A Study of the Reaction Rates Between Silica and Other Oxides at Various Temperatures. Part II. Reaction Rates in Ternary Mixtures.
JSGT 1953 V37 T155-T167
The work on binary mixtures described in Part I has been extended to a number of ternary mixtures consisting of silica and pairs of other oxides. These ternary mixtures were made up from the binary mixtures either by adding a third oxide in part replacement of one or other of the original binary constituents or by mixing known weights of the binary mixture and of the third oxide. The firing of the mixtures, the regulation of temperature and the estimation of the extent of reaction by the X-ray-diffraction technique have been described in detail in Part I. The results thus obtained from measurements of reaction rates indicate that: (1) In ternary mixtures containing equivalent proportions of Na2O and K2O, the rates of reaction in the potash mixtures are more rapid than in the soda mixtures at temperatures exceeding 900°, though the differences are small or in the reverse order at 900°. (2) The addition of boric oxide to a silica–alkali oxide mixture replacing a small quantity (2%) of the alkali oxide reduces the rate of reaction. (3) The addition of boric oxide to a silica–alkali oxide mixture replacing a small quantity (2%) of silica increases the rate of reaction. (4) The addition of small amounts of lime or magnesia to binary mixtures of silica and soda or silica and potash increases considerably the rate of reaction. (5) The addition of either soda or potash in quite small quantities to a lime–silica, a magnesia–silica, a boric oxide–silica or an alumina–silica mixture increases the reaction rates considerably. (6) The various oxides can be arranged in decreasing order of their rates of reaction with silica as follows: K2O, Na2O, B2O3, CaO, MgO and Al2O3.
Abd-El-Moneim Abou-El-Azm & H. Moore
