Desorption and Reuse of Pb-BHA-NaOL Collector in Scheelite Flotation

Pb and BHA in Pb-BHA-NaOL collector assembled by lead nitrate (Pb), benzohydroxamic acid (BHA), and sodium oleate (NaOL) with a 240:120:1 molar ratio in scheelite flotation have the common defects of flotation reagents including high cost, environmental pollution and reducing hydrometallurgy efficiency. Therefore, in this study, the efficient desorption and reuse of Pb and BHA adsorbed on the scheelite surfaces was first proposed. The desorption test results showed that 80.71% Pb and 70.93% BHA could be efficiently desorbed from the scheelite concentrate surfaces through strong stirring for 15 min at pH 13.0 and a speed of 1600 r/min. The reuse of the desorbed collector could save 67% Pb and 75% BHA. The results of desorption and reuse tests of the real ore also exhibited high feasibility in industrial application. Fourier transform infrared spectroscopy analysis revealed that Pb-O, C=O, and C-N groups of Pb and BHA adsorbed on the scheelite surfaces obviously weakened or disappeared. Atomic force microscopy analysis further confirmed that most of the Pb and BHA on the scheelite surfaces were removed. Therefore, this work not only solves the above defects of the collector but also provides a reference for the desorption and reuse of other flotation reagents.