| 摘要 |
<PICT:0831305/III/1> Heavy metals, particularly metals which have undergone fission reaction such as uranium, thorium or plutonium, are treated to remove lighter constituents by applying heat to melt a horizontally extending zone and moving the molten zone upwardly through the metal to the top region. Purification may be assisted by adding a metal or an intermetallic compound capable of dissolving the impurities to the lower portion of the metal undergoing treatment, the added metal being insoluble in the treated metal. Thus cerium and/or lanthanum may be added to remove fission products and magnesium may be used to remove plutonium where plutonium is a reaction product. Alternatively silver may be used to perform both functions. In the apparatus shown, a rod 1 of thorium or uranium in a cylindrical container 3 is supported at top and bottom by supports 2 and 5 respectively. The rod is moved downwardly through induction heater 9 by servo mechanisms 4 and 7 to move a molten zone 11 containing an absorbent metal upwardly along the rod. Cooling means 10 cools that portion of the rod leaving the heating zone, and, if desired, that portion immediately above the heater. |
