A1 Journal article (refereed)
Dry chlorination of spent nickel metal hydride battery waste for water leaching of battery metals and rare earth elements (2022)

Perämäki, S., Tiihonen, A., Rajahalme, J., Larsson, S., Lahtinen, E., Niskanen, J., Budhathoki, R., & Väisänen, A. (2022). Dry chlorination of spent nickel metal hydride battery waste for water leaching of battery metals and rare earth elements. Journal of Environmental Chemical Engineering, 10(5), Article 108200. https://doi.org/10.1016/j.jece.2022.108200

JYU authors or editors

Publication details

All authors or editors: Perämäki, Siiri; Tiihonen, Antti; Rajahalme, Joona; Larsson, Sylva; Lahtinen, Elmeri; Niskanen, Joni; Budhathoki, Roshan; Väisänen, Ari

Journal or series: Journal of Environmental Chemical Engineering

ISSN: 2213-3437

eISSN: 2213-3437

Publication year: 2022

Publication date: 01/07/2022

Volume: 10

Issue number: 5

Article number: 108200

Publisher: Elsevier

Publication country: Netherlands

Publication language: English

DOI: https://doi.org/10.1016/j.jece.2022.108200

Publication open access: Openly available

Publication channel open access: Partially open access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/82653


An efficient leaching process was developed for nickel, cobalt, and the rare earth elements (REEs) from spent nickel metal hydride (NiMH) battery waste. The process involves dry chlorination with ammonium chloride in low temperature to produce water-soluble chlorinated compounds, followed by simple water leaching. The factors affecting the conversion and solubilization were studied, including the amount of ammonium chloride, residence time and temperature in dry chlorination, and solid to liquid ratio, time and temperature in water leaching. As a result, the dry chlorination process was found to produce ammonium and chloride containing products, depending on the temperature of the process: ammonium metal chlorides were produced in temperatures of 250-300 ℃, while increasing the temperature to 350 ℃ resulted in formation of metal chlorides. Overall, highest metal recoveries were achieved during 60 min residence time at a temperature of 350 °C, where ammonium is no longer present and ammonium metal chlorides and metal chlorides have formed. Water leaching was found to proceed rapidly, especially for REEs, and yields of 87% for Ni, 98% for Co, 94% for Ce, and 96% for La were attained during 60 min of leaching in room temperature. This study introduces a process, which is considered as an environmentally more benign alternative to traditional mineral acid leaching, resulting in high metal leaching efficiencies with neutral leachates, requiring no chemical-intensive neutralization steps in the following processing.

Keywords: rare earth metals; nickel-metal hydride batteries; nickel; cobalt; dissolution (active); chlorides; processes; accumulators; waste utilisation; friendliness to the environment

Free keywords: NiMH; battery; dry chlorination

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Ministry reporting: Yes

Reporting Year: 2022

Preliminary JUFO rating: 1

Last updated on 2022-20-09 at 14:17