含磷酸根离子和三价铁离子的溶液中镓的沉淀行为研究

研究了磷酸根离子对镓离子和三价铁离子沉淀过程的影响以及在含磷酸根离子的溶液中三价铁离子对镓离子沉淀过程的影响。实验结果表明磷酸根离子能促进镓离子和三价铁离子的沉淀,其沉淀率都随磷酸根离子浓度的增加而增加,直至磷酸根离子与待沉淀的金属离子摩尔比达到1∶1,进一步提高磷酸根离子浓度,镓离子和铁离子沉淀率几乎不变。在相同的磷酸根离子浓度和pH下,三价铁离子比镓离子容易沉淀。在含磷酸根的溶液中,三价铁离子对镓离子的沉淀过程具有促进作用,并且镓的沉淀率随Fe3+/Ga3+摩尔比的增加而增加,Fe3+/Ga3+摩尔比从0增加至5∶1时,镓完全沉淀所要求的pH从3.5降低到3.0。采用共沉淀法可以在较低的pH下比较完全地从溶液中回收镓。

Study on the Precipitation Behavior of Gallium from Solutions Containing Ferric Iron and Phosphate

The effect of phosphate on the precipitation of Ga3+ and Fe3+ has been studied.The results have shown that phosphate prompted the precipitation of Ga3+ and Fe3+,the precipitation percentage of both Ga3+ and Fe3+ increased with increasing phosphate concentration until the phosphate-to-metal ratio exceeded 1∶1.Thereafter,a further increase in the phosphate concentration did not significantly affect the precipitation of Ga3+ and Fe3+.The pH values at which Ga3+ began to precipitate and was completely precipitated were higher than that for Fe3+.The effect of Fe3+ on the precipitation of Ga3+ from solutions containing phosphate has also been studied.It was found that in solutions containing phosphate,the presence of Fe3+ enhanced the precipitation of Ga3+.The precipitation percentage of Ga3+ increased with increasing Fe3+-to-Ga3+ ratio.The pH at which Ga3+ was completely precipitated decreased from 3.5 to 3.0 as the Fe3+-to-Ga3+ ratio was increased from 0 to 5∶1.Gallium could therefore be recovered at a relatively lower pH by the co-precipitation method.