Cryogenic purification of waste rubber to valuable granules for recycling

摘要

The process recycles rubber, especially reinforced by steel and/or textile. A known cryogenic process embrittles the rubber at -200 deg C, using liquid nitrogen. The process comprises electronic measurement of the metal content at this stage. The metal is then flash-heated inductively, in seconds. It is thereby rendered tough or resilient, whereas the rubber remains brittle. The rubber is then mechanically granulated, but the resilient metal structure stays largely unaffected. Any metal is removed, leaving behind the rubber granules, and if appropriate any non-metallic (textile) inclusions.