How Does Car Recycling Work?

Recycling a milk carton is easy. The item comprises entirely of paper. We do not need to separate plastic from paper, or glass from metal. However, recycling a car is more complicated. A car comprises of many intricately linked parts, and many materials: plastics, rubber, metals, and glass. How does car recycling work?

The first step of recycling, be it a water bottle or a car, is to collect the alike, and separate the unlike. For instance, frozen orange juice concentrate is sold in contains made of paper and metal. We separate the paper and metal, and place them into different boxes.

We must perform the same step with a car. Must workers meticulously disassemble the car by hand? The car recycling process, as it is currently implemented, is a combination of manual and automated labour.

A car is fairly big. Workers, with the aid of power tools, take the car apart, breaking it down into more manageable components. Then, the car is sent to a machine to be crushed. This is mostly to reduce volume, so more cars can be processed by the recycling centre.

Traditionally, car crushers have been big and clumsy. They took up lots of space, and could not be transported. However, most car crushers today are mobile, and can be transported from lot to lot. The machines’ mobility reduces the cost of rent, and thus the cost of car recycling.

The crushed car components are then sent to a shredder. The shredder whips around hammers and pieces of wire, at 175mph. The thrashing shreds the cars into fist-sized pieces of material. In one minute, about six cars can be shredded.

A shredder is a terrifyingly powerful machine. The hammers and wires receive so much damage, that the workers replace them everyday. The vibrations it produces are so powerful, that it could start an earthquake! For this reason, the shredder is placed on special, shock-absorbent material.

After this preliminary shredding, the fist-sized pieces of material may be fed to another shredder. This shredder will make the pieces even smaller. By making the pieces smaller, we decrease the probability that two different materials will be found together.

The shredded materials are dumped onto a conveyor belt. The conveyor belt carries the shreds below a powerful magnet, which attracts ferrous metals, such as iron. What about plastics, glass and non-ferrous metals? Currently, workers must sort out these materials by hand, rendering car recycling costly and time-consuming.

However, there are exciting new developments. In the parallel field of computer and electronics recycling, researchers have been scratching their heads at the same problem. Computers comprise of a plethora of different plastics and metals. How can we separate them?

Although the materials themselves may not be magnetic, we can place them in a magnetic environment. A thick ferromagnetic fluid is poured over the conveyor belt, underneath which lies an electromagnetic field. Non-ferrous shreds are poured over the ferrofluid. Plastics rise to the top. Metals such as gold fall to the bottom.

This exciting new technique is only in its developmental stages, but so far, it looks promising. In the future, car recycling will become even more automated, and even more efficient.