用磷酸三丁酯浸渍树脂从硝酸介质中提取铈(Ⅵ)

摘要

用磷酸三丁酯(TBP)溶剂浸渍高分子交换树脂XAD-16来制备浸渍树脂.在室温下,将未稀释的磷酸三丁酯与树脂按液固比6(磷酸三丁酯体积与树脂质量比)浸渍24 h得到的浸渍树脂的质量比为1.944;按液固比3.0浸渍24 h,得到的浸渍树脂的质量比为1.88.将从埃及独居石矿砂得到的含37％铈、1.6％钍和40％三价稀土氧化物的氧化铈(Ⅵ)精矿浸出得到的硝酸铈溶液,用所制备的浸渍树脂从该铈溶液提取铈.在室温下,用该浸渍树脂从硝酸介质中提取Ce(Ⅳ)的效果是令人满意的.在溶液中含51.57 g/L铈、2.48 g/L钍、5.0 mol/L游离硝酸,溶液与树脂比为10.0,浸渍时间为5.0 min的条件下,该浸渍树脂对Ce(Ⅳ)的负载容量达到理论值(173 g/kg (Ce/SIR))的95.6％.在其他条件不变的情况下,将铈的浓度提高到91.43 g/L,浸渍树脂对Ce(Ⅳ)的负载容量达到理论值的98.75％.%Tributyl phosphate (TBP) solvent was used for impregnation into Amberlite XAD-16 nonionie polymeric resin beads using the wet method to prepare solvent impregnated resin (SIR).Undiluted TBP in a ratio to the resin support (volume to mass) of 6.0 at room temperature (RT) in 24 h was impregnated the resin with a mass ratio of 1.944,while the prepared gross sample of SIR at the ratio of solvent to resin of 3.0 was impregnated with a mass ratio of 1.88.Cerium(Ⅳ) oxide concentrate,prepared from crude Egyptian monazite sand,containing 37％ cerium,1.6％ thorium and about 40％ the other trivalent rare earth oxides,was used to prepare cerium(Ⅳ) nitrate solution for extraction using the prepared SIR.The impregnated resin was satisfactory for Ce(Ⅳ)extraction from nitric acid medium at room temperature.Cerium loading capacity of the impregnated resin reached 95.6％ of the calculated theoretical capacity (173 g/kg (Ce/SIR)) under the conditions of 51.57 g/L cerium and 2.48 g/L thorium,5.0 mol/L free nitric acid,solution to resin ratio of 10.0 and contacting the phases for 5.0 min.The loading capacity reached 98.75％ when cerium concentration was increased to 91.43 g/L under the same conditions.