| 摘要 |
<p>Manganese of 98% or even of 99.9% purity is obtained by vacuum distillation of a ferro-manganese containing not more than 1% C, the residue always containing at least 30% of manganese. Temperatures of 1200 DEG -1300 DEG C. and pressures below 1 Torr (10-1 to 10-4 Torr) are used. Low boiling point impurities (e.g. Pb, Zn) may be driven off in a preliminary distillation.</p> |
