Primary ingot comes from ore and is sold by purity; secondary ingot is remelted from scrap and sold by alloy code. How chemistry predictability, trace elements, energy footprint and price differ, and which one your process needs.
The first distinction in aluminum ingot supply is not the purity grade but where the metal came from. Primary ingot is smelted from ore and sold by purity. Secondary ingot is remelted from scrap and normally sold under an alloy code. The two cannot be compared on a single price line, because they are selling different things: one sells purity, the other sells a finished alloy chemistry.
Primary aluminum is produced from alumina in Hall-Héroult electrolysis cells, and the liquid metal is cast as small ingot, T-bar or sow. Secondary aluminum is produced by sorting, then melting, scrap, swarf and process returns; during melting the chemistry is measured and alloying elements are added to bring it onto a target code.
| Topic | Primary ingot | Secondary ingot |
|---|---|---|
| Input | Bauxite / alumina | Scrap, swarf, process returns |
| Sold on | Purity (99.7%, 99.8%) | Alloy code (e.g. EN AB-46000) |
| Typical designation | A7, A8, P1020A, Al99.70 | EN 1676 alloy codes |
| Chemistry predictability | High, narrow band | Can vary lot to lot |
| Trace element risk | Low | Depends on the scrap mix |
| Energy footprint | High | Substantially lower |
| Typical price level | Higher | Lower |
The most discussed risk in secondary metal is trace elements. Zinc, lead, nickel or chromium arriving with the scrap mix do not show up among the alloy code's main elements, but they can affect heat-treatment response and surface quality. When buying secondary ingot, ask for a full spectrographic analysis per lot rather than accepting a report on the main elements only.
If an offer simply says "aluminum ingot", the information is incomplete. Primary should state the purity tier plus the silicon and iron maximums; secondary should state the alloy code plus the main element bands. This is where most specification disputes begin: the name A7 cannot be used for secondary metal.
