China Clay for White ware Industry:
Required Specification for Bone China:
The addition of China clay in the Bone China composition is required to provide plasticity and green strength for handling of green wares as ball clays cannot be used in bone china due to high iron oxide and titania contents. The china clay also increases the whiteness of the fired products and also controls the shape of the wares during firing.
1. China Clay for Bone china should be white burning, quick slaking and the residue over 325 mesh sieve should not be more than 1 wt%
2. The content of iron oxide (Fe2O3 and titania (TiO2) should preferably be less than 1.0% in each case and should not exceed 1.5% in total.
3. The china clays should also be plastic and the green strength should not be less than 15kg/cm2
