(1. 中南大学 冶金与环境学院，长沙 410083；
2. 中南大学 国家重金属污染防治工程技术研究中心，长沙 410083)
摘 要: 针对高铁锌焙砂现有冶炼方法的不足提出选择性还原-浸出处理锌焙砂工艺。锌焙砂中锌铁主要物相为铁酸锌，首先采用热力学软件Factsage对铁酸锌还原过程进行分析，得出铁酸锌选择性还原控制条件，并结合热重分析和化学分析对热力学分析结果进行验证。结果表明：以可溶性锌和亚铁含量为评价指标的最佳磁化焙烧条件为焙烧时间60 min，焙烧温度750 ℃，CO分压8%(体积分数)，VCO/(VCO+VCO2)气氛比30%，此时的占总锌比率(可溶锌率)为91.89%，亚铁占总铁的比例(亚铁率)为51.19%。将上述理论计算和分析结果应用于锌焙砂处理，焙烧产物中的锌通过酸浸回收，铁以磁性氧化铁形式赋存于焙砂中；以铁锌浸出率为考察指标得出最佳浸出条件为温度30 ℃、初始酸度90 g/L、液固比10:1、反应时间10 min，此时选择性浸出效果较为理想。
关键字: 铁酸锌；锌焙砂；磁化焙烧；浸出
（1. School of Metallurgy and Environment, Central South University, Changsha 410083, China;
2. Chinese National Engineering Research Center for Control and Treatment of Heavy Metal Pollution,
Central South University, Changsha 410083, China）
Abstract:A kind of selective reduction roasting-leaching process which is against deficiencies of existing treatment of zinc calcine was proposed. The Factsage 6.2 program was used for the thermodynamic analysis of the selective reduction and the optimal roasting condition was obtained. Then, TG analysis and chemical analysis of zinc ferrite was applied to verify the results of thermodynamic analysis. The results show that using the content of soluble zinc and ferrous iron as the evaluation index of the reduction roasting, the optimal roasting conditions are obtained as follows: roasting time of 60 min, roasting temperature of 750 ℃, CO volume fraction of 8%, VCO/(VCO+VCO2) of 30%. The soluble zinc ratio of 91.89% (mass fraction) and ferrous iron content of 51.19% in the total iron content are achieved. Then, this roasting method was applied in the treatment of zinc calcine, the roasting product was subjected to acid leaching to recover zinc, and iron remains in residues as magnetite. The optimum leaching conditions with the leaching efficiency of zinc and iron as the evaluation index are obtained as follows: leaching temperature of 30℃, sulfuric acid concentration of 90 g/L, liquid to solid ratio of 10:1 and leaching time of 30 min.
Key words: zinc ferrite; zinc calcine; magnetic roasting; leaching
