As the mining of large flake graphite is approaching exhaustion, fine flake graphite becomes the main resource for the future. The fine flake graphite ores in the Heilongjiang area of China are very representative of China. Based on a large amount of fine flake graphite in Luobei, Heilongjiang, China, the characteristics of the fine flake graphite have been studied by process mineralogical analysis. The study shows that the large flake graphite content in the raw ore samples in the Luobei area, Heilongjiang, China is about 16.81%, and most of the graphite exists in the form of fine flakes less than 150 μm. In addition, the main reason why graphite minerals are difficult to liberate is that the graphite flakes in the samples are interlocked with Muscovite. Some graphite flakes are distorted in the ore and it is easy to cause the flakes to be severely crushed during the grinding process which can affect the application value of graphite. A part of graphite minerals or gangue is distributed in the ore in the form of a fine disseminated state, which can result in a low grade of the flotation concentrate.

In this study, the surface modification of arsenopyrite and pyrite with low temperature oxygen plasma was developed as an effective approach to improve the flotation separation efficiency of minerals. The micro-flotation experiments results indicated that plasma pre-treatment can achieve selective flotation of arsenopyrite from pyrite. The XPS analysis results indicated that the oxidation degree of plasma-modification arsenopyrite surface is much higher than that of pyrite. A large number of sulfide components on the surface of the mineral were oxidized to highly-valence hydrophilic oxides by plasma pre-treatment. ICP-MS analysis results revealed that the dissolution rate was determined by the oxidation degree of minerals and plasma modified accelerated the dissolution of arsenopyrite and pyrite. Zeta potential determination results confirmed that plasma can keep a relatively higher adsorption of SBX on the pyrite surface but inhibit the adsorption of collector onto the arsenopyrite surface.

This study examined the appropriate hematite (Fe₂O₃) collector for the concentration of pyrolusite (MnO₂) in a reverse flotation. Actual ore flotation studies were performed to determine how sodium oleate, sodium dodecyl sulfonate, and oxidized paraffin soap affect hematite removal during reverse flotation of pyrolusite ore. In order to explore the flotation mechanism, simulation experiments were carried out. Firstly, the crystal models of pyrolusite and hematite were established. Then, in order to verify the reliability of the simulation results, the simulated XRD spectra of the crystal model were compared with the measured spectra. Finally, density functional theory and molecular dynamics modeling were used to study the interaction between collector molecules and mineral surfaces. The flotation test results show that oxidized paraffin soap is the best hematite collector and promotes its flotation, removing iron from pyrolusite. Molecular dynamics simulations and density functional theory show that the three collectors (oxidized paraffin soap, sodium oleate, and sodium dodecyl sulfonate) have a much stronger interaction with hematite than with pyrolusite. Therefore, it is possible to separate pyrolusite and hematite through flotation. The simulation results also show that oxidized paraffin soap has the highest adsorption strength and selectivity for hematite. This characteristic makes oxidized paraffin soap an excellent collector for effectively removing hematite from pyrolusite in the reverse flotation process.