Who invented the process to remove impurities by blasts of cold air blown through heated iron?
Basic oxygen steelmaking is essentially an improved version of the Bessemer process (decarburization by blowing oxygen as gas into the heat rather than burning the excess carbon away by adding oxygen carrying substances into the heat). The advantages of pure oxygen blast over air blast was known to Henry Bessemer, but the 19th-century technology was not advanced enough to allow for the production of the large quantities of pure oxygen to make it economically feasible for use.
What Englishman invented the process to remove impurities by blasts of cold air blown through heated iron?
Henry Bessemer
Bessemer process
The modern process is named after its inventor, the Englishman Henry Bessemer, who took out a patent on the process in 1856. The process was said to be independently discovered in 1851 by the American inventor William Kelly though the claim is controversial.
What American independently discovered  the process to remove impurities by blasts of cold air blown through heated iron?
William Kelly
Bessemer process
Bessemer process
https://en.wikipedia.org/wiki/Bessemer%20process
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. 
Bessemer process
The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with air being blown through the molten iron. It is named after its inventor, Englishman, Henry Bessemer who took out a patent on the process in 1856. The process was said to be independently discovered in 1851 by the American inventor, William Kelly, though the claim is controversial.