Simandou has faced delays due to legal disputes, political changes, and the challenges of building a 600 km rail and port infrastructure.
Portugal already has the largest copper mine in the European Union, operated by Lundin Mining.
Zimbabwe’s largest gold producer is negotiating with potential partners to boost production at its Shamva mine.
Oversupply and weak prices of materials such as lithium, cobalt and rare earths are dampening cash flows of Western start-ups.