采用模拟湿法磷酸工艺,研究了温法磷酸的过滤、洗涤工艺和养晶工艺对磷石膏中可溶磷含量的影响.当萃取反应料浆液固比为2.5:1时,絮凝剂的适宜掺量为12mg/kg料浆,在料浆中适宜停留时间为3～5min,得到的磷石膏中可溶磷含量仅为0.48％,与没有添加絮凝剂的磷石膏相比,可溶磷含量降低了57％；洗涤水温度应控制在80℃左右,洗涤液固比(2～2.5):1,洗涤3次,得到的磷石膏中可溶磷含量为0.14％,与现有的工艺相比降低了86％；在磷酸萃取反应之后,过滤、洗涤之前,应增加养晶工艺,养晶温度为85℃,养晶时间1h,得到的磷石膏中可溶磷含量仅为0.6％,与没有养晶工艺的相比降低了39％.%The main study focuses on the processes impacting the soluble phosphorus content of phosphogypsum, such as the filtration, washing process and crystal growing process with simulating wet phosphoric acid process methods. When the extraction reaction slurry liquid-solid ratio is 2.S : 1, the appropriate amount of flocculant is 12 mg for per kilogram slurry, the suitable dwell time in slurry is about 3~5 min, and the soluble phosphate content of phosphogypsum is only 0.48%, reduced by 57% compared with that without flocculant in filtration process. The washing water temperature should be controlled at about 80 V, washing liquid to solid ratio at (2-2.5): 1 and wash three tunes, under the process conditions, the soluble phosphorus content of phosphogypsum is 0.14%, reduced by 86% compared with the existing conditions. After the extraction reaction of phosphoric acid, before the filtering and washing, the crystal growing process should be added, the crystal growing temperature at about 85 ℃, crystal growing time is 1 h, the soluble phosphorus content of phosphogypsum is only 0.6%, reduced by 39% compared with that without crystal growing process.
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