高致密小粒径CoOOH液相合成条件的优化

以硫酸钴和氢氧化钠为原料、压缩空气为氧化剂、氨水为络合剂,通过液相沉淀制备高振实密度小粒径羟基氧化钴(CoOOH)。考察搅拌速度、氨水流量和pH值对产物形貌、振实密度和杂质的影响。转速为340 r/min时,可提供足够的传质传热能量,使合成的CoOOH具有较高的振实密度;氨水流量为0. 6 ml/min可稳定控制合成过程,得到较小的结晶粒子,堆积成高振实密度的颗粒; pH值为11. 2～11. 4可降低颗粒杂质S的含量,并使颗粒表面形貌更加平整。制得的CoOOH样品振实密度高,杂质S含量低,中位粒径为3μm、振实密度为2. 14 g/cm³,合成过程中,上清液中钴含量低于0. 001 5 g/L。

Optimization of liquid phase synthesizing condition ofhigh tap density and small-size CoOOH

The small-size cobalt oxyhydroxide(CoOOH)with high tap density and small-size was prepared by liquid phase precipitation,in which cobalt sulfate and sodium hydroxide were used as raw materials,compressed air was used as oxidant and ammonia was used as complexing agent.The effects of stirring speed,ammonia flow rate and pH value on the morphology,tap density and impurities of the product were investigated.The stirring speed of 340 r/min provided sufficient mass and heat transfer energy,the prepared CoOOH had a higher tap density.The ammonia flow rate of 0.6 ml/min could stably control the synthesis process,the prepared could obtain a smaller crystallizing particle,stacking into the particle with high tap density.The pH value in 11.2-11.4 could reduce the content of particulate impurity S,could make the surface morphology of the particles more flat.The prepared CoOOH samples had a higher tap density of 2.14 g/cm 3,median particle size of 3μm and a lower content of impurity S,the cobalt content of the supernatant in the synthesis process was less than 0.0015 g/L.