[RuI_4^-]从乙醇-水-硫酸铵析相体系中的“绿色”化学萃取分离

“Green”Chemical Separation of [RuI_4^-]by Extraction from a Phase-Separation System of C_2H_5OH-H_2O-(NH_4)_2SO_4

试验表明,在保持乙醇与水的体积比为3比7的条件下,如乙醇3.0mL与水7.0mL混合,加入硫酸铵3.0g(即每1mL溶液中含硫酸铵0.3g),充分振荡后,此溶液可分成界面清晰的醇-水两相。如溶液中含钌(Ru3+),且同时含浓度达到3.0×10-3 mol·L-1的碘化钾,则钌将以[RuI4-][C2H5OH2+]离子缔合物的形式萃取入乙醇相中。上述萃取体系的酸度要求在pH 0.5~4.4范围内。进一步试验了钌与其他12种金属离子(Al 3+、Zn2+、Mn2+、Pb2+、Ni 2+、Cr3+、Ga3+、Co2+、Fe3+、Mg2+、Ag+及V5+)共存的二元或多元体系的分离情况,结果都较满意,萃取率在98.9%~99.5%之间。此分离方法避免用有害的有机溶剂,有利于环境保护。

It was found that Ru3+ in the form of[RuI4-]can be separated by extraction from a phaseseparation system of C2H5OH-H2 O mixture with optimum volumic ratio of 3to 7(e.g.,mix 3.0mL of C2H5 OH with 7.0mL of H2O)in which solid(NH4)2SO4is added to attain to a concentration of 0.3g·mL-1[i.e.3g of(NH4)2SO4in 10 mL of solution]and KI is added to attain a concentration of 3.0×10-3 mol·L-1.When this mixture is shake thoroughly,phase-separation between C2H5 OH and H2 O takes place giving a clear interface between the 2phases,and[RuI4-]enters into the C2H5 OH phase in form of an association complex of[RuI4-][C2H5OH2+].Optimum acidity of the extraction system was found in the range of pH 0.5to 4.4.Separation of Ru3+from binary and multiple mixture with 12 other metal ions(Al 3+,Zn2+,Mn2+,Pb2+,Ni 2+,Cr3+,Ga3+,Co2+,Fe3+,Mg2+,Ag+and V5+)was tested further,giving satisfactory results with values of recovery of Ru3+range from 98.9%to 99.5%.It was shown that the proposed method is beneficial to environmental protection,as it prevents the use of harmful organic solvents.