Patent GB-1001238-A (GB)
Title: A method of recovering gallium from alkaline solutions containing a gallium compound
IPC: C25C1/22
Filed: 1962-04-26
Abstract: <PICT:1001238/C6-C7/1> <PICT:1001238/C6-C7/2> A modification of the method of recovering gallium from an alkaline solution of a gallium compound as claimed in the parent Specification comprises performing the method by reacting the gallium-containing solution and alkali metal amalgam in a reaction chamber 1 having a superposed settling chamber 2 integral therewith whereby a solution of reduced gallium content separates as a clear liquor in the settling chamber and gallium-containing amalgam flows downwardly into the reaction chamber, passing clear liquor from the settling chamber through a pipe line incorporating pump means to the base of the reaction chamber for further reaction with the amalgam in the reaction chamber, withdrawing gallium-enriched amalgam from the upper part of the reaction chamber through a pipe line connected thereto, and recovering gallium from said withdrawn amalgam.  The starting solution may be the sodium aluminate liquors of the Bayer alumina process.  As shown, gallium-containing liquors are introduced via manifold 16, pipe 17, and nozzles 5 into mercury contained in reaction chamber 1.  The flow of the liquor through the mercury entrains mercury globules which are carried into settling chamber 2 where they settle and return to reaction chamber 1.  Clear liquor is withdrawn via pipe 18 and returned by pump 4 to reaction chamber 1 via pipe 3.  The settling chamber is clad with cooling jacket 19 through which water is circulated via pipes 20 and 21.  Mercury is withdrawn via pipe 8 by pump 9 and gallium-depleted liquors are withdrawn via pipe 7.  For continuous performance, the mercury is recharged with sodium in cell 10.  Gallium is extracted from the mercury in known manner, e.g. by washing with NaOH solution in tank 12 and passing the gallium-containing solution therefrom to electrolytic cell 15 wherein gallium is deposited.ALSO:<PICT:1001238/C1/1> A modification of the method of recovering gallium from an alkaline solution of a gallium compound as claimed in the parent Specification comprises performing the method by reacting the gallium-containing solution and alkali metal amalgam in a reaction chamber 1 having a superposed settling chamber 2 integral therewith, whereby a solution of reduced gallium content separates as a clear liquor in the settling chamber and gallium-containing amalgam flows downwardly into the reaction chamber, passing clear liquor from the settling chamber through a pipe line incorporating pump means to the base of the reaction chamber for further reaction with the amalgam in the reaction chamber, withdrawing gallium-enriched amalgam from the upper part of the reaction chamber through a pipe line connected thereto, and recovering gallium from said withdrawn amalgam.  The starting solution may be the sodium aluminate liquors of the Bayer alumina process, and the method may be performed continuously or intermittently. As shown, gallium-containing liquors are introduced via manifold 16, pipes 17, and distributer nozzles 5, into mercury contained in reaction chamber 1.  The flow of the liquor through the mercury entrains part of the latter in the form of globules, which are carried into the setting chamber 2, where they settle and return to reaction chamber 1.  Clear liquor is withdrawn via pipe 18 and returned by pump 4 to reaction chamber 1 through pipe 3.  The clear liquor enters the head of the distributer manifold through pipe 3a and flows through pipe 17 to nozzles 5 at the foot of the manifold. The settling chamber is clad with a cooling jacket 19 through which water is circulated via pipes 20 and 21.  Mercury is withdrawn via pipe 8 by pump 9 and gallium-depleted liquors are withdrawn via pipe 7.  For continuous performance, the mercury is regularly recharged with sodium in a sodium chloride electrolytic cell 10, from whence it is returned via pipe 11 into reaction chamber 1.  Alternatively, recharging may be effected by mere addition of sodium.  When the mercury contains, for example, 0.1% by weight gallium based on mercury, gallium is extracted therefrom in known manner e.g. by washing with sodium hydroxide solution in tank 12 and passing the gallium-containing solution therefrom to electrolytic cell 15 wherein gallium is deposited.