Pedro Rosário Gismonti, Júlio Carlos Afonso
This work describes a route for recovering nickel, cobalt, iron, zinc, and lanthanides from spent nickel-metal hydride batteries using formic acid as leachant. Experiments were conducted at temperatures ranging from 25 to 50°C for durations of 1 to 4 hours. Under optimal conditions, leaching yields exceeded 99 wt.%, with the exception of iron, which was predominantly found in the insoluble matter as iron(III) basic formate. The leachate underwent six separation procedures, combining solvent extraction with D2EHPA extractant and precipitation reactions. Both Fe2+ and Zn2+ were successfully extracted from the original leachate (pH ~1.5) with extraction rates above 99 wt.%. Yttrium and lanthanides were precipitated as oxalates directly from the raffinate (exceeding 99.9 wt.%) following the addition of sodium oxalate. Further, Mn2+ and Co2+ were extracted with D2EHPA at buffered pH levels of 3 and approximately 4.8, respectively, following the addition of NaOH. Around 10 wt.% of leached Ni2+ coextracted with Co2+, while the remaining Ni2+ was precipitated from the raffinate post sodium oxalate addition at pH 6. After precipitation of Al3+ via NaOH addition until pH ~8, sodium formate was recovered through slow evaporation of the final aqueous solution at 60°C, achieving approximately 90 wt.% of formate from the leachant.
@article{48badba3-45a5-4b7c-9527-1a00b0658797,
title={RECOVERY OF METALS FROM ELECTROACTIVE COMPONENTS OF SPENT N i-MH BATTERIES AFTER LEACHING WITH FORMIC ACID},
author={Pedro Rosário Gismonti and Júlio Carlos Afonso},
year={2021},
language={pt}
}TY - JOUR TI - RECOVERY OF METALS FROM ELECTROACTIVE COMPONENTS OF SPENT N i-MH BATTERIES AFTER LEACHING WITH FORMIC ACID AU - Pedro Rosário Gismonti AU - Júlio Carlos Afonso PY - 2021 LA - pt ER -
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