Pollution
Humain
Environnement
Economique

In a ferrous waste treatment centre of an aluminium refinery, a fire broke out in the smoke treatment plant’s dust filter housing at approximately 9:30 p.m. The fire alarm system shut down the plant after having detected a temperature difference of more than 5 °C between the probes located at the inlet and outlet of the filter housing. The fire brigade was alerted while the staff tried unsuccessfully to extinguish the flames with fire extinguishers. The electrical installations we locked out as a precaution, and the fire was eventually put out at around 11:30 p.m.

Two employees were taken to the hospital for smoke inhalation. The smoke filtration unit (dust collector) was damaged, but the building structure remained intact. Repair costs were estimated at 70,000 euros. The extinguishing water had been confined to the site.

The unit continued to operate normally during the incident. By 8:30 p.m., 1,060 kg of aluminium components had been placed in the melting furnace. Apparently, this batch had an abnormally high wood content. The combustion of this wood in the furnace would have led in the formation of incandescent particles that were then drawn into the ventilation system and accumulated in the dust collection filters. Their slow combustion resulted in an outbreak of fire in the dust collector.

Following the accident, the operator:

  • reminded its employees of the criteria for accepting delivered materials and the materials that must not be loaded into the oven;
  • initiated a procedure to ensure compliance of the materials before transfer to temporary storage bins prior to loading;
  • installed spark detectors upstream of the filters. If a small quantity of sparks is detected, water and a wetting agent are injected into the smoke intake duct (1st control level). If a higher quantity of sparks is detected, the injection of water continues, but the burners in the refinery’s ovens and the dust removal fan are stopped (2nd control level).