Aluminium Scrap

TECHNICAL PROCESS DESCRIPTION:

 

Production of Aluminum Ingots from Aluminum Scrap

 

1. Introduction

This document outlines the standard industrial process for converting aluminium scrap into secondary aluminium ingots. The process includes sorting, melting, refining, and casting, with full control of chemical composition and quality.

 

2. Input Material (Scrap)

• Aluminum scrap is classified according to type and quality:

  • Clean scrap (profiles, sheets, wires)

  • Cast scrap (cast components)

  • Mixed scrap

  • UBC – Used Beverage Cans

• Prior to melting, scrap is mechanically and manually cleaned to remove:

  • steel, copper, plastics, rubber, paint, oils, and other contaminants

• Pre‑treatment may include shredding, cutting, and de‑coating.

 

3. Melting

Melting is carried out in one of the following furnace types:

• Reverberatory furnace (most common for large volumes)

• Rotary furnace (suitable for lower‑grade scrap)

• Induction furnace (for high‑quality alloys)

Process:

• Scrap is heated to 660–750°C, depending on the alloy.

• Fluxes are added to remove oxides and impurities.

• Alloying elements (Si, Mg, Cu, Zn) are added as needed to achieve the required specification.

 

4. Refining and Quality Control

• Degassing: removal of dissolved hydrogen and gases, typically using argon or a rotary degasser.

• Skimming: removal of oxide dross from the melt surface.

• Chemical analysis (OES): determination of alloy composition and adjustment of alloying additions.

• Filtration: ceramic filters used to remove solid inclusions.

 

5. Casting into Ingots

The molten metal is cast into standardized forms:

• Ingots / Sows (300–800 kg)

• T‑Bars

• Small ingots (6–25 kg)

• Billets (for extrusion)

Process:

• Controlled cooling ensures structural homogeneity.

• Homogenization heat treatment may be applied if required.

 

6. Finishing and Packaging

• Visual inspection of ingots.

• Marking of batch number, chemical composition, and weight.

• Packaging on pallets or in bundles, ready for transport.

 

7. Typical Specifications of Secondary Aluminums Ingots

Commonly requested specifications include:

• Al99.7 / Al99.8

• ADC12

• A380

• AlSi7Mg, AlSi9Cu3, AlSi12

• 6063/6061 remelt ingots

Specifications can be customized according to buyer requirements.

 

8. Advantages of Secondary Production

• Up to 95% energy savings compared to primary aluminums production.

• Lower CO₂ footprint.

• Stable quality with proper scrap control.

• Economical and sustainable production method.

 

How much aluminium scrap is needed to produce one ton of aluminum A7?

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To produce 1 metric ton of aluminums A7, you typically need slightly more than 1 ton of aluminums scrap, depending on the scrap quality and the efficiency of the melting/refining process.

Here is the practical industry range:

If the scrap is clean and well‑sorted

• Required scrap: approx. 1.02–1.05 tons

• Metal yield: 95–98%

This applies to high‑quality scrap with low contamination and minimal oxidation.

If the scrap is mixed or lower quality

• Required scrap: approx. 1.08–1.15 tons

• Metal yield: 85–92%

Losses increase due to:

• oxides

• coatings

• oils

• dirt

• non‑metallic inclusions

• higher dross formation

Important note for A7 purity

A7 (99.7% Al) requires very high purity, so in real industrial practice producers often use:

• high‑grade scrap +

• primary aluminium or high‑purity remelt ingots

to “lift” the chemistry to A7 specification.