Effect of the oxygen-containing functional group on the adsorption of hydrocarbon oily collectors on coal surfaces

Abstract

The oxygen-containing functional groups (OCFG) on the coal surface affect the adsorption effect of hydrocarbon oily collectors (HOC). An investigation of the interaction between the HOC and OCFG in the absence and presence of water is conducive to understanding the effect of OCFG type on the adsorption of HOC on the coal surface. In this paper, FTIR analysis was used to analyze the OCFG type of coal surface. The adsorption behavior of HOC on different OCFG surfaces was investigated using molecular dynamics simulation. The results indicated the presence of OCFG such as -OH, -COOH, -C=O, and -COCH3 on the coal surface. In conditions without water, the effect of OCFG on HOC adsorption capability follows the order -COOH > -C=O > -OH > -COCH3. In an aqueous solution, the effect of OCFG on HOC adsorption capability follows the order -C=O>-COCH3>-OH>-COOH. Moreover, the hydrophilicity of OCFG is the key factor that affects the adsorption effect of HOC. In other words, the adsorption effect of HOC on the coal surface in an aqueous solution does not depend on the strength of the interaction between the OCFG and HOC in the absence of water, but on the hydrophilicity of the OCFG. The -COOH and -OH on the coal surface are not conducive to the adsorption of HOC onto the coal surface. Masking the -COOH and -OH of the coal surface is beneficial in improving the coal flotation performance with HOC as a collector.

Influences of the Introduced O-Containing Functional Groups on the Gaseous Pyrolysis Product of Superfine Pulverized Coal

“…O-containing functional groups can exert influences on the adsorption characteristics of coal [3,4]. Guorui Feng et al [3] discovered that in upgraded brown coal, O-containing functional groups and 5-10 nm pores had a synergistic effect on the readsorption of water.…”

“…Additionally, the monolayer water concentration was mainly controlled by the oxygen content. -COOH and -OH on the coal surface had strong hydrophilicity, meaning it was proven that these two functional groups reduced the coal flotation performance when hydrocarbon oily collectors were used [4].…”