DRY PROCESS FOR PRODUCTION OF QUARTZ GLASS CONCENTRATE Russian patent published in 2015 - IPC B07B9/00 

FIELD: process engineering.

SUBSTANCE: invention relates to glass industry, particularly, to production of quartz glass concentrate by dry dressing of quartz sand. Proposed process comprises dry screening of initial stock. Drying of undersize and classification of dried product at the screen. Grinding of classification oversize, 1^st stage of magnetic separation of classification undersize and the product of grinding at magnetic field intensity of 0.45 Tl for removal of strong-magnetic field. 2^nd stage of magnetic separation of nonmagnetic products of the 1^st stage undertaken to remove weak-magnetic materials consists in feeding of quartz glass concentrate to finished product storage. Dry screening is executed over the interface of 1.2 mm to 3.0 mm depending upon the content of harmful admixtures in stock coarse fractions. Dried product is subjected to dry attrition for removal of clay component and oxide film from quartz grain surface and separation to grain fraction and dust fraction to be removed from the process. Grain fraction is classified over interface of 0.3 mm to 0.8 mm depending on consumer requirements to concentrate to coarseness upper limit. Classification oversize is ground to upper coarseness limit of 0.3 mm to 0.8 mm depending on consumer requirements to concentrate to coarseness upper limit. In grinding, crushed product is dedusted over coarseness limit of 0.1-0.16 mm depending upon distribution of harmful admixtures in fine fractions of the product. Second stage of magnetic separation is conducted at magnetic field intensity of 1.1-1.8 Tl.

EFFECT: higher yield and quality.

1 dwg