Basics of Preprocessing for Scrap Metal Recycling:

Firstly, the scrap aluminum is initially categorized and stacked by grade, such as pure aluminum, wrought aluminum alloys, cast aluminum alloys, and mixed materials. The raw material processing is highly computerized, with incoming materials stored in designated areas, and inventory managed by quantity, chemical composition, recovery rate, and cost. This enables the melting process to calculate an economic material formula for producing alloy ingots, ensuring product quality.

For scrap aluminum products, they must be disassembled to remove steel and other non-ferrous metal components attached to the aluminum. After cleaning, crushing, magnetic separation, and drying, the scrap aluminum is produced. For thin, loose, and flake-like scrap aluminum parts, such as lock arms on cars, speed gear shaft sleeves, and aluminum shavings, they should be compressed into bundles using hydraulic metal baling machines. For steel-core aluminum stranded wire, the steel core should be separated first, followed by winding the aluminum wire into coils.

Reducing its mechanical properties and corrosion resistance, the iron content should generally be controlled below 1.2%. Waste aluminum with iron content above 1.5% can be used as a deoxidizer in the steel industry, while high-iron content waste aluminum is rarely used in the smelting of commercial aluminum alloys. Currently, there is no very successful method in the aluminum industry that can satisfactorily remove excessive iron from waste aluminum, especially iron in the form of stainless steel.

Aluminum scrap often contains organic non-metallic impurities such as paint, oils, plastics, and rubber. Before being remelted, these impurities must be removed. For wire-type scrap aluminum, measures such as mechanical grinding, shearing and stripping, heating stripping, and chemical stripping are generally used to remove the sheathing.