... /copper/silver/zinc mines, power plants and cement factories. Forged Steel Balls,Mill Balls:Our Forged Steel Balls,Mill Balls, with diamater from ... preparation and extra-fine deep processing in sectors such as cement building materials, metal mining, coal paste thermal power plants, chemical ... including: RIO TINTO,COdel20CO CHILE, FREE PORT S.A. Forged Steel Balls for Cement Factories