Abstract: A method is disclosed for treating dore slag resulting from smelting of a dore furnace charge, by grinding such slag and then subjecting the obtained pulp to froth flotation in the presence of a suitable frother and collector to produce a precious metals concentrate which is then filtered and returned to the dore furnace with the next charge. The tails from the froth flotation may then be finely ground and subjected to several additional flotation stages to improve recovery of the precious metals, and the entire operation is preferably carried out as a closed loop process so that only the tailings from the rougher flotation are removed and shipped to the smelter.