Abstract: Taking vein quartz ore from a certain area in Shaanxi as the research object,based on mineral processing pretreatment,
a mixed system of hydrochloric acid-nitric acid-hydrofluoric acid was used as the leaching agent to carry out hotpressure
leaching tests. The effects of liquid-solid ratio,reaction time and reaction temperature on the leaching behavior of impurity
elements were systematically studied. The results show that the optimal process conditions are a liquid-solid ratio of 3∶1
mL/ g,a reaction time of 5 h,and a reaction temperature of 200 ℃. Under these conditions,the leaching rates of Al,Fe,K,and
Na are 17. 12%,63. 14%,50. 26%,and 55. 96% respectively. The SiO2 purity of the obtained quartz concentrate reaches
99. 993%,meeting the 4N3 grade (quasi) high-purity quartz standard. Kinetic analysis shows that the leaching process of Fe
conforms to the Avrami model. The fitting correlation coefficient R2 at each temperature is greater than 0. 97,and the apparent
activation energy is 38. 54 kJ/ mol,which reveals that the leaching mechanism is controlled by the combination of chemical reaction
and diffusion. This study provides a theoretical basis and process reference for the development of high-purity vein quartz
purification technology.

Key words: gangue quartz,hot-press leaching,impurity removal,kinetic analysis