Ore types and analysis of high purity quartz application potential of the natural quartz sand deposit in Hepu, Guangxi

Natural quartz sand mine in Hepu, Guangxi is an important raw material based for low-iron quartz sand（washed sand） used in ultra-clear glass in China. In order to provide a scientific basis for the efficient utilization of this quartz ore and explore its application potential of high purity quartz, the purification and processing technology of high purity quartz and modern analytical and testing methods such as ICP-OES, SEM-EDS and XRD are adopted to systematically study the mineral materials characteristics such as the composition structure and purification and processing effect of samples of different particle sizes at the representative mineral point in the mining area. A new classification scheme for the ore types is proposed, and the industrial application potential of different ore types is analyzed. The results show that: ① This deposit is mainly caused by the sedimentary formation of ancient river channels. According to the particle size and material source of the ore, the SiO₂ content and purification processing effect, as well as the industrial application potential, the natural quartz sand ore in Hepu, Guangxi is classified into three ore types: gravel ore （＞2 cm）, coarse sand ore （20−0.43 mm）, and fine sand ore （−0.43mm）. ② It is found that the material source of the gravel ore is vein quartz. The average SiO₂ content of the raw gravel ore is 99.981%, and the average Fe and Ti contents are ≤30×10⁻⁶ and 5×10⁻⁶ respectively. The average SiO₂ content of acid washed sand is ≥99.995%（4N5）. After chlorination roasting, the purity of SiO₂ in some individual samples can reach 4N8. It meets the purity standards of high purity quartz ore and has the potential to develop 4N5 intermediary grade products of high purity quartz. ③ Material source of coarse sand ore is mainly vein quartz. The average SiO₂ content of its washed sand is 99.936%, and the average Fe and Ti contents are ≤30×10⁻⁶ and 83×10⁻⁶ respectively. It is the main raw material for low-iron quartz sand used in processing ultra-clear glass. The average SiO₂ content of acid washed sand is ≥99.988%（3N8）, and it has the potential to develop high-end silicon micropowder and other products for integrated circuits. ④ Material source of fine sand ore is mainly the weathering products of granite. The average SiO₂ content of its washed sand is 99.736%, and the average Fe content is ≤302×10⁻⁶, which can be processed into refined quartz sand. If it is mixed with coarse sand ore at a ratio not exceeding 13%, it can be used as raw material for low-iron quartz sand for ultra-clear glass.