Aluminous cement - with setting retarder and hardening activator

摘要

Aluminous cement contains a setting retarder (a polyaminecarboxylic acid or its salt or a nitrilotriacetic cpd.) and a hardening activator (one or more Li salts). Pref. compsn. is 0.10-5.000 (pref. 0.3-3.0) % of R2N(CH2)nNR2 (where n = 3 to 7, at least 2R groups are lower carboxylic acids or their alkali(ne earth) ammonium or triethanolamine salts) 0.001-1.0(0.005-0.1)% Li2CO3 and up to 15% (pref. 0.75 to 2%) tri-Ca sulphate. The cement remains workable for a longer period without deterioration in final mechanical strength.