丙醇-硫氰化钾-氯化钠-水体系析相萃取分离铂

研究了铂在丙醇-硫氰化钾-氯化钠-水体系中的析相萃取行为及与一些金属离子分离的条件。结果表明,丙醇的水溶液在氯化钠的作用下可分成醇/水两相,在分相过程中,Pt (Ⅳ) 与硫氰化钾生成的Pt(SCN)6]2-可与质子化的丙醇PrOH2]+形成离子缔合物Pt(SCN)6]2-·2PrOH2]+而被丙醇相完全萃取。当溶液中丙醇、硫氰化钾和氯化钠分别为30%(V/V)、6.0×102-mol/L和0.16g/mL时,Pt (Ⅳ) 的萃取率达到98.2%以上,而试液中的Mo(Ⅵ)、Ce (Ⅲ)、Ni(Ⅱ)、V(Ⅴ)、Cr(Ⅲ)、Ag(Ⅰ)、Mn(Ⅱ)、Mg(Ⅱ)、Cd(Ⅱ)、Ga(Ⅲ)、Fe(Ⅱ)和Al(Ⅲ)几乎不被萃取,从而实现了Pt(Ⅳ)与这些金属离子的分离。方法应用于Ni-Pt/Al2O3催化剂中铂的分离萃取和测定,测得结果与参考值基本一致,相对标准偏差(RSD,n=5)为2.3%。

Phase extraction separation of platinum with n-propanol-potassium thiocyanate-sodium chloride-water system

The behavior and conditions for phase extraction separation of platinum from other metal ions in n-propanol-potassium thiocyanate-sodium chloride-water system were investigated. The results showed that the aqueous solution of n-propanol could be divided into two phases with the effect of sodium chloride, and in the phase separation process, the Pt(SCN)₆]^2- formed by Pt(Ⅳ) and potassium thiocyanate reached with protonated PrOH₂]⁺ to form Pt(SCN)₆]^2-·2 PrOH₂]⁺ ionic associate which could be completely extracted with n-propanol phase. When the concentrations of n-propanol, potassium thiocyanate and sodium chloride in the solution were 30%(V/V), 6.0×10^-2 mol/L and 0.16 g/mL, respectively. The extraction yield of Pt(Ⅳ) was more than 98.2%. Mo(Ⅵ)、Ce(Ⅲ)、Ni(Ⅱ)、V(Ⅴ)、Cr(Ⅲ)、Ag(Ⅰ)、Mn(Ⅱ)、Mg(Ⅱ)、Cd(Ⅱ)、Ga(Ⅲ)、Fe(Ⅱ) and Al(Ⅲ) in the solution could not be extracted, realizing the separation of Pt(Ⅳ) from these metal ions. The method has been applied to the extraction separation and determination of platinum in the sample of Ni-Pt/Al₂O₃ catalyst, and the results were consist with reference values with the relative standard deviation(RSD,n=5) of 2.3%.