Effects of particle size and wettability on froth stability in a collophane flotation system

The properties of mineral particles have significant effects on the flotation process of collophane, especially the froth stability. In this research, the influence of two vital parameters, the size and wettability, of typical mineral particles (quartz, collophane (fluorapatite), dolomite, and calcite) existing in collophane ores on the froth stability was studied in detail. The modified Bikerman method was used to generate froth and investigate the dynamic froth stability. The high-speed microscopic imaging method was used to investigate bubble coalescence behaviour in the presence of the mineral particles. The interactive effects of the particle size and wettability on the froth stability are illustrated using the theory of minimum remove energy (Delta G(remove)) and maximum capillary pressure (P-c(max)). The results show that finer mineral particles promote froth stability, and that calcite exhibits the highest capacity for froth stability improvement, followed by dolomite, collophane, and quartz. Furthermore, the wettability of the mineral particles significantly affects the froth stability, with the optimum contact angles of mineral particles to stabilise froth being similar to 60-70 degrees. This study provides a significant guideline for controlling the parameters and achieving optimal froth stability in collophane reverse flotation systems. (C) 2020 Elsevier B.V. All rights reserved.