Silicon material task. Part III. Low-cost silicon solar array project. Quarterly report No. 3

Abstract

Effort during the report period was directed toward proving feasibility of reacting silica and carbon in a dc plasma and involved the use of equipment at the vendor's facility. Results of large-scale (kilogram quantity) tests in a 350 kW dc plasma furnace are reported as well as smaller scale tests with a 40 kW dc torch. A moderate degree of success was achieved in that a small amount of silicon was detected in the product formed from material (in rod form) reacted in the dc torch. The complete reduction of silica to silicon was found to be keyed to achieving sufficient residence time for the raw materials to reach an optimum reaction temperature. The experimental work was to verify the results of the test runs with the vendor's equipment and to continue the feasibility study with an in-house reactor. Theoretical analysis was to continue keyed to specific experiments which would include investigation of various forms of carbon and silicon oxide reactants. The thermodynamic study to date points to the current reaction as a feasible approach. Actual plasma flame temperature was determined to be an important parameter which must be known, and an apparatus was assembled for making the necessary spectralmore » measurements.« less