Comparison between Helical and Elliptical Static Mixers Performance in Column Flotation of Sungun Copper Plant

The flotation circuit in the Sungun copper plant consists of two column flotation cells as the cleaners having a fixed-spargers system. In order to achieve the expected aims in the flotation step, there are serious operational challenges such as the fast choking of the static mixers, boiling problem, burping phenomenon and pulp overflow to concentrate lander, and maintenance and control problems. An attempt was made by implementing a new helical static mixer in one of the cleaner cells instead of the old elliptical type to overcome the challenges. The changes resulted in the proper performance of the column, whereas due to choking, the burping phenomenon was eliminated, finer bubbles were produced, and the boiling and overflow problems were solved. Also the static mixer life time was increased up to 7 months in the helical column cells from one month in the elliptical column cells. In addition to 40% air consumption reduction and 20% solid increase in the final product, the grade of Cu and Mo increased by the helical static mixer replacement up to about 18.7% from 16.8% (11%) and to 511.1 ppm from 263 ppm (94%) in the cleaner step, respectively. The recovery of Cu and Mo was increased by about 1.5% and 0.2%, respectively. Finally, the results obtained proved that the effectiveness of finer bubble generation on grade improvement was dependent on the mineral hydrophobicity as the Mo grade increased more than Cu.