Not sure how much coal you really need. Sure steel is an iron alloy with carbon, but most coal in a steel mill is used as a reducing agent. Hydrogen can be used instead. Or you can use electrolysis to reduce which is even more efficient.
It must take a lot of coal to make steel. The mine I used to work for shipped 3-4 million tonnes of metallurgical coal to Japan every year.
It's about 14-15% of global coal consumption last I checked. That shifts around a bit as use in electrical generation and alternate steelmaking technologies vary. (Electric minimills processing scrap and not requiring coking are a significant source of steel.)