Ultrahigh purity silane and silicon production

Abstract From the Canadian patent

Abstract of the Disclosure, Tri-and dichlorosilanes formed by the reaction of metallurgical silicon, hydrogen and silicon tetrachloride as subjected to disproportionation in the presence of an ion exchange resin to form high purity silane, with unreacted and by-product materials being recycled. Said chlorosilanes are passed through distillation zones and disproportionation reaction zones to progressively replace chlorine molecules with hydrogen molecules so that product silane is eventually recovered from the process and silicon tetrachloride is recycled for further hydrogenation. The process flow employed ensures that all of the process fluid passes through at least one disproportionation …