... are 98% min. About us : Qingdao Central Chemical Co., Ltd. locates in Qingdao,the beautiful seaside ... city ,which engages in the manufacturing and marketing of Sodium sulfate , Cryolite , Soda ash , Edible alkali, Polyaluminium ... Chloride, Polyacrylamide, Polyaluminium Ferric Chloride ,Polymerization iron sulfate , potassium sulfateand Sodium Tripolyphosphate . And our products mainly ...