| 摘要 |
<p>PURPOSE:To raise the efficiency of refining Al and its productivity, while saving the consumption of electric power, by cooling molten Al at an upper portion inside a vessel to precipitate high-purity primary Al crystals, scraping the crystal off, accumulating them at a lower portion in the vessel, compacting them, and growing said crystals. CONSTITUTION:Molten Al is poured in a graphite crucible 6, a graphite supporting rod 1 equipped with a graphite disc 11 at its top end is set, a cover body 2 is attached, and Ar gas is introduced through an inflow opening 4 and let escape through a gap 5. Air is let flow into a cooling section 10, and primary Al crystals are precipitated on the inner surface of the crucible 6. The graphite disc 11 is periodically moved up and down in the vicinity of the cooling section 10 to scrape the primary crystals off. The primary crystals are accumulated through holes 12 for the passage of a liquid onto the bottom of the crucible 6 and then rammed after the laps of a certain time. This operation is repeated until the deposite reaches a level near the bottom of the cooling section 10. In addition, the deposit is heated by an input temp.-adjusting section 14 in a manner such that it is partially melted and that the other part is held at a temp. below that of the melted part, and heated by a means 8 for heating a top section in a manner such that the top part of the melt is not solidified.</p> |
