摘要：
采用盐酸法制磷酸，每生产1 t磷酸约产生7~8 t氟质量浓度约4 000 mg/L的酸性氯化钙废水。采用Ca（OH）2与聚合氯化铝（PAC）+聚丙烯酰胺（PAM）对该废水进行了除氟处理。结果表明，加入5.68% Ca（OH）2、25℃下反应1 h，废水中氟质量浓度降低至37.1 mg/L。Ca（OH）2沉淀除氟后的废水加入1.5 g/L PAC+5 mL/L 1%阴离子型PAM，40℃下反应15 min后废水中氟质量浓度为9.06 mg/L。对于酸性高浓度氯化钙废水，该除氟方法具有氢氧化钙用量少、不引入新的杂质、成本低、可深度除氟的优势，是一种具有工业应用价值的废水处理方法。
关键词:
湿法磷酸,
除氟,
氯化钙废水,
聚合氯化铝,
混凝沉淀
Abstract:
It is about 7-8 t acidic calcium chloride wastewater with 4 000 mg/L fluoride produced for 1 t phosphoric acid preparation by hydrochloric acid process. Ca(OH)2, polyaluminum chloride(PAC) and polyacrylamide(PAM) were combined for removal of fluoride from calcium chloride wastewater. The results showed that the content of fluoride in wastewater decreased to 37.1 mg/L at the condition of adding 5.68% Ca(OH)2, 25℃ for 1 h. When 1.5 g/L PAC and 5 mL/L 1% anion-type PAM was added to the wastewater after fluoride removal precipitated by Ca(OH)2, and the content of fluoride in the wastewater was 9.06 mg/L after reacting at 40℃ for 15 min. In the above defluorination process, no new impurities were introduced with low cost and deep defluorination. It is a valuable wastewater treatment method for industrial application.
Key words:
phosphoric acid from the wet process,
defluorination,
calcium chloride wastewater,
polyaluminium chloride(PAC),
coagulation precipitation
中图分类号:
廖杭,吕莉,唐盛伟,张涛. 盐酸法制磷酸中氯化钙废水的除氟工艺[J]. 工业水处理, 2021, 41(11): 89-93.
Hang LIAO,Li LÜ,Shengwei TANG,Tao ZHANG. Defluorination process of calcium chloride wastewater from phosphoric acid production by hydrochloric acid method[J]. Industrial Water Treatment, 2021, 41(11): 89-93.