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Synergistic effect of CaO and MgO addition on coal ash fusibility in a reducing atmosphere
Author(s) -
Wu Chengli,
Xin Yu,
Liu Xiang,
Li Hanxu,
Jiao Facun
Publication year - 2019
Publication title -
asia‐pacific journal of chemical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.348
H-Index - 35
eISSN - 1932-2143
pISSN - 1932-2135
DOI - 10.1002/apj.2324
Subject(s) - anorthite , eutectic system , coal , fly ash , reducing atmosphere , materials science , bottom ash , metallurgy , slag (welding) , bituminous coal , mineralogy , lime , chemical engineering , chemistry , microstructure , composite material , organic chemistry , engineering
During coal gasification in entrained‐flow slagging gasifiers, the addition of additives is a promising method to improve coal ash fusibility. In some cases, mixed additives are more effective in decreasing ash fusibility than single additive addition with the same content added. However, mechanisms of mixed additive addition for improving ash melting are scarce. In this study, the effect of CaO, MgO, and their mixtures on the ash flow temperature (FT) of Chinese bituminous coal was investigated. The results show that the single addition of CaO or MgO influenced the ash FT of the test coal sample. The addition of CaO and MgO mixture synergistically decreased the ash FT relative to their single addition. When the ratio of CaO to MgO was 5:5 (mass ratio) in the mixture, the FT decreased to 1297°C, which is 69°C and 110°C lower than that of the single addition of CaO and MgO, respectively. The formation of a low‐temperature eutectic from the interactions between anorthite and olivine caused such synergistic effects.