Oxygen refining of molten high-carbon ferromanganese

The effects of the oxygen/argon mixing ratio and temperature on the decarburization behaviour of high-carbon ferromanganese melts were investigated. The decarburization reaction was promoted and the oxidation reaction of manganese diminished by increasing temperature and decreasing the oxygen/argon mixing ratio. However, the carbon content in the melt appeared to increase during blowing at low temperatures and high oxygen/ argon mixing ratios because of faster manganese oxidation. An empirical equation was derived to predict the utilization ratio of oxygen for decarburization. The lower oxygen/argon mixing ratio and higher melt temperature were found to be essential in enhancing the efficiency of decarburization and suppressing the oxidation of manganese in the early stage of oxygen/argon refining of high-carbon ferromanganese melts.     

氧气底吹铜熔池熔炼过程的机理及产物的微观分析

对氧气底吹熔炼过程气体喷吹行为、造锍熔炼化学反应机理及熔炼炉内热工作状态进行理论分析及水模型实验和取样分析验证。结果表明,氧气底吹气流能使熔体形成均匀的扩散区,实现熔体的搅拌,在气体连续相区和液体连续相区,气液、液液之间的相互作用强烈,为炉内化学反应及传热传质提供了良好的动力学条件;氧气底吹熔炼过程在零配煤的情况下能达到自热熔炼,在节能减排方面,该工艺具有很强的优势;获得了铜渣、冰铜和蘑菇头中各组分的形貌,确定了铜渣、冰铜和蘑菇头的物相组成,渣样主要由冰铜相、磁铁矿相、铁橄榄石相和玻璃体相组成,熔炼内的氧势和硫势分布有利于反应的进行,能有效抑制Fe3O4的形成以及降低渣含铜。     

EFFECTS OF TEMPERATURE ON DISTRIBUTION BEHAVIORS OF MINOR ELEMENTS IN COPPER FLASH SMELTING──COMPUTER SIMULATION

ＥＦＦＥＣＴＳＯＦＴＥＭＰＥＲＡＴＵＲＥＯＮＤＩＳＴＲＩＢＵＴＩＯＮＢＥＨＡＶＩＯＲＳＯＦＭＩＮＯＲＥＬＥＭＥＮＴＳＩＮＣＯＰＰＥＲＦＬＡＳＨＳＭＥＬＴＩＮＧ──ＣＯＭＰＵＴＥＲＳＩＭＵＬＡＴＩＯＮ￥ＴａｎＰｅｎｇｆｕ；ＺｈａｎｇＣｈｕａｎｆｕ（Ｄｅ...     

Flash smelting copper concentrates

Flash smelting is a comparatively new method of smelting copper and nickel sulfide concentrates. It takes place when the concentrate, with or without additional fuel, is suspended in gases containing oxygen whereby the heat of oxidation reactions bring the suspended particles to a smelting temperature. From the suspended state the hot particles are separated and molten slag and matte are deposited on the furnace hearth.     

EQUILIBRATING PARTITION RATIOS OFNb,Mn AND Si BETWEEN LIQUID IRON AND MgO-SiO_2-MnO SLAG MELTS

The liquid iron containing elements Nb,Mn and Si has been equilibratedwith MgO-SiO_2-MnO slag melts at 1600℃ in a Mo wire-wound resistance furnace with aduration of 4h.The oxygen activities in liquid iron were measured with oxygen sensors.Usingthe known equilibrium constants of concerning reactions and the oxygen activities in liquidiron,the activities of components in the slag melts can be calculated.It was found that the par-tition ratios of Nb.Mn and Si have a close linear relationship with α_(FeO) in logarithmicscale.The dependence of Nb partition ratio on mole fractions of the slag components was al-so obtained.     

INTERFACIAL TENSION BETWEEN SLAG AND COPPER MATTE

The interfacial tension between FeO-CaO-SiO_2-MgO system slag and Cu-Fe-S systemmatte was determinated by the X-ray radiograph sessile drop method.The effects ofFeO/SiO_2 ratio in the slag,contents of CaO,FeO,ZnO and CaF_2 in the slag on interracialtension and the relation of inter facial tension with the grade of matte and temperature havebeen studied.The floatation coefficient and film coefficient of slag-matte system has beencalculated and the mechanism of the transition of iron and oxygen from slag to matte has alsobeen discussed.     

