Procédé de purification de substances solides

摘要

Silicon is purified by allowing drops thereof to fall through a vacuum or a purifying atmosphere. As shown, the lower end of a rod of silicon 13 is heated in a silica tube 1 by means of an induction coil 11 so as to form a drop 14 which falls into a silica crucible 9, the rod being lowered as melting proceeds. Hydrogen-containing water vapour may be passed through the tube via inlet 2 and outlet 3 at a rate of 21/min. The rod may have a diameter of 10 cm. and may be lowered at a rate of 1 to 10 cm./hr., e.g. 5 cm./hr. The drops may fall 25 to 50 cm.