... %Min 4)Form:White crystal powder,granule Zinc Sulfate Heptahydrate Agriculture GradeWe are Tianjin Xinxin Chemical ... Factory, the largest manufacturer of zinc sulfate heptahydrate in China,and our product ... When the temperature is above 500, it will decompose.2)Usage:As a kind of microelement used ... quick absorbable for the plant.Low content of heavy metal, Fe,Cd,Cr,As meet with China ...