Specific characteristics of coating glazes based on basalt

Investigations in this paper has been carried out in order to define the correlation between specific characteristics of coating glazes based on basalt, fired faience and appearance and the quality of the ceramic product surface. The paper presents the initial results of research on possibilities for utilisation of basalt from the locality "Vrelo" - Kopaonik Mountain (Serbia) for producing the opaque glaze. From frits with different basalt content (25%, 30%, 35%, and 60%) with addition of water and 5% of the kaolin "Zetlizer", the liquid glazes-suspensions were made (G-1/25, G-2/30, G-3/35, and G-4/60). The primary fired biscuit-shaped faience was used for applying the glazes by dipping, pouring and brushing methods. The further firing process of glazes took place in a laboratory tunnel furnace, under the following operating parameters: temperature T = 980 degrees C and retention time t = 3 h (hours). The initial investigation has shown that the basalt from the locality Vrelo is suitable for obtaining applicable glazes, bringing the attractive and decorative colours to the surfaces of the faience ceramics. The best results were achieved by adding the iron pigments. (C) 2012 Elsevier Ltd. All rights reserved.