Study of Mutual Separation of Silicon and Quartz Using Liquid-Liquid Extraction

抄録

The objective of this investigation was to separate silicon and silica for recycling by the liquid-liquid separationtechnique. In the preparation of silicon (Si) single crystal, a small amount of silicon is fixed on thesurface of silica (quartz, SiO₂) crucible. The used crucible is crushed for recycling both silicon and silicain high purity from the mixed powder. Zeta-potential of silicon and silica are almost the same at pH higherthan 3. Their separation by simple flotation is ruled out. However, their hydrophobic characteristics are differentin several different organic solvent from the measurement of contact angle. Therefore, the liquidliquidextraction is employed to separate silicon and silica. The result indicates that the organic solventmixed with dodecylamine acetate could extracted the silicon powder at high purity (97-100%) with highrecovery from the silica powder in the water phase.