硝酸钾-碘化钾-十八烷基三甲基溴化铵微晶吸附体系浮选分离铅(Ⅱ)

Flotation separation of lead(Ⅱ) in microcrystalline adsorption system of potassium nitrate-potassium iodide-octadecyl trimethyl ammonium bromide

建立了一种微晶吸附体系浮选分离铅(Ⅱ)的新方法。探讨了不同影响因素,如碘化钾溶液用量、十八烷基三甲基溴化铵(OTMAB)溶液用量、各种盐和酸度等对Pb2+浮选率的影响,探讨了Pb2+的浮选分离机理。结果表明,在最佳条件下,十八烷基三甲基溴化铵阳离子(OT-MAB+)与I-反应产生OTMAB+.I-微晶物质。由Pb2+和I-生成的PbI24+,再与OTMAB+形成的不溶于水的三元缔合物(OTMAB)2(PbI4)被定量吸附在OTMAB+.I-微晶物质表面且被浮选至盐水相中,而Fe3+,Co2+,Ni 2+,Zn2+,Mn2+,Al 3+等离子不被浮选,实现了Pb2+与这些离子的定量分离,据此建立了微晶吸附体系浮选分离Pb2+的新方法。该方法用于合成水样中Pb2+的定量浮选分离测定,浮选率为95.0%～105.2%。

The paper presents a novel method for the flotation separation of lead（Ⅱ） in microcrystalline adsorption system.The effects of different parameters,such as the dosages of KI and octadecyl trimethyl ammonium bromide（OTMAB）,various salts and acidity etc on the flotation yield of Pb2＋ have been investigated.The possible flotation separation mechanism of Pb2＋ was discussed.The results showed that under the optimum conditions,octadecyl trimethyl ammonium bromide cation（OTMAB＋） reacted with I-to produce the microcrystalline matter（Ms-M） of（OTMAB＋·I-）,the water-insoluble ternary association complex of（OTMAB）2（PbI4） which was produced by Pb2＋,I-,and then by OTMAB＋ was quantitatively adsorbed on the surface of Ms-M of（OTMAB＋·I-） and floated above the salt-water,while Fe3＋,Co2＋,Ni2＋,Zn2＋,Mn2＋ and Al3＋ could not be floated.The quantitatively separation of Pb2＋ from those metal ions was achieved by flotation.A new method for the flotation separation of trace Pb2＋ was established.The proposed method has been successfully applied to the determination of trace Pb2＋ in the samles of synthetic water,and the flotation yield was 95.0%-105.2%.