矿化剂对铝酸钙粉的结构与光谱性能的影响

Study on the Influence of Mineralizer on the Structures and Spectral Properties of Calcium Aluminates

研究了矿化剂对制备铝酸钙粉的结构与性能的影响。研究中以铝矾土和石灰石为原料,加入一定量的矿化剂,混合均匀,经高温煅烧制得铝酸钙粉。借助于红外光谱、X射线粉末衍射、差热-热重分析等手段对不同原料的铝酸钙粉的结构、组成及性能进行了表征和研究,并对矿化剂在合成铝酸钙中的矿化机理进行探讨。研究表明:加入矿化剂后,可在更低温度条件下煅烧制备出铝酸钙粉,有利于节能减排。红外光谱分析、XRD分析、DTA-TG分析显示:未加矿化剂煅烧时,生成的产物主要是Ca3Al10O18,CaAl2Si2O8。加入矿化剂后煅烧生成的产物主要是易浸出Al2O3的CaAl3BO7和Ca3Al10O18,而不易浸出Al2O3的CaAl2Si2O8的含量大大降低。同时显示,加入矿化剂后,原料中的方解石(CaCO3)分解更容易;CaCO3与铝矾土反应更充分;更有利于促使铝矾土中的Al—Si键断裂,将铝矾土中的Al释放出来;并可降低铝酸钙的煅烧温度。研究还显示:加入矿化剂后,可以改变原产物的晶体结构与成分,有利于降低煅烧反应温度。

The present paper investigated the effect of mineralizer on the structure and properties of calcium aluminates formation. Calcium aluminates powder was synthesized under high temperature calcination by mixing bauxite,limestone and a certain amount of mineralizer. The product structure,compositional information and spectral properties were carefully characterized by XRD,IR and DTA-TG,and the mineralization mechanism of mineralizer was studied during the process of calcium aluminates preparation. The results showed that calcium aluminates powder could be obtained under lower temperature calcination after adding mineralizer to the raw materials. The main products of the reaction were CaAl10O18 and CaAl2Si2O8 without mineralizer,however,the main products of the reaction were CaAl3BO7 and Ca3Al10O18 with mineralizer,in which Al2O3 could be extracted easily,while CaAl2Si2O8 was reduced greatly in which Al2O3 could not be extracted easily. At the same time,it is easy for calcspar to decompose after adding mineralizer. It is favorable to Al—Si bond break and Al stripping from bauxite.These facts could improve the extraction rate of Al2O3 from raw materials. Also,in the case of adding mineralizer to the raw mixes,the crystal structure and composition are changed,which is beneficial to reducing calcination temperature.