共沉淀法制备钛酸钡微粉的研究

对以ＴｉＣｌ_４和ＢａＣｌ_２为原料，以ＮＨ_４ＨＣＯ^３＋ＮＨ_３·Ｈ_２Ｏ作沉淀剂，制备钛酸钡粉末的过程进行了详细的热力学分析，找出了合成钛酸钡的条件和范围，详细地讨论了反应方式和前躯体洗涤条件．实验研究了反应物钡钛比，终点ｐＨ值，煅烧温度，以及分散剂对产物理化性能的影响．结果表明：在ＮＨ_４ＨＣＯ_３／ＢａＣｌ_２＝１．２，ＴｉＣｌ_４／ＢａＣｌ_２＝１－１．０１，充分搅拌反应１ｈ，煅烧温度９２０℃，煅烧时间２ｈ条件下，可以制得较理想的产物．在反应体系中加入适量分散剂可以明显降低产物的粒径．

Preparation of Ultrafine Barium Titanate Powder by Coprecipitation

This paper investigated the preparation of ultrafine barium titanate powders by using titanium tetrachloride and barium chloride as starting materials and NH₄HCO₃+NH₃·H₂O as the precipitant. First of all, a thermodynamic analysis was made in detail to find out optimum synthesis conditions. Experiment results show that the Ba/Ti ratio of starting materials, calcination temperature, pH value of solution, have a close effect to the physical and chemical performances of the obtained powders. The best conditions are NH₄HCO₃/BaCl₂·2H₂O=1.2; TiCl₄/BaCl₂·2H₂O=1～1.01; reaction time=1h; calacination temperature=920℃ and calcination time 2h. The addition of some dispersants into the reactant system can obviously reduce particle sizes of the product.