Halogenation and/or redn. of metals, semi-metals or their cpds. - by heating the initial materials, esp. oxide(s) with tri:chloro: fluoromethane

摘要

The agents employed for the process consist of fluorinated chlorohydrocarbons (I), which are pref. employed for direct conversion or metal- or semimetal- cpds. into the pure metals or semimetals; and the reaction temp. is pref. used to control the halogenation and/or redn. of the initial materials, esp. for selective halogenation and/or redn. of mixts. of initial materials. Agent (I) is pref. a fluorochloro deriv. of methane or ethane, and is esp. CFCl3; and may also be used for the prodn. or selective prodn. of pure surfaces on metals or semimetals. As compared with conventional processes using e.g. C, CO,Cl2 etc. for the redn. of oxides, the invention uses a much lower temp. and produces metals o r semimetals with high purity. Method can be used to produce pure Fe, Al, Si, Ti etc. and to form Si or Ge on surface of semiconductive elements.