Recent Advances in Mechanism and Enhancement of Acid Purification of Quartz Sand

High-purity quartz (HPQ) is an essential material for photovoltaic, semiconductor, optical fiber, and advanced glass industries. However, natural quartz commonly contains gangue minerals, inclusions, and lattice impurities, and therefore requires deep purification. Owing to its ability to dissolve impurity-bearing components, acid leaching is widely adopted for quartz purification. This review critically summarizes recent advances in the mechanisms and enhancement strategies of acid purification of quartz sand. The partitioning characteristics of impurities in quartz are discussed; fundamental mechanisms of acid leaching are then reviewed. Particular attention is given to the differences between non-HF acid systems and HF-containing systems. Process enhancement strategies, including mechanical activation, thermal pretreatment, pressure leaching, and ultrasound-assisted leaching, are critically discussed. These strategies improve impurity accessibility, accelerate mass transfer, and improve reaction kinetics. This review provides guidance for the design of efficient, selective, and sustainable acid purification for HPQ production.