Cenospheres characterization from Indonesian coal-fired power plant fly ash and their potential utilization

This study presents the cenospheres formation based on the characteristic of the fly ash and the coal as well as the potential production of cenospheres from fly ash from six coal-fired power plants in Indonesia. For cenospheres characterization, SEM-EDS, petrography analysis, and particle analyzer distribution were applied through all samples. Coal and fly ash chemical composition were analyzed using proximate analysis and ICP-MS. Based on the characterization of cenospheres and fly ash chemical components, we correlate the concentration of SiO2, Al2O3, SiO2/Al2O3, Fe2O3, Fe2O3+TiO2, CaO, MgO in the fly ash with cenospheres yield and diameter. The cenospheres yield in six Indonesian coal-fired power plant fly ash is in the range of 0.04-0.16 and inline with the ash content in the initial coal. Moreover, it was found that the cenospheres yield and diameter are in positive correlation with the concentration of SiO2 and Al2O3 in the fly ash, but they are in vice versa correlation with other chemicals. Ternary diagram of the cenospheres was made to their potential application and found that most of the cenospheres are in the ferrocalsialic. © 2020 Elsevier Ltd.