THE EFFECT OF SURFACE-TREATED ANHYDROUS BORAX ADDITIONS ON HARD PORCELAIN PROPERTIES

The utilisation of surface-treated anhydrous borax to facilitate densification of hard porcelain bodies, prepared by slip casting from suspensions containing mixtures of silicate-based raw materials, was investigated. After surface treatment with stearic acid, anhydrous borax powders were added to the initial mixture by partial substitution with potassium feldspars up to 3 wt% to examine their potential effects on the finished product. By the addition of surface-treated borax to the suspensions, stabilised with different dispersants (Darvan 821A and Dolapix CE-64), hard porcelain bodies of high strength, which were fired at a lower temperature than the industrial firing temperature, were obtained. After studying the effects of the different amounts of surface-treated borax addition on the porcelain properties, it was found that the addition of borax causes distinct effects on the physico-mechanical properties of hard porcelain.