Platinum Recovery from Industrial Process Solutions by Electrodeposition-Redox Replacement

Area of Science:

• Metallurgy and Materials Science
• Electrochemistry
• Environmental Science

Background:

• Industrial hydrometallurgical solutions often contain platinum at concentrations below 1 part per billion (ppb).
• Traditional methods are insufficient for recovering such trace amounts of platinum.
• Pyrolyzed carbon (PyC) electrodes have not been previously applied for metal recovery.

Purpose of the Study:

• To investigate the electrodeposition-redox replacement (EDRR) method for recovering trace platinum from industrial solutions.
• To evaluate the efficiency and selectivity of EDRR using pyrolyzed carbon (PyC) electrodes.
• To demonstrate the potential of EDRR for recovering other precious metals like palladium and silver.

Main Methods:

• Developed and applied an electrodeposition-redox replacement (EDRR) process using pyrolyzed carbon (PyC) electrodes.
• Optimized EDRR parameters using synthetic nickel electrolyte solutions.
• Tested the EDRR method on real industrial hydrometallurgical process solutions with complex matrices.

Main Results:

• Achieved a 3 × 10^5-fold increase in the platinum-to-nickel ratio ([Pt]/[Ni]) on the electrode surface using synthetic solutions.
• Demonstrated significant platinum selectivity in real industrial solutions, with deposited nanoparticles comprising 90 wt % platinum.
• Obtained a [Pt]/[Ni] enrichment ratio of 10^11 compared to the industrial solution, with potential for Pd and Ag recovery.

Conclusions:

• The EDRR method on PyC electrodes is a highly effective technique for recovering ultra-trace platinum from complex industrial solutions.
• This method offers a significant advancement in platinum recovery, unlocking previously unutilized sources.
• The EDRR process shows promise for the simultaneous recovery of other valuable precious metals like palladium and silver.