METHOD OF PRODUCING HIGHLY PURE CONCENTRATE FROM NATURAL QUARTZ Russian patent published in 2011 - IPC C01B33/00 

FIELD: chemistry.

SUBSTANCE: quartz is crushed into 15-40 mm chips. Pure quartz is separated from other minerals and contaminated chips. The pure quartz is ground into powder with particle size 0.1-0.4 mm. The powder undergoes magnetic separation and acid treatment in a medium of 10-15% hydrofluoric acid or in a mixture of hydrofluoric acid and hydrochloric acid. The powder is separated from the spent acid, washed with deionised water and dried to moisture content less than 1%. The pure quartz chips are ground without calcination. Gas-liquid inclusions undergo decrepitation via high-frequency electromagnetic exposure. The surfaces of quartz grains are cleaned from remains of technogenic and natural contaminants via attrition of the powder with 5% solution of chloroazotic acid at temperature 80-90°C for 20-30 minutes. The washed and dried powder is then calcined to temperature 1350±10°C and held at that temperature for 5-10 minutes for agglomeration of mineral impurities with quartz sand and sieved. The sieved sand undergoes magnetic separation and chemical cleaning in 10-15% solution of equal volumes of hydrofluoric acid and hydrochloric acid, washed, dried and packed.

EFFECT: invention reduces the number and duration process operations, material and power consumption, provides deep purification of quartz powder, increases purity of production while reducing the environmental load.

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