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

(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) beneficia-tion. 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 center dot center dot center dot FeOH+center dot center dot center dot TTC (S = 1) and FeOH+center dot center dot center dot TTC (S = 0) complexes on MLT and CPY, respectively, of com-plexation 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 bond-ing, 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. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

The experimental and theoretical investigation of (3S,4S,5S,6R)-3,4,5,6-tetrahydroxyoxane-2-carboxylate (TTC) acid as a chalcopyrite (CPY) depressant during molybdenite-chalcopyrite (MLT-CPY) beneficiation was conducted. The adsorption of TTC onto CPY was found to be higher than onto MLT. The most stable complexes on MLT and CPY were Mo(OH)-4 center dot center dot center dot FeOH+center dot center dot center dot TTC (S = 1) and FeOH+center dot center dot center dot TTC (S = 0) complexes, respectively. The complexes were governed by traditional hydrogen bonding, as well as covalent and other non-covalent interactions. Flotation tests using an economical TTC depressant yielded satisfactory grade, recovery, and separation efficiency for the synthetic mixture of MLT and CPY.