次氧化锌渣与污酸浸出工艺条件研究

Leaching Conditions of Secondary Zinc Oxide Slag and Waste Acid

次氧化锌渣和污酸中分别含有ZnO和H_(2)SO_(4)等有价成分。针对现有次氧化锌渣和污酸回用技术中存在的氟、氯、砷等杂质分离困难的问题,提出了次氧化锌渣和污酸的联合浸出工艺,并对浸出工艺条件进行了研究,考察了硫酸浓度、浸出pH值等对浸出液浓度的影响。结果表明,当硫酸质量浓度为10~150 g/L时,控制锌与硫酸物质的量比为1∶1,次氧化锌渣中锌的浸出率均高于90%。当浸出pH值为1.39~5.25时,锌浸出率为93.3%~98.1%,氟浸出率为28.9%~42.2%,氯浸出率为43.2%~51.6%,砷浸出率为0.05%~0.12%。因此,通过次氧化锌和污酸浸出,不仅可以得到高硫酸锌浓度溶液,而且可以适当降低氟、氯、砷等杂质浓度,为后续硫酸锌浸出液的资源化利用奠定基础。

The secondary zinc oxide slag and waste acid contain valuable components such as ZnO and H_(2)SO_(4),respectively.In view of the difficulty in separating impurities such as fluorine,chlorine and arsenic in the existing recycling technology,a combined leaching process of zinc oxide slag and waste acid was proposed,and the leaching process conditions were studied.The effects of sulfuric acid concentration,leaching pH on the concentration of leaching solution were investigated.The results show that when the concentration of sulfuric acid is 10~150 g/L,and the molar ratio of zinc to sulfuric acid is 1∶1,the leaching rate of zinc in secondary zinc oxide slag is higher than 90%.When the leaching pH value is 1.39~5.25,the zinc leaching rate is 93.3%~98.1%,the fluorine leaching rate is 28.9%~42.2%,the chlorine leaching rate is 43.2%~51.6%,and the arsenic leaching rate is 0.05%~0.12%.Therefore,high zinc sulfate containing solution can be obtained by the leaching process,while the concentration of fluorine,chlorine,arsenic and other impurities can be also appropriately reduced.This study lays a foundation for the subsequent utilization of zinc sulfate leaching solution.