Comparative study on coal blending and coke-making property of two kinds of thermal dissolution soluble fractions from lignite and coking coal

Abstract

Thermal dissolutions (TDs) of Xilinguole lignite (XL) and coking coal (CC) with different solvents were performed, and feasibility of applying TD soluble fractions (TDSFs) to coke-making was evaluated. The results show that the TDSFs yield of XL (< 30%) is lower than that of CC (> 40%) in both polar and non-polar solvents at 360 °C. Methanol remarkably enhances TDSF yield of XL from 30% to 45.3% with 10% addition to 1-methylnaphthalene (1-MN) due to methanolysis. All TDSFs prepared show better caking property, lower softening temperatures, and greater caking indexes (GR.I) than the commonly used fat coals for coke-making. Using 5 wt.% TDSFs to substitute equivalent amount of fat coal in coal blends effectively improves the quality of the resultant coke, verifying the feasibility of using TDSFs from low rank coals for coke-making.