雾化碳化法制备超细针状纳米碳酸钡粉体

Preparation of ultrafine acicular nano barium carbonate powder by atomization carbonization

采用可溶性钡源Ba(OH)(2)·8H_(2)O作为原材料,在60℃热水中充分溶解,溶质溶剂比例1∶6。溶液通过高压雾化进入到天然气燃烧产生大量的高温CO2的反应室内,反应室进气口温度控制为220(±10)℃。雾化后的含钡水溶液瞬间接触高温CO_(2)生成BaCO_(3),同时高温蒸发水溶液,通过引风滤袋过滤,获得高分散、超细碳酸钡粉体。过程考察了雾化压力、酒石酸作为抑制剂对粉体粒度的影响。采用XRD对粉体物相进行表征,采用激光粒度仪对粉体二次粒度进行表征,采用SEM和比表面积分析仪对粉体形貌和一次粒度进行表征。结果表明,通过采用雾化压力0.8 MPa, 3%的酒石酸作为抑制剂,可制备SSA为30 m^(2)/g~40 m^(2)/g的碳酸钡粉体,粉体一次平均粒径40 nm。

Soluble barium source Ba(OH)(2)·8H_(2)O was used as raw material, which was fully dissolved in hot water at 60 ℃, and the ratio of solute to solvent was 1 ∶ 6. The solution enters the reaction chamber where a large amount of high-temperature CO_(2) is produced by natural gas combustion through high-pressure atomization, and the temperature of the inlet of the reaction chamber is controlled to 220(± 10) ℃. The atomized barium containing aqueous solution is instantly contacted with high-temperature CO_(2) to generate BaCO_(3). At the same time, the aqueous solution is evaporated at high temperature and filtered through induced draft filter bag to obtain highly dispersed and ultra-fine barium carbonate powder. The effects of atomization pressure and tartaric acid as inhibitor on the particle size were investigated. The powder phase was characterized by XRD, the secondary particle size was characterized by laser particle sizer, and the powder morphology and primary particle size were characterized by SEM and specific surface area analyzer. The results show that barium carbonate powder with SSA of 30 m^(2)/g ~ 40 m^(2)/g can be prepared by using atomization pressure of 0.8 MPa and 3% tartaric acid as inhibitor. The average particle size of the powder is 40 nm at one time.