外场辅助制备低氯氧化镧前驱体

Preparation of the precursor of lanthanum oxide with a low chlorine content with the assistance of microwave and ultrasonic

通过微波与超声波外场辅助作用,以氯化镧溶液为原料,碳酸氢铵为沉淀剂,采用液相沉淀法制备了低氯氧化镧前驱体.研究了加料方式、加热方式、反应温度、料液浓度、摩尔比(LaCl3∶NH4HCO3)以及超声波模式对沉淀产物中氯根含量和氧化镧前驱体形貌的影响,确定了较优反应参数.结果表明:在微波与超声波作用下,反应温度50℃,氯化镧溶液浓度0.1 mol/L,氯化镧与碳酸氢铵的摩尔比为1∶3.5,并流加料,超声波功率为500 W,超声波模式1∶1,通过液相沉淀法制备了分散性良好、表面光滑的梭棒状氧化镧前驱体,其氯根含量低至0.005 2%.

The precursor of lanthanum oxide with a low chlorine content was obtained by liquid precipitation with the assistance of microwave and ultrasonic. In this process, ammonium bicarbonate was taken as precipitant and lanthanum chloride solution as raw materials. Better optimum reaction parameters were determined by studying how the feeding mode, heating mode, reaction temperature, solution concentration, molar ratio of reactants and ultrasonic mode would affect the chlorine content of precipitate and the morphology of the precursor of lanthanum oxide. The results showed that a bar-like precursor of lanthanum oxide with a good dispersity, a smooth surface and a chloride content as low as 0.005 2 % could be prepared by liquid precipitation with the assistance of microwave and ultrasonic when the reaction temperature reaches 50℃ with parallel flowing mode used, the concentration of lanthanum chloride solution being 0.1 mol/L, the molar ratio of lanthanum chloride to ammonium bicarbonate 1：3.5, the ultrasonic power 500 W and the ultrasonic mode 1：1.