• Resources Recycling
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• v.9 no.3
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• pp.22-28
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• 2000

A study on the recovery of gallium from zinc residues is carried out by alkali leaching using NaOH. The results show that in case of alkali leaching of zinc residues, Zn, K and Si are mainly leached out and Fe and other base metals are scarcely leached out, which results in that gallium is easily recovered by solvent extraction. The leaching efficiency of gallium increases with increasing alkali concentration and solid density. Especially, alkali consumption is considerably reduced by washing the zinc residues with water before leaching in order to eleminate the soluble zinc compounds. The gallium from zinc residues is found to be leached out with a recovery of 80% or higher for 2hrs leaching with 1~1.25 M/L NaOH solution and solid density 333 g/L at $25^{\circ}C$.

• Resources Recycling
• /
• v.9 no.3
• /
• pp.29-36
• /
• 2000

A study on the recovery of gallium from leaching solutions is carried out by solvent extraction in order to produce gallium oxide of high purity. The results show that the extraction of gallium is found to be increase with acidities of aqueous solution up to 7.4 M/L when pure isopropyl ether is used. And the extraction of iron also increases with increasing acidity of aqueous solution. It appears that the separation of gallium from iron cannot be satisfactorily accomplished with isopropyl ether. But, in the case of extaction with D2EHPA, almost complete extraction of iron is achieved-leaving all the gallium in the aqueous solution-by maintaining the acidity of aqueous solution at 2 M/L. Accordingly, $Ga_2O_3{\cdot}H_2O$ of more than 99wt.% in purity can be produced from zinc residues through the processes comprising of alkali leaching, precipitation by neutralization and solvent extraction using isopropyl ether and D2EHPA as extractants.