Recovery of Residual Lead from Automotive Battery Recycling Slag Using Deep Eutectic Solvents

Area of Science:

• Environmental Science
• Materials Science
• Chemical Engineering

Background:

• Automotive battery recycling generates hazardous foundry slag with high lead content.
• Existing disposal methods pose ecological challenges due to toxic waste accumulation.
• Lead concentrations in slag, primarily as anglesite (PbSO4), exceed regulatory limits.

Purpose of the Study:

• To develop an environmentally friendly and economical method for lead removal and recovery from automotive battery slag.
• To evaluate the efficacy of deep eutectic solvents (DES) in the hydrometallurgical processing of hazardous waste.
• To optimize DES leaching parameters for maximum lead dissolution and subsequent recovery.

Main Methods:

• Systematic evaluation of five operational variables: sample type, DES solvent, concentration, temperature, and time.
• Utilized X-ray fluorescence (XRF) and X-ray diffraction (XRD) for material analysis.
• Employed electrowinning for lead recovery from the optimized leaching solution.

Main Results:

• A choline chloride and glycerin DES (2:1 molar ratio) achieved 95% lead dissolution from acidic slag.
• Optimal conditions included 90 °C, 470 rpm agitation, 5% pulp concentration, and 5-hour duration.
• Successfully recovered 55% of the dissolved lead via electrowinning.

Conclusions:

• Deep eutectic solvents offer a viable, safe, and biodegradable approach for decontaminating hazardous slag.
• The developed method facilitates regulatory compliance and enables valuable metal recovery.
• This research opens new avenues for sustainable management and material reuse in battery recycling.