From Zimbabwe's lithium-rich rocks to Democratic Republic of Congo's cobalt, minerals critical for clean energy technologies are increasingly in demand from Africa's trade partners as part of the global green transition from planet-warming fossil fuels.

Yet on a continent long blighted by the so-called "resource curse" — whereby nations rich in oil or gold, for example, have failed to convert this into wider prosperity — governments have increasingly restricted or banned mineral exports in recent years in a bid to boost processing and retain more of the gains.

This strategy could backfire, however, by deterring foreign investment, several analysts said.