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.     

Mass balance calculations in copper flash smelting by means of genetic algorithms

This paper presents mass balance calculations using genetic algorithms for copper smelting in an Outokumpu flash furnace. Based on the elemental composition of the copper concentrates being fed to the reactor, the mineralogical composition of the concentrate mixture is adjusted by means of genetic algorithms. The macroscopic mass balance equations for the species entering and leaving the furnace are solved and the compositions and flow rates of matte, slag, and the off-gas stream are computed. Good agreement between the predicted and plant data was obtained in terms of matte and slag flow rates, matte grade, and copper, iron, magnetite, and silica contents in the slag. Predictions are more suitable and faster to obtain with this method than a conventional method in which the mineralogical composition of the feed is not adjusted. Future applications of the formulation are discussed. For more information, contact V.M. Sanchez-Corrales, Universidad de Sonora, Departamento de Ingeniería Química y Metalurgia, Blvd. Luis Encinas y Rosales, Hermosillo, Sonora, 83000, Mexico; +662-259-2105; fax +662-259-2105; e-mail vsanchez@guaymas.uson.mx.     

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...     

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.     

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…     

铜闪速熔炼中微量元素行为的计算机模拟

在热力学平衡的基础上，利用描述闪速熔炼中微量元素行为的数学模型，结合闪速熔炼整体平衡计算结果，对Ａｓ，Ｓｂ，Ｂｉ在铜闪速熔炼中的行为进行计算机模拟。计算结果与文献结果及工业观测数据吻合较好。     

铜复杂资源熔炼过程中杂质锑脱除的热力学模拟（英文）

研究铜冶炼过程Sb的反应机理,分析Sb在4种典型铜冶炼工艺中多相分配差异。建立富氧底吹铜冶炼工艺的多相平衡模型,研究原料中Cu、S和Sb含量对Sb多相分配比的影响。同时,应用该模型研究铜锍品位、富氧浓度、熔炼温度和氧矿比(标准状态下氧气流量与精矿加料速率之比)等工艺参数对Sb分配行为的影响。结果 表明,计算数据与实际生产结果和文献数据吻合良好。提高精矿中Cu含量、降低S和Sb含量,提高铜锍品位、富氧浓度和氧矿比,同时适当降低冶炼温度,有利于Sb向炉渣中定向富集。模拟结果可为复杂资源清洁高效处理及伴生元素综合回收提供理论指导。     

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。     

Minimization of Copper Losses in Copper Smelting Slag During Electric Furnace Treatment

In the quest to achieve the highest metal recovery during the smelting of copper concentrates, this study has evaluated the minimum level of soluble copper in iron-silicate slags. The experimental work was performed under slag-cleaning conditions for different levels of Fe in the matte and for a range of Fe/SiO₂ ratios in the slag. All experiments were carried out under conditions where three phases were present (copper?Cmatte?Cslag), which is the condition typically prevailing in many slag-cleaning electric furnaces. The %Fe in the electric furnace matte was varied between 0.5?wt.% and 11?wt.%, and two different Fe/SiO₂ ratios in the slag were used (targeted values were 1.4 and 1.6). All experiments were performed at 1200°C. From thermodynamic considerations, from industrial experience, and from the results obtained in this study, the minimum soluble copper content in the electric furnace slag is expected to be near 0.55?wt.% Cu. This level does not account for a portion of the copper present as mechanically entrained matte/metal droplets. Taking this into account, the current authors believe an overall copper level in discard slag between 0.7?wt.% and 0.8?wt.% can be obtained with optimal operating conditions. For these conditions, the copper losses in the slag are roughly 75% as dissolved copper and 25% as entrained matte and copper. Such conditions include operating the electric furnace at metallic copper saturation, maintaining the %Fe in the electric furnace matte between 6?wt.% and 9?wt.%, not exceeding a slag temperature of 1250°C, and controlling the Fe/SiO₂ ratio in the smelting furnace slag at ??1.5. In addition, magnetite reduction needs to be performed efficiently during the slag-cleaning cycle so as to maintain a total magnetite content of ??7?wt.% in the discard slag. The authors further consider that under exceptionally well-controlled conditions, a copper content in electric furnace discard slag between 0.55?wt.% and 0.7?wt.% can be obtained, by minimizing entrained matte and copper solubility in the discard slag.     

