Hydrometallurgy is considered a promising method to produce solar-grade silicon (SOG-Si) from metallurgical-grade silicon (MG-Si) due to its advantages of low cost, simple operation, and easy control. Researchers have investigated different hydrometallurgy techniques for impurity removal from MG-Si. This study systematically reviews hydrometallurgy techniques for the removal of impurities from MG-Si and provides perspectives in this field. Traditional leaching techniques, including single-acid leaching, successive acid leaching, and mixed acid leaching, are summarized. These methods face challenges for preparing high-purity silicon because of the insoluble impurities in MG-Si. Intensive methods for improving impurity removal in hydrometallurgical processes, including adding oxidizing agents, introducing external fields, and increasing the impurity exposure to the etchants, are classified and discussed. The combinations of secondary refining processes and hydrometallurgical processes are efficient in removing insoluble impurities from MG-Si. Representative research topics and the results of these combination methods are classified and summarized. It is expected that this review will help researchers select appropriate hydrometallurgy techniques for producing low-cost SOG-Si.

湿法冶金被认为是一种由冶金级硅（MG-Si）生产太阳能级硅（SOG-Si）的有前途的方法，因为它具有成本低，操作简单和易于控制的优点。研究人员研究了不同的湿法冶金技术从MG-Si中去除杂质。这项研究系统地回顾了湿法冶金技术以去除MG-Si中的杂质，并提供了该领域的观点。总结了传统的浸出技术，包括单酸浸出，连续酸浸和混合酸浸。由于MG-Si中不溶的杂质，这些方法面临制备高纯度硅的挑战。在湿法冶金过程中改善杂质去除的集约化方法，包括添加氧化剂，引入外部电场，以及增加杂质对蚀刻剂的暴露，进行了分类和讨论。二次精炼工艺和湿法冶金工艺的结合可以有效地从MG-Si中去除不溶性杂质。对代表性的研究主题和这些组合方法的结果进行了归类和总结。预计这次审查将有助于研究人员选择合适的湿法冶金技术，以生产低成本的SOG-Si。