| 摘要 |
Unicrystalline metallic or silicon oxide material is produced by feeding a volatile compound of a metal or of silicon as vapour, optionally in a carrier gas stream, into a high temperature oxygen-containing gas stream, and collecting the oxide or oxides formed on the molten surface of a seed-crystal. Typical <PICT:1058773/C1/1> <PICT:1058773/C1/2> starting materials are ferric chloride, aluminium chloride, aluminium bromide, titanium tetrachloride, silicon tetrachloride, tetramethyl silane, chromyl chloride, vanadium tetrachloride and iron pentacarbonyl. Typical products are sapphire, ruby, corundum, rutile, mullite and chromium oxide. In a process for producing rutile (Fig. 1), a stream of dry hydrogen passing through tube 1 picks up TiCl4 from the liquid TiCl4 in chamber 2. The feed stream passes through tube 7 and mixes with oxygen and hydrogen fuel gases entering at 8. The product crystallizes on seed crystal 9. In a process for producing ruby (Fig. 2) aluminium rod 14 is chlorinated by burning chlorine from 12 in hydrogen from 13. Hydrogen carrier gas from 17 sweeps the aluminium chloride into the oxyhydrogen burner 16, the hydrogen and oxygen being fed through 19 and chromium oxide being introduced as chromyl chloride vapour via 20. |
