Process for combination metal reduction and distillation

In a reduction process wherein a furnace having an inner liner is used and wherein one of TiCl.sub.4, HfCl.sub.4 or ZrCl.sub.4 to be reduced reacts with Mg to produce, by way of a redox reaction, a desired corresponding solid Ti, Hf or Zr metal phase and molten MgCl.sub.2, the specific improvement comprising.

• (a) initially charging a furnace having a first vessel containing said inner liner having at least one opening in the lower portion thereof and said first vessel being in fluid communication with a second vessel of said furnace, said charging being with sufficient MgCl.sub.2 to establish a molten salt seal at the bottom of said inner liner;
• (b) establishing and maintaining a temperature and pressure within said furnace consistent with promoting said desired redox reaction;
• (c) at least periodically adding said TiCl.sub.4, HfCl.sub.4 or ZrCl.sub.4 to be reduced and at least a stoichiometric amount of Mg to said furnace;
• (d) at least periodically draining a portion of said molten MgCl.sub.2 to readjust said molten salt surface whereby the amount of said corresponding solid reduced Ti, Hf or Zr that can be formed by the redox reaction is increased while the seal is maintained;
• (e) upon completion of said redox reaction, draining said molten MgCl.sub.2 salt and at least a portion of the excess Mg from said furnace;
• (f) removing unreacted Mg metal from said furnace by distillation by maintaining said first vessel of said furnace at a temperature above the temperature of said second vessel while pulling a vacuum on said furnace, thus isolating purified solid Ti, Hf or Zr metal;
• (g) recovering said liner and said purified solid Ti, Hf or Zr metal from said furnace, whereby the production of said Ti, Hf or Zr metal outside the liner is avoided, thus facilitating removal of the liner and reduction and whereby distillation of large quantities of high purity metal is achieved;
• and
• (h) loading and melting reducing metal salt in said first vessel and then melting reducing metal and reducing metal salt remaining in said second vessel from a previous run, whereby reducing metal floats up into the inner liner of said first vessel thereby recycling said reducing metal.