Zinc sulphate heptahydrate  crystal 21.5% 1.lower heavy metal level. 2.zn>21.5%. 3.other name:zinc sulphate. Products name: zinc sulphate heptahydratecrystal 21.5%. 1)zn>21.5%,pb<1ppm. Cd<1ppm. 2)packing:25 kg pp bags. Other name:zinc sulphate. Basic description. Formula: ZnSO4.7h2o. Cas no.: 7446-20-0. Hs code: 283329300. Eiencs: 231-793-3. Quality: iso9001:2000. Physical description. Mol weight: 287.56. Appearance: white crystalline powder or granular. Odour: odorless. Melting point: it loses water at 30 degree c to give the hexahydrate and more water is lost at 70 degree c to form the monohydrate. The anhydrous salt forms at 280 degree c. Density: 1.957. Zinc sulphate hepthydrate. Content 98%min. Item. Unit. Specification. Zn content. %min. 21.5. Specification. Pb. Ppm max. 1. Fe. Ppm max. 15. Cd. Ppmmax. 1. Use. Znso4 is mainly used as raw made of ... For the production of lithopone and zinc salts. It is also used in synthetic fiber industry, zinc plating, pesticides, flotation, fungicide and water, purification. In agriculture, it is mainly used as feed additive and trace element fertilizer,, etc. Package. 25 kg bags with plastic woven bag, or 1250/1000 kg bags with inner bags on pallets or according to your request. Storage. Dry and hermetic.