Characterization of Fe-based sediments received from chemical pre-treatment of hydrometallurgical waste leachate from the recycling of alkaline batteries

• Published in: Journal of hazardous materials Vol. 403; p. 123988
• Main Authors: Yang, Zhendong, Karczewska-Golec, Joanna, Styczynski, Michal, Bajda, Tomasz, Drewniak, Lukasz
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 05.02.2021
• Subjects: (Bio)weathering; Iron sediment; Iron sorbent; Sediment management; Sediment management; Iron sediment; Iron sorbent; (Bio)weathering
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2020.123988

The waste leachate from the hydrometallurgical recycling of spent batteries contains a significant amount of undesirable iron that needs to be precipitated before the recovery of target metals. The produced Fe-sediments are usually disposed of or stored at the treatment site as waste and are often poorly managed. This work estimates the environmental stability and application potential of Fe-sediments produced from highly acidic hydrometallurgical leachate during the recycling of spent alkaline batteries. After pH neutralization of the leachate by Na2CO3, a primary Fe-sediment (PFS), mainly composed of highly unstable metal (i.e., Fe, Zn, and Mn) sulfates, was obtained. The subsequent rinsing of this unstable PFS sediment led to the production of a secondary Fe-sediment (SFS), which was composed of an amorphous-phased ferric iron sulfate hydrate – Fe16O16(SO4)3(OH)10·10H2O. The results of single extraction using chemical reagents and biological dissolution by iron-transforming bacteria confirmed that despite most of the ions in PFS were dissolvable, the processed SFS was environmentally safe. The sorption efficiency of SFS towards Pb(II) and As(V) (up to ~ 99% and 94%, respectively, with an initial concentration of 100 mg/L) was found to be promising, suggesting the high potential for economical reuse of SFS. [Display omitted] •Fe removal from the leachate of alkaline batteries recycling results in the precipitation of Zn and Mn. •Secondary Fe-sediments have much higher chemical and biological stability than primary ones. •Secondary Fe-sediments are an effective sorbent for lead and arsenic.