Electronic structures and floatability of pyrite,marcasite and pyrrhotite

The electronic structures of pyrite,marcasite and pyrrhotite were calculated using the first-principles method which was based on the density functional theory(DFT),and the relationship between the electronic structure and floatability of the three sulfurous iron minerals was discussed.The calculation results show that pyrite is a direct band-gap semiconductor,and marcasite is an indirect band-gap semiconductor,while pyrrhotite is a conductor.The density of state analysis reveals that pyrite and marcasite are in low spin state,while pyrrhotite is in spin-polarized state.In addition,the calculation of the frontier orbital indicates that the oxidized order of the three sulfurous iron minerals from easy to difficult is as follows: pyrrhotite,marcasite,pyrite,and the floatability order of the three sulfurous iron minerals from easy to difficult using xanthate as a collector is as follows: marcasite,pyrite,pyrrhotite.The interaction between the three sulfurous iron minerals and oxygen,and the floatability of the three sulfurous iron minerals collected by xanthate can be well explained by the calculation results.