... production:20,000mt Quality standard : Q/320124JM02-2003Index name Premium grade Super gradeFirst gradeSalable productIndustrial gradeSodium sulfite ( Na2SO3 ) , % ... industry3, Bleaching4, Tannage and food5, Dyeing and painting industry Package Storage and transportation:1, Double-layer plastic woven ... ) Hunan Yueyang Sanxiang Chemical Co.,Ltd. Super grade of Anhydrous Sodium Sulfite(ASS1)