Study concerning the recovery of zinc and manganese from spent batteries by hydrometallurgical processes

• Published in: Waste management (Elmsford) Vol. 33; no. 3; pp. 699 - 705
• Main Authors: Buzatu, Traian, Popescu, Gabriela, Birloaga, Ionela, Săceanu, Simona
• Format: Journal Article
• Language: English
• Published: United States Elsevier Ltd 01.03.2013
• Subjects: Acid leaching; Alkaline leaching; Electric Power Supplies; Extraction yield; Manganese; Manganese - isolation & purification; Metallurgy - methods; Refuse Disposal - methods; Solid Waste; Solubility; Sulfuric Acids; Zinc; Zinc - isolation & purification; Alkaline leaching; Acid leaching; Extraction yield; Zinc; Manganese
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2012.10.005

► Zn and Mn recovery from used batteries was investigated. ► Was performed leaching in NaOH and in sulphuric acid solution. ► In alkaline medium Zn efficiency for Zn–C batteries was 82% and for alkaline batteries was 64%. ► Zn–C batteries, performed in acid medium had an efficiency of 96% Zn and 43% Mn. ► Zinc extraction yield was lower for alkaline batteries. Used batteries contain numerous metals in high concentrations and if not disposed of with proper care, they can negatively affect our environment. These metals represent 83% of all spent batteries and therefore it is important to recover metals such as Zn and Mn, and reuse them for the production of new batteries. The recovery of Zn and Mn from used batteries, in particular from Zn–C and alkaline ones has been researched using hydrometallurgical methods. After comminution and classification of elemental components, the electrode paste resulting from these processes was treated by chemical leaching. Prior to the leaching process the electrode paste has been subjected to two washing steps, in order to remove the potassium, which is an inconvenient element in this type of processes. To simultaneously extract Zn and Mn from this paste, the leaching method in alkaline medium (NaOH solution) and acid medium (sulphuric acid solution) was used. Also, to determine the efficiency of extraction of Zn and Mn from used batteries, the following variables were studied: reagents concentration, S/L ratio, temperature, time. The best results for extraction yield of Zn and Mn were obtained under acid leaching conditions (2M H2SO4, 1h, 80°C).