Progress in recovery and recycling of kerf loss silicon waste in photovoltaic industry

Abstract

With the rapid growth of the photovoltaic (PV) industry, the amount of the silicon waste has substantially increased, resulting in serious environmental problems. This waste mainly consists of the silicon waste powder from kerf loss slurry of wire saw wafer cutting process and the scrap pieces from silicon ingot casting process. To reduce the cost of crystalline Si production and relief the existing environmental pollutions, it is of significant interest to recover and recycle the silicon value from the Si waste. This paper presents a literature overview of the current technologies and research progress in the recovery and recycling of high purity silicon from the silicon wastes generated in the PV industry. First, the source and classification of Si wastes, including slicing silicon waste and scraps of Si ingots are summarized. Second, various techniques related to the separation and recovery of high purity Si from the waste are reviewed and compared based on the experimental results. The characteristics and advantages of different technologies are evaluated based on the current conditions. Third, the applications of silicon waste are explored in a detailed manner. Last, the assessment of different Si recovery technologies is elaborated. This review gives an outlook on the recycling and recovery of high purity silicon from the silicon waste, which shows great potential for further research in this field.