zone-refinehttp://www.oed.com/dictionary/zone-refine_v%3Ftab%3Dmeaning_and_usezone-refine, v.
First published 1986; not fully revised

zone-refineverb

  1. 1962–
    (transitive) .
    1. 1962
      To zone-refine and produce single crystals from such [refractory] materials, N. V. Philips's Gloeilampenfabrieken, Eindhoven,..has developed a carbon-arc image furnace.
      New Scientist 5 April 813/2
    2. 1978
      Bismuth is normally regarded as a hard, brittle metal, yet when it has been zone refined it forms rods which can be bent without fracture.
      P. W. Atkins, Physical Chemistry x. 301

Originally published as part of the entry for zone, n.

zone, n. was first published in 1921; not fully revised.