摘要
将不同粒径（〈15μm、43～77μm和〉100μm）的粉煤灰微珠分别与一定比例的（低于理论用量20％、理论用量、高于理论用量10％）活性炭均匀混合后，置于氧化铝坩埚中，在高温氮化炉中分别于1300℃、1350℃、1400℃、1450℃和1500℃保温6h处理制备β-SiAlON空心球。借助XRD和SEM研究了温度、微珠粒径和活性炭用量对粉煤灰微珠氮化后相组成和形貌的影响。结果表明：粉煤灰微珠的氮化反应开始于1300℃；过量的活性炭是形成β-SiAlON空心球的必要条件，粒径是微珠氮化后维持球形形貌的重要因素；1500℃，在活性炭过量10％的条件下，利用粒径大于100μm的粉煤灰微珠制备的β-SiAlON空心球，具有表面粗糙、空心度大和密度低等特点。
The β-SiAION hollow spheres were prepared by carbothermal reduction method, using coal fly ash （ 〈 15 μm,43-77 μm and 〉100 μm） and active carbon in some proportion （20% less than theoretical dosing,the-oretical dosing and 10% excess theoretical dosing） as starting materials, putting into alumina crucible in high temperature nitriding furnace after well mixed and firing at 1300 ℃, 1350 ℃,1400 ℃, 1 450 ℃ and 1 500 ℃ for 6 h. Effects of temperature, particle size of the microsphere and additon of active carbon on the phase composition and microstructure of the nitridized products were studied by means of XRD and SEM. The results show that,the nitridation reaction starts at 1 300 ℃;excess active carbon is necessary to form β-SiAION. hollow spheres,and particle size is the important parameter to form the hollow spheres nitridized products β-SiAION;at 1 500 ℃, when the active carbon is 10% in excess,the β-SiAION hollow spheres, which were prepared using coal fly ash with particle size 〉 100 μm, are featured with rough surface, perfect hollowness and low density.
出处
《耐火材料》
CAS
北大核心
2008年第2期105-108,112,共5页
Refractories
基金
国家自然科学基金(50472030)
天津市社会发展资助项目(05YFSYSF00300)
