Technology for Producing Crystalline Silicon with the Use of Non-Traditional Reducing Agents

Abstract

The process of reducing silicon from SiO2 includes a stage that involves the formation of a gas phase which contains lower oxides of silicon and carbon. The primary product is silicon carbide, which is formed from the reaction of gaseous silicon oxide with carbon on the surface of the reducing agent. It is shown that it is possible to obtain crystalline silicon which meets the requirements of the standard by using quartz from the Karaganda deposit and employing a reducing agent comprised of special low-ash coke and long-flame coal. A distinguishing feature of the new technology is the replacement of costly charcoal and petroleum coke with new, unconventional reducing agents – the special low-ash coke and long-flame coal from the Shubarkol field in Kazakhstan.