Aggregation of anthracite and graphite dispersions under the action of alkaline-earth metal carbonates

Abstract

A model for the electrical conductivity of a heterogeneous system based on alkaline-earth metal carbonates and anthracite and graphite dispersions is proposed. The electrical properties of heterogeneous dispersions in the carbonates of alkaline-earth metals depend on several basic parameters. The degree of aggregation of electrically conducting particles and the electrical conductivity of a single aggregate are the most important of these parameters. The threshold concentration of the electrical conductivity of graphite dispersions in alkaline-earth metal carbonates, which is 0.05, is much lower than the threshold concentration of electrical conductivity for the liquid systems of graphite dispersions in electrolytes, which is 0.15. This is likely due to a higher value of the Hamaker constant in the test systems. The aggregation of the dispersions of anthracites is insignificant, and particles are evenly distributed in the volume. The apparent activation energies of electrical conductivity were determined for the dispersions of anthracites and graphites in alkaline-earth metal carbonates. It was found that the activation energy of electrical conductivity increased with the weight fraction of dispersions. Lower values of the apparent activation energy of electrical conductivity were observed in barium and strontium carbonates.