According to Waste King, a specialist collection, clearance and recycling company based in Hemel Hempstead, its fluorescent tube ‘coffins’ are proving attractive to customers who want to dispose of their spent tubes in the most environmentally friendly way.
Waste King’s operations director, Andy Cattigan, explained: “We offer customers a nine-step process to help them recycle their waste fluorescent tubes safely and efficiently.”
That nine-step process is:
1. A specially designed container is delivered to the customers for the safe collection and storage of spent lamps.
2. The container with the spent lamps is collected and taken to Waste King’s site for sorting, prior to being recycled.
3. The container is placed in the site storage area to await processing.
4. Waste King loads the lamps onto racked trolleys for processing in a crush and separation plant.
5. The plant is fully automatic and easy to operate. Its versatility allows processing of the various types and sizes of lamps, separating them into soda lime glass, aluminium end caps, lead glass /ferrous metal components and phosphor powder.
6. The crush and sieve plant operates at sub-pressure, thereby preventing mercury from being released into the environment as exhaust air (which is constantly discharged through the internal carbon filters).
7. The entire crush and separation plant is incorporated in a container in which a conveyor feeds the tubes to a hammer mill. The resulting combined fractions are air-conveyed through a separation tower, where the glass and metal are removed.
The glass and metal parts are then crushed further and air-conveyed to a second separation tower. Glass resulting from the sieving operation (after the first separation tower) is crushed further and air-conveyed through a third separation tower. The glass fragments, removed by the third separation tower, are fed to a rotary drum-feeder and transferred to a discharge conveyor to transfer the by-product out of the processing unit.
8. The air stream that has passed through the separation towers contains phosphor powder. This air stream passes through a cyclone, where the powder is collected in a distiller barrel, and then passes through two dust filters, where the remaining dust is removed and deposited in distiller barrels. The air stream then passes through four-carbon filters to remove any mercury vapour before passing into the atmosphere via a combined vent.
9. Recovered glass, aluminium and metals are sent to other companies for use as raw materials or for further processing.
The mercury powder is distilled on-site. The appropriate programme is selected and the distillation process begins.
A vacuum is applied to the unit. The after-combustion chamber and process chamber are then electronically heated.
Any organic content in the resulting vapour is oxidised in the after-combustion chamber and the mercury vapour is condensed, in a condenser, which is cooled by a chilled glycol refrigeration unit. The condensed mercury is removed from the collection chamber and stored before being despatched as a product.
Waste King’s managing director, Glenn Currie, said: “This may sound complex but it is extremely simple for the customer. Waste King supplies and delivers the fluorescent tube ‘coffin’, or ‘bulb recycling box’; the customer fills the box with spent tubes; we exchange the full box for an empty one and so the process continues. It really is that simple for our customers – and they have the satisfaction of knowing that they’re also helping to prevent polluting the environment with the toxic chemicals in the fluorescent tubes.”
Comment: Waste King claims that it aims to increase value for its customers and minimise the environmental impact of its activities. This initiative involving fluorescent tubes would seem to be in-keeping with this laudable and, apparently, achievable aim.