Rapid identification method for evaluating high-purity quartz

The rapid growth of semiconductor, photovoltaic, and other emerging industries has led to a sharp increase in demand for high-purity quartz in China, particularly for 4N5-grade (99.995% SiO2) and above. However, the heavy reliance on imported high-purity quartz poses a significant risk to the security of key national strategic industries. To address this challenge, China is focusing on identifying domestic sources of high-purity quartz and developing efficient evaluation methods. This study investigates the inclusion content in three types of quartz: pegmatite, vein quartz, and white granite. A grading system based on the transmittance of quartz grains was established by analyzing the number of inclusions. Five quartz ore samples from different regions were purified, and the resulting concentrates were analyzed using inductively coupled plasma mass spectrometry (ICP). The relationship between the inclusion content of raw quartz, the composition of the purified quartz, and the quality of the sintered fused quartz products was examined. The findings demonstrate that quartz with fewer inclusions results in lower impurity levels after purification, higher SiO2 purity, and the more translucent the glass, as confirmed by firing tests. Herein, This study establishes a clear connection between quartz inclusions and the overall quality of high-purity quartz. The proposed approach enables rapid assessment of quartz deposit quality by identifying inclusions, offering a practical and efficient method for locating high-quality quartz resources.