GB1006232A - Improvements in or relating to molten bath electrolytic-metallurgical apparatus - Google Patents

Abstract

<PICT:1006232/C6-C7/1> Electrolytic molten bath apparatus, e.g. for producing pure Zr, comprises a cell 1, an isolating valve 3 (e.g. as described in Specification 930,365), a lock-chamber 4, an injection pipe 9 slidable through a stuffing box at the top of the chamber 4, a perforated basket 6 at the lower end of the injection pipe 9, and a tube 11 round the injection pipe and in which a sheath of heat insulating material, e.g. a gas, can be enclosed, whereby a substance may be introduced in a gaseous state through the injection pipe 9 into the molten bath and the perforated basket 6 may be introduced into the bath without modifying the atmosphere above the bath. The lock chamber 4 has a pipe and valve (not shown) so that it may be placed in a state of vacuum or controlled atmosphere. The injection pipe 9 may be heated electrically or by hot fluid flowing through a coaxial tube between it and the tube 11, the tube 11 containing heat insulation. The outer surface of the tube 11 may be degassed as it is lowered into the lock chamber. A deflector 25 prevents radiant heat and splashings from the bath from reaching the tube 11. A device 22 cleans the outside of the tube 11 as it is raised. In preparing pure Zr, the basket 6 is filled with Zr wastes and this and the injector pipe 9 are lowered into the molten bath 2. ZrCl4 in gaseous form is then passed from a heated chamber through the heat insulated injector pipe 9 and basket 6 to form zirconium sub-chlorides in the bath. When the desired concentration is reached the pipe and basket are withdrawn to the lock chamber, the valve 3 closed, the flange 14 unfastened and the unit 5 replaced by the electrode necessary for electrolysis.