| 摘要 |
1489346 Aluminium whiskers HEPWORTH & GRANDAGE Ltd 18 March 1975 [18 March 1974] 11995/74 Heading ClA Whiskers of Al 2 O 3 are prepared by (a) contacting an intimate mixture of aluminabearing material and carbon with a stream of a gaseous aluminium trihalide in a first reaction zone maintained at an elevated temperature, in which a reaction occurs to form an aluminium monohalide and CO, and (b) transporting the gaseous products comprising the monohalide and CO to a second reaction zone at a lower temperature, whereupon the reverse reaction 3AlX + 3CO#AlX 3 + 3C + Al 2 O 3 occurs, with formation of alumina whiskers from the Al 2 O 3 - supersaturated gas stream. The aluminium trihalide may be prepared by the action of the gaseous halogen on molten aluminium metal, the product (carried in a stream of a Group O carrier) being purified by passage over a heated but unmelted aluminium metal. Preferably, the temperature in the first reaction zone lies between 1400‹ and 1800‹ C., while that of the second reaction zone is 200-400‹ C. lower, and less than 1400‹ C. |
