溴化四丁基铵—硫氰酸铵—水体系浮选分离钯(Ⅱ)的研究

Study on floatation separation of Pd(Ⅱ) with ammonium thiocyanate-tetrabutyl ammonium bromide-water system

研究了溴化四丁基铵-硫氰酸铵-水体系浮选分离Pd(Ⅱ)的行为及与一些金属离子的分离条件。研究表明,在水溶液中,Pd(Ⅱ)与硫氰酸铵、溴化四丁基铵形成不溶于水的三元缔合物Pd(SCN)_4^(2-)·2TBA^+,此三元缔合物沉淀可浮于水相上层形成界面清晰的液-固两相。当硫氰酸铵、溴化四丁基铵的浓度分别为5.0×10^(-3)mol/L,2.0×10^(-3)mol/L,在pH 1～4时,能使Pd(Ⅱ)的浮选率达到100%,Pd(Ⅱ)可与Cu(Ⅱ),Zn(Ⅱ),Ni(Ⅱ),Cd(Ⅱ),Cr(Ⅲ),Mn(Ⅱ),Au(Ⅲ),Co(Ⅱ),Bi(Ⅲ),Rh(Ⅲ),Al(Ⅲ),Ru(Ⅲ)等离子定量分离。对合成水样和钯镍电镀液中的钯进行了定量浮选分离测定,测定结果与原值相符,相对标准偏差为1.98%。

The floatation separation behavior of Pd（Ⅱ） with ammonium thiocyanate-tetrabutyl ammonium bromide-water system and the separation of Pd（Ⅱ） from other metal ions were studied. The results show that Pd（Ⅱ） combines with ammonium thiocyanate and tetrabutyl ammonium bromide into a ternary ion association precipitate Pd（SCN）4^2-·2TBA^＋ in the aqueous solutions. The precipitate was floated on the surface of water phase to make the system to divide into both liquid and sold phases with distinct boundary layer. The floatation yield of Pd（Ⅱ） reaches 100% in the solution of 5.0 × 10^-3mol/L ammonium thiocyanate and 2.0×10^-3 mol/L tetrabutyl ammonium bromide at pH 1-4. Pd（Ⅱ） could be quantiatively separated from Cu（Ⅱ）, Zn（Ⅱ）, Ni（Ⅱ）, Cd（Ⅱ）, Cr（Ⅲ）, Mn（Ⅱ）, Au（Ⅲ）, Co（Ⅱ）, Bi（Ⅲ）, Rh（Ⅲ）, Al（Ⅲ） and Ru（Ⅲ） by floatation . The method has been applied for the separation and determination of Pd（Ⅱ） in the sample of synthetic water and Pd-Ni electroplating liquid with RSD of 1.98%.