Processes for flotation of mineral substances

摘要

A method of concentrating a metalliferous ore containing also substantial quantities of pyrites and/or pyrrhotite and/or sphalerite and comprises subjecting an aqueous pulp of the ore to a froth flotation process in the presence of a depressant and in which (1) pyrites and/or pyrrhotite, and/or (2) sphalerite, is depressed by using as the depressant a condensation product of an aldehyde with a compound containing at least two amine or amide groups.