How does the SDS addition in talc grinding affect its floatability?

Talc processing starts with grinding followed by flotation. The flotation feed preparation significantly affects the concentrate quality. In this study, the preparation of talc flotation feed by grinding was investigated in the absence and presence of sodium dodecyl sulfonate (SDS), one of the well-known flotation reagents. The natural floatability of talc was compared to its floatability after adding the SDS in either grinding or flotation. The results proved a significant effect of grinding conditions on its natural floatability. The higher flotation recovery is achieved by grinding at the alkaline medium compared to the acidic medium at 30% solids. More interestingly, adding the SDS in flotation produced a higher talc recovery than that the achieved recovery by its flotation after adding SDS in grinding although it has more chance for mixing the reagent with particles and adsorption of SDS to talc particles. Thus, the tested variables in grinding tests negatively affect the SDS effectiveness as a flotation reagent for talc.