... %,99%Min 4)Form:White crystal powder,granular Zinc Sulfate Heptahydrate MedicineGradeTianjin Xinxin Chemical Factory is the largest manufacture ... of Zinc Sulfate(30,000Tons/Year),Calcium Hypochlorite (30,000Tons/Year),Zinc ... .C.Have little heavy metal. Lead(pb)cadmium(Cd),chromium(Cr),arsenic(As)mercury(Hg) etc infaust elements fit ...