Evaluation of the effects of different hydroxamates and a sulfosuccinamate in the direct flotation of iron ore tailings

Abstract

Recent events involving iron ore tailings dam collapses have emphasized the need for developing alternative ways of depositing tailings. This study aims to evaluate the effects of using three hydroxamates and a sulfosuccinamate as collectors in the direct flotation of iron ore tailings, using a bench flotation. The best result obtained on bench flotation was tested in a pneumatic cell. The sample used in this study (10.8% of Fe) consists of quartz and hematite. The Aero® 6494 Promoter hydroxamate showed the highest selectivity among the analyzed reagents, reaching 64.31% of Fe in the final product of the test with the < 150 µm sample. The possibility of using these reagents as constituents of a mixed collector with dodecylamine was also investigated. In this case, the Aero® 845 Promoter sulfosuccinamate yielded the best results, with 62.84% of Fe and 59.01% of metallurgical recovery of Fe. The synergistic effect between the two reagents might be explained by the stability of the monolayer formed by the intercalation of the ions from the dodecylamine and the Aero® 845 Promoter, which reduces the electrostatic repulsion between ions of the same species This mixed collector was tested in a pneumatic cell. However, it had a lower performance in terms of Fe metallurgical recovery than in a bench-scale cell test, mainly for the finest particles, due to the greater control of the process’s variables in the bench cell.

Keywords:
iron ore tailings; direct flotation; hydroxamate; sulfosuccinamate; mixed collector; dodecylamine; pneumatic cell