Impurity optimized silicon is needed for the advancement of terrestrial photovoltaic power generation. In this study the possibility of producing solar grade silicon from rice husks has been pursued. An integrated process flowsheet was developed and practiced that included initial leaching, reduction of Rice husk ash (RHA) and post-reduction purification of silicon. Metallothermic reduction of purified RHA with magnesium was investigated within the temperature range of 500-950 oC. The reduction product was purified by two stage acid leaching sequence. Analysis of the final silicon powder product by XRD and ICP-OES showed crystalline silicon with boron content to be less than 3ppm- corresponding to reduction by a factor greater than 10, whilst the phosphorus content was reduced by a factor of over 20 and reaching less than 73ppm. The effects of temperature, magnesium amount and leaching agents were optimized in this study. A one step test melting was also carried out to convert the silicon powder into silicon chunks.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/24595 |
| Date | 27 July 2010 |
| Creators | Larbi, Kingsley Kweku |
| Contributors | Barati, Mansoor, McLean, Alexander |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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