Characterization of band sawing dusts generated in cutting of multi-crystalline silicon ingots

Physical-chemical characteristics of the band sawing dusts regarding to recovery of pure silicon from them were investigated. The experimental results show 50vol%–60vol% amorphous phases exist in the dusts, which is mostly amorphous silica. The as-received saw dusts are found to form hard agglomerates of larger than 50 microns in diameter. The iron-based inclusions collected by magnets are found to match well with the band saw material in XRD patterns. Weight loss in heating was observed by thermal gravity tests, up to 900 °C, presumably due to reaction of the amorphous silica with carbon contaminant in the dusts. The saw dusts were variously treated to examine their physical-chemical responses, and the results were also presented.