Abstract: Poor iron ore treated by fatty acid will have good index, while has problems of high cost from heated flotation. Collector KK-2 was prepared using special structure of block polyoxyethylene-polyoxypropylene, and reverse flotation test was conducted on the mix magnetic concentrate with 47.91% Fe. Results indicated that, collector KK-2 can improve dispersity of fatty acid at low temperature, increase quartz surface contact angle, improve floatability, decrease the pulp temperature from 39~42 ℃ to 25 ℃, closed-circuit flotation flowsheet was simplified as one roughing-one cleaning-one scavenging from one roughing-one cleaning-three scavenging, iron grade of concentrate was also 68.30% around as the original, iron recovery increased from 88.68% to 91.15%, the separation index is well, the process was shorted, cost reduced, separation index improved. The results can provide reference for the plant.

Key words: Reverse flotation, Surfactant, Shortened procedure, Flotation temperature