New efficient way to recycle alkaline batteries with an environmentally friendly process

Good news! In this battery hungry world, we can uses better recycling methods! This new process seems to be straight forward and requires only basic chemicals.

"... The technique uses hydrometallurgy, where a water-based solution is used to leach metals out of a substance.

Unlike other battery-recycling processes, hydrometallurgy doesn’t need high temperatures and pressures to work, which makes it much less energy intensive. ...
“The most important factor was to find a suitable leaching agent (in this case sulphuric acid) and a reducing agent (hydrogen peroxide), which increased the extraction of these minerals,” ..."

From the abstract:

"BACKGROUND

Batteries play a vital role in meeting global energy needs.  ... In this sense, the recycling of metals contained in spent batteries could mean a huge advantage if they are extracted and purified using environmentally friendly processes.

RESULTS

In this study, the recovery of potassium (K), zinc (Zn) and manganese (Mn) from alkaline batteries was performed using a hydrometallurgical process consisting of neutral, acid and acid reductive leaching steps at room temperature and atmospheric pressure to extract K, Zn and Mn. In the neutral leaching step, 76.8 ± 3.4 (wt. %) of the K present in the spent batteries was extracted. Thus, in the acid leaching step, 90.9 ± 0.1 (wt. %) of the initial Zn and 36.7 ± 0.4 (wt. %) of the initial Mn was extracted using sulfuric acid (H2SO4) 2 M. In a subsequent acid reductive leaching step using H2SO4 2 M and oxygen peroxide (H2O2) 0.8 M as reducing agent, 8.7 ± 0.1 (wt. %) of the initial Zn and up to 49.4 ± 0.2 (wt. %) of the initial Mn were extracted.

CONCLUSION

The three-unit process led to an overall extraction of 99.6 ± 0.3 (wt. %) of Zn and 86.1 ± 0.1 (wt. %) of Mn. Regarding the latter step, the extraction was not 100% because Mn complexes which are nearly insoluble were generated. This shows that extraction of valuable minerals from industrial residues is possible by hydrometallurgical processes."

New efficient way to recycle alkaline batteries

Extraction and separation of potassium, zinc and manganese issued from spent alkaline batteries by a three-unit hydrometallurgical process (open access)

Fig. 1 Simplified flow sheet of the 3-step leaching process for a mass basis of 1 kg of BM.