Bone china is a special kind of porcelain, very hard and translucent, nowadays manufactured almost exclusively in England and in few other parts of the world, but not in Brazil. Its raw-materials comprise about fifty percent of bone ash, together with kaolin and a feldspar mineral. This paper presents the preparation and the characterization of bone ash obtained from bovine bones, with the objective of obtaining bone china. The preparation of the bone ash involves the use of an autoclave, manual removal of the meat, firing, and milling the bones. The preparation conditions were studied as a function of the firing conditions, milling, and washing the powder bones. The firing step was studied by thermal analyses TG-DTA and X-ray diffraction, whereas the obtained powder was characterized in terms of its chemical composition (X-ray fluorescence), particle size distribution (laser diffraction), and scanning electron microscopy. The results indicate that the obtained raw-material exhibits similar properties to the ones of the bone ash used by the English industry, with low iron content and colloidal particles when calcined at temperatures lower than 1000 °C.
bone china; bone ash; powder characterization
