| abstract |
Pb: 0.05ppm or less, Zn: 0.005ppm or less, S: 0.02ppm or less, and a purity of 7N (99.99999%) or more. (Pb, Zn, S) is reduced by adding SrCO 3 to the electrolytic solution at the time of electrolytic refining of 5N (99.999%) of In to obtain a purity of 7N (99.99999%) or more. In InGaN, AlInGaP, etc., there is a possibility that the demand for In for LED is increased. In the future, it is demanded to manufacture in large quantities and inexpensively. However, the present invention provides a technology that can cope with this. |