The Kaolite 2000-LI castable meets both the strength and properties needed for high-performance linings. The strength-to-density ratio of the Kaolite 2000-LI is in the range of 11-12 psi/pcf, which is 10 times higher than the typical super-lightweight castable. The low k values of Kaolite 2000-LI, along with high cold crushing strengths (450 psi at densities of 38-41 pcf), translates into a superior insulating castable that design engineers can use to substantially strengthen the refractory lining. Kaolite 2000-LI castable also has low iron oxide content so it can be used in carburizing furnaces or where high concentrations of CO gas are present.