 A "V" shaped hearth using charcoal was used to heat up the pig iron bar that was presented to a tuyere that decarbonized it and made it melt and fall in drops that solidified in a pool of slag where the decarburization continued.The iron drops were picked up with an iron bar and presented again in front of the tuyere and one by one agglomerated into a ball.That heterogeneous iron was full of slag and the carbon content ranged from pure iron to nearly pig iron.