by conversion of the silicon into a compound, optional purification of the compound, and reconversion into silicon

Full Title

Silicon; Compounds thereof ( C01B21/00, C01B23/00 take precedence; persilicates C01B15/14; carbides C01B32/956) > Silicon (forming single crystals or homogeneous polycrystalline material with defined structure C30B) > Purification (by zone-melting C30B13/00) > by conversion of the silicon into a compound, optional purification of the compound, and reconversion into silicon