On-line version ISSN 1678-4553
GOUVEA, D.; KANEKO, T. T. and KAHN, H.. Bone ash as a sintering additive in the porcelain production. Cerâmica [online]. 2009, vol.55, n.335, pp. 252-256. ISSN 1678-4553. http://dx.doi.org/10.1590/S0366-69132009000300003.
Bone ash is typically used as raw material to produce high quality porcelain denoted bone china. The total amount of bone ash is around 50%. With about 200 million head, Brazil has the largest commercial herd of cattle in the world but the bovine bones are not employed in the Brazilian ceramic industry. Nevertheless, additions of bone ash in the raw material composition used in the porcelain fabrication reduce the liquidus temperature and could be an additive for liquid phase sintering. In this work, bone ash was used as a sintering additive in the fabrication of classic porcelain: kaolin, feldspar and quartz. Porcelain was produced containing bone ash (0, 1, 2 and 5%) and sintered from 1100 to 1350 ºC. Water absorption and modulus of rupture were measured and related with the microstructure observation by MEV and phase formation by X-ray diffraction. The sintering temperature was reduced by 50 ºC for 2% of bone ash while the mechanical strength was increased. A high residual porosity was observed for sample with over firing.
Keywords : bone china.