Deterioration process and property evolution of anthracite lump coal in blast furnace.

The anthracite lump coke is the ideal fuel to replace coke for blast furnace (BF) operation due to its huge demand market and performance advantages. In this work, the degradation behavior of anthracite lump coal in blast furnace phenomenon is systematically studied. The results show that, compared to the anthracite lump coal with size of 20–30 mm, the percentages of intermediate size range and remaining original size range were larger for the of lump coal with size of 10–20 mm after gasification, which is helpful for the gas permeability and stability of stock column in BF. The depolymerization occurs first in the gasification process of anthracite coal. CO₂ erosion gradually penetrates from the surface into the interior of the anthracite lump coal. With the increase of temperature, the surface structure suffers a large area of melting damage, and the alkyl side chains, aliphatic side chains and bridge bonds (aromatic carbon-carbon bonds) outside the internal aromatic nuclei are broken and continuously consumed. The smaller microcrystalline structure is removed, leaving the large microcrystalline with high Lc and La values and low reactivity. At the same time, the basic structural unit condenses and forms a graphite-like microcrystalline structure, resulting in a more orderly macromolecular structure of carbon. [ABSTRACT FROM AUTHOR]