用粉煤灰合成不同组成的Sialon环境材料

以粉煤灰和炭黑为原料,采用碳热还原氮化法在1 350~1 550℃下保温6 h合成出不同组成的Sialon环境材料.研究了合成温度对材料相组成的影响,观察了其显微结构,并分析了粉煤灰的碳热还原氮化过程.研究结果表明:合成温度对材料的相组成影响显著;提高合成温度有利于莫来石的分解和Sialon的生成,通过控制加热温度可以合成不同组成的Sialon材料;1 350~1 400℃,1 450~1 500℃和1 550℃保温6 h可以分别合成(O′+β)-Sialon/莫来石、(X+β)-Sialon/刚玉和β-Sialon材料;在1 550℃下合成β-Sialon的平均粒径约为2~3μm.粉煤灰的碳...

Synthesis of Sialon Ecomaterials with Different Compositions Using Fly Ash

Sialon ecomaterials with different compositions were synthesized by a carbothermal reduction-nitridation process with fly ash and carbon black as raw materials.Effect of synthesis temperature on the phase composition was investigated.The microstructure was observed by SEM.The carbothermal reduction-nitridation process of fly ash was also analyzed.The results indicated that synthesis temperature has a remarkable effect on the phase composition of the materials.Increasing synthesis temperature accelerates the decomposition of mullite and the formation of Sialon.The Sialon materials with different compositions can be synthesized by controlling the temperature.The(O′+β)-Sialon/mullite,(X+β)-Sialon/corundum and β-Sialon materials can be synthesized at 1 350~1 400 ℃,1 450~1 500 ℃ and 1 550 ℃ for 6 h,respectively.The average particle size of β-Sialon synthesized at 1 550 ℃ is around 2~3 μm.The carbothermal reduction-nitridation process of fly ash consists of the nitridation formation process of O′-Sialon,X-Sialon and β-Sialon,and the conversion processes of O′-Sialon to X-Sialon and β-Sialon as well as X-Sialon to β-Sialon.