrothermal method, iron precipitation ratio, morphology.

Based on the principle of Gibbs energy minimization, a multiphase equilibrium model for estimating the substance flowing in the process of oxygen bottom blowing copper smelting (SKS) is proposed in this paper. The mechanical entrainment and complex behavior of S2 in the SKS process are both quantitatively depicted using mathematical models. An improved particle swarm optimization (HLPSO) algorithm that suits for the highly dimensional and linear constraints optimization problem is devised to calculate the substance contents and element distributions in detail when the system is close to equilibrium. A set of industrial data is compared with the predicted data. It is found that the matte grade may reach 71.075% under the condition of oxygen blowing speed at 10885 Nm3/h, air blowing speed at 5651 Nm3/h and mixed copper concentrates input speed at 66 t/h. The tri-phase (matte, slag and gas phase) distribution coefficients of arsenic are 0.061, 0.112, 0.827, of antimony are 0.128, 0.706, 0.166, of bismuth are 0.198, 0.113, 0.689, of lead are 0.556, 0.248, 0.197 and of zinc are 0.178, 0.643, 0.179. The results are overall in good accordance with the actual plant production data and the model can be used for prediction in different conditions.

KIVCET was the only commercial process for lead flash smelting until 2010. In 2011, Chinese process LOFS (Lead Oxygen Flash Smelting) joined KIVCET. The layer of carbon material formed in the smelting shaft at the surface of the melt bath under the flares of charge-oxygen burners is used as the reduction reactor in both processes. Conventionally, screened fraction of coke fines is used as a carbon material for formation of the porous layer. The possibility of usage of other carbon-bearing materials is reviewed in this Paper.

The volume of a fluid model in FLUENT software was adopted to simulate the gas-liquid two-phase flow motion in the oxygen bottom blown smelting process. The energy transfer process between gas-liquid phase, the variation law of the velocity field and pressure field and the formation, division and mergence behaviors of bubbles in the bath were mainly studied. The results showed that the formation, division and mergence behaviors of bubbles were closely linked with the velocity field and pressure field in the bath. Bubbles breakup was mainly caused by the interaction of bubbles at an earlier stage, then caused by gas-liquid two-phase movement effect. The energy transfer occured when the gas phase entered into the liquid phase at a certain speed. The flow velocity in the upper part of the oxygen lance zone was relatively high while the flow velocity was slow on both sides in the bath. With gas phase entering into liquid phase continuously, the distribution of velocity field and momentum filed expended gradually in the bath which stirred the bath efficiently. The variation of vector and momentum distribution showed that there was a symmetrical gas-liquid two-phase action region on both sides in the bath in which spinning motion of bubbles was helpful to generate tiny air bubbles to improve the efficiency of bath reaction.

A compact porous layer of lump carbon material is used as the main reduction reactor in flash smelting processes for lead raw materials. Such layer, which was named as “coke checker”, forms at the surface of slag melt bath directly under the flare of the charge burner. Reduction of highly-dispersed oxidized lead melt, which is produced during charge flash smelting, is performed during the infiltration of the melt through the carbon reductant layer. The Paper provides the results of studies of the specified process by means of the mathematic model of the coke checker with due consideration of phenomena of heat and mass exchange in the layer, its geometry and continuity of the melt flow. The results of model calculations are compared with the established industrial practices.
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[21] A.S. Kulenov, Y.I. Sannikov, L.V. Slobodkin, N.N. Ushakov: The KIVCET Process – A unique technology for the smelting of Raw Material containing Lead, Zinc and/or Copper, Erzmetall, 1998, V.51, Nr.4, p.273-279.
[22] A.P. Sychov, A.S. Kulenov, Yu.I. Sannikov et. al.: An important stage of development KIVCET-CA process at UKSTSK completed // Nonferrous metals, 1988, &#8470;1, p.14-19 (Russian original).

