When a building is renovated or demolished, a metal roof is 100 percent recyclable in those cases. Whereas some roofing materials end up in a landfill — it’s estimated that 11 million tons of asphalt shingles are in landfills — metal can be reused in its entirety.
But how does the recycling process work? The following information comes from the group Conserve Energy Future:
- The metals are first sorted in terms of the base of their properties. The quality of the metal goes a long way when it comes to recycling it, so this is an important step in the process.
- The metal is then squeezed and compacted so that they don’t take up as much space on the conveyor belts.
- It’s now time to shred the metal. The material is broken down into small sheets or pieces so they can be processed with ease. The smaller-sized pieces can be melted and will use less energy to do so. Steel is normally changed into steel blocks, while aluminum is changed into sheets.
- The scrap metal is then melted in a large furnace. (Each type of metal will be placed in a separate furnace.) This process does require energy, but not as much as it would take to make it from raw material.
- The metals are then purified in different methods, with the help of electrolysis. The blocks are transported to different mills so that they can be remade into new products.