Settling separation and quantification of silicon slurry wastes

• Main Authors: Zong-Hau,Li, 李宗樺
• Other Authors: 蔡子萱
• Language: zh-TW
• Online Access: http://ndltd.ncl.edu.tw/handle/4vbsjb

碩士 === 國立臺北科技大學 === 資源工程研究所 === 103 === A lot of silicon sawing slurry is produced in Si-ingot slicing process. Some materials in silicon sawing slurry are valuable like silicon, silicon carbide and glycol liquor. A low-cost, clean and simple recycling process will help decreasing the amount of silicon sawing slurry, manufacturing cost and environmental impact. This study tried to use water as the carrier to recover silicon from silicon sawing slurry by sedimentation. The results show when initial solid content was 5 g/dL, the Si content of upper layer was 93.2 wt.% and the Fe content was 4.82 wt.% after settling for 300 minutes. Besides, the increasment of temperature was disadvantageous to separate Si and SiC particles because of agglomeration. In the meantime, the increasment of ionic strength was advantageous to separate Si and SiC particles although the Si content of upper layer decreased slightly, the recovery increased obviously. Ultrasonic vibration was also advantageous to separate Si and SiC particles. When increasing the number of sedimentation, the Si content of upper layer was up to 70.38 wt.%, but the Si recovery was very low after settling for 25 minutes. In Si quantification, the results show alkali treatment was useful to remove Si from solid powder. And ICP-OES was suitable for measuring Si content in this study.