| Spodumene is a type of lithium mineral, which belongs to monoclinic system chain silicate mineral, as well as one of the most widely exploited lithium mineral resources in the world. Because of spodumene’s nature, difficulty of develop, beneficiation process and other factors, its processing cost has been high and the overall economic efficiency is poor, leading to its low utilization. Therefore, study on spodumene crystal structure can further understand the nature of spodumene, promoting the oxidized ore and silicate minerals flotation theory.Mineral flotability is closely associated with the nature of the crystal’s internal eletronic structure. Mineral crystal structure including the chemical composition, mineral chemical bonds and crystal structure affects the flotability of the mineral. In this paper, the effect of crystal structure on the flotation of spodumene mineral is researched.The band structure, density of states, Mulliken populations, electron density difference and frontier orbital of spodumene crystal were calculated and analyzed using the quantum mechanical theory and the relationship between the spodumene crystal structure and its flotability was discussed in this paper. In addition to the main dissociation surface (110) of spodumene was analyzed in band structure and density of states. Quartz, common gangue minerals, was analysed and optimized. The common impurities in spodumene were simulated and their influence on flotation of spodumene was analyzed. At the same time, interaction energy of collector on the surface of spodumene was calculated using the computer simulation and was verified with the aid of pure spodumene flotation results.The study of electronic structures shows that the density of state near Fermi energy level is main contributed by O atom, so O atom is the most active and it may synthesize substantial hydroxide radical with H+in water making spodumene carry negative electricity within a large pH range and a low PZC. So spodumene has a good flotability with positive ion collector lauryl amine, while has a poor flotability with negative ion collector sodium oleate. Besides, the frontier orbital energy of spodumene with sodium oleate I△E I is3.301eV, and the front orbital energy of spodumene and lauryl amine I△E2I is2.846eV. The frontier orbital theory suggests that the flotation result of lauryl amine with spodumene is better than that of sodium oleate, which is consistent with spodumene flotation theory.Quartz electronic structure was also analyzed by quantum chemistry. The quartz’s O atoms and O atoms of spodumene were similar in population value and bond length, showing the necessity of inhibition of quartz in spodumene flotation. The existence of impurities enhanced the interaction between the collector and the spodumene. The keys formed by chromium, manganese and iron impurities and oxygen atoms showed the nature of covalent bond. At the same time impurities reduce negative charge in oxygen atoms and interaction energy I△E I of sodium oleate and lauryl amine. Front orbital results showed that spodumene contains chromium and iron impurity was well collected with lauryl amine, however, spodumene contains manganese impurities was better collected used sodium oleate.In the guidance of molecular simulation theory, Forcite module was used to calculate the surface energy of dissociation surface (110) before and after action with lauryl amine and sodium oleate. The total system energy of spodumene with dodecylamine after effection is-11.1694kcal/mol, which is higher than that of sodium oleate’s-8.8331kcal/mol, so the effect of the lauryl amine is better than sodium oleate. Pure mineral spodumene flotation test verified that the spodumene was more likely to use the lauryl amine. |
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