May 15, 2014· Dry grinding – when subsequent concentration process is dry ( concentrating ores of Cr, Au, Pb, Mn, Mo, coal..). Wet Grinding – Normally used in mineral dressing ( subsequent concentration processes - flotation, leaching etc are wet processes ). 81 76. DRY GRINDING. 1. Feed material should have low ( < 1 % ) moisture content. 2.