Showing papers on "Calcium aluminates published in 1972"

Interactions Between Cement Minerals and Hydroxycarboxylic‐Acid Retarders: II, Tricalcium Aluminate‐Salicylic Acid Reaction*

Abstract: Extensive apparent adsorption of salicylic acid from aqueous solution, previously reported to occur on C3A (and on hydrated calcium aluminates and calcium aluminate sulfates as well), is attributed in large part to precipitation of an amorphous hydrolysis product containing salicylic acid. The product is somewhat gelatinous, especially when generated in salicylic acid solutions of intermediate concentration, but measured BET surface areas were not particularly high. The initial product is not stable, but partly decomposes or rearranges on continued shaking, returning some salicylic acid to the solution. Nearly saturated solutions inhibit the hydrolysis of C3A somewhat, but what product is formed seems entirely amorphous. In contrast, solutions of intermediate concentration do not slow hydrolysis and rapidly generate some tetracalcium aluminate hydrate as well as the amorphous product.