- Covanta Energy, a waste-to-energy firm based in New Jersey, has increased its ferrous metal recovery rates from ash by upgrading its magnetic sorting system.
- The company has installed rare earth magnets at two of its facilities, one in Niagara Falls and one in Pennsylvania. One facility increased its metal recovery by 50% after its first day of using the new magnet.
- Even with the new technology, Covanta estimates that approximately 250 million tons of metals in waste are landfilled annually. 3% of that waste contains about 3% in metals—about 7.5 million tons of lost metal.
Covanta's process uses combustion to burn municipal solid waste as a fuel source. The process creates an ash made of two by-products: bottom ash and air pollution control residue. The amount of ferrous and nonferrous metals recovered through the process is substantial. In one year, Convanta's waste-to-energy facilities recover about 430,000 tons of ferrous and 15,000 tons of nonferrous metals for recycling.
The secret to success, according to Steve Bossotti, vice president of organic growth and innovation at Covanta, is the strength of the rare earth magnet. Because the drum is so strong, it can be installed further away from the conveyer, where its efficacy at handling the different sized metal objects in bottom ash is improved. Now, after testing the technology at the two facilities in Delaware and Niagara Falls, the company will expand the initiative:
"We were so impressed by it, at the two facilities, we wound up buying four more," Bossotti said. "We looked to upgrade six more facilities, and rare earth magnets will be a part of that equation."