摘要
脱氟渣是湿法磷酸化学沉淀脱氟过程产生的固体废渣。分别用甲醇、乙醇和丙酮浸取脱氟渣来回收脱氟渣中的磷酸,研究了浸取时间、温度和液固比对于五氧化二磷、氟的浸取率以及浸出液磷氟比[m(五氧化二磷)/m(氟)]的影响,得到了适宜的浸取条件。浸取液经蒸发浓缩回收浸取剂后,浓缩液均可满足饲料级磷酸氢钙生产对于湿法磷酸磷氟比的要求。综合考虑浸取剂成本、五氧化二磷浸取率和浸出液磷氟比,确定甲醇为优选浸取剂,并用响应面法对甲醇浸取工艺条件进行优化。优化工艺条件下五氧化二磷的浸取率为97.13%、浸出液磷氟比为51.62,甲醇在5次循环回收利用后对脱氟渣仍有较好的浸取效果。
The fluoride residue is a solid waste produced in the chemical defluorination process of wet-process phosphoric acid.The effects of leaching time,temperature and liquid-solid ratio on the leaching ratio of P_(2)O_(5) and F and the phosphorfluorine ratio[m(P_(2)O_(5))/m(F)]were studied by using methanol,ethanol and acetone to leach the fluoride residue for recycling phosphoric acid.The suitable leaching conditions were obtained.After the leaching solution was evaporated and concentrated to recover the leaching agent,the concentrated solution all could meet the requirements of the m(P_(2)O_(5))/m(F)of wet-process phosphoric acid for producing feed-grade calcium hydrogen phosphate.Considering the cost of the leaching solvents,the leaching ratio of P_(2)O_(5) and m(P_(2)O_(5))/m(F),methanol was selected as the optimal leaching solvent,and the leaching conditions of methanol was optimized by response surface methodology.Under the optimized conditions,the leaching ratio of P_(2)O_(5) was 97.13%,and the m(P_(2)O_(5))/m(F)of the leaching solution was 51.62.After 5 cycles of solvent recovery and leaching,recovered methanol still had good leaching effect on the fluoride residue.
作者
付子启
张程
盛勇
纪利俊
FU Ziqi;ZHANG Cheng;SHENG Yong;JI Lijun(School of Chemical Engineering,East China University of Science and Technology,Shanghai 200237,China;Sinochem Yunlong Co.,Ltd.)
出处
《无机盐工业》
CAS
CSCD
北大核心
2022年第7期129-134,共6页
Inorganic Chemicals Industry
关键词
湿法磷酸
脱氟渣
浸取
响应面法
wet⁃process phosphoric acid
fluoride residue
leaching
response surface methodology
