Strengthening the flotation enrichment of scheelite with an amino-hydroxamate collector

Improving the flotation recovery of scheelite is an ongoing problem. In this study, N -(3-(octylamino)) hydroxamic acid (NOHA) was designed as a strong collector to strengthen the enrichment of scheelite without the pre-activation of lead nitrate. Micro-flotation results indicated that NOHA exhibited excellent collecting capability in scheelite flotation, achieving more than 95.0% scheelite recovery at pH 8.0 under 2.0×10 −4  mol/L. Zeta potential investigations found that NOHA effectively adsorbed on scheelite surface. The enhanced adsorption was attributed to the protonated amino group (-NH 2 + -), which promoted the chelation of hydroxamate on the negatively-charged scheelite surface. Comprehensive characterization through Fourier transform infrared spectroscopy (FTIR), contact angle, and adsorption capacity verified that the treatment of NOHA strengthened the hydrophobicity of scheelite. X-ray photoelectron spectroscopy (XPS) analyses further indicated that the hydroxamate group in NOHA mainly anchored on the scheelite surface through the interaction with calcium sites. Therefore, NOHA offered an excellent collector in scheelite flotation.