The main impurities such as Fe, Ca, Al, K, Na and other elements in vein quartz often reach thousands of μg/g. When the content of K and Na elements in the high-purity quartz crucible for single crystal silicon growth is too high, the softening temperature of the crucible will be too low and the crystal cannot be pulled. When the Al element is too high, the purity of the single crystal silicon will be affected. Quartz raw materials for the production of TFT-LCD substrates have high requirements for alkali metal oxides, and at the same time, the glass is required to have less defects such as lumps and bubbles in the processing process. high demands. How to effectively remove these impurities has become the difficulty in producing high-quality quartz sand.

At this stage, the research methods of domestic and foreign scholars on the beneficiation and purification of vein quartz generally follow the principle of combination of beneficiation processing and deep purification. The impurities inside the quartz particles are roasted and water quenched, and the quartz raw material can also be purified by the wet leaching process mainly using acid leaching.

Considering the differences in the distribution of impurities among the quartz particles and the occurrence state of gangue minerals, and the differences in the quality of each grade of quartz obtained under different treatment conditions, it is necessary to classify the gangue quartz and then purify it. Using low-quality vein quartz in a certain area in Gansu as raw material, the classification-sorting process test was carried out. The crushed raw ore was screened-grinding-screening to obtain four samples, and then the four samples were respectively subjected to high gradient magnetic separation And reverse flotation, evaluate the effect of classification and separation on each graded product and the quality difference of each grade of quartz based on the content of Fe, Al and other elements, and investigate the sorting effect of vein quartz classification and purification and the concentration of each grade of concentrate. Quality and optionality, the results show:

   1) The four samples of (-0.60+0.10) mm and (-0.10+0.045) mm in the original ore and the (-0.60+0.10) mm and (-0.10+0.045) mm samples obtained by grinding were subjected to magnetic After selection and flotation, a better purification effect is obtained. The quality of the four concentrates is quite different. The best one is the (-0.60+0.10) mm particle size produced by grinding, with a SiO2 content of 99.67%, an Al2O3 content of 2271.92μg/g, and a Fe2O3 content of 38.64μg/g; the most The worst is the (-0.10+0.045) mm particle size in the raw ore, the content of SiO2 is 99.62%, the content of Al2O3 is 2546.83μg/g, and the content of Fe2O3 is 70.26μg/g.

  2) The products of different grades of vein quartz ore are different in quality. The (-0.60+0.10) mm grain size samples produced by raw ore and grinding are dominated by large quartz particles, while the (-0.10+0.045) mm grain size samples are dominated by broken large quartz particles and primary fine quartz particles . The fine-grained mica aggregates dissociate and enter the fine-grained fraction to increase the aluminum content. Therefore, based on the research conclusions of process mineralogy, it is necessary to adopt classification and classification for different grain grades of vein quartz, and the results of purification experiments show that classification and classification have a significant effect.