Structural and electrochemical investigations of the electrodes obtained by recycling of lead acid batteries

XANES, EXAFS, Voltammetric, and Microhardness Studies of Manganese Dioxide-Lead-Lead Dioxide Vitroceramics

In this work we investigated the electrochemical performances and mechanical behavior of the manganese dioxide-lead dioxide-lead vitreous system. The structural and electrochemical properties of vitroceramics were investigated by the analysis of X-ray diffraction (XRD) spectra, X-ray absorption spectroscopy (XAS), and measurements of cyclic voltammetry and linear sweep voltammetry. The mechanical properties of the studied samples were determined by Vickers hardness values using the indentation method. The analysis of X-ray absorption near edge structure (XANES) data for the L3 edge of the lead and the radial distribution function data for the PbO₂ and Pb model indicate the modification of Pb-O interatomic distances by the doping process. The voltammetric study reveals the vitroceramic with x = 90 mol% Pb as the most suitable for application as a lead acid battery electrode.

Multi-Criteria Evaluation of Best Available Treatment Technology for Waste Lead-Acid Battery: The Case of China

Improper waste lead-acid battery (LAB) disposal not only damages the environment, but also leads to potential safety hazards. Given that waste best available treatment technology (BATT) plays a major role in environmental protection, pertinent research has largely focused on evaluating typical recycling technologies and recommending the BATT for waste LABs. First the evaluation indicators were selected based on the analysis of main factors affecting the pollution control of waste LAB treatment. The relative weights of each indicator were determined via the Delphi-attribute hierarchy model (AHM) in the second step. To determine the BATT, the attributive mathematics theory was adopted to calculate the attribute measure of single and multiple indices. Then, five recycling technologies commonly used in the secondary lead industry were estimated using the proposed evaluation system, and the feasibility of the recommended BATT was preliminarily verified. The results indicated that mixed smelting technology (MST), pre-desulfurization and multi-chamber smelting technology (PD-MCST), and direct smelting technology (DST) were found to perform well and were therefore deemed optimal for waste LAB disposal at this stage. The validation study showed that the DST can meet the requirements of pollution control, which is consistent with the evaluation results.

Efficiency of the Air-Pollution Control System of a Lead-Acid-Battery Recycling Industry

The air-pollution control system of a lead-acid-battery recycling industry was studied. The system comprised two streams with gravity settlers followed by filter bags for the factory indoor air and the metal-recycling furnace, respectively. Efficiency in particle removal according to mass was found to be 99.91%. Moreover, filter bags and dust from the gravity settlers were analyzed for heavy metals by Wavelength Dispersive X-Ray Fluorescence. The results showed high concentrations of Pb and Na in all cases. In the filter bag samples from the indoor atmosphere stream, Ca, Cu, Fe, and Al were found in concentrations higher than that in the filter bag samples from the furnace stream. The opposite was found for Na. Tl and K were only found in furnace stream bag filters. The elemental concentration of the dust from the furnace fumes stream contained mainly Fe, Na, Cd, Pb, Sb, and Cl, while the indoor main stream contained mainly P, Fe, Na, Pb, and Sb. In all cases, impurities of Nd, Ni, Rb, Sr, Th, Hg, and Bi were found. The high efficiency of the air-pollution control system in particle removal shows that a considerable reduction in emissions was achieved.