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How was slag removed from early blooms of wrought iron?
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iron processing
Iron ore is one of the most abundant elements on Earth, and one of its primary uses is in the production of steel. When combined with carbon, iron changes character completely and becomes the alloy steel.
In the early bloomery process, the iron produced was a spongy mass known as a bloom, which contained entrapped slag and pieces of charcoal.12
To remove the slag and create wrought iron, the bloom was subjected to a process of repeated reheating and hot hammering. By heating the bloom in a forge and striking the red-hot metal on an anvil, the smith could expel the semiliquid slag from the porous iron. This mechanical working was essential for refining the metal into a more usable, malleable form.1234