Energy Efficiency of the Outotec<Superscript>®</Superscript> Ausmelt Process for Primary Copper Smelting

The global, non-ferrous smelting industry has witnessed the continual development and evolution of processing technologies in a bid to reduce operating costs and improve the safety and environmental performance of processing plants. This is particularly true in the copper industry, which has seen a number of bath smelting technologies developed and implemented during the past 30 years. The Outotec^® Ausmelt Top Submerged Lance Process is one such example, which has been widely adopted in the modernisation of copper processing facilities in China and Russia. Despite improvements in the energy efficiency of modern copper smelting and converting technologies, additional innovation and development is required to further reduce energy consumption, whilst still complying with stringent environmental regulations. In response to this challenge, the Ausmelt Process has undergone significant change and improvement over the course of its history, in an effort to improve its overall competitiveness, particularly with respect to energy efficiency and operating costs. This paper covers a number of recent advances to the technology and highlights the impacts of these developments in reducing energy consumptions for a range of different copper flowsheets. It also compares the energy efficiency of the Ausmelt Process against the Bottom Blown Smelting process, which has become widely adopted in China over the past 5–10 years.     

Matte Entrainment by SO2 Bubbles in Copper Smelting Slag

JOM - The attachment of copper matte by bubbles in slags, during the copper smelting process, plays a key role in the copper loss. This paper aims to provide an in-depth insight into the copper...     

Oxidation Potentials in Matte Smelting of Copper and Nickel

The oxidation potential, given as the base-ten logarithm of the oxygen partial pressure in bars and the temperature [log pO₂/T, °C], defines the state of oxidation of pyrometallurgical extraction and refining processes. This property varies from copper making, [?6/1150]; to lead/zinc smelting, [?10/1200]; to iron smelting, [?13/1600]. The current article extends the analysis to the smelting of copper and nickel/copper sulfide concentrates to produce mattes of the type Cu(Ni)FeS(O) and iron silicate slags, FeO_xSiO₂—with oxidation potentials of [?7.5/1250].     

Some Notes On Oroya Copper Slags

This paper is a study of the interrelationship between copper and magnetite content of reverberatory slags. During an experimental run converter slag was withheld from a reverberato ry, resulting in much cleaner waste slags. The possibilities of treating converter slags outside the normal copper smelting circuit are briefly discussed.     

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.     

Applying ausmelt technology to recover Cu, Ni, and Co from slags

The technical feasibility of recovering copper, nickel, and cobalt from smelting and converting slags using Ausmelt’s top-submerged lancing process has been demonstrated at the pilot-plant scale and in several commercial applications. Process conditions may be tailored to achieve the maximum economic recovery of valuable metals and to yield a product composition that is suitable for downstream processing requirements. Strong economic justification for a slag-cleaning process exists where the contained value of metals recovered exceeds $50 per tonne of slag treated. The top-submerged lance system offers a relatively low-cost solution where this value is predominantly associated with the recovery of cobalt. For more information, contact S. Hughes, Ausmelt Limited, P.O. Box 1003, Dandenong, Victoria 3175, Australia; telephone 61-3-9794-6200; fax 61-3-9794-9411; e-mail info@ausmelt.com.au.     

Impurity control and removal in copper tankhouse operations

During copper smelting, most of the undesirable impurities such as Pb, Sb, Bi, and As are only partially removed by oxidation. When white metal and blister copper are in equilibrium, these impurities are distributed mainly into the copper phase, from which their removal is difficult. When copper dissolves during electrorefining in a copper tankhouse, these impurities are continuously released from the anodes either as insoluble phases (slimes), which fall to the bottom of the cell, or as dissolved species in the electrolyte, the transfer of which to the cathode must be inhibited. This article presents impurity control methods in copper tankhouse operations with traditional and newly developed processes. It also summarizes the technologies demonstrated for removal of impurities from electrolyte that prevent them from being recycled in the copper smelting and refining circuit. For more information, contact Shijie Wang, Phelps Dodge Refining Corporation, 850 Hawkins Blvd., El Paso, TX 79915; (915) 775-8836; fax(915) 775-8352; e-mail swang@phelpsdodge.com.     

基于地球化学的水热还原矿化稳定砷的技术思路

砷作为有色金属矿物的共伴生元素,在有色金属冶炼过程中以含砷“三废”形式大量产出。由于砷具有强致癌性及毒性,导致砷的安全处置问题严重困扰着有色金属冶炼企业。本文通过阐述含砷废水中砷的两种稳定化工艺的研究进展,对比了现有稳定化工艺的优缺点,结合药剂稳定化和矿物稳定化的优点,借鉴砷元素在地球化学中的成矿规律,提出了硫化沉砷?水热还原矿化稳定砷的技术思路。首先采用硫化法脱除含砷废水中的砷,砷的沉淀率高达99.65%,硫化沉淀物在TCLP毒性检测中砷的浓度达到212.9 mg/L。然后采用As-S系一元水热还原矿化法和As-Fe-S系二元水热还原矿化方法稳定砷,稳定化产物分别为雌黄和雌黄?铁硫系(黄铁矿、硫化亚铁)混合物,在TCLP毒性检测中砷的浸出浓度分别为3.86 mg/L和2.65 mg/L。水热还原矿化工艺实现了含砷废水中砷的脱除及稳定化的目的,为水溶液中砷的脱除和稳定化提供了新的思路。     

