硫酸亚铁废液的综合回收利用

Comprehensive Recovery and Utilization of Ferrous Sulfate Waste Liquid

在工业生产中每年都会产生大量的硫酸亚铁废液,其中钢铁深加工过程的产出量最大。硫酸亚铁废液中含有硫酸,pH值较低,且含有铁、钴、镍、铝、铬等金属离子,直接排放不仅浪费其中的金属资源,还会对土壤和水体造成严重污染。综合回收硫酸亚铁废液对企业具有巨大的经济效益,对社会具有一定的环境效益。目前主要的处理方法有中和处理法、化学沉淀法、结晶析出法、溶剂萃取法、微生物法等。针对不同生产过程产生的硫酸亚铁废液应采用相应的处理办法。由于中和处理法产生大量金属污泥、结晶析出法的产品市场需求低、溶剂萃取法处理能力低、微生物法处理周期长,化学沉淀法是目前主要采用的回收方法。化学沉淀法操作简单、无需高性能设备,但试验影响因素多,产品性质波动大。硫酸亚铁废液回收产品主要被应用于颜料行业、水处理行业、磁性材料行业等。多数产品仅利用了废液的铁元素,而硫酸和硫元素并未得到回收利用,如何对废液进行综合回收是一个研究重点。由于硫酸亚铁废液中杂质元素含量较多,对其进行提纯具有很大的难度,所需生产成本也较高,因此如何直接利用废液也是未来研究的主要方向。

In industrial production,a large amount of ferrous sulfate waste liquid is produced every year,and the output of iron and steel deep processing process is the largest.Ferrous sulfate waste liquid contains sulfuric acid with low pH value and metal ions such as iron,cobalt,nickel,aluminum and chromium.Direct discharge not only wastes metal resources,but also causes serious pollution to soil and water.How to comprehensively recover ferrous sulfate waste liquid has great economic benefits for enterprises and certain environmental benefits for society.At present,the main treatment methods are neutralization treatment,chemical precipitation,crystallization precipitation,solvent extraction,microbial method and so on.According to the ferrous sulfate waste liquid produced in different production processes,corresponding treatment methods should be adopted.Because a large amount of metal sludge will be produced by neutralization method,the product market demand of crystallization precipitation method is low,the treatment capacity of solvent extraction method is low,and the treatment cycle of microbial method is long,so chemical precipitation method is the main recovery method at present.The chemical precipitation method is easy to operate and does not need high-performance equipment,but there are many influencing factors in the test and the product properties fluctuate greatly.From ferrous sulfate waste liquid recovered products are mainly used in pigment industry,water treatment industry,magnetic materials industry and so on.Most products only use iron in waste liquid,but sulfuric acid and sulfur are not recovered.How to comprehensively recover waste liquid is a research focus.Because there are many impurityelements in ferrous sulfate waste liquid,it is very difficult to purify it,and the production cost is alsohigh.Therefore,how to directly utilize the waste liquid is also the main research direction in the future.