連続自焼成式酸化マグネシウム・炭素陽極を用いるマグネシウムの電解採取に関する研究 (予備的実験)

酸化物・炭素陽極の溶融塩電解への応用 (第2報)

抄録

In the first paper, it was described that the prebaked anode. of intimate mixture of magnesium oxide and carbonaceous materials was successfully applied in a small scale reduction cell contatining electrolyte consisted of magnesium chloride and sodium chloride. In this study, the electrolysis was continuously carried out for 64 days by using self-baked anode (Söderberg anode) instead of the prebaked one in the 1, 000-2, 000 amp cell.
The results are summarized as follows.
1) During the electrolysis, the anode was gradually baked from the lower part to the upper one by heat transfer from the bath and heat generation owing to its own electrical resistance.
2) The lower part of the anode was sometimes seperated from the upper part and fell into the bath because the baking was not always enough.
3) Magnesium chloride was formed by reaction of anode materials with chlorine generated on the anode surface, but a small amount of chlorine was sometimes detected together with carbon monoxide and dioxide in the anode gas since the reaction was not perfect.
4) The cathodic current efficiency was 71% on the average. It was observed that some magnesium metal particles were partially covered with black floating matter which happened to appear in the bath and coagulation of the particles was disturbed.
5) A slimy matter called “sludge” was apt to accumulate on the bottom of the cell and the bath had to be. kept clean by removing the sludge at intervals.
6) It is preferable to perform the electrolysis by using such a self-baked anode in a much larger scale reduction cell.