Reductive smelting of spent lead–acid battery colloid sludge in a molten Na₂CO₃ salt

Abstract

Lead extraction from spent lead–acid battery paste in a molten Na₂CO₃ salt containing ZnO as a sulfur-fixing agent was studied. Some influencing factors, including smelting temperature, reaction time, ZnO and salt dosages, were investigated in detail using single-factor experiments. The optimum conditions were determined as follows: T = 880°C; t = 60 min; Na₂CO₃/paste mass ratio = 2.8:1; and the ZnO dosage is equal to the stoichiometric requirement. Under the optimum conditions, the direct recovery rate of lead reached 98.14%. The results suggested that increases in temperature and salt dosage improved the direct recovery rate of lead. XRD results and thermodynamic calculations indicated that the reaction approaches of lead and sulfur were PbSO₄→Pb and PbSO₄→ZnS, respectively. Sulfur was fixed in the form of ZnS, whereas the molten salt did not react with other components, serving only as a reaction medium.

Keywords

lead–acid batteries / molten salts / lead smelting / desulfurization / solid waste recycling

References

[1] Zhu X.F., He X., Yang J.K., Gao L.X., Liu J.W., Yang D.N., Sun X.J., Zhang W., Wang Q., Kumar R.V. Leaching of spent lead acid battery paste components by sodium citrate and acetic acid. J. Hazard. Mater., 2013, 250-251, 387.

[2] Zhu X.F., Li L., Sun X.J., Yang D.N., Gao L.X., Liu J.W., Kumar R.V., Yang J.K. Preparation of basic lead oxide from spent lead acid battery paste via chemical conversion. Hydrometallurgy, 2012, 17-118, 24.

[3] Chen T.T., Dutrizac J.E. The mineralogical characterization of lead-acid battery paste. Hydrometallurgy, 1996, 40, 223.

[4] Brent H.J., Wadsworth M.E. Hydrometallurgy: fundamentals, technology and innovations. Proceedings of the International Symposium on Hydrometallurgy, 1993 1185.

[5] Yang J.Z. Harmless treatment and recycling industry chain for waste lead-acid battery. Nonferrous Met. Min. Sect., 2012, 64(4): 1.

[6] Chen Y.Q., Wang D. Recycling of waste lead-acid battery and its pollution control. Environ. Sci. Technol., 2012, 35(6I): 439.

[7] Anderws D., Raychaudhuri A., Frias C. Environmentally sound technologies for recycling secondary lead. J. Power Source, 2000, 88(1): 124.

[8] Lyakov N.K., Atanasova D.A., Vassilev V.S., Haralampiev G.A. Desulphurization of damped battery paste by sodium carbonate and sodium hydroxide. J. Power Sources, 2007, 171(2): 960.

[9] Yang D.N., Liu J.W., Wang Q., Yuan X.Q., Zhu X.F., Li L., Zhang W., Hu Y.C., Sun X.J., Kumar R.V., Yang J.K. A novel ultrafine leady oxide prepared from spent lead pastes for application as cathode of lead acid battery. J. Power Sources, 2014, 257, 27.

[10] Lin D.Q., Qiu K.Q. Recyling of waste lead storage battery by vacuum methods. Waste Manage., 2011, 31(7): 1547.

[11] Chen G.Z., Fray D.J., Farthing T.W. Direct electrochemical reduction of titanium dioxide to titanium in molten calcium chloride. Nature, 2000, 407, 361.

[12] Zhou D., Zhao C.Y., Tian Y. Review on thermal energy storage with phase change materials (PCMs) in building applications. Appl. Energy, 2012, 92, 593.

[13] Long Y.Y., Li J.Z., Timmer D.H., Jones R.E., Gonzalez M.A. Modeling and optimization of the molten salt cleaning process. J. Clean. Prod., 2013, 68, 243.

[14] Yang J.G., Tang C.B., Chen Y.M., Tang M.T. Separation of antimony from a stibnite concentrate through a low-temperature smelting process to eliminate SO₂ emission. Metall. Mater. Trans. B, 2011, 42(1): 30.

[15] He D.W., Yang J.G., Tang C.B., Chen Y.M., Tang M.T. Separation of bismuth from a bismuth glance concentrate through a low-temperature smelting process. Miner. Process. Extr. Metall. Rev., 2013, 34(2): 73.

[16] Wei J.C., Gao X.M., Marinova D., Fan J. Industrial SO₂ pollution and agricultural losses in China: evidence from heavy air polluters. J. Clean. Prod., 2014, 64, 404.

[17] Brain I., Knacke O., Kubaschewski O. Thermochemical Properties of Inorganic Substances, 1977, New York, Springer-Verlag, 1.