Abstract: To address the problem that physical beneficiation can hardly remove minerals on particle surfaces,inclusions,and impurities within the crystal lattice during the preparation of quartz sand from quartz sandstone,quartz sandstone from a certain area in Hebei with a SiO₂ content of 98. 07% was used as the raw material. After pretreatment by crushing,grindingclassification,and magnetic separation to a particle size of 0. 212～ 0. 106 mm,a quartz sand flotation concentrate with a SiO₂ content of 99. 67% was obtained by flotation purification. The purification effect under the synergistic action of acid leaching and chlorination roasting was systematically studied. The results show that during acid leaching,hydrofluoric acid made a prominent contribution to impurity removal. When 0. 8 mol/L hydrofluoric acid and 4 mol/L phosphoric acid were mixed at a volume ratio of 1 ∶ 1 and used for leaching at 80 ℃ for 4 h,the removal rates of Al,Fe,and Ti reached 85. 28%,67. 64%,and 16. 75%,respectively. To further improve the purification efficiency,chlorination roasting was introduced. Quartz sand was mixed with 3% sodium chloride and subjected to chlorination roasting at 900 ℃ for 4 h,and a process system of " acid leaching pretreatment（primary acid leaching）-chlorination roasting-secondary acid leaching" was established. Finally,the removal rates of Al,Fe,and Ti increased to 89. 86%,79. 43%,and 56. 18%,respectively;The SiO₂ content of the quartz sand increased from 99. 670% to 99. 979%,and the total impurity content decreased to 212. 1 mg/kg. This study reveals the synergistic mechanism of acid chemical etching and chlorination roasting on impurity migration/replacement and surface dissolution-mediated removal in quartz,providing an efficient and feasible process route for purifying quartz sandstone to prepare high-purity quartz sand.