| 摘要 |
<p>PURPOSE:To obtain extremely high purity Mo or W powder, by bringing aq. soln. obtd. by decomposing material powder of Mo or W having prescribed average grain size with H2O2 water, into contact with cation exchange resin, then hydrogen reducing the heated and condensed solid material. CONSTITUTION:Mo or W powder cong. a much quantity of impurity having 0.1-100mum average grain size favorably about 1-30mum is decomposed while being cooled by H2O2 water having 5-35wt% concn. especially 20-35wt%. The cooling under <=60 deg.C is favorable. Next, above described aq. soln. after decomposition treatment is brought into contact with cation exchange resin, and impurity existing as cation is adsorbed to it and removed. Next, aq. soln. after ion exchanging treatment is heated and condensed at 100-300 deg.C conventionally, obtd. solid material is heated and condensed at 800-1,000 deg.C in H2 atmosphere to obtain extremely high purity Mo or W powder having ppb order impurity content.</p> |
