Investigations on the effect of filling materials on the flotation index of copper sulfide ore and its elimination test

In a mining area from Anhui province, the cemented filling method is used to change the original properties of flotation pulp by mixing some filling materials into the raw ore sample, which increases the difficulty coefficient of copper and sulfur resource separation. In this paper, the filling materials and raw ore samples were mixed as samples, and the beneficiation test was conducted based on the existing process. The iron concentrate was obtained by magnetic separation after the mixed samples were ground to ≤0.074 mm accounting for 75%. A mixed flotation test was conducted after the magnetic separation tailings were settled and concentrated. Copper concentrate and sulfur concentrate were obtained by mixing rough concentrate. According to the test results, the mixing of filling materials could change the pH value of pulp, the initial copper grade of mixed ore, and the copper grade of magnetic separation tailings. Compared with the closed-circuit test results without adding filling materials, the Cu grade and Cu recovery of final copper concentrate with adding filling materials decreased by 0.39% and 1.01%, respectively. The sulfur grade and recovery of sulfur concentrate decreased by 0.75% and 4.80%, respectively. The elimination test showed that adding ammonium sulfate 1000 g/t or mechanical stirring for 30 min could reduce the viscosity of the pulp, increase the turbidity value of the pulp, and restore the adsorption capacity of the collector on the surface of copper sulfide ores, thereby eliminating the deterioration effect of filling materials on copper sulfide flotation. The Cu recovery in the final copper concentrate increased from 70.37% to more than 70.80%.