Ground-granulated blast-furnace slag (GGBS or GGBFS) is obtained by quenching molten iron slag from a blast furnace in water or steam, to produce a glassy,. GGBF slag is specified by ASTM C989  in three grades (Grade 80, Grade 100, and Grade 120), depending on the relative mortar strength. This study investigates the improvement of the CO2 sequestration percentage of a ground granulated blast furnace slag (GGBF-slag) with surface modification. Slag cement is a hydraulic cement formed when granulated blast furnace slag ( GGBFS) is ground to suitable fineness and is used to replace a portion of. Blast furnace slag is a nonmetallic coproduct produced in the process.