Diosynth – Waste Chemical Effluent Tank Lining

Diosynth – Waste Chemical Effluent Tank Lining Concrete Waste Chemical Collection Sump. Diosynth (Akzo Nobel) had a concrete waste chemical collection sump that had been previously lined some years ago and the lining had severely failed. The original internal lining had been almost completely eaten away and much of the concrete that formed the body of the sump had been dissolved exposing the hard-core in several places. In some locations the severity of the attack was so severe we found cavities in the sump wall over 75 mm in depth (3 inches). The sump is used for the collection of waste chemicals including various solvents, Hcl and caustic with a range of 0 to 14pH. The operating temperature of the sump would be ambient. The system we chose for direct contact with the harsh chemical environment for this project was a vinyl ester based system with glass flake reinforcement. The materials have a proven track record for elevated temperature tolerance, chemical resistance and suitable for use in aggressive tank lining environments. For making good the substrate we used a two-pack epoxy resin concrete repair system for the walls and floor of the sump. The advantage in using the epoxy based concrete repair system meant that the entire project could be completed in less than a week and the sup returned to active service. The sump was high pressure jet washed and then we used a medium grade grit blast abrasive to remove any remaining contamination and to clean the surfaces to the required standard on to which we would apply the new lining system. The new lining system was applied in seven separate coating applications - a moisture tolerant epoxy primer, an epoxy resin based concrete repair render system, a water based epoxy resin primer, followed by three coats of glass flake reinforced Vinyl Ester tank lining system and a final glass flake reinforced Vinyl Ester topcoat. Each coat was applied in different colours to aid identification, to ensure correct wet film coverage and to make application easier. On completion of the work the new lining was tested for micro porosity and dry film thickness. The average dry film thickness of the chemical resistant lining system was 1,100 microns. The thickness of the render repair system ranged from 3mm to over 100mm. The sump with it's new lining will now have an expected working life in excess of 15 years.

For more information on Diosynth – Waste Chemical Effluent Tank Lining talk to Specialist Coatings (GB) Ltd