It isn’t quite as developed as the Bessemer process, but they were producing steel with a precursor, using a cold blast: https://en.m.wikipedia.org/wiki/Scienc

It isn’t quite as developed as the Bessemer process, but they were producing steel with a precursor, using a cold blast: https://en.m.wikipedia.org/wiki/Science_and_technology_of_the_Song_dynasty#Metallurgy https://en.m.wikipedia.org/wiki/Science_and_technology_of_th...