Utilization of cetylpyridine bromide as an efficient collector for flotation separation of quartz from gypsum

The purification of phosphogypsum (PG) is crucial for its resource utilization and environmental protection. The flotation method is commonly used to remove quartz impurity from PG. In this study, a new collector, cetylpyridinium bromide (CPB), was exploited for the flotation separation of quartz and gypsum. Micro-flotation experiments were carried out to investigate the flotation performance of quartz and gypsum treated with CPB. The collection mechanism of CPB on quartz was examined through Zeta potential, contact angle, Fourier Transform Infrared Spectrometer (FTIR) and X-ray Photoelectron Spectroscopy (XPS) analysis. The flotation results showed that CPB exhibited strong collecting ability and selectivity for quartz from gypsum across a wide pH range of 1.8 to 9.5. Further analysis suggested that the interaction mechanism between CPB and quartz involved hydrogen bond and electrostatic attraction. Through these two interactions, CPB was adsorbed onto the surface of quartz, enhancing the hydrophobicity and floatability of quartz, thus enabling the selective separation of gypsum and quartz. Overall, this research provides a valuable insight for phosphorus chemical industry to achieve the purification of PG.