Abstract: Research on application, comparing with the conventional collector, of low temperature resistant BK425 collector in reverse flotation of high-magnesia cellophane for magnesium reduction was carried out. The grinding fineness, dosage of sulfuric acid, dosage of BK425, temperature, etc. on the influence of magnesium reduction was researched with fixed additional conditions. The results showed that BK425, has the best performance on reverse flotation of magnesium reduction and scarcely affected by temperature, is a promising collector. Phosphorus concentration, with P2O5 grade of 28.76%, P2O5 recovery of 91.78%, MgO content of 1.17% can received through one rough, one cleaning, and one scavenge closed-circuit flotation process, with the grinding fineness of 70% passing 0.074 mm, BK425 dosage of 600 g/t, sulfuric acid as regulator.

Key words: High-magnesia cellophane, Reverse flotation, Magnesium reduction, Low-temperature resistance property, Collector