Preparation of precipitated batch compositions for glass ceramics in the system SiO2-Al2O3-Li2O-TiO2-B2O3-ZnO-MgO

The purpose of this paper is to describe the preparation of precipitated batch compositions for glass ceramics. In this work the hydroxide ion is used for the precipitation and so all the cations are precipitated as hydroxides. The required silicon dioxide, in this case amorphous silicon dioxide, is obtained from sodium water glass. The precipitates obtained were washed to remove the chlorine and sodium ions to yield clean precipitates of the hydroxides. In addition to the basic oxides 5 .0 wt% B2O3 was added together with MgO and ZnO. The melting point for the batch material prepared from pure oxides was over 1600 degreesC while the melting point of the precipitated batch material was between 1400 and 1500 degreesC.