Stepwise process for the sustainable recovery of rare metals and earth elements

This technology is a supercritical CO₂ and antisolvent stepwise method for the recovery of precious metals and rare earth elements from waste.

Unmet Need: A sustainable high-recovery metal extraction method

With the yearly increases in discarded phones and computers, environmental concerns are significant, and greener alternatives must be identified. The critical minerals in discarded electronic waste are commonly isolated through pyrometallurgy, a process that releases toxic components as byproducts. The use of supercritical CO₂ combined with acid has been proposed as a potential solution for precious metal recovery; however, the mechanism of this process is poorly understood, which limits its application in industrial settings.

The Technology: Combined supercritical CO₂ and antisolvent green recycling process

This technology is a recycling process that utilizes supercritical CO₂ hydrometallurgy and a stepwise anti-solvent process to recover precious metals and rare earth elements. The extraction of gold involves a unique supercritical CO₂, acid, and exfoliation method, while calcium and magnesium are leached. Other rare earth elements are separated through solvent extraction with organic ligands and electrochemical separation. This straightforward approach for high-yield isolation streamlines the process for metals and rare-earth elements, offering an environmentally friendly and green method.

Applications:

• Metal and rare earth element isolation method
• Electronic waste processing and recycling
• Extraction method for different waste types (municipal, industrial, renewable)
• Toxic metal processing from runoffs
• Negative emission technology

Advantages:

• Stepwise separation of rare earth elements
• Recovery of gold as a solid product
• High purity of isolated elements
• Greener solvent options
• Limited use of strong acids
• Calcium and Magnesium storage
• Easily integrated into waste collection and recycling streams

Lead Inventor:

Ah-Hyung Alissa Park, Ph.D.

Patent Information:

Patent Pending (US20230220514)

Related Publications:

• Hsu E, Durning CJ, West AC, Park A-HA. “Enhanced extraction of copper from electronic waste via induced morphological changes using supercritical CO2” Resources, Conservation & Recycling. 2021 May; 168: 105296.

• Peng P, Park A-HA. “Supercritical CO2-induced alteration of a polymer-metal matrix and selective extraction of valuable metals from waste printed circuit boards” Green Chem. 2020 Aug; 22(20): 7080-7092.

Tech Ventures Reference:

• IR CU21163

• Licensing Contact: Dovina Qu