Recycling Insider's look - the Pulverizer or Shredder

Wow, it has been more than a year and a half since my last post. I guess I sorta lost interest in posting about scrapping, even though I still do it for extra cash. For this post I plan on taking a different tack, as I now have a new perspective.

Have you ever wondered what happens to scrap after you drop it off and collect your cash?  I am now able to offer a behind the scenes look into the entire operation.

This year I got a job at a local recycling facility. I work on the iron "frag" line, so my main topics will be the iron end of the process.

At a typical scrap yard you have two major areas where you drop off scrap.  you have the "iron pile", which is sort of a misnomer because it is the huge pile where you drop off large items that contain metal of any sort. That is the huge mountain of debris you see in the yard, typically with cranes with claws placing piles onto a large conveyor belt.

Many scrap yards are not set up to pulverize the metal - they typically sell scrap in bulk to operations such as the one I work at. At our plant, light metal which includes anything up to the size of a conversion van, is fed unto a huge conveyor called the InFeed, which then drops it into the pulverizer or shredder. The shredder is referred to as "the Mill" in the industry.

If you have ever seen one on operation, you will notice an immense cloud of steam emitting from the mill. This is caused by water evaporating. Water is run into the machine to keep it and the metal scrap cool.

As the metal is fed into the machine, it enters the pit which is a large square room about 10' x 10' by 10', more or less.  The walls are around 8 inches thick, all steel.

Inside the room are two circular rotors with four sets of axles that contain hammers, bell shaped cast steel that swing and pound entire cars through steel grates - turning the scrap into four to six inch pieces of frag. The rotors turn at an insane speed, turning an automobile into scrap in a matter of seconds.

The metal coming out of the mill can reach temperatures in excess of 150 degrees Fahrenheit. The stuff exiting the mill is a mass of shredded metals and dirt and debris which then has to be separated to be of any value. In future posts I will go into detail about the rest of the process.