METHOD OF DRY CONCENTRATION OF QUARTZ SAND Russian patent published in 2013 - IPC B07B9/00 

FIELD: process engineering.

SUBSTANCE: invention relates to production of dressed quartz concentrates. Proposed method comprises feeding quartz sand for first screening stage into intake bins with grates for removal of lumps sized to over 150 mm. Sand is fed from intake bins via electrovibrating feeders onto two belt conveyors into two mid bins with feed distributors wherefrom initial stock with moisture content of 10-12 wt % is fed onto belt conveyor and, further, on vibrating screen for screening second stage for sizing to 50 mm. Oversize fraction is carried by belt conveyor into service stack while undersize fraction is fed into drying drum. After drying, sand is classified in three step. Sand obtained at first step with moisture content of up to 0.5 wt % is fed to vibrating screen to be sized to 4.0 mm. Oversize is fed to storage stack while undersize is fed into elevator intake device. The latter carries the product onto conveyor and, further, into process bin wherefrom said product is fed to second and third classification stages. First oversize (-0.4+0.8 mm) and second oversize (-0.8+0.63 mm) is fed into different-volume vessels. Undersize (-0.63+1 mm) is separately fed to magnetic separators to remove strong- and weak-magnetic inclusions. Additionally, vacuum sizing to 0.16 mm is performed by removing air-dust mix from the main process equipment at dried product feed and discharge points. This allows complete isolation and further catch of (-0.16+0.1 mm) fraction, the finished product, by two-step cleaning system. After vacuum classification (-0.63+0.16 mm) fraction if carried by belt conveyors to elevator intake bin and therefrom into containers.

EFFECT: higher quality of concentrate and process efficiency.

5 cl, 1 dwg, 2 tbl