The reason you have to pay for tire recycling is that tires are hard to recycle. A lot of people think all you do is grind them up and your done. The problem is that tires are complex prices of engineered material. tire-derived fuel (TDF) continues to be the largest end market for recycled scrap tires.
Your typical tire has 3 big parts when it comes to recycling. First and most pertinent is the rubber body of the tire. This is ground up and used in a number of different applications. Being it is a vulcanized rubber it can’t really be melted and reformed so must be ground up and used with a binder.
The second part is the bead. This is a steel or Kevlar “cable” that is embeddd in the body of the tire that keeps the edge firmly seated to the rim. For Kevlar it can be ground up with the rest of the body but tends to shred rather than breakup into little pieces. The other variety is steel and it must be removed from the rubber matrix.