The invention relates to the technical field of
quartz sand purification
processing, in particular to a purification process for improving the
sodium ion removal rate of high-purity
quartz sand. The technology aims at solving the technical problems that when soluble
sodium salt and lattice embedded state
sodium (such as Al < 3 + >
charge compensation type) coexist in high-purity
quartz sand, removal is not thorough through a traditional technology, and precipitates are likely to be generated. Efficient removal is achieved through a hydrothermal
dissolution-acid
pickling impurity removal-flotation separation
synergistic mechanism. Firstly, soluble
sodium salt is dissolved out preferentially under the hydrothermal condition of 65 DEG C, so that it is avoided that in subsequent acid
pickling, HF reacts with the
sodium salt to generate Na2SiF6
sediment; then, an HF-HCl mixed acid
system is adopted to selectively etch lattice channels at 70 DEG C and open a gas-liquid inclusion, so that embedded sodium is promoted to migrate and dissolve out; and finally, separating sodium-containing
gangue (such as
albite) exposed by
pickling through flotation. According to the process, the hydrothermal times (2-3 times) can be dynamically adjusted according to the ore characteristics, stable production of
semiconductor-grade quartz sand is achieved with low
energy consumption which saves more than 30% of energy compared with a chloridizing
roasting process, and the process is suitable for high-valued utilization of domestic
vein quartz ore.