A mill is a device that breaks solid materials into smaller pieces by grinding, crushing, or cutting .. SAG mills are primarily used at gold, copper and platinum mines with applications also in the lead, zinc, silver, alumina and nickel industries. . Arrastra, simple mill for grinding and pulverizing (typically) gold or silver ore.
Small Mining Equipment for Gold, Silver, Copper, Zinc, Lead . all Metals . SAG mills tumble mainly ore but they use up to 15% volume of steel balls to assist . The autogenous mill itself is a coarse grinding device, consisting of tumbling drum.