Seven Hypothesis about Spam Filtering

This invention relates to a froth flotation process for selectively recovering nonferrous metal-containing sulfide minerals or sulfidized metal-containing oxide minerals from ores using froth flotation. The collector employed in the process is an epithio compound of the formula: wherein m=1, 2 or 3; each R is independently hydrogen, a hydrocarbyl group or substituted hydrocarbyl group; each R1 is independently hydrogen, a hydrocarbyl group or substituted hydrocarbyl group, provided one R or R1 is not hydrogen; and each R2 is independently hydrogen, hydrocarbyl, hydrocarbyloxy or hydrocarbyl thioether.