The objective of this study is to investigate the hygroscopic properties of the mixed lead concentrate (MLC) and recycle dust (RD) and to discuss the relationship between their hygroscopicity and microstructure. The hygroscopisity of MLC and RD was investigated by the moisture adsorption test performed over the temperature range of 25-85¡æ and relative humidity (RH) of 35-95%. The microstructure was investigated by the scanning electron microscopy (SEM) and the laser particle size analysis (LPSA). The results indicate that the equilibrium moisture content (EMC) of MLC and RD vary from 0.076% to 0.667% and 0.033% to 0.354%, respectively. Besides, the EMC of MLC is higher than that of RD under the same condition of RH. The changing trends of EMC for both materials are different which indicates that MLC and RD accord with different hygroscopicity rules. Moreover, the SEM results show that the microstructure of MLC tends to be more irregular and much rougher than that of RD. According to the LPSA results, the average particle sizes of MLC and RD are 5.319¦Im and 2.657¦Im, respectively, and the size distribution of RD particle is more homogeneous, which cause the different hygroscopic properties of the two materials. Lastly, two kinds of isothermal adsorption models are fitted to help predicting equilibrium moisture adsorption content of the MLC and RD during the production.

Interface mass-transfer dynamics control and thermodynamics restriction of interphase distribution coefficient are the common problems in the process of producing high-purity silicon at present, especially for low concentration impurities B and P with high harmfulness. Traditional metallurgical purification method is difficult to remove impurities B and P simultaneously, which can lead to low efficiency and high energy consumption problem. Flux treatment can be efficient to remove B from silicon, but not for P due to the weaken ability to combine with oxygen. In order to efficiently remove P under the condition of slagging remove B, the addition of Na2O into slags were carried out to improve the oxidizability of slag for the simultaneous removal of B and P. Metallurgical grade silicon was subjected to refining by liquid CaO-SiO2-(Na2O) slags at 1823K(1550¡æ). The removal efficiency of B and P was examined under a range of slag compositions with different amount of Na2O. The results showed that the removal efficiency of B and P increased with the addition of Na2O to slags. For the slag without Na2O, the removal efficiency of B and P were 40% and 57%, respectively. When the Na2O in slag increased to 30%, the removal efficiency of B and P increased to 85% and 67%, respectively. A thermodynamic evaluation of the slags system showed that the addition of Na2O led to a substantial increase of free oxygen ion activity and oxygen partial pressure, which enhanced the removal of impurity B and P.

The industrial area around RTB Bor encompasses about 9,190,940 tons of techno genic deposits of copper smelting slag with an average of 0.715% copper content. As part of a project to recuperate copper from these deposits, this work investigates the effect of the rapid cooling of these slags on their physicochemical milling and flotation properties.
Two sets of samples from these deposits were analyzed and compared. The first set of samples were analyzed as is, without any pre-treatment. The second set of samples were melted in a furnace and then quenched and granulated in the water.
Both sets of samples were analyzed and compared in terms of their physicochemical, milling and flotation properties. This included the results of chemical and SEM - EDS tests, Bond Work Index in rods and balls mills, milling kinetics and flotation parameters. The analysis and comparison served to draw proper conclusions on the copper recovery of each set of conditions.

This paper introduces a lead oxygen-enriched flash smelting (LOFS) process. Compared with the existing bath smelting technologies, LOFS has many advantages, such as suitable for treating low grade secondary lead-bearing materials, high yield of lead bullion, low energy consumption for recovering zinc in raw materials, little uncontrolled emission of lead containing dust and considerable recoveries of valuable metals. A series of tests were carried out and the results showed that increasing CaO content of the slag could effectively reduce the lead content in the slag. Thereby, the appropriate FeO-to-SiO2 mass ratio was 1.15 and the appropriate CaO-to-SiO2 mass ratio was 0.6 for LOFS. The testing commissioning indicated that when using LOFS to treat lead-bearing raw material with about 30% of lead, the residual lead in slag can be decreased to 4-10%, and then after zinc volatilization by ore-smelting electric furnace, the contents of lead, zinc, silver, gold and copper in the final slag were below 2%, 2%, 6 g/t, 0.1 g/t and 1%, respectively. Moreover, the total recoveries of lead, zinc, silver, gold, copper and sulfur were above 98%, 90%, 99.5%, 99.5%, 85% and 98%, respectively. In addition, the energy-intensive zinc fuming furnace was eliminated in the LOFS process.

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