Production of solar-grade silicon by refining of liquid metallurgical-grade silicon Available to Purchase

The growth of the photovoltaic industry will be limited by the availability of silicon feedstock. Currently, feedstock supplies are scraps and surplus from the microelectronics industry. A program has been initiated to produce solar grade (SoG) silicon by upgrading metallurgical grade (MG) silicon using pyrometallurgical techniques in the liquid state followed by directional solidification. This approach is based on earlier results when all impurities, including B and P, were reduced to <1 ppm level. It is intended to analyze the earlier data, undertake thermodynamic analysis and produce SoG silicon that can be extended to a commercial scale operation. The feasibility of this approach will be demonstrated in charge sizes up to 500 kg.