Effect of Mechanical Activation on the Heat of Fusion of a Conventional Batch Used for the Manufacture of Float Glass

Abstract

An initial mixture of raw materials (batch) typically used for the manufacture of conventional soda-lime float glass was subjected to a mechanical activation process for 30 or 60 minutes in a planetary ball mill. An intensification of the chemical reactivity of the batch, which was directly related with the increase in the milling time, was observed. This accelerated the chemical reactions that took place during the batch melting process between sodium, calcium and magnesium carbonates and other components of the mixture, which happened at significantly lower temperatures with respect to the batch without mechanical activation. The heat of fusion of the batch, estimated using a methodology previously reported in the literature, indicated that the mechanical activation given to the initial mixture of raw materials decreased the energy consumed during the batch melting. This was also evidenced by a decrease in the temperature at which the release of CO2 ended, which was considerably larger than that previously reported in the literature based solely on the decrease in the particle size of a batch of similar composition achieved by dry sieving.