氧化锌碱法脱氯工艺研究及应用

基于湿法炼锌用次氧化锌原料必须进行脱氯预处理的特点, 采用碳酸钠碱液湿法工艺对氧化锌脱氯工艺进行了研究, 研究结果表明, 最佳工艺条件为: 温度80 ℃以上, 液固比5∶1, 搅拌速度为500 r/min, 碱浓度2%以上, 反应时间为1 h, 此时氧化锌含氯量可降到了0.07%以下。投入工业实践应用思路是, 采用一段碱液和一段清水洗涤的逆流二段工艺, 在恒定碱量时, 通过降低液固比为2∶1, 溶液碱浓度提高, 脱氯效果明显, 渣中含氯量降到0.03%以下。

Study and Its Application of Zinc Oxide Dechlorination by Alkaline Process

Since the secondary zinc oxide taken as raw material for zinc hydrometallurgy must be pretreated for dechlorination, some experimental studies have been conducted for it. Results showed that under the following optimum process conditions: at a temperature of above 80 ℃, with liquid-to-solid ratio of 5∶1, stirring speed of 500 r/min, alkali concentration of above 2% and reaction time of 1 h, the chlorine content of zinc oxide decreased below 0.07%. In the industrial practical application adopting two-stage countercurrent washing process by one-stage with alkali solution, one-stage with water, the alkali concentration of the solution increased by decreasing liquid-to-solid ratio to 2∶1 at a constant alkali dosage. It brought a significant dechlorination effect, with the chlorine content in the slag decreased below 0.03%.