自动反洗表面过滤器在净化污酸处理中的应用

介绍了重庆华强化肥有限公司2×80 kt/a硫铁矿制酸净化工序技术改造情况。采用"文—电"稀酸洗净化工艺代替"文—间—电"水洗净化工艺,用板式稀酸冷却器代替间冷器,用自动反洗表面过滤器代替澄清池和斜板沉降池,用陶瓷真空过滤机代替压滤机。改造后w（H₂SO₄）约30%的稀酸送入干吸工序和磷铵萃取工序回用,陶瓷真空过滤机产生的w（Fe）>61%滤渣直接外售,每年增加直接经济效益约350万元。

Application of automatic backwash surface filter in treatment of waste acid from cleaning section

Revamping of cleaning section of Chongqing Huaqiang Fertilizer Co.＇s 2 X 80 kt/a pyrite-based sulphuric acid are described.In revamping,a dilute acid-scrubbing cleaning process with venturi-electrostatic precipitator was substituted for existing water scrubbing-cleaning process with venturie-indirect cooler-electrostatic precipitator,plate acid cooler for indirect cooler,automatic backwash surface filter for clarifiers and inclined plate sedimentation pond,and ceramic vacuum filter for press filter.After revamping,sulphuric acid at about 30 wt%was recycled to drying and absorption section and ammonium phosphate extraction section and the residues containing over 61%Fe from ceramic vacuum filter was sold.With utilization of polluted acid and residues,the direct income per year increases about 3 500 000 vuan.