Mechanism of the effect of long-chain and cyclic hydrocarbon collectors on the flotation performance of coking coal

GENG Dajiang; XU Guangqian; ZHANG Guangwei; ZHAI Deping; ZHANG Deke

doi:10.11799/ce202602026

Abstract：To enhance the flotation efficiency of scarce coking coal slime,a 1/3 coking coal from Xinwen Coal Preparation Plant was selected as the research object,with n-hexane and cyclohexane chosen as flotation reagents.The influence of long-chain and cyclic molecular structures on the flotation performance of coal slime was systematically investigated.Through flotation experiments,spreading angle tests,Density Functional Theory(DFT)calculations,and molecular dynamics simulations,the mechanism of reagent molecular structure on flotation performance was revealed from both macroscopic and microscopic perspectives.The results show that n-hexane exhibits superior flotation performance compared to cyclohexane:at a collector dosage of 2000 g/t,the combustible recovery of n-hexane reached 68.93%,while that of cyclohexane was only 64.79%.Spreading angle tests indicated that the spreading angle of coal slime particles treated with n-hexane was 178°,significantly higher than the 152° for cyclohexane.DFT analysis revealed that the Molecular Polarity Index(MPI)of n-hexane is 2.85 kcal/mol,higher than the 2.45 kcal/mol for cyclohexane,indicating stronger adsorption capacity on the coal slime surface.Molecular dynamics simulations further confirmed that n-hexane spreads more effectively and exhibits lower mobility on the coal slime surface compared to cyclohexane.The findings demonstrate the significant advantage of long-chain structured collectors in the flotation process of coal slime,providing a theoretical basis for the molecular design of high-performance flotation collectors.