铜冰铜—炉渣间界面张力的研究

用X射线照相座滴法测量了Cu-Fe-S系冰铜与FeO-CaO-SiO_2-MgO系炉渣之间的界面张力。实验结果的相对误差为5-9％。讨论了1200℃下炉渣中FeO/SiO_2的重量比值、渣中CaO,Fe_3O_4,ZnO及CaF_2含量对渣-锍界面张力的影响,考察了冰铜品位、温度与渣-锍界面张力间的关系。计算了渣-锍系的浮游系数和膜系数,对O,Fe由渣相向冰铜相的传输机理作了探讨。     

不锈钢VOD精炼吹氧阶段脱碳保铬的热力学分析

为了保证VOD吹氧阶段高脱碳量和铬的高回收率,以不锈钢ZG06Cr13Ni4Mo为研究对象,采用热力学计算软件FactSage8.1对VOD精炼过程吹氧阶段的供氧量、温度及真空度等参数对钢液中碳、铬含量的影响进行了分析,并在单因素计算的基础上设计了三因素三水平的正交试验,确定了供氧量、温度及真空度对脱碳保铬影响的顺序以及优化参数。结果表明,吹氧阶段供氧量应控制在4.68~6.10 m3/t(标准态)范围内;开吹温度应设置在1 585~1 600 ℃内且停吹温度不应超过1 750 ℃;压强应控制在5~9 kPa。此外,3种因素对吹氧阶段脱碳保铬的影响顺序为供氧量>真空度>温度,优化结果为供氧量4.9 m3/t(标准态)、温度1 600 ℃、压强7 kPa,且在此条件下的碳、铬质量分数分别为0.027%、12.201%。     

Manganese loss during the oxygen refining of high-carbon ferromanganese melts

Decarburization tests of high-carbon ferromanganese melts by oxygen refining were successfully carried out in a model converter with 2-ton production capacity. During the oxygen refining, the manganese loss was inherently accompanied by oxidation and evaporation. The oxidation loss of manganese into slag was affected by slag composition, melt temperature and slag weight. The oxidation loss of manganese into slag was minimum at a slag basicity of about 1.5 and it increased with temperature and slag weight. The amount of manganese evaporation loss was comparable to that of oxidation loss. An empirical equation for the evaporation loss of manganese was derived as a function of process variables. The apparent vaporization coefficient, β, was significantly affected by the oxygen mixing ratio in bottom blowing gas and the fraction of top blown oxygen.     

Thermodynamic Consideration for Oxygen Pressure in a Copper Flash Smelting Furnace at Toyo Smelter

JOM - Based on the emf measurements of the galvanic cell (Fe, MgO/O in slag or matte) and the equilibrium calculations, the oxygen pressure in a copper flash smelting furnace at Toyo smelter is...     

高磷铁矿石熔融还原中铁浴和熔渣间磷分配行为的研究

通过对铁浴与CaO-SiO2-MgO-Al2O3-FeO-2.3％P2O5熔融还原渣系间磷分配行为的热力学实验研究,考察了高磷铁矿石熔融还原中温度、炉渣成分、CO2/CO气氛对磷在铁浴和熔渣间分配行为的影响.实验结果表明,渣金间磷分配行为的氧势为(％FeO)控制的炉渣氧势,CO2/CO控制的气氛氧势则要高于该氧势,但是气氛氧势与该分配行为的氧势仍存在相关性.在光学碱度为0.65～0.69的范围内,a3/2O2-/γPO43-随着光学碱度的上升而升高;在高光学碱度条件下,温度对于渣中磷酸根活度系数的影响不大.     

