Study on flotation separation and determination of trace copper in water samples using ammonium sulfate-potassium iodide-ascorbic acid-dodecyl dimethyl benzyl ammonium chloride system

摘要

The paper presents a novel method for the flotation separation and determination of trace copper in water samples using ammonium sulfate-potassium iodide-ascorbic acid-dodecyl dimethyl benzyl ammonium chloride system. The effects of the dosages of KI, Ascorbic Acid (AA) and Dodecyl Dimethyl Benzyl Ammonium Chloride (DDBAC), various salts and pH on the flotation yield of Cu~(2+) have been investigated. The possible flotation separation mechanism of Cu~(2+) was discussed. The results showed that under the optimum conditions, Cu~(2+) could be reduced to Cu~+ by AA, and then Cu~+ reacted with I to form the precipitation of CuI. The precipitation of CuI was quantificationally flotated above salt-water phase by DDBAC and formed solid -liquid phase. While Fe~(2+), Co~(2+), Zn~(2+) Mn~(2+) and Ni~(2+)' could not be floated. Therefore, Cu~(2+) was separated completely from the above metal ions. The proposed method has been successfully applied to the determination of trace Cu~(2+) in various environmental water samples after flotation separation using ammonium sulfate-potassium iodide-ascorbic acid-dodecyl dimethyl benzyl ammonium chloride system. The recoveries were 94.3%~96.2%.