The Influence of Cullet on the Reactions Occurring During the Melting of Glass

JSGT_1936_V20_T095_T103

A study has been made of the reactions occurring between 500° and 900° in binary and ternary mixtures of Na₂CO₃, CaCO₃, and SiO₂ when heated for 1, 2, and 3 hours alone and in the presence of 40% by weight of cullet to form a glass of composition, SiO₂ 75%, CaO 10, Na₂O 15. The addition of cullet accelerated the reactions in the batch. Reactions in mixtures of Na₂CO₃ with SiO₂ or cullet were not appreciably affected by the grain size of the materials and were complete at 900°. With CaCO₃–cullet mixtures, the reactions were almost complete after 3 hours at 700°. In the ternary mixture the acceleration of the reactions was greatest with cullet of 0-0·15 mm grain size and least with the largest grain sizes 1·00 to 1·50 mm. The rates of reaction of Na₂CO₃,CaCO₃ mixtures were less than the rates of reaction of the individual components heated with cullet at the same temperature.

M. A. Besborodov, N. D. Zavjalov & E. N. Zeliger