Abstract: The present invention comprises rice hull ash which is pelletized subsequent to its admixture with a bentonite clay binder. A preferred product according to the present invention is pelletized rice hull ash which contains both bentonite clay and organic cornstarch binders. The bentonite clay contains approximately 58-68% SiO.sub.2, 18-21% Al.sub.2 O.sub.3, 2.5-2.8% Fe.sub.2 O.sub.3 /FeO, 2.5-3.2% MgO, 0.1-1.0% Cao, 1.5-2.7% Na.sub.2 O, 0.2-0.45% K.sub.2 O, and 4.5-9.0% free H.sub.2 O. Insulator pellets according to the present invention, when placed atop molten steel in ladles or tundishes, insulate well and do not smoke or generate unwanted dust.