Question is....do you know what a ball mill does? The ball mill has nothing to do with floatation process and the problems with the OXIDE ORE.......the ball mill is nothing more than a crusher or a grinder to get it into a smaller form.....a sledge hammer could do the same thing.......that is not where the problem is.......the problem has always been in the floatation part of it. It is extremely hard to remove oxide ore chemically thru a floatation process.