Abstract: Porous cordierite ceramics were synthesized from coal gangue,wasted slide gates and wasted magnesia carbon bricks with graphite,starch and compound additives as pore-forming materials.The relationships between properties and synthesis conditions,such as the type and addition of pore-forming materials and heating temperature,were investigated.The result showed that high-purity porous cordierite was synthesized from coal gangue and used refractories at 1 350 to 1 400 ℃ while the compound additives was used as pore-forming materials and their addition is 15% to 25%.At the addition of the compound additives of 20%,1 350 ℃ and sintering for 3 h,porous cordierite ceramics with homogeneous pores distribution were obtained,their apparent porosity is 44.9%,thermal expansion coefficient is 2.14×10^-6 K^-1,and softening point load is 1 290 ℃.Because of these good comprehensive performances,all bricks can meet the demands of service at high temperature.