稀土冶炼厂酸性含氟废水处理工程改造

Acid Fluoride-containing Wastewater Treatment Project in Rare Earths Refinery

介绍了广西某稀土冶炼厂酸性含氟废水处理改造工程。该厂废水成分复杂、酸性强、含氟高、含有多种重金属离子,采用天然石灰石中和沉淀预处理,然后再投加石灰乳和PAM进行二次沉淀,出水的氟离子及金属离子含量能够达到《污水综合排放标准》(GB8978—1996)一级标准,并且形成的化学沉淀少、操作简单方便;与传统的石灰乳中和法相比,该工艺能大幅降低废水处理成本。

The reconstruction project of acid fluoride-containing wastewater treatment in rare earths refinery was introduced. The wastewater was characterized by complex composition, strong acidity, and high content of fluoride with contents of many kinds of heavy metal ion. In the pretreatment process, natural limestone was used for neutralization and precipitation, and then the lime cream and PAM were added for secondary precipitation. The result shows that the effluent fluoride and heavy metals can reach Iclass criteria specified in the Integrated Wastewater Discharge Standard （ GB 8978 - 1996） , and the process has the advantages of less chemical precipitates, easy operation, and much lower treatment cost than the conventional lime cream neutralization.