### Common & Basic Formulas for Mineral

Formula (32) is very convenient for milling calculations on ores of this type. Example: An ore contains 5% lead and 1% copper. The ratio of perfect concentration for a concentrate of maximum grade and recoveries of lead and copper would be: by (29) K perfect = 100/5.775+2.887 = 11.545 and % Pb in perfect concentrate = 11.545 x 5 = 57.7%