Improving technology and setting-up a production line for high quality zinc oxide (99.5%) with a capacity of 150 ton/year by evaporation-oxidation process

This report presents the technology improvement and a production line to produce high quality zinc oxide of purity upper than 99.5% ZnO by evaporation-oxidation method. Secondary zinc metal recovered from galvanizing industrial will undergo a pre-treatment to meet all requirements of standardized feed material for evaporation-oxidation process. Zinc metal is melted at a temperature of about 650^oC, some impurities and metallic oxides are separated preliminary, then zinc metal is converted into liquid in evaporation pot. Here the temperature is maintained around 1050^oC, zinc liquid is evaporated, zinc vapor is oxidized by air in the oxidation chamber naturally by oxygen in the air and then zinc vapor is converted to zinc oxide. Zinc oxide is passed through a product classification systems and then go to a product collection of filtering bag design. The whole process of melting, evaporation, oxidation, particles classification and product collection is a continuous process. The efficiency of the transformation of zinc metal into zinc oxide can reach the value of 1.1 to 1.2. ZnO product quality is higher than 99.5%. (author)