... , filtering, filtrate heating, add potassium permanganate, iron, manganese impurities such as oxidation, filtration, clarification, concentration, cooling crystallization, centrifugal separation, drying system ... 2326-2005F),Execution standard :HG/T2326-2005 ITEMIndicatorsI( technical grade zinc sulphate monohydrate )II (industrial-strength heptahydrate )high-class first glassqualifid producthigh ...