Abstract: The surface of a certain quartz sandstone exhibits distinct rust-like staining.The quartz grains are tightly ce mented by clay minerals and siliceous cement,with fine and unevenly distributed impurities.The main iron and titanium-contai ning impurity minerals include pyrite,ilmenite,and magnetite,among others.To exploit and utilize this ore resource,a process study was conducted to remove impurities and purify the material.The results showed that after crushing and grinding,define and desliming,and high-intensity magnetic separation,followed by one neutral reverse flotation and one alkaline direct flota tion,and finally a mixed acid (hydrofluoric acid + phosphoric acid) leaching,calcination,re-leaching process,a quartz sand concentrate with an SiO2 content of up to 99.979% was obtained from a feed sample with an SiO2 grade of 98.07%.The total impurity content was reduced to 212.1 g/t,and the cumulative total removal rates of the key limiting impurities Al,Fe,and Ti reached 98.58%,95.89%,and 87.95%,respectively,meeting the quality standard for low-iron quartz sand.

Key words: quartz sandstone,define and desliming,high-intensity magnetic separation,reverse flotation,direct flotation, mixed acid leaching with hydrofluoric and phosphoric,calcination,impurity removal and purification