Manufacture of non-whiteware ceramic articles

A process for the preparation of non-whiteware ceramic articles comprising

• (a) preparing a slip, which is essentially free of added elemental sulfur, by mixing an additive, in an amount effective to increase the green strength of articles prepared from the slip composition, said additive selected from the group consisting of (1) a polyalkylene polyamine, comprising linear isomers and having an average molecular weight of less than about 1000 and (2) a mixture of a first component consisting of a polyalkylene polyamine, comprising linear isomers and having an average molecular weight of less than about 1,000 and a second component selected from the group consisting of latexes, lignosulfonates, polyvinyl alcohols, alkanolamines, polypropylene glycols and polyethylene glycols or mixtures thereof in an amount, less than about 6.5 weight percent based on the solids contents of the slip, which is effective to maintain the viscosity of the slip and the cast weight of non-whiteware ceramic articles prepared therefrom, in an amount effective to increase the green strength of articles prepared from the slip composition with a slip medium and a dispersant;
• (b) mixing a particulate material selected from the group consisting of alumina, zirconium oxide, silicon carbide, silicon nitride, and mixtures thereof with the mixture of step (a) to form the slip;
• and
• (c) using slip casting, pressure casting, pressing, or plastic-forming techniques to prepare non-whiteware ceramic articles from the mixture of step (b).