煤矸石还原氮化合成O’-Sialon及热力学研究

Thermodynamic Study and Reduction-nitridation Synthesis of O'-Sialon from Coal Gangue

采用拟抛物面规则评估了O’-Sialon、X相的吉布斯生成自由能,并从热力学上分析了O’-Sialon、β-Sialon、X相的合成过程.研究了以中国山西煤矸石为原料,还原氮化合成O’-Sialon的影响因素,包括还原剂(C或者Si)的用量、氮化温度等;结果表明,以金属Si为主要还原剂时O’-Sialon的合成效果较佳,其相对含量最高可以达到80％左右,提高氮化温度有利于O’-Sialon的合成.

The Gibbs energy values of O'-Sialon and X phase were calculated by the thermodynamic quasi-paraboloid rule, and the process of synthesizing O'-Sialon, beta-Sialon and X phase was analyzed thermodynamically. The effects of technological factors (such as amount of reducing agent added, nitriding temperature etc.) on the synthesis of O'-Sialon based on coal gangue by the reduction-nitridation method were investigated. The results show that the use of metallic Si powder as reducing agent is more effective in prompting O'-Sialon formation. About 80% O'-Sialon content may be attained, and the increase in nitriding temperature is advantageous to the synthesis of O'-Sialon.