Secondary aluminium is aluminium produced by remelting scrap rather than smelting alumina. Recyclers sort and melt old and new scrap, remove impurities with fluxing and degassing, correct the chemistry with primary metal, silicon or master alloys, and cast the result as alloy ingots. Most Indian secondary output goes into foundry alloys such as ADC12, LM6, LM24 and LM25.
Why it matters when buying
- Chemistry varies more than in primary metal, so insist on a heat-wise spectro report and check Fe, Cu, Zn and Mg against the standard you buy to.
- Ask about melt treatment: degassing, flux cleaning and filtration affect porosity and inclusions in your castings.
- Secondary ingots are usually priced below primary, which makes them the economic choice for die casting and general castings.
- Recycled content is a growing buyer requirement for ESG and export reporting; ask the supplier to state it in writing.
Notes
Remelting scrap uses only a small fraction of the energy needed for primary production, which is why recycled metal is central to green aluminium claims. See the blog on primary vs secondary ingots for a side-by-side view.