After scrap reaches a refinery, it undergoes sorting, processing, melting, refining, and recasting into reusable metal products. These industrial steps transform discarded metal into standardized raw material that can re-enter manufacturing supply chains. The process begins with identification and separation. Scrap is sorted by metal type—such as steel, aluminum, copper, or mixed alloys—using manual inspection, magnets, sensors, and density-based systems. Proper sorting prevents contamination and ensures chemical consistency during refining. Once separated, the scrap is processed. This stage includes shredding, cutting, baling, or crushing to reduce size and remove non-metal components such as plastic, rubber, or insulation. Clean, size-controlled scrap improves furnace efficiency and melting performance. The prepared material then moves into high-temperature furnaces. During melting, the scrap liquefies, and impurities separate from the molten metal. Slag forms and rises to t...
Slag (metallurgy) is a byproduct formed during metal smelting and refining when impurities separate from molten metal. In high-temperature furnaces used to extract metals such as iron, copper, and aluminum, non-metallic materials combine with fluxing agents to create a lighter liquid layer known as slag. This layer floats on top of the molten metal, allowing smelters to remove unwanted compounds efficiently. In iron and steel production, slag forms when limestone or other fluxes react with silica, alumina, and other impurities present in the ore. The result is a distinct molten material that can be skimmed off before the purified metal is cast. Because slag has a lower density than molten metal, it naturally separates, making the refining process more controlled and consistent. Slag plays a functional role in metal production. It helps: Remove impurities from molten metal Protect the metal surface from oxidation Stabilize furnace temperature Improve overall refining effi...