The influence factors on high-purity gallium electrolysis refining such as current density, NaOH concentration, platinum electrode, cyclical reverse electrolysis and so on were studied.The optimum technical parameters were determined based on plant practice.The 1# gallium after one-cycle electrolyzing, almost all of the product met meanwhile, the criterion of 99.999% high-purity gallium, over 70 percent rearched 99.9999%.The current efficiency exceeded 98%.
Change of electrode surface and separates out conditione
Current efficiency/%
Straight receiving rate/%
60
Naked
Platinum electrode surface chang black and is packaged by grey crystal, has hydrogen to separate out, cathode space surface covers entirely oxide film
97.45
44.2
3120
Naked
Platinum wire becomes dark even blows fuse, by white crystallization package. Hydrogen separates out intensely. Anode region surface changesthe black deactivation
93.16
13.21
60
Airproofed
Platinum wire acme luminous, separates out without gas, anode region surface does not have oxide compound
98.27
61.35
120
Airproofed
Platinum wire acme does not have platinum black, separates outwithout gas, separates out normally
98.64
69.87
表4 电解产品杂质成分*
Table 4 Impurity component of electrolysis product
Batch number
Impurity/10-4%
Si
Al
Cu
Fe
Mg
Ni
Pb
Sn
Zn
Mn
Cr
1#
0.074
0.017
0.002
0.048
0.03
0.012
0.091
0.34
0.23
0.017
<0.05
2#
0.12
0.005
0.002
0.017
0.007
0.006
0.018
<0.1
0.013
<0.05
0.009
3#
0.087
0.005
0.004
0.008
0.009
0.009
0.007
0.008
0.007
0.007
0.011
4#
1
0.1
1.5
0.8
0.6
0.1
1.8
0.8
0.4
-
-
5#
0.2
-
0.05
0.1
0.1
0.05
0.06
0.1
0.1
0.05
0.05
4# as 99.999% Ga Criterion, 5# as 99.9999%Ga criterion
