The closure of the Strait of Hormuz, separating a large share of the world’s oil and gas from its consumers, is therefore a problem. More so, in fact, for sulphur than for oil, a fifth of which passes through the Strait. Even before the closure, curbs on Russian exports had pushed up prices. The cost for buyers in Africa, where miners also use sulphur to leach metal from ores, is up nearly 20 per cent this month, according to Platts.