process for the production of an active siliziumpulvers for the manufacture of alkyl - or aryl halogensilanen

摘要

Preparing metallurgical silicon incorporating at least one catalyzing element or promoter of the Rochow reaction in a form which makes it more reactive. The catalytic action being improved when the catalyst and/or promoter is ground thereby allowing fixation to the silicon grains. A process for the preparation of active silicon powder for use in the Rochow reaction comprises grinding metallurgical silicon containing more than 98 wt.% of silicon, iron up to 0.4 wt.%, aluminum up to 0.2 wt.% and calcium up to 0.2 wt.%, with a particle size less than 350 mu m in the presence of at least one catalyst and/or reaction promoter, in order to deposit this (these) elements) on the grain surface. Independent claims are also included for: (a) an active silicon powder for the preparation of alkyl or aryl-halosilane where the active silicon powder comprises 0.003-0.03 g/m2 tin at the grain surface; (b) the same as (a) except that the active silicon powder comprises 0.003-0.03 g/m2 of copper at the grain surface.