Selective separation of anglesite from iron ore sintering Dust: A novel aggregate flotation method

Abstract

Iron ore sintering dust, a solid waste produced during steel manufacturing, contains high levels of lead and iron compounds, particularly anglesite and hematite. Traditional sulfidation flotation methods struggle to effectively separate these fine-grained minerals. This study introduces a selective aggregate flotation method that enhances selectivity through a synergistic use of sodium lauryl sulfate (SLS) and sodium tripolyphosphate (STPP). The results from flotation experiments show a remarkable reduction in hematite recovery to 7.3% from 19.0%, while maintaining a high recovery of over 90% for anglesite, yielding a more efficient separation. Analytical tests such as grading analysis, zeta potential, FT-IR and XPS analysis observed that SLS’s ability to chemically adsorb onto the lead ions in anglesite aids in the aggregation of these particles, enhancing their recovery. In contrast, STPP adsorbs onto iron ions on the hematite surface, preventing SLS from adhering to it and thus promoting the dispersion of hematite particles. This differential chemical interaction creates significant physical differences between anglesite and hematite, enabling their effective separation during beneficiation. Overall, this innovative approach provides new ideas for an efficient strategy to recover precious metals from sintering dust.