Characteristics and Potential Concentration of Cenospheres in Fly Ash from Tanjung Jati B Combustion Power Plant, Jepara, Central Java, Indonesia

Fly ash and bottom ash (FABA) are residual products from a power plant coal combustion that can be processed into products with economic value. One component of FA that has the potential to proceed is the cenospheres. However, the concentration of cenospheres in FA is limited so further analysis is needed to maximize this potential. The study was conducted using FA samples at Tanjung Jati B combustion power plant covering units 1 and 2, unit 3, and unit 4 located in Jepara, Central Java, Indonesia. Samples were analyzed to determine the composition of FA and the concentration of cenopsheres within. The main oxide compounds in FA were determined by XRF analysis. The organic and inorganic components of FA were identified through petrographic observations. The mineralogical composition of FA was generated by XRD analysis. The cenospheres retrieval test used the sink-float method with three trials on each sample and the presence of the cenospheres was confirmed through SEM analysis. The results showed that the inorganic components of FA consist of glass, quartz, Fe-spinel, Mg-spinel, hematite, magnetite, mullite, kaolinite, smectite, K-feldspar, and calcite, while the organic component found in FA is Unburned Carbon (UC). The cenospheres concentration values obtained were in the global range of cenospheres concentrations. The relationship between the constituent components of FA and the concentration of the cenosphere indicates that the presence of quartz in the FA sample positively correlated with the amount of cenospheres that can be observed through petrographic analysis.