... purity min 88%, Industrial Grade, PH value:6-8 About us : Qingdao Central Chemical Co., Ltd. locates in Qingdao,the ... sulfate , potassium sulfateand Sodium Tripolyphosphate . And our products mainly export to North America,Asia and Europe .Our factory covers an area ... offer best products, reasonable price and perfect service,we hope to establish a long cooperation relationship with you ! Thanks for ...