Recovery of Si from Liquid Si-Zn Alloy Using Si Rod

This study delves into the recovery of high-purity silicon from liquid silicon-zinc alloys, presenting a novel approach to solar-grade silicon production. The research focuses on four key areas: the precipitation of silicon on high-purity silicon rods, the solvent refining of metallurgical-grade silicon using silicon-zinc alloys, the impurity removal process, and the overall feasibility of the proposed method. Through a series of experiments, the study demonstrates that silicon can be effectively recovered by immersing high-purity silicon rods into a liquid silicon-zinc alloy and gradually cooling the molten bath. The precipitated silicon particles, which exhibit good crystallinity, are easily detached from the rods, allowing for their reuse in subsequent cycles. The impurity concentrations in the recovered silicon particles are significantly reduced, with removal fractions exceeding 99% for elements like aluminum, iron, and titanium. The study also highlights the potential of the silicon-zinc alloy system for solvent refining, as residual zinc can be effectively removed through vacuum distillation and directional solidification. The research concludes that the proposed method offers a promising alternative to traditional solar-grade silicon production processes, with the potential to improve efficiency and purity. By exploring the precipitation and refining stages in detail, this study provides valuable insights into the development of next-generation solar cell manufacturing technologies.