ORALS

SESSION: BatteryMonPM2-R9	5th Intl. Symp. on Sustainable Secondary Battery Manufacturing and Recycling
Mon Nov, 5 2018 / Room: Asian (60/3rd)
Session Chairs: Thierry Djenizian; Vimalnath Selvaraj; Session Monitor: TBA

16:20: [BatteryMonPM210]
Dissolution of Spent Lead Acid Battery Paste for Lead Recovery, Bio-sensing and Bio-removal of Residual Pb Ions
Vimalnath Selvaraj¹ ; Vasant Kumar² ; Carsten Schwandt³ ; Subramanian Sankaran⁴ ; ¹University of Cambridge, Cambridge, United Kingdom; ²University of Cambridge, Cambridge, United Kingdom ; ³University of Nizwa, Nizwa, Oman; ⁴Indian Institute of Science, Bengaluru, India;
Paper Id: 392 [Abstract]

A spent lead acid battery consists of four parts, namely the electrolyte, lead and lead alloy components (for example the battery grid and plate), lead paste (the "redox", otherwise known as active, component of the battery) and organics or plastics with weight percentages of 11-30%, 24-30%, 30-40% and 22-30% respectively [1]. The spent battery paste is arguably the most complex component to recycle. It is complex as it is made up of a multitude of materials including PbSO₄ (~60%), which dominates in spent batteries, PbO₂ (~28%), PbO (~9%), free metallic lead (~3%) and a small but substantial concentration of impurities such as iron, antimony, tin and barium [1,2]. The recovery of Pb from spent lead paste is achieved conventionally through pyrometallurgical process requiring relatively elevated temperature (>900°C) for the decomposition of PbSO₄ [3]. The elevated temperature releases SO₂ gas and lead particulates into the environment, raising serious environmental concerns [4]. Hydro-electro metallurgical processing, which has been developed as an alternative, also consumes high energy and uses toxic acids like HBF₄ or H₂SiF₆ [5]. There is a need for eco-friendly method. In this study, a hydrometallurgical process for complete dissolution of spent lead paste at room temperature has been developed. Post recycling of the dissolved spent lead paste, the residual Pb ions are determined and removed using an eco-friendly biological method. The complete dissolution of spent lead acid battery paste is achieved in the presence of sodium hydroxide (NaOH), nitric acid (HNO₃) and hydrogen peroxide (H₂O₂). The concentration of Pb ions in the processed water is determined by deploying bacterial cells, Pseudomonas aeruginosa, using differential pulse anodic stripping voltammetry (DPASV). The parameters namely, pH, time, biomass loading and Pb ions concentration were optimized for maximum Pb ions removal by the selected bacterial cells.

References:
1. Zhu, X., Li, L., Sun, X., Yang, D., Gao, L., Liu, J., ... & Yang, J. (2012). Preparation of basic lead oxide from spent lead acid battery paste via chemical conversion. Hydrometallurgy, 117, 24-31.
2. Chen, T. T., & Dutrizac, J. E. (1996). The mineralogical characterization of lead-acid battery paste. Hydrometallurgy, 40(1-2), 223-245.
3. Yanakieva, V. P., Haralampiev, G. A., & Lyakov, N. K. (2000). Desulphurization of the damped lead battery paste with potassium carbonate. Journal of Power Sources, 85(1), 178-180.
4. Sonmez, M. S., & Kumar, R. V. (2009). Leaching of waste battery paste components. Part 1: Lead citrate synthesis from PbO and PbO2. Hydrometallurgy, 95(1-2), 53-60.
5. Yang, J., Kumar, R. V., & Singh, D. P. (2012). Combustion synthesis of PbO from lead carboxylate precursors relevant to developing a new method for recovering components from spent lead-acid batteries. Journal of Chemical Technology & Biotechnology, 87(10), 1480-1488.