(1) Silicon metal #553 Si:98.5%min. Fe:0.5%max. Al:0.5%max. Ca:0.3%max. Size:10-100mm,90%min. (2) Silicon metal 441 Si:99.0%min. Fe:0.4%max. Al:0.4%max. Ca:0.1%max. Size:10-100mm,90%min. ( 3) Silicon metal #3303 Si:99.0%min. Fe:0.3%max. Al:0.3%max. Ca:0.03%max. Size:10-100mm,90%min .