Study on Flotation Separation and Determination of Trace Copper in Water Samples Using Microcrystalline Adsorption System

Abstract

The paper presents a novel method for the flotation separation of Cu2+ using microcrystalline adsorption system and the determination of trace Cu2+ in water samples by spectrophotometry. The effects of the dosages of KI, ascorbic acid (AA) and cetyl pyridinium chloride (CPC),various salts and acidity on the flotation yield of Cu2+ have been investigated. The possible flotation separation mechanism of Cu2+ was discussed.The results showed that under the optimum conditions, CPC cation (CPC+) reacted with I- to produce the microcrystalline matter (Ms-M) of (CPC+·I-),Cu2+ could be reduced to Cu+ by ascorbic acid,and then Cu+ reacted with I- to form the precipitation of CuI.The precipitation of CuI was quantificationally adsorbed on the surface of Ms-M of (CPC+·I-) and was floated above salt-water phase. While Zn2+、Ni2+、Co2+、Mn2+ and Fe2+ could not be floated.Therefore, Cu2+ was separated completely from the above metal ions. The proposed method has been successfully applied to the determination of trace Cu2+ in various environmental water samples after flotation separation using microcrystalline adsorption system, and the results agreed well with those obtained by GFAAS method.The recoveries were 97.9%~100.7%, and the RSD is 0.8%~1.3%.