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.     

Removing arsenic from copper smelter gases

The pyrometallurgical processing of nonferrous minerals found in association with sulfur and arsenic generates arsenic-bearing SO₂ gases. Effective process gas cleaning presents technical problems due to the high volatility of the As₂O₃ compound and the elevated dew point of the sulfur-trioxidecontaining SO₂ gas. Critical factors for gascleaning technology selection pertaining to technical feasibility, economic acceptability, and environmental compatibility are the arsenic-to-sulfur ratio in the feed material, the operating parameters of the pyrometallurgical and gas cooling process, the admissible arsenic concentration of the SO₂ gas after arsenic elimination, and the most suitable form of the arsenic-bearing output material. Depending on these factors, the bulk of the arsenic can be eliminated from the process gas in concentrated form according to either the dry or wet method, after which final arsenic removal from the process gas to below the required admissible level must take place in a wet electrostatic precipitator. For more information, contact F. Dalewski, Lurgi Bischoff GmbH, Ruhrallee 311, 46136 Essen, Germany; telephone 49-69-5808-1141; fax 49-69-5808-2763; e-mail frank_dalewski@lurgi.de.     

高投料量下炼铜闪速炉内熔炼过程的数值模拟

以FLUENT 6.3为计算平台,建立了铜闪速炉熔炼过程数值模型,并针对高投料量下反应塔气粒两相变物理场信息分布变化特点展开仿真研究。结果表明:工艺风入炉后迅速膨胀,并在反应塔中心形成轮廓明显的主体气流柱;主体气流柱内外的温度和氧浓分布梯度变化较大;局部低温出现在精矿喷嘴下方,而高温反应核心区域则下移至反应塔中下部。综合多场耦合仿真结果可知:高投料量条件下精矿粒子与反应配风之间混合力度欠佳是造成高投料量反应塔内熔炼过程反应效率降低的主要原因。     

Applying Ausmelt processing to complex copper smelter dusts

Ausmelt technology opens up new opportunities for the economic processing of complex copper smelter dusts. Not only can the technology separate more of the unwanted elements to produce a clean blister copper for refining, but it can also allow production of fume and precious metal products that can be readily upgraded to produce high-grade, valuable products. Developments in the processing of copper-bismuth-gold flue dusts left over after the smelting of bismuth-bearing concentrates in flash furnaces are described, including pilot-plant trials and process and equipment development. Design considerations and capital and operating costs for the proposed plant are discussed.     

Current refractory practice as applied in copper smelting

Present indications are that the highest speeds of copper smelting have not yet been achieved. Although refractories are available which permit reasonable or satisfactory smelting costs, extensive research continues in an effort to develop refractories which will be capable of withstanding even more severe treatment.     

Slag cleaning: The chilean copper smelter experience

Chile has seven copper smelters, four that are linked to primary producers (three owned by Codelco and one by Disputada) and three custom smelters (two owned by Enami and one by Noranda). Each smelter employs a different strategy for slag cleaning, thus each smelter obtains different results. This article outlines and compares the different slag-cleaning systems that are currently in operation in the Chilean smelters, their strategies, the equipment in use, and their experiences. For more information, contact S. Demetrio, Cerro San Ramán 1491, Las Condes, Santiago-Chile; telephone 56-2-2145006; fax 56-2-2142358; e-mail smeltec@netline.cl.     

The oxidation mechanism in copper smelting and converting

The oxidation mechanism of copper-sulfide concentrates is of fundamental interest in an understanding of flash smelting and converting. The compositions of mattes follow simple, well-defined relationships, and the progression of iron and sulfur oxidation in smelting and converting occurs in such a manner that generates mattes of these compositions. J.W. Matousek earned his Ph.D. in metallurgical engineering at Queens University. He is currently an independent consulting engineer. Dr. Matousek is also a member of TMS.     

The toyo copper smelter of Sumitomo Metal Mining

Sumitomo Metal Mining and Company, Ltd., is a conglomerate company of nonferrous resources with a long history of more than 300 years in the copper business. Sumitomo Metal Mining engages not only in the worldwide mining of copper and gold, but also in smelting and refining copper, nickel, lead, and other nonferrous metals. Toyo copper smelter and refinery started its copper-smelting operation in 1971 and its copper-cathode production in 1973. During 26 years of operation, the company has established a reputation as a modern, clean, and pollution-free smelter of high productivity at low cost, drawing the attention of many smelters, refineries, and mines when they plan the modernization and reconstruction of their plants.     

Modeling and control of copper loss in smelting slag

A series of technical improvements have been implemented to address the issue of high copper losses in rotary holding furnace (RHF) slag, which were experienced at the Xstrata Copper Smelter at Mount Isa in 2007 and 2008. The copper losses in smelting slag in the RHF were more than 3% in 2006 and 2007. Thermodynamic models and viscosity models have been applied in the operation of Xstrata Copper Smelter in Australia. The theory of RHF key performance indicators has also been developed to reduce the copper losses in RHF slag. The RHF KPIs Theory has been applied in Mount Isa Copper Smelter. The copper losses in RHF slag dropped from 3.1% in 2007 to 0.76% in April 2009. The average copper loss in RHF slag in 2009 and 2010 was about 0.9%.     

Selecting an oxygen plant for a copper smelter modernization

The selection of an oxygen plant for the Cyprus Miami smelter modernization project began with a good definition of the use requirements and the smelter process variables that can affect oxygen demand. To achieve a reliable supply of oxygen with a reasonable amount of capital, critical equipment items were reviewed and reliability was added through the use of installed spares, purchase of insurance spare parts or the installation of equipment design for 50 percent of the production design such that the plant could operate with one unit while the other unit is being maintained. The operating range of the plant was selected to cover variability in smelter oxygen demand, and it was recognized that the broader operating range sacrificed about two to three percent in plant power consumption. Careful consideration of the plant “design point” was important to both the capital and operating costs of the plant, and a design point was specified that allowed a broad range of operation for maximum flexibility.     

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。     

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.     

Increasing the capacity of high-efficiency diffusion fiber beds in smelter gas plants

There are many available options to help increase capacity in existing sulfuric acid plants. Several advancements in de bottlenecking mist eliminator installations have been made over the years that resulted in increased plant production. Diffusion fiber bed devices, which collect particles by interception and impaction, also provide high-efficiency removal of fine submicrometer particles by Brownian diffusion. This article considers how to increase the capacity of diffusion fiber bed mist eliminators.