【作者】 郑东升； 李军； 周堃； 罗建洪；

【Author】 ZHENG Dong-sheng,LI Jun,ZHOU Kun,LUO Jian-hong (School of Chemical Engineering,Sichuan University,Chengdu,Sichuan 610065,China)

【机构】 四川大学化工学院；

【摘要】 为了了解湿法磷酸（WPA）中的H₃PO₄、杂质和水50℃时在磷酸三丁酯-煤油（TBP）体系中的萃取率和分配系数,以及TBP对WPA中各组分的选择性系数和水的协同萃取情况,针对WPA-TBP-煤油萃取体系,对酸中的主要组分（H₃PO₄,H₂O,TBP）、杂质在有机相的萃取率和杂质在水相、有机相的分配以及TBP对H₃PO₄、杂质的选择性和水的协同萃取进行了研究.结果表明,在WPA中H₃PO₄浓度在5%～75%P₂O₅,TBP对杂质的萃取能力顺序为:Al³⁺<Mg²+<SO₄^2-<SiF₆^2-<Fe³⁺,在相比6～7时,杂质(Mg²⁺,Al³⁺,Fe³⁺,SO₄^2-)选择性系数为1.5～2.2,达到最小值,而SiF₆^2-达到最大值1.5,因此相比6～7为分离净化湿法磷酸中磷酸和杂质的最优条件,而湿法磷酸中杂质的存在降低了水在有机相的协同萃取更多还原

【Abstract】 This work concerns the extraction ratio and distribution of the multi-component in wet process phosphoric acid（WPA） by solvent extraction with tri-butyl phosphate at 50℃,selection coefficient of TBP and co-extraction of water.An exhaustive study of the multi-component extraction system WPA-TBP was carried out.First,the distributions of main components（H₃PO₄,H₂O,TBP） and major impurities of WPA(Mg²⁺,Al³⁺,Fe³⁺,SO₄^2-,SiF₆^2-) between the aqueous and organic phases were systematically studied.Then selectivity of TBP for H₃PO₄ against the impurities and water co-extraction in the organic phase was expressed in a linear equation.The result shows that when the concentration of H₃PO₄ was in 5%～75%P₂O₅,the extraction power of TBP followed the order of Al³⁺<Mg²⁺<SO₄^2-<SiF₆^2-<Fe³⁺;when the phase ration was 6～7,the selection coefficient of impurities(Mg²⁺,Al³⁺,Fe³⁺,SO₄^2-) was the minimum,1.5～2.2,but SiF₆^2- was the maximum,1.5,so the phase ratio,6～7,was the best condition for purification process of WPA, however,the co-extraction of H₂O in the organic phase was reduced for the impurities in WPA.更多还原