Copper smelting mechanism in oxygen bottom-blown furnace

The SKS furnace is a horizontal cylindrical reactor similar to a Noranda furnace, however, the oxygen enriched air is blown into the furnace from the bottom. Mechanism model of the SKS process was developed by analyzing the smelting characteristics deeply. In our model, the furnace section from top to bottom is divided into seven functional layers, i.e., gas layer, mineral decomposition transitioning layer, slag layer, slag formation transitioning layer, matte formation transitioning layer, weak oxidizing layer and strong oxidizing layer. The furnace along the length direction is divided into three functional regions, that is, reaction region, separation transitioning region and liquid phase separation and settling region. These layers or regions play different roles in the model in describing the mechanism of the smelting process. The SKS smelting is at a multiphase non-steady equilibrium state, and the oxygen and sulfur potentials change gradually in the length and cross directions. The smelting capacity of the SKS process could be raised through reasonably controlling the potential values in different layers and regions.     

金锑精矿提金工艺的改进

在简要介绍我国金锑精矿鼓风炉挥发熔炼-贵锑电解工艺的基础上,重点阐述了锑锍处理、金银合金提纯、贵锑和贵铅富集金等工序改造的相关内容.将锑锍处理由原来的焙烧法改为选矿法,将金银合金处理工艺由电解改为溶解萃取,贵锑和贵铅富集金由电解改为控制电位选择性氯化浸出.这些工序的改进不仅保证了原有生产工艺的正常进行,提高了各种金属的直收率,而且缩短了工艺流程,减少了环境污染.     

铜闪速炉沉淀池渣中锍液滴沉降机理及其影响因素

通过分析沉淀池内锍液滴的沉降机理,导出了渣中最大锍液滴直径的计算公式。根据闪速炉的实际生产条件,计算出渣中最大锍液滴直径的理论值为0.063 mm,并用矿相显微镜对沉淀池出口处的渣样进行了观察,渣中最大锍颗粒粒径为0.06 mm,两者结果一致。由此证明了沉降机理分析的正确性。在此基础上,进一步分析渣中锍夹带损失影响因素。结果表明:增大熔体中离散态分布的锍液滴直径是降低渣中铜夹带损失的重要措施;其次是升高渣温度有助于渣中锍的沉降;减小渣层厚度等措施对降低渣中铜夹带损失作用不大。     

基于数值模拟的闪速连续炼铜炉型结构研究

分析4种闪速连续炼铜炉型的本质特性,提出将闪速连续炼铜过程视为由相对独立的闪速造锍熔炼过程和连续吹炼造铜过程构成,分别建立闪速造锍熔炼多相平衡数学模型和连续吹炼造铜局域平衡数学模型,并通过中间物料的传递将两模型有机结合,从而构建完整的闪速连续炼铜过程热力学模型。运用此模型,考察炉型结构对闪速连续炼铜过程的粗铜生成条件、Fe3O4行为、铜在渣中损失以及铜直收率等因素的影响。结果表明：相对于其他3种炉型,甩渣吹炼双烟道D型炉是比较理想的连续炼铜炉体;对于闪速连续炼铜,造锍熔炼段和铜锍吹炼段宜在相对独立的分区进行,各自炉渣和烟气也应分开排出炉体。     

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.     

