湿法磷酸生产尾气氨洗法工业化技术研究

Industrialized ammonia washing technology for fluoride-containing tail gas from wet-process phosphoric acid production

以氨水作为吸收剂,采用逆流洗涤及氟硅料浆强制过滤技术,依次经二氟洗涤塔、一氟洗涤塔及文丘里洗涤器吸收湿法磷酸含氟生产尾气,研究得出,最佳尾气氨洗法工艺为二氟洗涤液p H 7.5,温度45℃,停留时间35 min,喷淋密度6.5 m3/(m2·h)及空塔气速4.0 m/s,该条件下,系统尾气氟化物质量浓度为6.31 mg/m3,一氟洗涤塔离心滤液氟化物质量分数为11.33%,联产无水氟化氢及白炭黑转化直接经济效益1 102.76万元/a。

Ammonia is used as absorbent to absorb the fluorinated compound in tail gas from wet-process phosphoric acid production by countercurrent washing technology and forced filtration technology of fluosilicic slurry through the second fluorine scrubber, the first fluorine scrubber and Venturi scrubber. The results indicate that the fluoride concentration in tail gas and centrifugal filtrate of the first fluorine scrubber are 6. 31 mg·m-3 and 11.33%, respectively, under the following conditions ： 7. 5 of pH of second fluorine scrubbing solution, 45℃ of temperature, 35 minutes of residence time,6. 5 m3/（m2 ·h） of spray density and 4.0 m/s of the superficial gas relocity. The direct economic benefit from the integrated production of anhydrous hydrogen fluoride and silica can reach 11. 027 6 million RMB Yuan/a.