While the world has been obsessing over his oil, Dangote has quietly been cornering another market: the global fertiliser trade.

While the world has been obsessing over his oil, Dangote has quietly been cornering another market: the global fertiliser trade.

Africa’s richest person, the Nigerian industrialist Aliko Dangote, has built the world’s largest single-train oil refinery in Lekki, on the southern outskirts of Lagos. With a…