湿法磷酸脱氟方法研究及其饲料磷酸氢钙的制造

DEFLUORINATION OF WET-PROCESS PHOSPHORIC ACID AND MANUFACTURE OF FEED-GRADE CALCIUM HYDROPHOSPHATE.

介绍了湿法磷酸中氟的存在形式 ,以及其它阳离子对脱氟效果的影响。通过对脱氟方法的研究与实践表明 :在汽相法脱氟中 ,将浓缩过程与脱氟过程结合起来 ,可将 2 7%P2 O5酸的氟含量由 2 .17%降至 0 .16 % ,F/P2 O5(质量比 )为 0 .0 0 35 ;在沉淀法脱氟中 ,综合考虑常规脱氟剂的局限性和二步法P2 O5肥料化机理 ,可将 45 %P2 O5酸制得磷酸氢钙 ,其干燥物含氟量 0 .11% ,P2 O5饲料利用率达 85 %。

F is removed from wet-process H 3PO 4 by using defluorinating agent SiO 2-NaCl and a functional promotive agent,the containing F precipitate is separated by filtration.The F content in the phosphoric acid(27% P 2O 5) can be decreased from 2.17% to 0.16% and F/P 2O 5 in the acid is 0.003 5.The feed-grade CaHPO 4 with F content 0.11%(dry base) can be made from the obtainable defluorinating H 3PO 4.