Study On Preparation Of Rutile Crystalline Glaze And Crystallization Mechanism

Crystalline glaze is a kind of art glaze with excellent decorative performance. Now, the system of willemite crystalline glaze as the most common crystalline glaze is single. Little theoretical analysis on the crystal growth has been reported. In this paper, TiO₂ was introduced into willemite crystalline glaze. The influence of TiO₂ addition and processing conditions on the phase constitution and patterns of crystal flowers of the crystalline glaze was studied. Also, the feasibility of using coal gangue as a substitute for clay to prepare crystalline glaze was investigated.The results showed that a rutile crystalline glaze with better aesthetic appearance was prepared under the conditions of melting temperature of 1250℃and crystallization temperature of 1130℃. The crystals in the crystalline glaze could self-grow and overspread the whole surface of the glaze. The amount of the crystals increased with the increase of the crystallization temperatures. XRD and optical microscope results indicated that the precipitated crystals were long columnar rutile crystals. The optimizing raw materials formula for the crystalline glaze was as follows: 14.5%TiO₂, 10.1%ZnO, 11.6%flint clay, 63.5%glass frit and 0.3%CuO. This paper also showed that.Rare earth oxides were also introduced into the crystalline gaze as colorant. The results showed that CeO₂ could make the crystalline glaze present steady yellowness and Er2O3 could make crystalline glaze present steady redness at high temperature. The addition of rare earth oxides made the long columnar crystals in the crystalline glaze became thinne. The crystal structure did not changed.Using coal gangue as a substitute for clay to prepare crystalline glaze body showed has little effect on the hygroscopic coefficient, the porosity, volume concentration, flexural strength and the bonding between the crystalline glaze and the body. When the rate of the coal gangue reached 46%, the performances mentioned above had little changes. The results indicated that it is completely feasible to use coal gangue as a substitute for clay to prepare crystalline glaze ceramic body.