Solid-phase extraction gold from alkaline cyanide solution with quaternary ammonium surfactant

Run-Fang Xie,Jing Chen,Yong-He Zhao,Yun-Shan Han,Qiu-Fen Hu,Zhen Li,Guang-Yu Yang

doi:10.1007/s12598-014-0323-2

Abstract

The solid-phase extraction (SPE) technique applied to the extraction of organic compound was creatively used as the extraction of inorganic gold in the paper. Two types of techniques were proposed and explored, namely the SPE and the liquid–liquid extraction (LLE) of the quaternary ammonium surfactant [cetytrimethyl ammonium bromide (CTMAB), cetyl pyridine bromide (CPB), benzyl dimethyl dodecyl ammonium chloride (BDMDAC), and dodecyl trimethyl ammonium chloride (DTMAC)]. The surfactant could react with Au(CN) 2 − to form the ionic complex, and the compound could be extracted by SPE column of reversed-phase bonded silica gel. Hence, a new method of SPE was proposed to extract gold with these features of the high selectivity, the reliability, and the simplicity. The experimental result shows that the recovery rate of gold is more than 98 %, and the solid-phase extraction column is not easily damaged and it can be repeatedly used. The new method can be used as the extraction process of gold from alkaline cyanide solution as well. Besides, the paper also puts forward a new process of gold extraction.

Highlights

Cyanidation is the dominant process in the domestic and foreign gold extraction process
3.1 Effect of molar ratio of surfactant to Au on recovery rate of gold loaded with a certain amounts of surfactant (C = 0.01015 molÁL-1) before the samples passed through the column, the recovery rate of gold can reach above 98 %
The experimental condition is recommended that the molar ratio of surfactants to Au is 1.5:1.0, and the solid-phase column must be loaded with a certain amounts of surfactant (C = 0.01015 molÁL-1) before the samples pass through the column

Summary

Introduction

Cyanidation is the dominant process in the domestic and foreign gold extraction process. The traditional methods used to extract gold from alkaline cyanide solution mainly contained the metal reduction method and the liquid–liquid extraction (LLE) method These two methods have a lot of disadvantages, such as the serious environmental pollution, high cost, time consuming, low enrichment factor, consuming large amounts of organic solvent, prone to the third phase, etc. Chen et al proposed the approach of first adding quaternary ammonium surfactant into the alkaline cyanide solution, and extracting gold with LLE method in the alkaline cyanide solution [1–8]. This method obtained a better result, it could not completely overcome the abovementioned disadvantages yet. To our knowledge, the successful literatures concerning the field can rarely be found in domestic and foreign reports up to now

Methods

Results

Conclusion