钙法提钒废水除锰并制备高纯碳酸锰

Removal of manganese from vanadium extraction wastewater by calcium process and preparation of high-purity manganese carbonate

采用化学沉淀法脱除钙法提钒废水中的锰同时制备高纯碳酸锰。先将提钒废水pH调至5.5左右再进行除钙处理,当n((NH_(4))_(2)C_(2)O_(4))∶n(Ca_(2+))=0.95时,有效除钙率(实际除钙率/理论除钙率)最高(90.7%)。再向废水中加入碳酸氢铵溶液进行沉淀,并调节废水pH为6.8-7.2,在n(NH_(4)HCO_(3))∶n(Mn^(2+))=1.9、搅拌转速为700 r/min的条件下反应60 min制得碳酸锰。废水中锰去除率达94.5%,制得的碳酸锰产品锰品味(锰的质量分数)达44.2%,其杂质含量达到软磁铁氧体用碳酸锰(HG/T 2836—2011)Ⅱ型一等品的要求,实现了提钒废水中锰的资源化回收。

The chemical precipitation method was used to remove manganese from vanadium extraction wastewater by calcium process and prepare high-purity manganese carbonate simultaneously.After adjusting the wastewater pH to about 5.5,Ca_(2+)in the wastewater was removed.When n(H_(2)C_(2)O_(4))∶n(Ca_(2+))=0.95,the effective Ca_(2+)removal rate(actual Ca_(2+)removal rate/theoretical Ca_(2+)removal rate)was the highest(90.7%).Then ammonium bicarbonate solution was added to the wastewater for precipitation,and the wastewater pH was adjusted to 6.8-7.2.Under the conditions of n(NH_(4)HCO_(3))∶n(Mn2+)=1.9,stirring speed 700 r/min and reaction time 60 min,manganese carbonate was prepared.The removal rate of manganese in the wastewater reached 94.5%,and the manganese grade(mass fraction of manganese)of the manganese carbonate product reached 44.2%,and its impurity content met the standard of first grade of Type Ⅱ in Manganese carbonate for soft ferrite use(HG/T 2836-2011),which realized resource recovery of manganese from vanadium extraction wastewater.