硫酸铵-碘化钾-十六烷基三甲基溴化铵体系浮选分离测定汞(Ⅱ)的研究

Study on flotation separation of mercury(Ⅱ) by ammonium sulfate-potassium iodide-cetyl trimethyl ammonium bromide system

研究了标题化合物体系浮选分离测定汞(Ⅱ)的行为及其与常见离子分离的条件。结果表明,控制pH7.0,在1.0g(NH4)2SO4存在下,当0.1mol/LKI溶液和0.01mol/L十六烷基三甲基溴化铵(CTMAB)溶液的用量分别为1.0、0.5mL时,体系中形成的不溶于水的KI-CTMAB-Hg三元缔合物可浮于盐水相上形成界面清晰的液-固两相,从而使Hg2+被定量浮选,而Zn2+、Mn2+、Ni2+、Co2+、Fe2+、Al3+等在此条件下不被浮选,实现了Hg2+与这些离子之间的定量分离,据此建立了浮选分离测定微量汞(Ⅱ)的方法。该方法对合成水样和工业废水中微量汞(Ⅱ)进行的定量分离测定,结果与双硫腙法相符,样品标准加入回收率为94.0%～106.7%,RSD为2.1%～2.8%。

The determination of mercury（Ⅱ）via flotation separation using the ammonium sulfate-potassium iodide-cetyl trimethyl ammonium bromide system and the conditions for the separation of mercury（Ⅱ）with other metal ions were studied.The test results showed that in the presence of 1.0 g of（NH4）2SO4 and at a dosage of 1.0 mL of 0.1 mol/L KI solution and a dosage of 0.5 mL of 0.01 mol/L cetyl trimethyl ammonium bromide（CTMAB）solution,respectively,the thereof formed water-insoluble ternary association complex of KI-CTMAB-Hg floated above the salt-water phase and formed the liquid-solid phase with clear interfaces.Under this condition,Zn^2＋,Mn^2＋,Ni^2＋,Co2＋,Fe^2＋,Al^3＋ could not float and Hg^2＋ could float quantitatively at pH 7.0.Therefore,the quantitative separation of Hg2＋ from the above-mentioned metal ions could be achieved,and the method for flotation separation of Hg^2＋ was established.The quantitative determination of Hg^2＋ via flotation separation using the samples of synthetic water and industrial wasterwater were performed,and the results agreed well with the dithizone method.The recoveries of studied metals were 94.0%～106.7%,and the RSD was 2.1%～2.8%.