Rapid and non-destructive evaluation of coal quality is critical for optimizing energy production and mining operations. This study investigates the application of a capacitive impedance-based approach as an alternative technique for estimating the relative dielectric properties of coal, which are key indicators in proximate analysis. Coal samples were characterized using electric field–based measurements and compared with conventional proximate analysis methods. The measurements employed a capacitive impedance system operating under low-frequency AC excitation to capture dielectric response parameters associated with moisture content. Subsequent linear and quadratic regression analyses were performed to assess the correlations between methods. The results demonstrated a positive correlation with acceptable relative deviations, supporting the feasibility of this technique for preliminary quality assessment. Furthermore, composite variables incorporating both capacitive measurements and ash content yielded significantly improved predictive performance. These findings indicate that capacitive impedance analysis offers a promising, rapid, and non-destructive alternative for estimating coal moisture content, particularly suited for field applications and early-stage quality control.
Haryono et al. (Mon,) studied this question.