萃取法制备工业级磷酸二氢铵-萃取剂的反萃取研究.pdf

化学工程师
oum 203 No08
Chemical Engineer
2012年第08期
文章编号:1002-1124(2012)08-0010-03
岸萃取法制备エ业级磷酸二氢铵
线发
萃取剂的反萃取研究
罗建洪,李军,金央’,马春磊
(四川大学化工学院,四川成都610065)
摘要:本课题以高效的2-乙基己基磷酸(D2EHPA)为萃取剂,采用溶剂萃取法来提取MAP溶液中的
Mg2杂质,从而实现生产高品质MAP的目的;但是实现其产业化的难点之一,就是反萃取剂的选择,而在选
择反萃取剂时关键是实现络合物D2EHPA-Fe的有效分离,因为络合物D2EHPA-Fe是非常稳定的,而且
Fe的富集能使萃取剂老化。因此,选择有效的反萃取剂来实现D2EHPA的循环回收利用是非常有必要的。
以HSO+添加剂A为反萃取剂,通过考察反萃取剂浓度,相比,反应温度,反应时间,搅拌速度等对反萃
取Fe反萃取率的影响,求得最佳工艺条件为H1SO4浓度:4molL,反应温度45℃,相比为1:1,搅拌速度
550r'min-,搅拌时间0.5h。
关键词:湿法磷酸;MAP;D2EHPA;溶剂萃取;H2SO2;反萃取
中图分类号:TQ126.3;TQ028.3
文献标识码:A
Study on the stripping of the extractant from the production of industrial-grade ammonium dihydrogen
phosphate solution by solvent extraction
,UO Jian-hong, LI Jun, JIN Yang,, MA Chun-lei
Dep. of Chemical Engineering, Sichuan University, Chengdu 610065, China
Abstract In this paper, e effectie MPA s emplyed as x ant Based on the extractant of DE,H-
PA, The abilities to extract Mg from ammonium dih rogen phosphate solution with the separation methods of ex-
traction, emulisification extraction, saponified D2EHPA, and predispersed solvent extraction have been studied
And superior grade NHH, PO (MAP)can be obtained by two levels of extraction under optimal condition. However
one of difficulties o realize industrialization is the choice of strippant. The key for selection of strippant is to real
ize the complex D2EHPA- effective separation, because complex D2EHPA-FEIS very stable, moreover con-
centration of Fe: can cause the extractant aging. Therefore the choice of the effective strippant to realize the ex-
tractant D2EHPA recycling use is necessary
In the stripping of Mg /Fe"in the organic phase, HSO,* additive A is used to strip Fe*. to study the strip
ping extraction ratio and advantages of the strippant H O in the removal of Fe*, various parameters: concentra
tion of reaction emperature, phase mass ratio, stirring speed, stirring time are studied and optimized. The
optimized parameters affecting the process are as follows: The concentraction of H S0 4mol."; the reaction tem
perature: 45C; the phase volume ratio: 1: 1; stirring speed: 550rmin, stirring time: 0. 5h.
Key words wet-process phosphoric acid MAP; D2EHPA; extraction; H, Soai reverse extraction
用湿法磷酸生产工业级MAP时,溶液一般中和不溶物超标。因此,在结晶之前需要采取其它方法
到pH值为4-4.5左右。在此pH值下,绝大部份金把Mg2脱除。
属阳离子已被除去。但由于Mg2水解pH值较高的
本课题以D2EHPA为萃取剂,采用溶剂萃取法
缘故,中和液中仍含有一定量的Mg2,会在后续的来提取MAP溶液中的Mg2杂质,从而实现生产工
浓缩、冷却结晶过程中形成水不溶物,造成产品水业级MAP的目的;但是实现其产业化的难点之
就是反萃取剂的选择,而在选择反萃取剂时关键是
收稿日期:2012-05-31
实现络合物D2 ARIPA-Fer的有效分离,因为络合物
基金项目:国家科技支撑计划项目(2007BAE58B0O)
D2EHPA-Fe是非常稳定的,而且Fe的富集能使
作者简介:罗建洪(1980-),男,讲师,2010年毕业于四州大学化学工
萃取剂老化。因此,选择有效的反萃取剂来实现
艺专业博士,现在四川大学化工学院从事教学及科研工
作
D2 DIPA的循环回收利用是非常有必要的。