we can offer you different grades with competitive price. Content(as Zn ): ≥57% Sulphate SO4: ≤0.6% Chromium: ≤0.1% Fe: ≤0.005% As: ≤0.0005% Acid insoluble substance: ≤0.003% Water: ≤2% ~ 3% Heavy metal: ≤0.01% Cautery loss: 25%~28% Application: Used for rubber products, used in making artificial filament, petroleum, chemical fertilizer, desulfurizer, catalyzer, oil paint, medicine, chemical ...