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MECHANISM OF THE HARDENING OF CLAY‐SODIUM‐SILICATE MIXTURES *
Author(s) -
Morgan W. R.,
Peskin W. L.,
Kronman S. J.
Publication year - 1940
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1940.tb14231.x
Subject(s) - sodium silicate , silicate , chemistry , sodium , magnesium , hardening (computing) , inorganic chemistry , sodium carbonate , carbonate , calcium silicate , mineralogy , chemical engineering , materials science , metallurgy , organic chemistry , layer (electronics) , engineering
A bstract Acid salts, such as might be expected to be present in clays, reacted readily with sodium‐silicate solutions and produced marked changes in viscosity out of contact with air. Magnesium salts gave the most gelatinous and bulky precipitates. Experiments with fuller's earth and a plastic fire clay, which were free of soluble salts and were saturated with hydrogen, indicated that base‐exchange reactions may also cause hardening of silicate mixtures out of contact with air. Natural plastic fire clays, which contained negligible amounts of soluble salts, were found to harden out of contact with air when calcium and magnesium were present as exchangeable bases, but they did not harden when these bases were absent. It was found possible to prevent hardening of clay‐sodium‐silicate mixtures by subjecting the clay to a preliminary treatment with nonprecipitating sodium ions, introduced as sodium carbonate, before mixing the clay with sodium silicate.