Submerged Gas Jet Penetration: A Study of Bubbling Versus Jetting and Side Versus Bottom Blowing in Copper Bath Smelting

Although the bottom blowing ShuiKouShan process has now been widely implemented in China, in both lead and copper smelters, some doubts, questions, and concerns still seem to prevail in the metallurgical community outside China. In the author’s opinion, part of these doubts and concerns could be addressed by a better general understanding of key concepts of submerged gas injection, including gas jet trajectory and penetration, and the concept, application, and benefits of sonic injection in jetting regime. To provide some answers, this article first offers a discussion on the historical developments of the theory and mathematical characterization of submerged gas jet trajectory, including the proposed criteria for the transition from bubbling to jetting regime and the application of the Prandtl–Meyer theory to submerged gas jets. A second part is devoted to a quantitative study of submerged gas jet penetration in copper bath smelting, including a comparison between bubbling and jetting regimes, and side versus bottom blowing. In the specific cases studied, the calculated gas jet axis trajectory length in jetting regime is 159 cm for bottom blowing, whereas it varies between 129 and 168 cm for side blowing for inclination angles of +18° to ?30° to the horizontal. This means that side blowing in the jetting regime would provide a deeper penetration and longer gas jet trajectory than generally obtained by conventional bath smelting vessels such as the Noranda and Teniente reactors. The theoretical results of this study do corroborate the successful high-intensity practice of the slag make converting process at Glencore Nickel in Canada that operates under high oxygen shrouded injection in the jetting regime, and this would then suggest that retrofitting conventional low-pressure, side-blowing tuyeres of bath smelting and converting reactors with sonic injectors in jetting regime certainly appears as a valuable option for process intensification with higher oxygen enrichment, without major process changes or large capital expenditure, i.e., no need for full reactor replacement.     

Reduction mechanism of stainless steelmaking dust and carbon pellets

1 INTRODUCTIONThe smelting temperature generally reaches1 600 ℃or higher in stainless steel making opera-tion. Under this condition,approxi mately 1 % 2 %(mass fraction) of the scrap charged into the fur-nace is converted to dust[1]as by-product of steel-making process .It has been assigned as a hazard-ous waste and banned from landfills by variousgovernment regulatory agencies because it containsa lot of heavy metals such as zinc ,lead,cadmium,chromium and nickel , which will be leached …     

A New Pyrometallurgical Process for Producing Antimony White from By-Product of Lead Smelting

Antimonial dust is a by-product of lead smelting and an important material for extracting antimony. A new pyrometallurgical process for producing antimony white from the antimonial dust is reported. The process mainly consists of three steps, which are reduction smelting, alkaline refining, and blowing oxidation. First, the reduction smelting of antimonial dust is carried out in an oxygen-rich bottom blow furnace to enrich antimony and lead in the crude alloy. The antimony and lead contents in the slag can thus be reduced to 2.8 wt.% and 0.1 wt.%, respectively. Second, the conventional method of alkaline refining is adopted to remove arsenic from the crude alloy, and arsenic content in the low-arsenic alloy could be decreased to 0.009 wt.%. Finally, the low-arsenic alloy is oxidized in a special oxidizing pan at 650°C by blowing compressed air or oxygen-rich air on the surface, during which qualified antimony white can be produced and collected in a bag house. The oxygen concentration and antimony content in the bottom alloy have a significant impact on production efficiency and product quality during blowing oxidation.     

Thermodynamic modeling of antimony removal from complex resources in copper smelting process

This work investigated the reaction mechanism of Sb in copper smelting process. The difference of multi-phase distribution of Sb in four typical copper smelting processes was analyzed. A multi-phase equilibrium model of the oxygen-enriched bottom-blow copper smelting process was developed. The impacts of Cu, S, and Sb concentrations in raw materials on Sb distribution in multiphases were researched. This model was also used to investigate the effect of process factors such as copper matte grade, oxygen-enriched concentration, smelting temperature, and oxygen/ore ratio (ratio of oxygen flow rate under standard conditions to concentrate charge rate) on Sb distribution behavior. The results showed that calculation data were in good agreement with the actual production results and literature data. Increasing the Cu content and decreasing the S and Sb contents in the concentrate, increasing the copper matte grade, oxygen/enriched concentration, and oxygen-ore ratio, and at the same time appropriately reducing the smelting temperature are conducive to the targeted enrichment of Sb into the slag. Modeling results can provide theoretical guidance for the clean and efficient treatment of complex resources and the comprehensive recycling of associated elements.     

