... producer with 2 factories 3.Low B&PSilicon metal:Grade:553/441/421/3303/2502/2202Size:10-100mm ,90%minPacking:in ... produce high purity of all grade Silicon Metal ,such as #553,#441,#421,#3303,#2202#,2502 with low P&B.Should ... Management System authorized by SGS in silicon field. silicon metal 553 grade