Hydrothermal Dissolution of Low-Quartz in Sodium Hydroxide Lyes: Kinetics and Equilibrium

Abstract

Quartz flours were dissolved at temperatures between 100 and 220 °C for up to 7 d in NaOH lyes. The starting materials were characterized by particle size analysis. Liquid and solid reaction products were characterized chemically and structurally. Sodium water glasses with silica concentrations of up to 20 wt % were obtained. Radius reduction of size distributed particle ensembles was calculated to evaluate the concentration control of the dissolution rate which is due to saturation effects. An equilibrium between low-quartz and the resulting water glass explains the obtained results.