Mathematical model of pyritic smelting process for copper-nickel mineral in oxygen top-blown furnace

1　INTRODUCTIONTheideaofrefiningcopperandnickelwithpyriticsmeltingprocessinoxygentop blownfurnacehascomeintobeingforitsachievementinoxygen converterofsteelmaking processfrom 196 0s.Thefirstpyriticsmeltingfurnacewithoxygentop blownsmeltingnickelhadbeenputintoproductionatNorthNickelCo .ofRussianin 1986 .Nowadays ,thistech nologyhasbeenimportedandemployedinJinchuanNonferrousMetalCo .ofChina .Inthepastdecades ,theutilizationofflashsmeltingfurnaceinnonferrous makinghasgotextensivedevelopmen…     

Magnetite in the Hurley Copper Smelter

Three aspects of magnetite smelting are discussed. The first is the working out of equilibrium conditions for eliminating sulfur. The second is the influence of magnetite solubility on the difficulty of tapping the reverb matte. The third is an approximation of the equilibrium conditions in the reverb gases which govern whether magnetite is made or reduced in the reverb slag by these gases and by any iron sulfide in the slag.     

Direct Production of Copper

The use of commercially pure oxygen in flash smelting a typical chalcopyrite concentrate or a low grade comminuted matte directly to copper produces a large excess of heat. The heat balance is controlled by adjusting the calorific value of the solid feed. A portion of the sulfide material is roasted to produce a calcine which is blended with unroasted material, and the blend is then autogeneously smelted with oxygen and flux directly to copper. Either iron silicate or iron calcareous slags are produced, both being subject to a slag cleaning treatment. Practically all of the sulfur is contained in a continuous stream of SO₂ gas, most of which is strong enough for liquefaction. A particularly attractive feature of these technologies is that no radically new metallurgical equipment needs to be developed. The oxygen smelting can be carried out not only in the Inco type flash furnace but in other suitable smelters such as cyclone furnaces. Another major advantage stems from abolishion of the ever-troublesome converter aisle, which is replaced with continuous roasting of a fraction of the copper sulfide feed.     

ELECTROCHEMICAL STUDY OF ACTIVITY OF Nb_2O_5 AND MnO IN Nb_(?)O_(?)-MnO-SiO_(?)SYSTEM

Equilibrium between liquid iron containing Nb with Nb_2O5-MnO-SiO_2 slag was investigatedat 1828 K,the solid electrolyte oxygen concentration cell being used to measure the activityof oxygen in the metal bath.The activity of Nb_O_5 and MnO in the slag was evaluated,accompanied with an iso-activity diagram of a_(Nb_2O_5) and a_(MoO) in Nb_2O_5-MnO-SiO_2 slay.     

Numerical analysis on fluid flow and heat transfer in the smelting furnace of mitsubishi process for Cu refining

To understand complex behavior in the smelting furnace of Mitsubishi continuous process for copper refining, comprehensive 3-D numerical simulation and field experiment were performed. The numerical simulation results showed that strong and complex velocity fields of gas, matte and slag were generated in the furnace and large amounts of matte and slag were splashed into the gas area. Temperature measurements at the lance during field operation revealed that wide range of temperature variation appeared depending on the injection condition of concentrates. Numerical simulation results provided good agreements with experiments results and showed that the chemical reaction induces temperature increase during gas injection period. On the other hand, lance temperature is decreasing because of cold concentrates during gas and particles injection period. From the FFT analysis results, the fluctuations of matte and slag volume fraction near the lance induce temperature fluctuations of the lance. Through these experimental and simulation results, it was revealed that the lances in the smelting furnace were exposed to severe conditions such as high temperature, repeated large temperature change and cyclic change of large temperature gradient across the thickness.