This paper focuses on the reaction technique of converting methyltrichlorosilane

the main by-product in the direct synthesis of dimethyldichlorosilane

to more valuable methylchlorosilanes.The conversion reaction of methyltrichlorosilane in a stirred bed reactor by the methylaluminumchloride method with aluminum powder and methylchloride as raw materials was systematically investigated.It was found that after an introduction period of about 100 min

the reaction reached a steady state with good activity in the absence of catalysts by the aid of mechanical stirring in the reactor which promoted the elimination of oxidized layer on the surface of the aluminum powder and speeded up the surface renewal process.Increasing the stirring speed and raising the reaction temperature to the optimum levels were favorable to the conversion reaction.The molar proportion of methyl chloride to methyltricholrosilane (m) in the feed had great effect on the reaction conversion and product composition.The concentrations of dimethyldichlorosilane and trimethylchlorosilane in the product were relatively higher while the reaction conversion of methyltrichlorosilane was lower when m<2.0

the trimethylchlorosilane was the main conversion product when m=2.0

and tetramethylsilane became the main product at a higher reaction conversion of methyltrichlorosilane when m>2.0.The reaction mechanism was discussed by analysing the SEM surface morphology of the aluminum powder before and after reaction.