锰电解行业铬钝化剂回收利用技术研究

以某电解锰工艺末端铬钝化废水为研究对象,采用氧化、除杂、反应制得成品,污水达标处理及回用的组合工艺,制备达到国家标准的中铬黄产品,以实现铬的回收利用。结果表明:对于H2O2氧化工艺,选用V(水样)/V(30%H2O2)为(600～1000):1;可采取加碱沉淀Mn的工艺去除杂质金属离子;铬酸铅的生成反应适宜温度为55～60℃,硝酸铅投加量为理论值的1.05倍～1.10倍;采取加石灰调pH、投加硫酸铝的方法可去除水样中剩余铅离子,V(上清液)/V(5%硫酸铝溶液)为1000～2000较合适;生产该产品基本上能够做到保本、微利,但具有显著的环境效益和社会效益。

STUDY ON CHROME RECYCLING AND UTILIZATION FROM K2Cr2O7 PASSIVATOR OF ELECTROLYTIC MANGANESE INDUSTRIES

A series of experiments were carried out for chrome recycling and utilization by oxidation,removing foreign substance,reaction and production process.The purpose was to gain standard medium chrome yellow from K2Cr2O7 passivator wastewater of electrolytic manganese.The results showed that the qualified production was gained by the series process.The optimum V(water)/V(30%H2O2)was 600~1000:1 for the oxidation process.Other metal ions could be removed by adding alkali.The optimum temperature for PbCrO4 generation was 55~60℃ and the dosage of Pb(NO3)2 was 1.05~1.10 times of the theoretic one.Surplus Pb ion could be removed by adding lime for pH adjust and the optimum V(upper liquid)/V(5% Al2(SO4)3)was(1000~2000):1.The economic benefit of the chrome recycling and utilization was slight,but the environmental and social benefits were outstanding.