Trichlorosilane production process

A process for producing trichlorosilane which comprises the steps of:

• providing a reactor having a first stage heated to about 550.degree.-650.degree. C. and a second stage maintained at about 310.degree.-340.degree. C.;
• charging each of said first and second stages with silicon particles;
• flowing a mixture comprising hydrogen and silicon tetrachloride in a ratio of about l:1 to about 3:1 through said silicon particles in said first stage and therein reacting said silicon, hydrogen, and silicon tetrachloride;
• adding hydrogen chloride to the effluent flowing from said first stage;
• flowing said hydrogen chloride and said effluent through said silicon particles in said second stage;
• and collecting the effluent flowing from said second stage.

A closed loop process for producing silicon which comprises the steps of:

• providing a two stage reactor for producing trichlorosilane;
• reacting in a first stage of said reactor hydrogen, silicon tetrachloride and silicon to produce reaction products including trichlorosilane;
• reacting in a second stage of said reactor hydrogen chloride plus said reaction products with silicon to produce additional trichlorosilane;
• conveying trichlorosilane from said two stage reactor to a silicon deposition reactor and therein reacting said trichlorosilane with hydrogen to deposit silicon with silicon tetrachloride and hydrogen chloride formed as by-products;
• conveying said silicon tetrachloride and hydrogen chloride by-products to said first and second stages of said reactor, respectively.