Abstract: Processes for recovering at least one triarylphosphine from a Group VIII metal catalyst triarylphosphine complex mixture are provided. The processes are particularly useful for recovering the triarylphosphine from spent Group VIII metal catalyst complex mixtures. The processes include the steps of (i) forming a distillate from a Group VIII catalyst complex mixture containing a Group VIII metal catalyst complex, a triarylphosphine, and a light ends component wherein the distillate contains at least a portion of the triarylphosphine as a vapor and at least a portion of the light ends component as a vapor; (ii) cooling the distillate to a temperature below the boiling point of the light ends component to form a condensate; (iii) crystallizing at least a portion of the triarylphosphine using the light ends component as a crystallizing liquid; and (v) recovering the crystallized triarylphosphine from the condensate.

Abstract: Improved yields of monohydrogentrihalosilanes are achieved by contacting the residual silicon obtained from the preparation of organohalosilanes by a metal-catalyzed direct process by contacting the residual silicon simultaneously with gaseous hydrogen halide and with gaseous alkyl halide to form a residual silicon contact mass; selecting a temperature between about 200.degree. C. and about 350.degree. C. at which alkylation of the silicon contact mass in inhibited and at which hydrohalogenation of the silicon contact mass occurs; and heating the silicon contact mass at the selected temperature. The silicon reacts with the gaseous alkyl halide and the gaseous hydrogen halide at the selected temperature to produce improved yields of the monohydrogentrihalosilane.