METHOD FOR CHEMICAL PURIFICATION OF NATURAL QUARTZ MATERIAL, APPARATUS FOR REALIZING THE METHOD AND GRAIN OBTAINED ACCORDING TO THE METHOD Russian patent published in 2024 - IPC C01B33/12 C03C1/02 B01J19/28 

FIELD: chemistry.

SUBSTANCE: invention relates to chemical purification of natural quartz material by acid etching and can be used in production of high-purity quartz concentrates for lighting and optical industries, including photovoltaics. Method comprises treating quartz grains with a solution of hydrofluoric acid for a time sufficient to achieve a given criterion of shelf life of quartz material, followed by washing the cleaned grains with deionized water, carried out in a sealed rotating reactor with a horizontally oriented central axis with continuous removal of hydrofluoric acid vapors formed when the temperature in the reactor rises above room temperature. Discharge of vapors is carried out through a gas outlet pipe located in the cavity of the shaft of rotation of the reactor coaxially to its axis, wherein the reactor is rotated for a time sufficient to achieve a given criterion of shelf life of the quartz material, then stopping, removing the spent hydrofluoric acid, further, deionized water is fed into reactor and its rotation is started for a time sufficient for washing of quartz grains from residues of hydrofluoric acid solution and dissolution products. Apparatus for realizing said method comprises sealed reactor 1 equipped with means 6 for feeding acid solution and deionized water. Reactor 1 is made with possibility of rotation relative to horizontally oriented central axis 10 and mounted on hollow shaft 9, inside of which there is gas discharge branch pipe 7 coaxially to its axis for removal of hydrofluoric acid vapors formed at temperature increase in reactor above room temperature. Quartz grains, purified according to the method, contain as contaminant elements in ppm: less than 5 aluminum, less than 0.3 calcium, less than 0.3 iron, less than 0.5 sodium, less than 0.3 potassium, less than 0.4 lithium, less than 0.02 copper, less than 0.02 chromium, less than 0.02 nickel, less than 0.02 manganese, less than 0.1 boron.

EFFECT: invention is aimed at improvement of purification efficiency and achievement of ready product purity parameters meeting requirements of modern semiconductor industry achieved in simpler device.

4 cl, 2 dwg, 1 tbl, 1 ex