高铝质磷酸盐陶瓷制备研究

以特级矾土细粉为主要原料、铝酸盐水泥为结合剂、六偏磷酸钠为减水剂,磷酸盐选择磷酸二氢铝,采用浇注成型的方法制备高铝质磷酸盐陶瓷,考察了保温时间、煅烧温度和磷酸二氢铝添加量对高铝质磷酸盐陶瓷性能的影响。研究结果表明：添加磷酸二氢铝可以提高高铝质磷酸盐陶瓷的性能,磷酸二氢铝用量为6%（质量分数）时,制备的高铝质磷酸盐陶瓷的抗弯强度达到24.15 MPa;磷酸二氢铝用量超过6%后,对高铝质磷酸盐陶瓷的抗弯强度不利;添加6%磷酸二氢铝,形成的主要物相有石英、刚玉、磷酸盐、硅线石和莫来石,说明添加磷酸二氢铝有利于陶瓷新相的形成。高铝质磷酸盐陶瓷适宜的制备工艺条件：矾土粉用量为96%（质量分数）,铝酸盐水泥用量为4%（质量分数）,减水剂用量为外加0.1%（质量分数）,磷酸二氢铝用量为外加6%（质量分数）,保温时间为4 h,煅烧温度为1 250 ℃

Preparation of high aluminous phosphate ceramics

With superfine alumina powder as the main raw material,aluminate cement as binder,sodium hexametaphosphate as water reducing agent,and chosing aluminum dihydrogen phosphate,the high aluminum phosphate ceramic was prepared by casting molding method.The effect of holding time,calcination temperature and aluminum dihydrogen phosphate content on the properties of phosphate ceramic were studied.Results showed that adding aluminum dihydrogen phosphate can improve the property of high aluminum ceramic;when aluminum dihydrogen phosphate content was 6%（mass fraction）,high aluminum ceramic flexural strength was 24.15 MPa.When the aluminum dihydrogen phosphate content was more than 6%（mass fraction）,which was unfavorable to the bending strength of high alumina ceramics.Adding 6% of aluminum dihydrogen phosphate to form the main phase was quartz,corundum,phosphate,sillite and mullite.The addition of aluminum dihydrogen phosphate facilitated the formation of new phase of ceramics.Suitable preparation conditions of high aluminum phosphate ceramics were as follows：the dosage of bauxite powder was 96%（mass fraction）,the dosage of aluminate cement was 4%（mass fraction）,the dosage of water reducer was 0.1% plus（mass fraction）,the dosage of aluminum dihydrogen phosphate was 6% plus（mass fraction）,the holding time was 4 h and the calcination temperature was 1 250 ℃.