Metal is a valuable material that we can recycle repeatedly without changing its properties. Since metal scrap can be resold to make money, it has encouraged many people to collect it and recycle it with special operations. Apart from generating income, metal recycling is also advantageous to the environment. Recycling metal helps in preserving our natural resources, as recycling consumes less energy than making products from the raw metal.
Processing of metal also releases harmful gases like carbon dioxide which is saved during the recycling process. Steel is one of the most recycled metal, other metals that can be recycled include gold, brass, silver, copper and aluminium. Let’s see how the recycling of metals is exactly done.
Collecting the Metals
The first step of metal recycling is the collection of metals. Since metals have monetary value, it is often sold to scrap dealers instead of being thrown in garbage landfills. The biggest source of the metal collection is obsolete vehicles. Other sources may include railroad tracks, steel structures, farm equipment, ships, and consumer scrap. So, most of the scrap metal is collected from scrap yards and then brought to the recycling centres.
Sorting the Metals
Once the scrap reaches the metal recycling centre, it has to be sorted to separate valuable and recyclable metals from other materials mixed with the scrap. Some automated recycling machines use sensors and magnets to separate metals from other materials. Some professionals use a magnet, while others consider the weight and colour of the scrap to separate the metals by hand. Important colours to look are silver for aluminium, yellow for brass, red for red brass, copper for copper, and others. Then they improve the value of the scrap by separating clean metals from dirty materials.
Processing the Metals
Processing of metals is then done by first shredding the separated metals. Shredding of metals helps in melting them, as shredded metals consume less space as compared to the non-shredded metal of the same weight. So, shredded metal can be melted while consuming much less energy. Usually, aluminium is processed to make sheets, while steel is processed to make small blocks after metal recycling.
Melting the Metals
A large furnace is used to melt down the scrap metal. There are separate furnaces to melt different metals, and the process of melting consumes a great deal of energy. However, the amount of energy required to melt metals is significantly less than the energy required to produce metals from raw materials. Depending on the size and capacity of the furnace being used, the entire process of metal melting can consume a few minutes to several hours.
Purifying the Metals
In most of the cases, the process of electrolysis is used to purify the melted metal so that the final recycled metal becomes free of any contaminants. Purified metal is also high in quality, and it is resold for a higher price.
Solidifying the Metals
The purified metal is then cooled down and solidified. This is the stage in which metal can be given the desired shape, such as bars, blocks or sheets. The shape is chosen as per the type of product to be manufactured from the recycled metal.
Transporting the Recycled Metal
Once the metal is purified, solidified and shaped, it is ready to be used for making new products. After the metal recycling is done, it is transported to factories where it is used to produce brand new products just like a raw material. When these new products come to the end of their life, they can be sold to scrap dealers again so that they can be recycled again to make more new products.
Since there is a limited supply of metals in nature, metal recycling seems to be a sensible solution. It not only saves money but also saves the environment.