Valorization of silica fumes to obtainment water glass by thermal analysis

Abstract

In the industry of the silicon it is generated as residual silica, of very fine size, with high content in SiO₂ (>92 %). In this work, the possibility of substituting, complete or partially, the residual silica for commercial sands is studied. At the moment, sands are used in the elaboration of soluble glasses by melting. This study is carried out by thermogravimetric and differential thermal analysis of the raw materials and mixtures of them. The energy balance of the system indicates that it is required lower energy when using the residual silica. The presence of impurities in the residual silica can give place to the formation of compound insoluble in the water glass. It is concluded that the residual silica can be used partially in the making of sodium silicate glass.