Recovery of sphalerite from a high zinc grade tailing

In this work, the flotation recovery of sphalerite and pyrite from an old high zinc grade tailing was studied. In particular, the effect of different flotation reagents such as collector, auxiliary collector, depressant, activators, and frother on the flotation performance were investigated. The synergic effect of the collector blends, as well as frother blends were also studied. In addition, the effect of the pre-conditioning of flotation pulp with scrubbing or ultrasonic on the selective separation of sphalerite and pyrite minerals were studied. More than 73% of the sphalerite was recovered from the accumulated tailings in the rougher stage. The pulp viscosity was considerably increased by increasing the pH from 5.5 to 10.5. As a result, sphalerite recovery and Zn selective separation were both considerably dropped. It was also found that frothers (MIBC and A65) have a synergic effect, and their mixture showed better metallurgical results than when each frother were solely used. The pre-conditioning with scrubbing or ultrasonic resulted in a major increase in the sphalerite floatability.