Study on the construction of a “two-stage progressive” investigation and assessment methodology for high-purity quartz resources

High-purity quartz (HPQ) is a critical raw material for strategic emerging industries, including next-generation information technology, new energy, and high-end manufacturing. Traditional HPQ resource evaluation systems rely heavily on experimental validation through mineral processing and purification. However, this approach suffers from paradigmatic defects, such as protracted cycles, high costs, elevated technical barriers, and significant risks regarding sample representativeness. Consequently, numerous geologically delineated industrial-grade ore bodies remain technically unviable resources due to the recalcitrance of key impurities, leading to substantial sunk costs. Based on the fundamental mechanisms underlying HPQ non-utilizability, this study identifies rigid technical bottlenecks within the purification process and proposes an innovative “two-stage progressive” methodology for efficient exploration and evaluation. Research indicates that the economic potential of high-purity quartz (HPQ) is not determined by the total SiO 2 grade, but is instead controlled by the content and occurrence of two types of recalcitrant impurities: fluid inclusions (especially small inclusions <10 μm) and lattice impurities (such as Al, Ti, and Li). Based on this, the “two-stage progressive” approach starts with a first stage using the oil immersion method on single minerals for rapid fluid inclusion screening. This stage establishes a 0–4 abundance scale, where samples with an abundance of grade 4 or higher are subject to immediate exclusion. The second stage employs LA-ICP-MS micro-analysis for mineral chemical mapping to construct spatial distribution maps of key lattice impurities, precisely identifying high-purity domains. Application validation in the Yamansu granitic pegmatite district of Hami, Xinjiang, demonstrates that mineral chemical mapping results are highly consistent with metallurgical purification data. In the western sector, the Al content in quartz is generally below 20 ppm, yielding a 4N78-grade product (SiO 2 > 99.9978%) after purification. In contrast, quartz from the eastern sector contains 30–50 ppm of Al and only achieves a 4N6 grade. This methodology implements an evaluation strategy of rapid exclusion and precise focusing, effectively mitigating the resource misallocation risks inherent in traditional methods. It provides an efficient, economical, and reliable technical framework for regional-scale rapid screening and strategic target selection of high-purity quartz resources.