The glass batches with different sand grain sizes and grain size distributions were studied by DTA, TG and XRD analysis regarding the silicate formation and succeeding melting. Adding water in the glass batches with different sand sizes shows strong effect on the process of silicate formation. When water is added, the glass batch with the fine sand grain size controlled not to be finer than 0.10 mm in diameter has the characteristics of silicate formation similar to that of glass batch with the very fine sand powder and no water added in a laboratory experiment. Notable agglomeration does not occur in the glass batch with this controlled sand grain size, which is indicated by both carbonate decomposition and silicate formation at lower temperature, and therefore an optimized glass melting is expected.