agents. The glass abrasive sludges were mixed with expanding agents and compacted into pellets. These pellets were sintered in the range of 700-900oC for 20min. The sintered porous materials had a surface layer with smaller pores and inner parts with larger pores. The surface layer and pores controlled the absorption ratio and physical properties. As the expanding agent fraction and the sintering temperature increased, the porosity and pore size increased. The porous materials with Fe2O3 and graphite as the expanding agents had a low absorption ratio of about 3% or lower while the porous material with CaCO3 as the expanding agent had a higher absorption ratio and more open pores.