Development of processes for the production of solar grade silicon from halides and alkali metals. First quarterly report, October 3-December 31, 1979

This program is directed toward the development of processes involving high temperature reactions of silicon halides with alkali metals for the production of solar grade silicon in volume at low cost. Experiments are being performed to evaluate product separation and collection processes, measure heat release parameters for scaling purposes, determine the effects of reactants and/or products on materials of reactor construction, and make preliminary engineering and economic analyses of a scaled-up process. Samples of the silicon product will be delivered to JPL for evaluation of solar cell performance. During this reporting period the silicon reactor test apparatus reached operational capabilities after a shutdown for two months. Several design improvements were made while returning it to an operational stage. During the initial series of experiments complete product separation of the silicon from the salt was achieved and small samples (approx. = 3 to 40 g) of fused silicon were collected. The test apparatus is now being operated on a routine basis for periods of about twenty minutes. Finally, the initial work began on the engineering and economic analysis for scale-up of the silicon production process.