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。     

铬铁合金氧化脱磷的热力学分析计算

通过热力学分析方法,结合相关热力学数据,从去磷保铬保碳的角度,对铬铁合金氧化脱磷的反应过程进行了分析计算。计算结果表明,BaO基高碱性渣更适合于铬铁合金的氧化脱磷,另外,加入适量的Cr2O3,可以更好的控制体系中的氧势值,提高初始碳含量、降低初始温度,有利于铬铁合金氧化脱磷,从而为铬铁合金的冶炼提供理论依据。     

Innovative Iron and Steelmaking

This paper addresses the need for radically new innovative technology to produce liquid iron and steel. The salient features of these so called “direct smelting” processes are also discussed, as are the developments in iron blast furnaces and steelmaking technology and processes. The energy required for a direct smelting process, based on injection of coal and domestic iron ores and other raw materials, has been calculated and compared with various similar direct smelting processes as well as existing blast furnaces. Finally, the future trends in the liquid iron and steelmaking technology and processes have been speculated.     

The use of solid-oxide-membrane technology for electrometallurgy

Solid oxide membrane (SOM) technology has been employed in developing several new metal reduction technologies. This overview describes the SOM process for copper deoxidation and SOM technology for metal smelting, as well as applications to magnesium, titanium, and tantalum. The examples illustrate various configurations of the SOM, anode, and cathode that are best suited to the needs of each metal.     

Thermodynamic analysis and process optimization of zinc and lead recovery from copper smelting slag with chlorination roasting

An efficient chlorination roasting process for recovering zinc (Zn) and lead (Pb) from copper smelting slag was proposed. Thermodynamic models were established, illustrating that Zn and Pb in copper smelting slag can be efficiently recycled during the chlorination roasting process. By decreasing the partial pressure of the gaseous products, chlorination was promoted. The Box−Behnken design was applied to assessing the interactive effects of the process variables and optimizing the chlorination roasting process. CaCl₂ dosage and roasting temperature and time were used as variables, and metal recovery efficiencies were used as responses. When the roasting temperature was 1172 °C with a CaCl₂ addition amount of 30 wt.% and a roasting time of 100 min, the predicted optimal recovery efficiencies of Zn and Pb were 87.85% and 99.26%, respectively, and the results were validated by experiments under the same conditions. The residual Zn- and Pb-containing phases in the roasting slags were ZnFe₂O₄, Zn₂SiO₄, and PbS.     

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.     

有色金属熔池熔炼的物理模拟研究

论述了熔池熔炼技术的发展、特点和在我国的应用现状.通过物理模拟的研究方法揭示许多熔池熔炼过程的基本现象及内在规律,对开发新技术和对已有设备技术改造提供理论依据.     

The behavior of sulfur in industrial pyrometallurgical slags

Dissolution of sulfur in industrial slags, even at such a low level as 1 mass% S or so, increases the solubility of certain valuable metals by an order of magnitude. The phenomenon is accounted for in terms of Flood-Førland-Grjotheim’s model for dianionic salt solutions, whereas its rigorous analysis requires the digaseous Gibbs-Duhem integration. In the research described here, the distribution of sulfur among gas, slag, and metallic iron phases in the bath smelting of iron ore was computer-simulated based on a two-sites model coupled with sulfide capacity data. The solubilities of Ag, Cu, Co, and Ni in industrial slags are reviewed by applying the sulfidic-oxidic dissolution model to copper-matte smelting, nickel-slag cleaning (Falconbridge, Canada), and the imperial smelting process for zinc and lead (Hachinohe, Japan).     

Thermodynamic potentials of oxygen dissolved in copper

Electrochemical sensors, based on ionic-conducting solid-electrolytes such as ZrO₂, for determining the oxygen content of molten metals or monitoring the oxygen potentials of mattes, slags, and exhaust gases are important in the control of metallurgical processes. This paper describes the theory and practice of their use in copper production.     

Steel from Copper Slags

A significant step toward the completion of plans for one of the largest steel mills in the Pacific Northwest was made with the initial prototype run at Strategic Materials Corp’s pilot-plant at Niagara Falls, Ontario, Canada. The operation utilized a modification of the Strategic-Udy process to produce steel from waste copper slags.     

半固态金属浆料制备新技术

半固态加工技术具有许多优良的特点，近年来得到迅速发展。广泛用于生产半固态金属的方法为触变成形，而流变成形与触变成形相比，前者更节约能源、流程更短、设备更简单，因此流变成形技术将是金属半固态加工技术的发展方向。半固态加工技术的发展趋势是，进一步简化加工工艺流程，进一步降低加工成本，扩宽半固态加工技术的应用范围。本文主要介绍最近几年在半固态浆料制备和加工中的几种新工艺和新技术的原理、特点及其应用，其中有新MIT工艺、冷却斜槽法、双螺旋流变注射成形法、剪切一冷却一轧制法、NRC工艺、不同液体混合法、近液相线铸造法等方法。     

Thermodynamics of Iron Oxidation in Metallurgical Slags

The state of oxidation of a pyrometallurgical process, given by the partial pressure of oxygen and the temperature, is one of the important properties monitored and controlled in the smelting and refining of iron and the nonferrous metals. This article reviews the thermodynamic background for this quantity and examines some empirical methods for its estimation and use. The emphasis is on copper smelting, but the same principles apply to iron, nickel, lead, and zinc processes.