· Two Duplex Selective Mineral Jigs concentrate the minus 6mesh manganese ore. Tailings from these jigs are sent to waste. The highgrade product produced by the jigs' selective action is sent to further screening. Screen No. 3. As the market requires that not more than 10% of the shipping ore is minus 20mesh, the selective jig concentrates are passed over a singledeck, 2'x 4′ Dillon ...