摘要
对福建五种高变质煤(永安、加福、尤溪、大田及永春煤)催化气化后的含碱灰渣进行煅烧脱碱研究。灰渣中碱含量随煅烧温度的升高及煅烧时间的延长而降低,870℃煅烧30 m in^40 m in灰渣中碱含量趋于定值,脱碱率均达90%以上;X射线粉晶衍射及能谱分析表明,脱碱过程的实质是含碱灰渣中被活化的主要物质S iO2、A l2O3与灰渣中的碱性物质Na2O发生化学反应,生成难溶于水的钠铝复合硅酸盐的固相反应过程;表观动力学研究结果表明,该脱碱反应属一级反应,反应速率常数随煤渣中硅铝比的增加而增大,给出的反应速率常数随煤渣中硅铝比变化的关系方程,相关系数为0.99175,可用以预测任一已知含碱煤渣或不同S i/A l比的煤渣在不同煅烧温度下的脱碱反应速率常数,得出最佳的煅烧脱碱时间,为"煤催化气化-煅烧脱碱"集成式工艺工业应用提供基础数据。
The de-alkali of alkali cinder produced from the catalytic gasification of five kinds of Fujian high-metamorphous anthracites(Yongan,Jiafu,Youxi,Datian,Yongchun) was investigated by calcining the alkali cinder in a laboratorial high temperature furnace.The results indicate that the alkali content in the cinder decreases with increasing the temperature and time,and when the cinder is calcined at 870 ℃ for 30 min～40 min,its alkali content can be decreased by 90%.By analyzing the calcined cinder by X-ray powder diffraction(XRD) and energy spectrum,it can be seen that at an appropriate calcination temperature,the activated SiO2 and Al2O3 in alkali cinder can react with Na2O to form Na-Al-silicates,which is the essential of de-alkali process for alkali cinder.The investigation on the apparent reaction kinetics shows that the apparent reaction order of the de-alkali reaction is 1. The de-alkali reaction velocity constant of different cinders increases with increasing the ratio of Si/Al of cinder,for which an experiential equation has been proposed as a function of the ratio of Si/Al with the correlation coefficient of 0.991 75.Based on the equation the optimum calcining temperature and time can be predicted.
出处
《燃料化学学报》
EI
CAS
CSCD
北大核心
2007年第4期391-396,共6页
Journal of Fuel Chemistry and Technology
基金
国家自然科学基金(20376014)
福建省科技厅重点资助(HG99-01)
关键词
含碱灰渣
XRD
煅烧脱碱
脱碱动力学
alkali cinder
XRD
calcination and de-alkali
de-alkali kinetics
