铁矾渣熔化-烟化过程中锌元素的物相演化规律

Phase evolution rule of zinc element during the melting-fuming process of jarosite slag

湿法炼锌热酸浸出-黄钾铁矾法炼锌工艺过程中产生的有害废渣铁矾渣,对人类的健康和生态环境造成极大的危害,且会导致有价金属的浪费,因此铁矾渣处理回收势在必行。本文通过对铁矾渣原渣的成分、物相等的分析,在热力学计算的理论指导下,讨论了基于碳热还原法的熔化-烟化回收铁矾渣中Zn元素最佳的工艺条件及其物相变化规律。通过计算得到铁矾渣中锌物相最终以氧化锌(ZnO)的形式富集于烟尘中;根据正交试验分析的结果验证了理论计算的合理性。基于降低能耗的考虑,最终确定试验研究结果:铁矾渣熔化-烟化过程中回收锌元素最佳条件为反应温度1200℃、保温时间100min空气流量600mL/min、配碳百分比30%,该条件下锌的回收率为99.70%。该研究为铁矾渣中锌元素的回收利用提供了现实的参考价值。

The jarosite slag produced in the process of zinc hydrometallurgy is harmful to human health and ecological environment,and will lead to waste of valuable metals.Therefore,it is imperative to treat and recover jarosite slag.Based on analysis of the composition and phase change of the raw jarosite slag,the optimum technological conditions and phase change law of Zn recovery from jarosite slag by melting and fuming based on carbothermal reduction method are discussed under the theoretical guidance of thermodynamic calculation.By calculation,the zinc phase in the jarosite slag is ultimately enriched in the form of zinc oxide(ZnO)in the fume;and the rationality of the theoretical calculation was verified based on the results of orthogonal experimental analysis.Considering reducing energy consumption,the experimental results were finally confirmed,and the optimum conditions for zinc recovery in the melting and fuming process of jarosite slag were as follows:reaction temperature 1200℃,holding time 100 min,air flow rate 600 mL/min and carbon ratio 30%,under these conditions,the recovery rate of zinc was 99.70%.The study provides a practical reference value for the recovery and utilization of zinc in jarosite slag.