Patent ID: 7560178

Claim:
An aqueous inorganic expandable refractory composition comprising: 1-3 wt % of a phosphorus-based flame retardant containing a carboxylic acid derivative represented by Formula 1; 15-20 wt % of a first metal oxide; 48-65 wt % of a second metal oxide containing silicon dioxide; 10-20 wt % of an aluminum hydroxide silicate mineral having a highly expandable layered structure, said aluminum hydroxide silicate mineral being a refractory material having an expansion capability of at least 500 times; and the balance of said composition being water; wherein the aluminum hydroxide silicate mineral consists of 62.0-68.0 wt % of SiO 2 , 18.0-23.0 wt % of Al 2 O 3 , 1.3-2.5 wt % of Fe 2 O 3 , 0.1-1.9 wt % of MgO, 0.05-1.5 wt % of Na 2 O, 5.0-8.0 wt % of K 2 O, and the balance of said aluminum hydroxide silicate mineral being at least one element selected from the group consisting of S, P, Pb, As and Hg; wherein R 1 represents —CH 2 COOH, —CH 2 CH 2 COOH or —COCH.