Aluminium recovery from the end caps of the light bulbs.
The batch crushing process consists of a crusher, separator, particle and vapour filtration systems, material handling systems and a program logic control system. A US plant using this technology can process up to 4000 lamps per hour. The system crushes and separates fluorescent lamps into glass, aluminium, and phosphor powder (containing mercury), which is thermally treated to recover elemental mercury for commercial reuse. Mercury vapours are absorbed in activated carbon filters.143,144
Emerging technologies for the treatment of waste fluorescent light bulbs include:
Dense medium centrifugation – This technology aims to separate low-density phosphors from high-density phosphors by processing them in a centrifuge and varying speed and retention time. Laboratory tests are being conducted in Japan;145 and
Thermal desorption – In Taiwanese tests of this technology, heat is used to convert toxic chemicals into gasses which can be captured.