Characterization and degradation studies of xanthates in mining waters

点击翻译按钮获取中文摘要

Xanthates are compounds used to aid froth flotation in the mining industry to improve metal extraction ofsulphide minerals by selectively separating hydrophobic and hydrophilic minerals. We recently completed anNSERC Engage project with New Afton Mine (New Gold Inc.) in which we successfully developed a capillaryelectrophoresis (CE) method for separating the xanthates - amyl, isobutyl, isopropyl, and ethyl. The developedmethod enables us to separate and quantify the different xanthates. In the Engage work, a good detection limitwas achieved in the lower part-per-million (ppm) range. However, we would like to improve upon thisdetection limit to enable the quantification of even lower concentrations of xanthates which may be present inthe tailings samples. Thus, in the Engage Plus work efforts will be made to attain a detection limit in thepart-per-billion (ppb) range. Accurate testing of xanthates in this ppb range will help to understand ways ofimproving the use of potassium amyl xanthate (PAX) in the circuit and limit its overuse so that the mill circuitis not wasting xanthate nor starving the circuit. Liquid chromatography-mass spectrometry (LC/MS) will alsobe developed to verify the accuracy of the CE results. We would also study the degradation process of variousxanthates using gas chromatography-mass spectrometry (GC/MS). This will allow for quantification of thevolatile degradation products evolved from each of the xanthates under varying conditions. The findings fromthis method would provide ideas on the method best suited for an on-stream analyzer and steps will be taken tounderstand the limitations of such an application. Benefits from development of an on-stream analyzer havehuge implications in the mining industry. Mill management is particularly interested in examining the potentialon-stream analyzer application of the developed methods. A comprehensive understanding of the degradationprocess is expected from this work and can then be applied to flotation circuits to improve flotation efficiencyand minimize degradation of product, thus providing extensive monetary and industrial benefit.