... white crystal or crystalline powder, it's alkali in water, pH is 9. Application: Sodium sulfite ... in medicine, paper making, tannage, leather, printing, dyeing, bleaching and food,waste water treatment, reducing and sulphonating agent for chemical ... and deoxidization ,floating agent for mining industry,auxiliary chemical in tanning process.product specification:ItemsuperfirstqualifiedPurity (na2co3)97.0 ...