二(2-乙基己基)膦酸连续多级逆向萃取法精制粗硫酸镍工艺研究

Purification of Unrefined Nickel(Ⅱ) Sulfate Solution Using Continuous Countercurrent Multistage Extraction

利用二烷基膦酸ＰＩＡ－８的庚烷溶液，考察了Ｚｎ（Ⅱ）、Ｃｄ（Ⅱ）、Ｍｎ（Ⅱ）、Ｃｕ（Ⅱ）、Ｃａ（Ⅱ）和Ｍｇ（Ⅱ）单一金属的萃取行为以及Ｃｏ（Ⅱ）、Ｎｉ（Ⅱ）混合溶液中Ｃｏ（Ⅱ）和Ｎｉ（Ⅱ）的萃取平衡，测定了ｐＨ０．５值以及相对于Ｎｉ（Ⅱ）的ΔｐＨ０．５值。运用连续逆向萃取技术，系统研究了高浓度Ｎｉ（Ⅱ）中少量Ｃｏ（Ⅱ）的萃取分离以及粗硫酸镍溶液的精制工艺，取得了满意的分离效果。

The bis(2 ethylhexy1) phosphinic acid(PIA 8) is used to investigate the extration behaviors of single metals of Zn(Ⅱ), Cd(Ⅱ), Mn(Ⅱ), Cu(Ⅱ), Ca(Ⅱ) and Mg(Ⅱ) and the extraction equilibria of Co(Ⅱ) and Ni(Ⅱ) in the both mixture solution in this paper. Their pH 0.5 values as well as ΔpH 0.5 values relative to Ni(Ⅱ)were determined. The continuous countercurrent extraction method is employed to study the small amount of Co(Ⅱ) separation from the high concentration Ni(Ⅱ) as well as refining technology for the unrefined nickel(Ⅱ) sulfate solution systematically, and the satisfactory separation results are also obtained.