Insights on the Flotation Separation of Hematite from Quartz with a 4-Tert-butyl-catechol Collector

Iron ore is the main raw material of the iron and steel metallurgy industry, but quartz in iron ore reduces metallurgical efficiency and increases metallurgical costs. Therefore, iron ore desiliconization by flotation plays an important role in the iron and steel metallurgy industry. In this study, 4-tert-butyl-catechol (TBC) was designed as a collector to directly float out hematite from quartz. The micro-flotation tests demonstrated that under pH ~9.0, 1 × 10⁻⁵ mol·L⁻¹ TBC recovered 98% hematite from its mixture with quartz, while the recovery of quartz was only about 17%. Zeta potential and contact angle results inferred that the adsorption affinity of TBC toward hematite was greater than that to quartz. The results of FTIR and XPS inferred that TBC adsorbed on the Fe³⁺ sites of hematite interfaced via the O atom of its two adjacent hydroxyl groups to form a stable five-membered chelating ring at pH 9.0. This study offered new research insight on the development of novel collectors for hematite flotation through bionics technology.