镀锌钢板废料中锌的碱浸过程影响因素分析

以强碱(NaOH)溶液为浸取剂,采用碱浸法回收镀锌钢板废料中的锌,考察了不同因素(反应温度、反应时间、碱浓度、添加剂)对锌浸出效果的影响,并对添加剂的作用机理进行了分析。实验结果表明:在NaOH质量浓度为250g/L、反应温度为90℃、反应时间为300min的最佳工艺条件下,锌的浸出率高达97.89%;添加NaNO3可提高锌在碱液中的腐蚀电位和腐蚀电流,从而加快镀锌钢板废料中锌的溶解,缩短反应时间;添加KMnO4对反应速率基本无影响。

Analysis on factors affecting alkaline leaching of zinc from galvanized steel scrap

Zinc was recovered from galvanized steel scrap by alkaline leaching process using alkali （NaOH）solution as leaching agent. The factors affecting zinc leaching were investigated,such as reaction temperature,reaction time,alkali concentration and additive agents. And the mechanism of the additive agents were analyzed. The experimental results showed that：Under the optimum process conditions of NaOH mass concentration 250 g/L,reaction temperature 90 ℃ and reaction time 300 min,the zinc leaching rate reached 97.89%;With the addition of NaNO₃,the corrosion current and corrosion potential of zinc in the alkali solution could be promoted,which could accelerate the dissolution of zinc in galvanized steel scrap and shorten the reaction time;however,adding KMnO₄ had no effect on the reaction rate.