高Al_2O_3粉煤灰在碳热还原氮化条件下的物相演变

Phases Transformation of High-alumina Fly Ash under Carbothermal Reduction and Nitridation

高Al2O3粉煤灰在N2气氛中,以焦炭为还原剂,在1450°C和1500°C下,反应生成了的Sialon粉体。研究了碳含量、合成反应温度、保温时间等因素对生成物物相的影响。结果表明:在1450℃和1500℃下,保温3 h可以生成Sialon。以焦炭粉作为还原剂,在温度为1450℃,保温3 h时,配碳量为理论值的200%,碳热还原氮化高Al2O3粉煤灰可以获得的Fe-Sialon材料。讨论了焦炭的加入量对碳热还原氮化产物的物相组成的影响。

Sialon powders were prepared by carbothermal reduction and nitridation method at 1450 ℃ and 1500 ℃ using high-alumina fly ash and carbon coke as raw materials.The effects of carbon coke content,heating temperature and holding time on the phase constitution and microstructure of the products were investigated by XRD and SEM.The results showed that Sialon powders were obtained at 1450 ℃ and 1500 ℃ for 3 h,respectively.A nearly pure Fe-Sialons were prepared at 1450 ℃ for 3 hours when carbon coke content was exceeding 100%.