Ausmelt铜熔炼炉用再生铝铬砖中Cr2O3稳定化机理及其抗铜渣/冰铜蚀损行为

The Ausmelt copper smelting is an important smelting technique in pyrometallurgy. Aiming at the problems in chromic stability and erosion resistance of the MgO-Cr2O3 refractory, recycled alumina-chromia bricks are fabricated by using aluminum-chromium slag in this project. By introducing the acidic oxide additives into the refractory, the formation of Cr6+ will be inhibited and the solid solubility of Al2O3 and Cr2O3 can be enhanced, thus reducing the volatilization of Cr2O3. In this project research, the mechanism of the sintering behavior and the Cr2O3 stability of the recycled alumina-chromia bricks under different influences will be systematically investigated. Such as the type, the way of introduction and the amount of additives, the employed sintering system etc.. As a consequence, the grain boundary characters of the refractory and its regulation mechanism on the microstructure evolution of the material can be discovered. By studying the interfacial reaction and microstructure change rules within the copper slag/matte of the recycled alumina-chromia bricks, the characteristics of materials during the continuous erosion process could be concluded, the inner relationship between the microstructure and the interfacial reaction kinetics of the recycled alumina-chromia bricks would be explored, the erosion mechanism of the refractory in the copper slag/matte could be revealed. Based on the investigation, this project will shed light on the microstructure controlling and property optimization of the recycled alumina-chromia bricks for the Ausmelt copper smelting furnace. In addition, related achievements have positive meanings for promoting the investigations of chromic stability and the harmless applications of aluminum-chromium slag resources.

Ausmelt（澳斯麦特）铜熔炼工艺是火法炼铜中重要的冶炼技术。针对Ausmelt铜熔炼炉内衬用镁铬质耐火材料的铬稳定及抗侵蚀等问题，本项目以铝铬渣为原料制备再生铝铬砖，通过酸性氧化物添加剂的干预，抑制Cr6+的形成，并增强Al2O3和Cr2O3的固溶，降低Cr2O3的挥发，系统研究添加剂的种类、引入方式、加入量、烧成制度等因素对再生铝铬砖的烧结行为及Cr2O3稳定性的影响机理，掌握再生铝铬砖晶界相特性及其对材料显微结构的调控机制，通过铜渣/冰铜与再生铝铬砖的界面反应及微观结构变化规律，归纳材料持续蚀损行为的阶段特性，探明再生铝铬砖显微结构参数与界面反应动力学特征的内在关联，揭示耐火材料在铜渣/冰铜熔体中的侵蚀机理，为Ausmelt铜熔炼炉用再生铝铬砖的微观结构调控与性能优化提供理论依据，相关研究成果对丰富铝铬渣资源的铬稳定研究与无害化应用有积极意义。

Ausmelt（澳斯麦特）铜熔炼工艺由于具有熔炼速度快、原料适应性强、炉体密封性好及环保等特点，已成为火法炼铜中重要的冶炼技术。针对Ausmelt铜熔炼炉内衬用镁铬质耐火材料的铬稳定及抗侵蚀等问题，本项目以铝铬渣为原料制备再生铝铬砖，通过酸性氧化物添加剂干预，抑制Cr6+的形成，并增强Al2O3和Cr2O3的固溶，降低Cr2O3的挥发，主要研究内容包括：①酸性氧化物（SiO2、TiO2）对再生铝铬砖烧结性能及Cr2O3稳定化机理；②再生铝铬砖物相组成及低熔相形成机制；③再生铝铬砖抗铜渣/冰铜侵蚀机理。结果表明：1）SiO2或TiO2的引入均能促进铝铬固溶体的形成，有利于再生铝铬砖的烧结致密化，同时利用其还原性抑制Cr(Ⅲ)向Cr(Ⅵ)的转变，进而实现Cr2O3的稳定；2）再生铝铬砖所属Al2O3-Cr2O3体系中杂质组分CaO高温下易与主晶相反应形成低熔相，并沿骨料边缘形成连续分布，CaO含量增大1wt%，晶间低熔相增加近6wt%。3）再生铝铬砖与铜渣/冰铜的侵蚀界面反应中，熔渣内的FeO与砖中的Cr2O3反应形成高熔点相铁铬尖晶石，既可稳定再生铝铬砖中的Cr2O3，又能提高砖的抗侵蚀性能。相关研究成果对丰富铝铬渣资源的铬稳定研究与无害化应用有积极意义。