A method of supplying both an oxygen steelmaking process and an ironmaking process with oxygen, comprising separating oxygen from air by rectification of the air, supplying a first stream of oxygen from the rectification to the steelmaking process, supplying a second stream of oxygen from the rectification to the ironmaking process, wherein the first and second streams of oxygen are both withdrawn from essentially the same stage of the rectification and both contain from 97 to 98% by volume of oxygen and less than 100 parts per million of nitrogen.