Tata Steel in IJmuiden used water to cool steel slag. Lime was dissolved in this water. Due to CO2 in the air, this precipitates into the cooling-water reservoir. Result: a substantial layer of lime at the bottom of the cooling-water reservoir. This is not desirable when using cooling water. Promeco was contacted in order to remove the layer of lime in a sustainable manner and to return clear water to the reservoir.
Pumping up the layer of lime
Engineering and consultancy firm Antea Group has conceived restrictive measures in order to minimise this problem in the future. For the time being, the layer of lime still has to be properly removed. For this purpose, the consultancy firm contacted Promeco. We were allowed to pump up the layer of lime (without damaging the underlying gravel layer and watertight construction) and collect it in Geotubes by means of flocculation.
Result: we have collected solidified lime in Geotubes and returned clear water in the settling reservoir. The soil sealing of the reservoir has been left intact. We deployed the dredging company Pruim Baggertechnieken for the accurate dredging of this layer of lime, i.e. without damaging the soil sealing. This company is specialised in small-scale precision dredging projects. Special note: the work was performed using an unmanned dredger. Remote- controlled: Geert Pruim had everything firmly under control.