One-Step Separation and Refinement of Sb from Pb-Sb Alloy by Electrolysis in Deep Eutectic Solvent: Leveraging...

Area of Science:

• Metallurgical Engineering
• Electrochemistry
• Materials Science

Background:

• Antimony (Sb) is a critical strategic resource with diverse industrial uses.
• Separating antimony from lead (Pb) is challenging due to similar physicochemical properties.
• High Pb-Sb alloys are common intermediates in jamesonite processing, necessitating efficient separation methods.

Purpose of the Study:

• To develop a one-step electrolysis method for separating antimony powder from high Pb-Sb alloys.
• To investigate the electrochemical behavior of Sb and Pb in a choline chloride-ethylene glycol + SbCl3 deep eutectic solvent (ethaline + SbCl3 DES).
• To provide an environmentally sustainable and straightforward approach for Sb separation and refinement.

Main Methods:

• Electrolysis using an ethaline + SbCl3 DES electrolyte.
• Electrochemical characterization using polarization curves and cyclic voltammetry.
• Analysis of anode dissolution, cathode deposition, and reaction mechanisms.

Main Results:

• Antimony exhibits a more positive oxidation potential than lead in the ethaline + SbCl3 DES, enabling electrochemical separation.
• Antimony has a more positive initial reduction potential, ensuring preferential deposition over lead.
• Optimized conditions yielded 99.98% pure Sb with 93.57% current efficiency and low energy consumption (749.18 kW·h·t-1).
• SbCl3 addition inhibits Pb dissolution, forming anode sludge, while Sb forms [SbCl6]3- complexes reduced to metallic Sb.

Conclusions:

• The proposed one-step electrolysis method effectively separates Sb from high Pb-Sb alloys.
• The ethaline + SbCl3 DES provides a suitable medium for selective Sb deposition.
• This method presents a sustainable and efficient route for antimony recovery and purification.