... anhydros which is used in paper making the purity is 96% or 98%min Product name: Sodium Sulfite Anhydrous, Sodium Sulphite Anhydrous Molecular ... grade Salable product Industrial grade Sodium sulfite ( Na2SO3 ) , % ≥97.0 96.0 93.0 90.0 Fe , ≤0.003 0.005 ...