Economic feasibility and profitability analysis of scCO2-based gold recovery process from waste printed circuit boards.

Although the growing number of electronic wastes poses environmental challenges, they also contain precious metals, such as gold, that has significant economic value if recycled properly. Supercritical-CO2-based gold extraction from printed circuit boards (PCBs) has been experimentally demonstrated, but its economic promise is not fully understood. Results in this study show that the main cost drivers of this process are the chemicals, including the acid used and the supercritical CO2. The analyses reveal that such process could be profitable when gold content in PCBs is above 0.02% and the extraction efficiency can be higher than 50%. Its profitability is also affected by the gold market price, and is promising if the gold price is above $60,000 per kilogram. However, assumptions such as the cost associated with material separation within the metals and solvents could be further refined, which are important directions for future studies.