Research on the efficient leaching and separation of iron, aluminum, and calcium elements in organic acids from high-carbon component of coal gasification fine slag—data set

The efficient extraction and separation of valuable metal elements in coal gasification fine slag (CGFS) is the key to realize the high value utilization of all components. In this paper, the high-carbon component of coal gasification fine slag (CGFS-H) is taken as the research object, and the selective leaching characteristics of calcium, iron and aluminum in CGFS-H by different organic acid (citric acid, tartaric acid and tetrasodium iminodisuccinate) extractants are investigated. The step-by-step extraction effect of iron, aluminum and calcium in CGFS-H was further explored. Combined with XRD, XRF and SEM analysis, the step-by-step extraction mechanism of iron, aluminum and calcium by different organic acids was clarified. The results showed that tetrasodium iminodisuccinate had the highest extraction selectivity for Fe3+ in CGFS-H, while tartaric acid had similar extraction selectivity for Fe3+ and Al3+, and citric acid had the highest selectivity for Ca2+. Fe3+, Al3+ and Ca2+ were extracted by tetrasodium iminodisuccinate, tartaric acid and citric acid. The step-by-step cumulative extraction rates of Fe3+, Al3+ and Ca2+ were 79.8 %, 65.08 % and 78.6 %, respectively. This indicates that the efficient extraction and step-by-step separation of Fe3+, Al3+ and Ca2+ in CGFS-H can be achieved by using different organic acid sequential extraction methods. This is of great significance for breaking through the preparation technology of Ca/Fe/Al hydrotalcite with CGFS-H as raw material and realizing the high value utilization of coal gasification fine slag.