Sand and gravel aggregate The fine aggregate of concrete Used as the ballast of railway Raw materials of cement The mixing materials of cement Corrective raw materials used in the cement clinker Raw materials to produce all kinds of bricks and tiles Reclaim field from beach land Landfill of waste rock or/and tailings in open pits to restore fields Used as the raw material for the production of silicon bricks Used for the production of calcium carbonate Used as the raw material of heavy calcium carbonate Tailings reprocessing: recovery of valuable components from tailings