Aliko Dangote, Africa’s richest man, is calling off plans to invest in a new steel plant in Nigeria after the government accused him of seeking to become a monopoly with his new refinery in the West African nation. “Our own board has decided that we should not have the steel plant. If we do, we will be called all sorts of names,” Dangote said at a media briefing Saturday at the refinery in Lagos, Nigeria’s commercial hub.