Mercury-containing lamps: maximum recovery of materials
The Indaver Relight facilities in Doel, Belgium, treat all mercury-containing lamps which are collected selectively in Belgium, half the fluorescent lamps, low-energy light bulbs and other gas discharge lamps collected in the Netherlands and a third of those collected in France. All together it accounts for around 30 million lamps a year. Up to 95% of the lamps is recycled, especially glass and metals which, cleared of mercury, are reused in the manufacture of new lamps or in the metal recycling industry. A fine example of the closed loop.
IndaTube: treatment of fluorescent tubes
Indaver has been treating linear fluorescent lamps with IndaTube since 2015. It recovers fluorescence powder, lime glass and the caps from the lamps. IndaTube removes the fluorescence powder more efficiently and extracts as many (environmental) pollutants as possible from the fractions.
The mercury is evaporated and converted into gaseous mercury in the IndaTube furnace. All the process air passes through an activated carbon filter which traps the mercury. With IndaTube, Indaver is able to keep the mercury concentration in the fractions structurally below the new and more stringent European limits.
The rest of the fluorescent lamps, low-energy lightbulbs and other mercury vapour lamps are treated in the cut-sieve unit. The lamps are first crushed by a crusher. A drum magnet separates the ferrous fraction. Afterwards, a sieve separates the non-ferrous fraction, plastics, glass and fluorescent powders.
Banking on the future: rare earth metals
The fluorescent powders are stored carefully. They contain rare earth metals, which are expensive raw materials used for new technologies. Indaver has contacts with other companies to assist with the recovery of rare earth metals.
To prevent mercury or mercury vapours from entering the work areas, the treatment units are completely closed off; the processed air is extracted and purified. The glass and metals are post-heated, if necessary, to vaporise the mercury.
The employees at Indaver Relight measure the mercury concentrations continuously to ensure that they do not exceed the ceiling limit. The standard used by Indaver in this process is stricter than the European standard. Also, inside and around these buildings very strict safety standards apply.