Introducing inverse gas chromatography as a method of determining the surface heterogeneity of minerals for flotation

Inverse gas chromatography has great potential in allowing an enhanced understanding of mineral surfaces, and the interactions between particles and air and water in mineral processing separations, such as flotation. Two minerals of different degrees of natural hydrophobicity were investigated, namely galena and quartz. The surface energy was determined as a function of surface area, with the quartz sample displaying a higher work of adhesion, implying a higher degree of hydrophilicity. This was then compared to microflotation experiments. The higher work of adhesion to water for the quartz than galena (114.54 mJ m(-2) compared to 101.71 mJ m(-2) @ 5% coverage; 86.78 mJ m(-2) compared to 71.69 mJ m(-2) @ 38% coverage) was related to a lower recovery of quartz (6.94%) than galena (27.63%) through collectorless flotation. (C) 2013 Elsevier B.V. All rights reserved.