Cooperative effect of SLS collector and SPP depressant on the flotation separation of lead oxide minerals from hematite

As a cornerstone of the national economy, the iron and steel industry also generates a significant amount of sintering dust containing both valuable lead resources and deleterious elements. Flotation is a promising technique for lead recovery from sintering dust, but efficient separation from Fe₂O₃ is still challenging. This study investigated the cooperative effect of sodium lauryl sulfate (SLS, C₁₂H₂₅SO₄Na) and sodium pyrophosphate (SPP, Na₄P₂O₇) on the selective flotation of lead oxide minerals (PbOHCl and PbSO₄) from hematite (Fe₂O₃). Optimal flotation conditions were first identified, resulting in high recovery of lead oxide minerals while inhibiting Fe₂O₃ flotation. Zeta potential measurements, FTIR analysis, adsorption capacity analysis, and XPS studies offer insights into the adsorption behaviors of the reagents on mineral surfaces, revealing strong adsorption of SLS on PbOHCl and PbSO₄ surfaces and remarkable adsorption of SPP on Fe₂O₃. The proposed model of reagent adsorption on mineral surfaces illustrates the selective adsorption behavior, highlighting the pivotal role of reagent adsorption in the separation process. These findings contribute to the efficient and environmentally friendly utilization of iron ore sintering dust for lead recovery, paving the way for sustainable resource management in the iron and steel industry.