Disentanglement of random access memory cards to regenerate copper foil: A novel thermo-electrical approach

摘要

This paper reports the development of a novel process combining thermal and electrical treatments, which are optimised to provide efficient recovery of copper foil from Random Access Memory cards (RAMs). A primary thermal transformation at 900 °C facilitates a highly efficient recovery of copper foils from RAMs during the secondary processing in the electrical fragmenter, using only 10 pulses at 150 kV. The process yield was 98% and inductively coupled plasma (ICP) analysis showed that the copper foils had 98% purity. X-ray diffraction (XRD) confirmed the presence of copper in a crystalline face-centred cubic (FCC) form. Scanning electron microscopy (SEM) – energy dispersive spectroscopy (EDS) analysis of the foils assisted in understanding the underlying mechanism of electrical separation. Transmission electron microscopy (TEM) gave a new perspective on the regeneration of copper foils wherein new copper grains depicted a ribbon like growth pattern. The copper foils had an electrical conductivity similar to that of commercially available pure copper sheets. Thus, the mechanism of thermo-electrical transformation was studied in detail and regenerated copper foils of high electrical conductivity were afforded from end-of-life RAMs.