Types of Refractory Castables

Designation HCC MCC LCC ULCC NCC
Cement Content High Medium Low Ultra Low None
CaO (%) >5 3 – 8 1.5 0.5 0.1
Al2O3 (%) >50 >35 >50 >70 >90
Fe2O3 (%) 0.5 – 20 0.5 – 4.0 <1.5 <1 <1 Workability ± ++ – – – – –