Effect of temperature and pressure on the mineralogical and fusion characteristics of Jincheng coal ash in simulated combustion and gasification environments

► Temperature effect on ash fusion characteristics strongly depends on atmospheres. ► High temperature minerals form in combustion, increasing ash fusion temperatures. ► Low-melting eutectics form in gasification, decreasing the ash fusion temperatures. ► Pressure influences mineral transformation by affecting reactions between minerals. ► Increasing pressure accelerates the formation of high-temperature minerals.