Periclase-hercynite bricks were prepared from fused or reaction-sintered hercynite. The microstructure of the obtained bricks was studied and their thermal conductivity in the simulated on-site condition was tested. The results show that the mutual diffusion of Fe or Al from hercynite and Mg from periclase forms more pores in the material. Compared with the brick prepared from fused hercynite, the brick from reaction-sintered hercynite has smaller pore size. The thermal conductivity simulation test of the two bricks at 1550 oC shows that the cold end temperature of the brick synthesized from the reactionsintered hercynite is 40 oC lower than that of the brick from the fused hercynite. Thus, in consideration of reducing the shell temperature of the cement rotary kilns, the reaction-sintered hercynite is more favorable for the production of periclasehercynite bricks.

Keywords: Fused hercynite, Reaction-sintered hercynite, Microstructure, Thermal conductivity