Abstract: With the rapid development of strategic emerging industries such as semiconductors and photovoltaics, China has become the world’s largest demand market for high-purity quartz. However, domestic raw materials still heavily rely on imports, restricting the security of the development of silicon-based strategic industry in China. Therefore, the development of non-traditional high-purity quartz raw materials has become a new research focus. This study selects a quartzite ore from Fengyang, Anhui Province, as the research subject and conducts a series of purification tests. Through systematic experimentation, the optimal process flow is determined to verify the feasibility of using this quartzite ore as a substitute for natural crystal in producing high-purity quartz sand. The results indicate that the optimal magnetic induction intensity for magnetic separation is 1.7 T, and the roasting-water quenching operation significantly enhanced the acid leaching efficiency. The finalized optimal process flow is as follows: 4-stage magnetic separation–8-stage scrubbing–3-stage washing–2-stage flotation–roasting–water quenching–acid leaching. This process increases the SiO₂ content of the quartz sand product from 99.642 3% in the raw ore to 99.992 9%, while the total impurity content decreases from 3 577.11 μg/g to 71.16 μg/g. Specifically, the Al content drops from 1 747.91 μg/g to 19.75 μg/g, K from 750.98 μg/g to 5.33 μg/g, Fe from 754.04 μg/g to 1.89 μg/g, and Mn from 86.35 μg/g to 0.03 μg/g. Therefore, this study provides a purification process for a quartzite ore from Fengyang, Anhui Province. The resulting quartz sand product meets the standards for mid-grade high-purity quartz sand, offering valuable guidance for utilizing quartzite ores as raw materials for high-purity quartz sand purification, further offering abundant raw materials for the silicon-based strategic industry in China.