Application and adsorption mechanism of 1-(3-(trifluoromethyl)phenyl)thiourea: A novel selective collector for flotation separation of azurite from K-feldspar

3-TPT is used for the efficient concentration of azurite for the first time. • 3‑TPT achieves a pronounced separation efficiency between azurite and K‑feldspar. • 3-TPT chemically adsorbs onto azurite via the formation of N Cu S C rings. The strong surface hydrophilicity of azurite leads to its low recovery, and the poor flotation separation between azurite and gangue minerals further reduces the utilization efficiency of copper. This study presents a novel selective collector 1-(3-(trifluoromethyl)phenyl)thiourea (3-TPT) for the efficient recovery of azurite from K-feldspar. Results from flotation tests and contact angle measurements indicate that with 150 mg/L 3-TPT, the contact angle of azurite surface raised to 79.4°, the recovery reaches 94.16 %, while K-feldspar remains hydrophilic, with a recovery of only 11.29 %. The selective adsorption mechanism of 3-TPT on azurite surface was revealed by X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR) and Scanning Electron Microscope-Energy Dispersive Spectroscopy (SEM-EDS) analyses. XPS and FTIR analyses indicate that after the interaction of 3-TPT with the azurite surface, the C N stretching in 3-TPT exhibits a notable shift, and changes in the chemical states of Cu and S are observed during adsorption, confirming that 3-TPT chemically adsorbs onto azurite via the formation of N Cu S C rings, whereas its adsorption on K-feldspar is negligible. SEM-EDS results further confirm the selective interaction of 3-TPT on azurite surface, as evidenced by changes in surface morphology and elemental analysis. Characteristic elements S, N, and F from 3-TPT were clearly detected on the azurite surface in EDS mapping. This research highlights the potential of 3-TPT in copper concentration, not only improving the recovery efficiency of copper resources but also contributing to the advancement of more environmentally friendly direct flotation practices for copper oxide minerals. Download: Download high-res image (251KB) Download: Download full-size image