Production and purification of zircon opacifier from zircon found in the coastal area of Bangladesh

In this study the potentiality of Bangladesh zircon as a raw material for opacifier was examined. Preparation of zircon flour was done by both wet and dry ball milling. Wet milling of zircon was found to be much efficient than dry milling. Zircon flour of peak size 8 μm obtained by wet milling was purified by leaching in concentrated H2SO4 acid. Leaching time was varied from 2 to 20 h and sulphuric acid concentration ranged from 10 to 80 ml/l. Both un-purified and purified Bangladesh zircon flour were tested for their performance as opacifier in a couple of local ceramic factories. The whiteness and glossiness of glazes made with Bangladesh zircon were compared with that made with imported zircon. It has been demonstrated that Bangladesh zircon is quite satisfactory for the production of zircon flour in the ceramic industries. Zircon flour made from Bangladesh zircon can effectively replace imported zircon flour in ceramic glaze, if adequate size reduction and purification is carried out.