BIOGENIC SILICA AS A RAW MATERIAL TO CREATE HIGH PURITY SILICON

摘要

A low cost process is provided for creating high purity silicon from agricultural waste, particularly rice hull ash. The process uses a series of chemical and thermal steps to yield high purity silica while using less energy and more efficient chemical processes. The high purity silicon features fewer impurities that negatively affect the use of high purity for PV cells and reduces capital and operating costs of processes to yield ultra-pure silicon.

主权项

1. A process to produce high purity silicon comprising:
1) milling rice hull ash with an acidic solution to yield purified rice hull ash; 2) converting the purified rice hull ash to polycrystalline silicon by carbothermal reduction; wherein impurities in the polycrystalline silicon meet SEMI III standards.