ECO-SOLAR FACTORY: UTILISATION OF KERF-LOSS FROM SILICON WAFER SAWING FOR THE MANUFACTURING OF SILICON NITRIDE CRUCIBLES

摘要

H2020-FOF-13-2015 Eco-Solar submitted in 2015 envisions to increase resource and energy efficiency over the entire photovoltaic value chain, while simultaneously maximising recycling possibilities, by introducing design for recovery, repair and reuse, and collaborating for improvements in waste reduction. Up to 50% of silicon is lost in form of fine powders (kerf-loss) during the mechanical processing of ingots to obtain wafers. The ability to recycle the kerf-loss has beneficial effect in terms of savings of precious poly-silicon consumption and of waste reduction. Due to the high energy requirement (150 kWh/kg) and CO_2 emissions (40 kg CO_2-eq/kg Si) associated with poly-silicon production with the traditional Siemens route, significant impact in environmental sustainability is expected by the recycling of the kerf-loss as secondary feedstock material. In this work recent results on reusing recovered silicon kerf-loss for manufacturing of silicon nitride crucibles are presented.