Differential adsorption of a high-performance collector at solid–liquid interface for the selective flotation of hematite from quartz

Different adsorption behaviors of the collector on the mineral surface play a crucial part in the flotation separation of different minerals by selectively modifying the wettability of mineral surfaces. In this investigation, to effectively remove quartz from hematite via reverse flotation, decaethoxylated stearylamine (DEOSA) was first introduced as a high-performance collector for quartz. The selective collecting performance and differential adsorption mechanisms of DEOSA for both hematite and quartz were studied by flotation experiments and surface analysis. Flotation results suggested that DEOSA displayed excellent collecting capacity for quartz against hematite and the effective removal of quartz from hematite was achieved. Adsorption capacity measurements and surface wettability analysis demonstrated that much larger amounts of DEOSA adsorbed onto quartz than hematite significantly enhanced the quartz surface hydrophobic whether the depressant starch was present or not, which resulted in the excellent flotation performance of quartz. Surface electrical characterization and Fourier transform infrared (FTIR) analysis further proved that the combination of hydrogen bonding and electrostatic attracting force enhanced the strong adsorption of DEOSA onto the quartz, achieving the efficient collection performance of DEOSA for quartz. Based on these findings, DEOSA can be used potentially as a strong-collection and high-performance quartz collector for recovering hematite from quartz via reverse flotation.