Removal of Iron Minerals from Glass Quartz Sand by Flotation

Flotation by a vapor-air mixture in a ‘two streams’ scheme was used to de-iron unconditioned sands with 0.34 wt.% Fe2O3: the foam product of the flotation stream I is separated from 1/2 of the sands and mixed with the other 1/2 of the sands by flotation stream II. A distinguishing feature of flotation stream II is that a mixture of air with hot (> 100°C) water vapor is used as the gas phase, which yields VS-030-V grade sand. The consumption of the warming vapor in the vapor-air flotation technology equals 9.7 × 10-4 Gcal/ton of sand.