Preparation of high purity gallium

Gallium extraction from Bayer Liquor is carried out by adopting techniques like (i) Amalgam metallurgy. (ii) Cementation with Al-Ga alloy as cementing agent, (iii) Solvent extraction and (iv) Ion-exchange resin process. The metal obtained by any of the above process has a purity of about 97-99.9%. There are several method of subsequent purification employed to get electronic grade metal (6N purity). The method presented here is simple and less cumbersome, consisting of acid and alkali leaching followed by anodic cleaning in HCl medium, multiple shaking of the resultant gallium metal using saturated KCl solution containing oxidising agent like H2O2 or (NH4)2S2O8 and acetic acid and finally subjecting it to differential solidification. The reported methods viz. electrorefining, vacuum heating/distillation, zone refining, etc could be avoided. Metal of the required 99.9999% purity is obtained which naturally commands higher prices than lower grades