川西甲基卡伟晶岩石英微量元素特征及高纯石英原料潜力OA

Objective:The Jiajika rare-metal mining area is currently the largest lithium-dominated granite-pegmatite type rare-metal field discovered in China,hosting a wide range of pegmatite dike types.Granite-pegmatite type high-purity quartz(HPQ)serves as one of the most important raw materials for global HPQ production.Quartz,as the principal rock-forming mineral in pegmatites,has trace-element compositions and concentrations that are critical indicators for evaluating its potential as a granite-pegmatite type HPQ siliceous raw material.However,previous studies have scarcely addressed the trace-element geochemistry of quartz in this field. Methods:In this study,quartz from representative pegmatite types was analyzed using in-situ LA—ICP-MS to determine trace-element concentrations and compositions,allowing evaluation of its potential as high-purity siliceous feedstock,identification of promising targets for HPQ exploration,and recommendations for the integrated utilization of quartz resources during rare-metal development. Results:The results indicate that quartz in different pegmatite types contains relatively high concentrations of trace elements such as Al and Li(Li=59.6× 10-6～181 × 10-6;Al=254× 10-6～672× 10-6),with the total concentration of 13 major impurity elements(Σ13)ranging from 340×10-6 to 1005× 10-6.Except for one sample,quartz exhibits a SiO2 content ≥ 99.9％(3N),corresponding to the lower limit of HPQ or high-purity quartz feedstock standards.Among the five pegmatite types,the spodumene-type pegmatite,currently exploited as an industrial deposit,is characterized by relatively low impurity concentrations in its quartz,with SiO2 content exceeding 99.95％(3N5).Consequently,the efficient utilization of this quartz should be given high priority during rare-metal resource development. Conclusions:Pegmatites formed through magmatic differentiation in the Western Sichuan rare-metal fields generally display elevated Al and Li concentrations,reducing their suitability as high-quality HPQ siliceous feedstock.Therefore,future exploration for high-grade granite-pegmatite type HPQ should focus on muscovite granite-pegmatites of metamorphic origin in the Danba area.