NH_3-CO_2系统中Y(OH)_3完全沉淀条件的研究

Study on Conditions of Y(OH) 3 Complete Precipitation in NH 3 CO 2 System

Ｙ３＋在氨的水溶液中可形成Ｙ（ＯＨ）３沉淀。在该体系中通入二氧化碳气体，随终点ｐＨ的不同，体系中存在的ＨＣＯ３－、ＣＯ３２－使Ｙ（ＯＨ）３溶解为［Ｙ（ＣＯ３）ｎ］３－２ｎ或［Ｙ（ＨＣＯ３）］３－络合离子。本试验研究了体系终点ｐＨ及起始氨浓度对ＣＯ３２－、ＨＣＯ３－浓度的影响以及进而对Ｙ（ＯＨ）３沉淀率的影响，得到了使Ｙ（ＯＨ）３完全沉淀的反应条件。

Y 3+ in NH 3·H 2O solution can precipitate in the form of Y(OH) 3, the molar ratio of HCO 3 - to CO 3 2- in the system changes with the final pH. Y(OH) 3 is soluble in water and changes into [Y(HCO 3) n ] 3- n or [Y(CO 3) n ] 3-2 n . The influences of the concentration of HCO 3 - and CO 3 3- on the precipitation rate of Y(OH) 3 were discussed, when CO 2 is flowed into the solution in which the concentration of NH 3·H 2O was different and the final pH was 8.00 or 10.00. The conditions of Y(OH) 3 complete precipitation were obtained.