Ferrous vs non ferrous metal recycling

This article delves into both ferrous and non-ferrous metals, helping you understand all there is to know about each type. Find out what they are, how they differ from each other, whether they’re recyclable and much more.

Ferrous Scrap Metals

Ferrous metals contain iron and are known for their strength and durability. Common examples include steel, cast iron, and wrought iron. These metals are magnetic, which makes them useful in a variety of applications such as the manufacturing of motors and electrical appliances. However, ferrous metals are susceptible to rust and corrosion due to their high carbon content, although wrought iron is an exception as it resists rust.

Non-Ferrous Scrap Metals

Non-ferrous metals do not contain iron and are generally more malleable and lighter than ferrous metals. Examples include aluminium, copper, lead, and zinc. These metals are not magnetic, which makes them ideal for use in electronic applications and wiring. Non-ferrous metals are also more resistant to rust and corrosion, making them suitable for use in environments exposed to the elements, such as in roofing and gutters.

Key Differences

  • Iron Content: Ferrous metals contain iron; non-ferrous metals do not.
  • Magnetic Properties: Ferrous metals are magnetic; non-ferrous metals are not.
  • Corrosion Resistance: Non-ferrous metals are more resistant to rust and corrosion compared to ferrous metals.
  • Weight: Ferrous metals are heavier than non-ferrous metals.
  • Cost: Non-ferrous metals are typically more expensive due to higher demand and limited supply.

Properties of Ferrous & Non-Ferrous Metals

Resistance to Rust & Corrosion

Ferrous metals generally have a high carbon content, which makes them vulnerable to rust when exposed to the elements. However, wrought iron – a type of ferrous metal – tends to resist rust due to its high iron content.

Non-ferrous metals, having no iron content, naturally have a higher resistance to rust and corrosion, making them ideal for use in gutters and roofing.

Magnetic Properties

Most ferrous metals have magnetic properties, which makes them useful in the manufacturing of motors and electrical appliances. This magnetic property allows ferrous metals to be used for fridge magnets and other applications requiring magnetic materials.

Non-ferrous metals aren’t magnetic, making them suitable for use in electronic applications and wiring.

Weight

Ferrous metals are heavier than their non-ferrous counterparts.

Cost

Non-ferrous metals are usually more expensive than ferrous metals due to higher demand and limited supply.

How to Recycle Non-Ferrous Metals?

Collection and Sorting

The recycling process begins with the collection of non-ferrous scrap metals from various sources such as households, industries, and construction sites. These metals are then sorted based on type and quality. Sorting can be done manually or through automated processes using sensors and magnets to separate non-ferrous from ferrous metals.

Cleaning and Pre-Treatment

Once sorted, the metals are cleaned to remove any contaminants such as dirt, plastic, or paint. This is a crucial step as impurities can affect the quality of the recycled metal. Pre-treatment methods such as shredding or baling may also be used to prepare the metals for the recycling process.

Melting

The cleaned non-ferrous metals are then melted in a furnace at high temperatures. Each type of metal has a specific melting point, so separate furnaces are used for different metals. For example, aluminium melts at around 660°C, while copper melts at approximately 1085°C.

Refining and Purification

After melting, the metals undergo refining to remove any remaining impurities. This can be done through processes such as electrolysis or the use of chemical agents. The goal is to achieve a high level of purity to ensure the recycled metal retains its original properties.

Casting and Cooling

The purified molten metal is then cast into specific shapes such as ingots, bars, or sheets, depending on its intended use. These castings are cooled and solidified, ready to be used in manufacturing new products.

Advantages of Recycling Non-Ferrous Metals

  • Energy Efficiency: Recycling non-ferrous metals saves a significant amount of energy compared to extracting and processing virgin ore. For instance, recycling aluminium uses only 5% of the energy required to produce new aluminium from bauxite ore.
  • Environmental Benefits: Recycling reduces greenhouse gas emissions, conserves natural resources, and decreases the amount of waste sent to landfills.
  • Economic Value: Recycled non-ferrous metals retain their value and can be used in a wide range of industries, creating economic opportunities and promoting sustainable practices.

Recycling non-ferrous metals is an efficient and environmentally friendly process that helps conserve valuable resources and reduce the environmental impact of metal production.

Ferrous Metal Examples & Uses

Steel: Known for its toughness and machinability, steel is widely used in the construction and manufacturing industries.

Cast Iron: Hard and wear-resistant, cast iron is perfect for cookware, water pipes, and machine tools.

Wrought Iron: Resisting corrosion and oxidation, wrought iron is frequently used for fencing and railings.

Non-Ferrous Metal Examples & Uses

Aluminium: Lightweight and easily machined, aluminium is used in aircraft manufacturing, food cans, cars, and kitchen utensils.

Copper: Highly ductile, malleable, and an excellent conductor of heat and electricity, copper is ideal for electrical wiring.

Lead: With a low melting point and low tensile strength, lead is typically used in electrical power cables, batteries, and soldering.

Non-Ferrous & Ferrous Metal Recycling

Scrap metal – both ferrous and non-ferrous – is highly sought after for recycling. The energy savings from recycling metals compared to mining new ores is substantial. For instance, recycling aluminium requires just 5% of the energy needed to produce virgin aluminium.

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