Formulation of traditional hard porcelain generally requires 50% kaolin, 25% silica and 25% feldspar. Four porcelains formulation using the casting me thod, were prepared with different percentages of kaolinitic clay, sand and Pegmatite referenced respectively NONG, SAB and PEG. The physico-chemical, mechanical and mineralogical characteristics were evaluated on specimens formulated and sintered at different temperatures from 1200˚C to 1300˚C. Xray diffraction has revealed the presence of mullite and quartz as essentially crystalline phases.
The specimen formulated with 55% NONG, 25% PEG and 20% SAB and sintered at 1240˚C gives better performance (water absorption: 0.17%, density: 2.42, open porosity: 0.42% and flexural strength: 53.54 MPa).

Raw Minerals Porcelain Characterization Chemical Durability Phase Transformations