Method of making a refractory article

A method of making a refractory article, the method comprising:

• a) mixing a binder system, a refractory charge, and a second colloidal binder to form an aqueous slurry;
• b) casting the aqueous slurry into a mold, wherein the aqueous slurry is at a slurry casting temperature;
• c) subjecting the mold containing the aqueous slurry to a temperature that is less than the slurry casting temperature for a time sufficient to form a green strength article;
• and
• d) firing the green strength article at a temperature of at least 450° C. for a time sufficient to achieve thermal homogeneity, thereby forming a refractory article,
• wherein the binder system comprises from 2 wt % to 10 wt % of the aqueous slurry, the refractory charge comprises from 40 wt % to 75 wt % of the aqueous slurry, and the second colloidal binder comprises from 20 wt % to 50 wt % of the aqueous slurry.