MACE纳米刻蚀与退火处理协同强化工业硅中杂质酸浸脱除研究

工业硅的湿法酸浸除杂因其具备成本低、操作简单及适合规模化应用等特点而被广泛用于冶金法提纯制备太阳能级多晶硅生产。然而，传统湿法酸浸处理在硅中杂质的深度去除方面仍然面临挑战。本项目中创新性地将纳米刻蚀技术、退火活化处理与传统湿法酸浸相结合，通过可控地纳米孔道引入及退火活化处理来强化酸浸过程中浸出剂与硅中包裹金属夹杂及固溶非金属杂质的接触和反应活性，最终实现工业硅中杂质深度脱除的目的。深入系统地研究不同多孔结构、不同退火温度、退火方式及酸浸条件对工业硅中各主要杂质形态及溶出行为的影响规律，探明多孔结构引入及退火活化处理在湿法酸浸强化除杂过程中的协同作用机理，为构建一种短流程、低能耗的冶金法高纯多晶硅制备新方案提供理论指导，为提升冶金法多晶硅的产品竞争力奠定基础。

The hydrometallurgical purification of industrial silicon with low produce cost, simple operation, appropriate for the large scale production, and other many advantages, has been widely used for producing low-cost solar grade polysilicon (SoG-Si) in the metallurgical process. However, the traditional hydrometallurgy purification technology confronts the deep impurity removal of MG-Si with the challenge. This project presents a novel hydrometallurgical purification industrial silicon method, which combines the metal-assisted chemical etching (MACE), high temperature activation and the acid leaching purification techniques, is designed to achieve deep removal of impurity in industrial silicon for producing low-cost and high-quality SoG-Si. Those nano-scale channels induced by MACE and the high temperature activation treatment would respectively improve the contact and reactivity of metal impurity and non-metal impurity with leaching agent. The coordination mechanism of the intensified impurity removal is discussed through studying the effect of channel structure, annealing temperature and mode and acid-leaching condition on the impurity form and dissolution behavior. The ultimate goal is to provide a theoretical basis for producing high purity polycrystalline silicon through metallurgical process with advantages of high efficient, short and low energy consumption innovative technology, which will be of significant interest to improve the product competitiveness of metallurgical polysilicon.