Thermal drying behavior and morphological characterization of recycled lead sulfate paste from decommissioned lead-acid batteries

The recovery and reprocessing of lead-acid battery paste represent a critical approach for mitigating hazardous waste contamination while advancing sustainable industrial practices. This investigation presents a detailed characterization of the thermal, morphological, and compositional properties of lead paste obtained from decommissioned lead-acid batteries using comprehensive analytical techniques, including oven drying, SEM-EDX analysis, FTIR spectroscopy, XRD analysis, BET surface area determination, TGA assessment, and pycnometric measurements. Experimental findings demonstrate that drying temperature exerts a substantial influence on moisture removal rate and dehydration kinetics within the recovered materials. Combined SEM-EDX, FTIR, and XRD investigations reveal PbSO4 as the predominant crystalline phase, accompanied by trace concentrations of carbonate compounds, oxide phases, and residual contaminants. The reclaimed lead paste exhibits consistently reduced thermal conductivity values, ranging from 0.5 to 0.9 W/m·K, at ambient temperatures of 24-28 °C, indicating lower thermal transport efficiency compared to conventional PbS-based compounds. Statistical validation, employing the Shapiro-Wilk normality test, confirms that the dataset follows normal distribution patterns (W = 0.9877, p = 0.4882). These comprehensive results facilitate the advancement of optimized recycling methodologies for waste lead paste materials, emphasizing the importance of environmentally responsible and secure industrial operations.