Question: Who invented the process to remove impurities by blasts of cold air blown through heated iron?
Answer: Song Dynasty
Disambiguated annotations:
qaPairs: question: What Englishman invented the process to remove impurities by blasts of cold air blown through heated iron?
answer: Henry Bessemer
question: What American independently discovered  the process to remove impurities by blasts of cold air blown through heated iron?
answer: William Kelly