Synchronous separation of limonite from calcite and quartz in the sodium dodecyl sulfate system

• Synchronous impurity removal of limonite was carried out under the SDS system. • GG realized the effective separation of calcite , quartz, and limonite. • GG selectively adsorbs onto gangue, while SDS adsorbs onto limonite. • The introduction of GG causes gangue minerals to repel bubbles. The synchronous flotation separation of limonite from its associated gangue minerals, calcite , and quartz, has long posed a significant challenge in mineral processing. Given that previous studies have focused more on the separation of limonite from single vein minerals or a certain type of vein mineral, as well as the common use of reverse flotation processes. This study innovatively investigated the synchronous positive flotation separation of guar gum (GG) from limonite, silicon containing vein quartz, and calcium containing vein calcite in the sodium dodecyl sulfonate (SDS) system. Flotation test results showed that GG significantly reduced the flotation recovery of calcite and slightly reduced the recovery of limonite and quartz, resulting in a significant flotation difference between limonite and calcite/quartz. Fourier-transform infrared spectroscopy and adsorption quantity tests revealed that in the presence of GG, SDS had weak adsorption ability on the surfaces of quartz and calcite, but strong adsorption on limonite surface. X-ray photoelectron spectroscopy analysis further indicated that GG slightly reduced SDS adsorption at Fe sites on limonite surfaces while substantially hindering SDS adsorption at Ca sites on calcite. Notably, GG showed negligible interference with the weak SDS adsorption at Si sites on quartz surfaces. Extended Derjaguin-Landau-Verwey-Overbeek theory calculations confirmed that the introduction of GG into the SDS system led to mutual attraction between limonite particles and bubbles while inducing mutual repulsion between quartz and calcite particles and bubbles. Therefore, GG significantly improved the separation efficiency of limonite and gangue minerals, and 98.55 % quartz and 84.77 % calcite were removed to achieve synchronous separation of limonite from quartz and calcite.