Cu2S-MoS2二元系相图的测定

针对现有辉钼矿氧化焙烧工艺生产效率低、设备结构复杂、炉料容易烧结、二氧化硫污染严重等不足,提出一种熔池熔炼辉钼矿的新方法.为了得到不同温度下辉钼矿在白冰铜中的溶解度,用干化学法合成硫化亚铜,并用步冷曲线法测定了Cu2S-MoS2二元系相图.实验结果表明,在MoS2质量分数为0～4.48％的范围内,Cu2S-MoS2二元系为简单的二元共晶体系,共晶温度为(1117.0±3.0)℃,共晶组成为(1.70±0.20)％MoS2;当MoS2含量超过4.48％时MoS2和Cu2S形成固溶体.在铜熔炼温度范围(1200～1300℃)内,白冰铜能够溶解辉钼矿,在1200℃时溶解度达到14.8％.     

Chemical Degradation Mechanisms of Magnesia–Chromite Refractories in the Copper Smelting Furnace

Magnesia–chromite refractory has been extensively used in the copper-making industry. It is necessary to understand the degradation mechanisms of the current refractory to develop new refractories. In the present study, post mortem refractories from a smelting furnace were analyzed and compared with the results of static corrosion tests on magnesia–chromite refractories in the laboratory at high temperatures. The microstructure and phase composition were carefully investigated by electron probe x-ray microanalysis to understand the degradation mechanisms of the magnesia–chromite refractory in copper smelting conditions. The degradation mechanisms between the magnesia–chromite refractory and the copper smelting slag and CuO transformed from matte are discussed based on the analysis of the post mortem refractory samples and laboratory tests. These results will enable optimization of the industrial process and development of new refractories for copper smelting furnaces.     

Operation optimization of concentrate burner in copper flash smelting furnace

The software that simulates the flow, temperature, concentration and the heat generation field in the Outkumpu flash smelting furnace, was developed by a numerical method of the particle-gas flow together with some chemical reaction models. Many typical operating conditions were chosen for simulation in order to obtain the effect of the distribution air, process air, central oxygen and the oil-burner position etc. The concepts about optimum op-eration, 3C(concentration of high temperature, high oxygen and laden concentrate particles), are concluded from these simulated results, which have been checked primarily by operational experiments.     

High Intensity Operation at Naoshima Smelter

This paper describes the successful test operation of a 50 t/h concentrate feed rate (or on the anode copper basis 9000 tlm) with the Mitsubishi Process. Particular emphasis is given to the analyses of the furnace capacity by the measurement of flow pattern and oxygen potential. Smelting rate on the unit hearth area of the smelting furnace is now one-ton of concentrate/m²·h. The results of the analyses show the further potential of the furnace capacity of the process.     

Top-blown injection smelting and converting: The Mitsubishi process

The Mitsubishi process is a continuous copper smelting and converting process comprising three steps—smelting of raw materials by injection, separation of slag and matte, and direct converting of high-grade matte. Since commercial operation began in 1974, the hearth productivity has been doubled, and several other improvements have been made, including higher-grade matte smelting and the treatment of various secondary materials. Because the Mitsubishi process is superior to the conventional process, it was decided to construct a larger unit of the Mitsubishi furnaces to replace the two existing smelter lines. This article discusses various technical considerations.     

Numerical simulation analysis of Guixi copper flash smelting furnace

A numerical simulation analysis for reactions of chalcopyrite and pyrite particles coupled with momentum,heat and mass transfer between the particle and gas in a flash smelting furnace is presented.In the simulation.the equations governing the gas flow are solved numerically by Eular method.The particle phase is introduced into the gas flow by the particle-source-in-cell technique(PSIC),Predictions including the fluid flow field,temperature field,concentration field of gas phase and the tracks of particles have been obtained by the numerical simulation.The visualized results show that the reaction of sulfide particles is almost completed in the upper zone of the shaft within 1.5m far from the central jet distributor (CJD)type concentrate burner,The simulation results are in good agreement with data obtained from a series of experiments and tests in the plant and the error is less than 2%.