Synthesis of B4C-C Composite Powder and Its Application in Low Carbon MgO-C Bricks
YAN Zheng-guo, CHEN Wei, YU Jing-kun
School of Materials and Matallurgy, Northeastern University School of Resources and Environmental Engineering, Wuhan University of Technology School of Materials and Matallurgy, Northeastern University
Abstract： B4C-C composite powder was synthesized from carbon black and boric acid by carbothermal reduction reaction. The effect of heating temperature on the synthesis of B4C-C composite powder was studied. The phase composition, morphology, structure and particle size of synthesized composite powder were characterized by XRD, carbon and sulfur analyzer, SEM, and laser particle size analyzer. The effects of the synthesized composite powder added in MgO-C brick were investigated by measuring the physical properties, oxidation resistance, and thermal shock resistance of specimens. The results show that the graphitization degree of the synthesized B4C-C composite powder rises, while B4C phase decreases with increasing of heating temperature. The graphitization degree of the composite powder synthesized at 1900℃ is 23.26%, the percentage of B4C is about 20%. The differential distribution of the synthesized composite powder is above 85% nanometer B4C and partly graphitized carbon black, except some micron and submicron B4C particles. The physical properties, oxidation resistance, and thermal shock resistance of the low carbon MgO-C brick specimens added with the synthesized B4C-C composite powder are excellent.
2009, Vol. 9 
