Investigations into the flotation of molybdenite in the presence of chalcopyrite using (3S,4S,5S,6R)-3,4,5,6-tetrahydroxyoxane-2-carboxylate acid as a novel selective depressant: An experimental and theoretical perspective

Abstract

(3S,4S,5S,6R)-3,4,5,6-tetrahydroxyoxane-2-carboxylate (TTC) acid was experimentally and theoretically investigated as a chalcopyrite (CPY) depressant during molybdenite-chalcopyrite (MLT-CPY) beneficiation. It was observed that the adsorption of TTC onto CPY was more than that onto MLT. The zero-point corrected complexation energies for complexes on mineral surfaces was calculated by using M06-2X/6–311++g(d,p)/def2-TZVPP level of theory in gas phase. It was established that Mo(OH)4-∙∙∙FeOH+∙∙∙TTC (S = 1) and FeOH+∙∙∙TTC (S = 0) complexes on MLT and CPY, respectively, of complexation energies of −189.0 kJ/mol and −831.0 kJ/mol, respectively, were the most stable complexes. The analyzed nature of bonding in complexes using Non-Covalent Interaction and Quantum Theory of Atoms in Molecules (QTAIM) suggested that the complexes were governed by traditional hydrogen bonding, as well as covalent, and other non-covalent interactions. Flotation tests carried out using a synthetic mixture of MLT and CPY (1:1) at pH 5.4 ± 0.1 1 in the presence an economical TTC depressant yielded a grade, recovery and separation efficiency of 58.7 %, > 97.6 % and 88.8 %, respectively. Therefore, TTC could be used as a potential depressant of CPY during the flotation of MLT.