Mineralogical and surface chemical characterization of flotation feed and products after wet and dry grinding

Abstract Wet processing after crushing is common practice in mineral processing circuits involving flotation but the need for more efficient water management has increased interest towards dry processing. In this study the effects of both wet and dry grinding on flotation of one sulphidic and one non-sulphidic ore were compared. Bench scale flotation tests were carried out and various microscopic and spectroscopic methods such as FESEM and XPS were used in characterization of flotation feeds and products. Bulk surface charge properties were tested with mass titration. Clear differences in surface properties and flotation results were observed from the wet and dry grinding methods, which encourages further research. Wet grinding was beneficial for the energy efficiency for both ores and promoted the selectivity of flotation particularly with sulphidic ore. The wear of the mill and grinding media seemed more extensive in wet grinding. Dry grinding produced more fine particles tightly attached to the surfaces, caused by the higher surface charge of the dry ground ore especially with non-sulphidic ore