How do they ensure the quality of steel made from scrap metal?

Question

There’s literally everything in scrap metal, aren’t there compounds that will worsen the quality of the steel produced?

In: Chemistry

Answer 1

They actually use a recipe like you would when baking a cake. Instead of say so much flour and so much butter, they will use so much of scrap #1 and so much of scrap #2, and so on. A yard may have 10 or so different scraps from different origins, each of which the plant knows the rough chemistry for based on what was in it’s previous life. There is actually a very lucrative business sorting junk yard scrap for steel plants.

After the initial scrap is melted they take molten samples and test the chemistry. They can then add small amounts of specific raw materials to trim the chemistry.