富铝煤矸石碳热还原氮化合成Fe-Sialon复相材料的研究

Synthesis of Fe-Sialon Composites Using High Alumina Coal Gangue by Carbothermal Nitridation

采用富铝煤矸石、铁精矿粉、焦炭为原料,经过碳热还原氮化在1 400～1 550℃保温4h条件下合成Fe-Sialon复相材料。利用XRD、SEM和EDS检测手段研究合成温度、焦炭添加量对富铝煤矸石碳热还原氮化的影响。结果表明:①制备得到了Fe-Sialon复相材料,所得产物的主要物相为β-Sialon和Fe3Si;②反应温度为1 400、1 450、1 550℃时,焦炭添加量对产物物相的影响较大。焦炭添加为理论量或过量10%时,所得产物中莫来石、Fe3Si相为主晶相,次晶相为X-Sialon或α-Al2O3,均没有β-Sialon相生成;当焦炭过量大于50%时,X-Sialon作为过渡相向β-Sialon转变,有利于β-Sialon相的生成;③1 500℃下合成的Fe-Sialon复相材料中,β-Sialon为主晶相,其发育成不是很完善的棱柱状晶体。在β-Sialon相周围分散的球状颗粒为Fe3Si相,颗粒直径1～2μm。在本试验条件下,合成Fe-Sialon复相材料的适宜温度为1 500℃,焦炭适宜添加量为理论添加量和焦炭过量10%。

Fe-Sialon composites was prepared using high alumina coal gangue,iron ore concentrate powders and carbon as raw materials by carbothermal reduction and nitriding reaction.The influence of temperature and carbon addition on the carbothermal reduction and nitridation of high alumina coal gangue has been investigated by using XRD and SEM.The results showed that Fe-Sialon composites could be synthesized by carbothermal reduction reaction using high alumina coal gangue,iron ore concentrate powders and carbon as the starting materials,and the main phase of products was β-Sialon and Fe3Si;the composites with different compositions were obtained with different carbon addition and temperature;at 1 500℃,β-Sialon and Fe3Si was main phase in Fe-Sialon composites,and it showed not very well-developed prismatic crystals.Some globular particle with 1～2μm around β-Sialon was Fe3Si phase.The proper temperature to synthesize Fe-Sialon composites was 1 500℃,and addition of carbon was theoretical addition and exceeding 10% in this experiment.