Quantum-chemical substantiation of collecting properties of acetylene reagents in flotation of sulphide minerals

Abstract

The paper presents the analysis results of known data and performed adsorption and spectral IR studies of MIG-4E, DMIPEK and DC-80 acetylene reagents in interaction with galena (PbS) and molybdenite (Mo2S) sulphide minerals. The IR spectra analysis of pure reagents and products of their interaction with the surface of sulphide minerals has showed that the adsorption of MIG-4E molecules takes place on the surface of lead sulphides, and DMIPEC molecules are adsorbed on the surface of molybdenite. Quantum-chemical calculations of the total potential energy of the complexes have shown that the complex formed by a molecule of MIG-4E – PbS of (HUMO) complexes by nucleophilic mechanism has 2514.0873 kcal/mol, which is almost an order of magnitude greater than the total potential energy (270.0439 kcal/mol) of MIG-4E – PbS (HUMO) complex formed by electrophilic mechanism. Analysis of the calculated data of the total potential energy of complexes formed by MIG-4E reagent molecules with PbS surface and DMIPEC molecules with Mo2S surface has showed that the total energy of π-complexes formed by reagents by electrophilic mechanism differs by 47.7% among reagent molecules and amounts to 270.0439 kcal/mol for (MIG-4E + PbS) complex, and 141.9386 kcal/mol for (DMIPEC + Mo2S) complex in the (HUMO) state. Such a difference in the values of total energies of the complexes can correlate with the conformational ability of DMIPEC reagent molecules. Usage of acetylene alcohols as additional selective collectors during flotation of a number of non-ferrous and precious metal ores has shown a significant increase in the extraction of target metals, which makes it possible to consider the reagents based on acetylene derivatives as promising for industrial applications.