Fundamental Studies of the Glass Melting Process. The Effect of Particle Size...
JSGT 1940 V24 T124-T138
A study has been made of the rate of melting in small platinum elliptical capsules heated in an electric furnace of a batch mixture, of approximately 2-5g in amount, yielding a glass of percentage composition 73.5 SiO2, 10 CaO, 16.5 Na2O. Pure soda-ash and calcium carbonate, both of controlled, constant particle size, were employed together with silica grains in one of two forms, the first derived from pure Brazilian quartz, the second from a sieved Dutch sand. Quenched Brazilian quartz was found to break down with peculiar characteristics leading to grains mainly of columnar or needle shape. As the result of a series of experiments at temperatures ranging from 1100° to 1450° it was shown that the rate of glass melting was approximately doubled for each 50° rise in temperature. The rate at any one temperature was found to be proportional to the area of the grains of silica. The violent chemical reactions were found to occupy 10 per cent of the total time of glass melting, and the solution of the residual silica 90 per cent under the conditions of experiment, the solution of the residual silica was at the rate of 0.003mm per minute of the grain diameter.
Eric Preston, Ph.D., D.Sc., F.I.C., F.Inst.P., and Professor W. E. S. Turner
