Title: STEP PROJECT. Quarterly Technical Report, October 1965--December 1965.

Kinetics and equilibria for the hydrogenation of silicon tetrachloride have shown that conversion to trichlorosilane is substantially increased at higher operating pressures; these results greatly improve the practicality of the overall process. An integrated process development unit for converting metallurgical silicon and hydrogen to high-purity silane has been commissioned. A quartz fluid-bed reactor capable of operating at temperatures of up to 1000/sup 0/C was designed, constructed, and successfully operated. A total of 6.7 Kg of silicon powder was produced in two separate experiments in the free-space reactor without opening the reactor between experiments. No measurable impurities were detected in themore » silicon powder produced by the free-space reactor, using the cathode layer emission spectroscopic technique. A 152 mm-diameter melt consolidation apparatus was attached to the free-space reactor. The first objective for the overall process was the definition of a preliminary set of functional specifications. All process design efforts are based on these specifications. Preliminary block flow diagrams and heat and material balances for every battery-limit stream were completed for the 25 MT/year experimental facility. A brief parametric study was conducted to select an optimum range of operating pressures for the distillation columns. Conceptual designs have been initiated for the hydrogenation reactor, the free-space reactor, and the consolidation system.« less