摘要
在NaOH和NaClO作复合浸出剂从磷酸废砷渣中浸出砷的基础上,以SO2对氧化脱硫后的浸出液进行砷还原,然后进行冷冻结晶得HAsO2晶体,实现砷的回收。研究表明,还原反应的适宜条件为:温度30℃,还原时间3 h,溶液pH0,反应液五价砷浓度为33.10 g/L,此时HAsO2一次结晶率达53.85%;HAsO2的冷冻结晶适宜条件是:温度?15℃,溶液pH0,冷冻时间3 h,此条件下砷结晶率为90.22%。
On the basis of leaching arsenic from waste arsenic residue of phosphoric acid with NaOH and NaClO as compound leaching agents, SO2 was used to reduce arsenic in the leaching solution af-ter oxidative desulfurization, and then the HAsO2 crystal was obtained by freezing crystallization to realize arsenic recovery. The results showed that the optimum conditions for reduction reac-tion were: temperature 30?C, reduction time 3 h, solution pH0, concentration of pentavalent ar-senic in reaction solution 33.10 g/L, and the primary crystallization rate of HAsO2 reaching 53.85%. The suitable conditions for freezing crystallization of HAsO2 were: temperature ?15?C, solution pH0, freezing time 3 h, under which the primary crystallization rate of HAsO2 was 90.22%.
出处
《化学工程与技术》
CAS
2020年第2期119-126,共8页
Hans Journal of Chemical Engineering and Technology
基金
广西科技计划项目(桂科AB16380279)。
