硫酸铵-硫氰酸铵-乙醇体系萃取分离铂

SEPARATION OF PLATINUM BY THE EXTRACTION SYSTEM OF AMMONIUM THIOCYANATE AND ETHANOL IN PRESENCE OF AMMONIUM SULFATE

从pH 3.0的水溶液中,在较大量的硫酸铵存在下,Pt(Ⅳ)以Pt(SCN)62-形式定量萃取入乙醇中。萃取体系中各试剂的适宜用量为硫氰酸铵溶液20 g.L-1,硫酸铵溶液300 g.L-1,乙醇0.30 mL.mL-1,按此条件可达到Pt(Ⅳ)与适量的Ni(Ⅱ),Cr(Ⅲ),Co(Ⅱ),Fe(Ⅱ),Mn(Ⅱ),Al(Ⅲ),Rh(Ⅲ)等离子分离。此方法已用于催化剂Ni-Pt/Al2O3试样分析中作为分离手段。对一件上述催化剂试样进行5次测定,测得铂的平均结果为w(Pt)0.104%,RSD为1.7%。

It was found that platinum（Ⅳ） was quantitatively extracted into ethanol in the form of Pt（SCN）6^2- in the presence of relatively large amount of ammonium sulfate from a solution of pH 3. 0. The optimum amounts of the reagent present in the extraction system were as follows： NH4 SCN 20 g · L^-1, （NH4）2 SO4 300 g · L^-1 ethanol 0. 30 mL · mL^-1. Under these conditions, Pt（Ⅳ ） was effectively separated from appropriate amounts of Ni（ Ⅱ ）, Cr（Ⅲ）, Co（Ⅱ ）, Fe（ Ⅱ）, Mn（ Ⅱ ）, Al（ Ⅲ ） and Rh（ Ⅲ ）. This method has been applied to the analysis of Ni-Pt/ Al2O3 catalyst as a separation process, and 5 determinations of Pt（ Ⅳ ） in a catalyst sample were performed giving an average result of w（Pt） 0. 104% with RSD of 1.7%.