两步纯化溶液法制备高纯氢氧化铝粉

以工业氢氧化铝和硫酸为原料,采用两步纯化溶液法制得了纯度为99.99%的氢氧化铝粉.此外,对活性炭和离子交换树脂对溶液的纯化效果,以及有屏蔽剂A存在时pH值对铁离子平衡浓度的影响进行了研究.研究结果表明:活性炭、吸附树脂、强碱性、弱碱性阴离子交换树脂纯化溶液的效果较差,螯合树脂Da纯化溶液的效果最好,其饱和容量大约是树脂体积的6倍;当没有屏蔽剂存在时,约有80%的铁离子以沉淀析出;当有屏蔽剂A存在时,在pH值为5时只有4.02%的铁离子以沉淀析出,在pH值为6.5时有16.41%的铁离子以沉淀析出,达到了用屏蔽剂阻止杂质离子析出的二次纯化的目的.

Two-step purifying solution for preparation high pure aluminium hydroxied

Aluminium hydroxide with 99.99% of purity was obtained by two-step purifying aluminium sulfate solution made from aluminium hydroxide and sulfuric acid with industry purity. The effects of the activated carbon and the ion exchange resins, and the effect of pH value in the presence of the shielding reagent on the purification were investigated. The results show that the chelate exchange resin Da is the best one for purification of solutions with 6 times of saturation exchange capacity in volume. In the presence of shielding reagent, 4.8% Fe~(3 ) and 16.41% Fe~(3 ) was co-precipitated in aluminium sulfate solution at pH 4.5 and 6.5 , respectively. In the absence of the shielding reagent, 80% Fe~(3 ) is co-precipitated .The experiment results are in good agreement with the calculation results based on mass balance. Therefore the shielding reagent A is selected for the second purity step in the course of precipitation.