Dithiouracil, a highly efficient depressant for the selective separation of molybdenite from chalcopyrite by flotation: Applications and mechanism

Abstract

In the present study, dithiouracil was employed as the chalcopyrite depressant to selectively change the properties of chalcopyrite surface and separate molybdenite from chalcopyrite. Micro-flotation experiments were carried out to investigate the separation efficiency of dithiouracil on the flotation separation of molybdenite from chalcopyrite. Furthermore, the depression mechanism of dithiouracil was explored at molecular level via zeta potential measurements, fourier transform infrared (FTIR), X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectrometry (ToF-SIMS) analyses. The results showed that dithiouracil strongly depressed chalcopyrite flotation while had less impact on molybdenite flotation, and a satisfactory separation result was acquired by using dithiouracil. Zeta potential measurements and FTIR analyses illustrated that dithiouracil was chemisorbed on chalcopyrite surface. Furthermore, XPS and ToF-SIMS measurements confirmed that dithiouracil could react with Cu atoms on chalcopyrite surface through forming a four membered chelating ring. This paper indicated that dithiouracil can be employed as a high-performance chalcopyrite depressant for the Cu-Mo flotation separation.