Silver Recycling From Defective GdBCO/Ag High-Temperature Superconducting Bulks

The silver used as a mechanical reinforcement in REBCO bulks accounts for approximately half of the total material costs. Despite this, no viable recycling techniques have yet been published. Thus, we have developed a simple method for silver recycling from end-of-life and failed REBCO bulks based on their dissolution in azeotropic nitric acid and subsequent selective precipitation. The phase compositions of the REBCO waste, intermediates and final product were studied by XRD, which confirmed the preparation of pure metallic silver. The recycled silver was then used to manufacture 28 mm EuBCO single-domain bulks, whose superconducting properties showed no significant differences from reference bulks containing commercial Ag ₂ O. SEM confirmed that the microstructure of the cut bulks was also typical of REBCO bulks. Thus, it appears that the implementation of silver recycling within the REBCO production chain can increase the cost-competitiveness and adoption of REBCO/Ag products while maintaining their properties and microstructure.