Low-temperature collecting performance of a new combined collector on scheelite flotation

The reduced ability of fatty acids to dissolve and disperse at low temperatures limits their effectiveness in winter applications. In this study, a green and environment-friendly reagent, polyethylene glycol 2000 (PEG-2000), was used to evaluate its effect on the collecting performance of sodium oleate during scheelite flotation at low temperatures. The effect of PEG-2000 on the flotation of scheelite with the collector sodium oleate (NaOL) was studied by flotation tests, surface tension tests, infrared spectral analysis, and zeta potential measurements. Flotation tests showed that adding PEG-2000 can enhance the collecting ability of NaOL on scheelite at low temperature (5 degrees C). The recovery of scheelite with the mixed collector of PEG-200 and NaOL is 4.39% higher than that with NaOL only. The surface tension tests, infrared spectral analysis and zeta potential measurements revealed that PEG-2000 and OL- are co-adsorbed on the scheelite surface at low temperatures. The presence of PEG-2000 promoted the increase of the adsorption concentration of oleate ions (OL-) on the scheelite surface. The reason was that PEG-2000 has a shielding effect on the electrostatic repulsion between the OL- groups, which changes the micellar configuration of OL- in the solution system and makes the OL- gather more tightly on the surface of scheelite, leading to the enhancement of its hydrophobicity. This discovery provides a reference for the development of collecting reagents for efficient flotation recovery of scheelite under low temperature environment.