Various carbon contents in the MgO-C refractory were studied with respect to the oxidation resistance and the wetting behavior with slag. The bulk density, apparent porosity, cold crushing strength, oxidation rate, and mass loss rate of the fired MgO-C refractories with various carbon contents were measured and compared. The wetting and penetration behavior of the cured MgO-C refractory with the molten slag were observed in-situ. The contact angle and the shape parameters of molten slag, including the apparent radius, height, and volume were compared. The results showed that the regenerated MgO effectively restrained the carbon oxidation in the MgO-C refractory, which was more evident at the low carbon content refractory. The contact angle between the MgO-C refractory and the molten slag increased as the carbon content increased. The increased contact angle decreased the penetration of the molten slag.

Porous reaction-bonded silicon nitride(RBSN) ceramics were fabricated by using potassium chloride(KCl) and urea(CO(NH 2) 2) as pore-forming agent, respectively. Green bodies with 30% in mass KCl were subjected to presinter in Ar atmosphere at 1200℃ and then reaction-sintered. The properties of porous silicon nitride ceramics adding different pore-forming agent were explored. And the influence of presintering on apparent porosity, bulk density and bending strength of porous ceramics were investigated. The results indicated that the porosity of Si 3 N 4 ceramics showed a nearly linear increase as the content of KCl increasing, but urea was not. And after presintering, the porosity had small decrease, but bending strength increased obviously. Low bulk density with about 58.6% porosity Si 3 N 4 ceramic was prepared by adding 50wt% KCl, and the main phase composition of porous ceramic was α-Si 3 N 4. Lots of needle-liked α-Si 3 N 4 , especially in the pores, could be observed.