When the Simandou project in the Guinean mountains inaugurated its mining operations, it was no ordinary start-up of a new mine. It was a moment that could fundamentally redraw the map of the global iron ore market in the years to come - a raw material that no economy in the world can do without. Guinea, long considered poor and politically unstable, has now positioned itself as a player that can influence the price of steel from Shanghai to Rotterdam.

The Simandou project, worth more than $23 billion, is the result of three decades of planning, litigation, international agreements and strategic changes. At its core is one of the richest iron ore resources in the world - with an average purity of around 65%, significantly higher than its Australian or Brazilian competitors. It is this quality that may be the key to the transition to 'green steel' that the world's industrial economy desperately needs to reduce its carbon footprint.

The project involves a Chinese consortium, Winning Group,…