Method of Refining Silicon by Alloying
For refining crude silicon, a new method consisting essentially of electrolysis of Al-Si anode obtained by alloying crude silicon into molten aluminium was proposed. The principles of the method as well as the results of observations on the behavior of the impurities contained in the crude silicon during the process are described. As a plan for carrying out the present refining method in practice, the flow-sheet is shown in Fig. 8, with the aim of estimating the quantity and the cost of the materials required in practical application of this purifying method. The impurities contained in the purified silicon were found to be as follows : Al : 0.18, Fe : 0.003, Ca : trace, C : 0.022, Ti : 0.001, and P : 0.003 in per cent. The quantity of several materials, chemicals and the electric power as well as their cost were estimated in order to produce 1 kg of purified silicon.
- Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy
Science reports of the Research Institutes, Tohoku University. Ser. A, Physics, chemistry and metallurgy 9 118-130, 1957