Development of Reusable Materials from Soil Washing Plant Operations

In 2020, Soil Treatment Systems Ltd initiated a long-term R&D project to look at the potential to utilise the filter cake from the Soil Washing Plant and stop this material from going to landfill, which is the current method for disposal. This material, being sub-400 microns, was believed to be ideal for modification into a product that could be used for flood alleviation, hydraulic barriers, and to extinguish underground fires.

The project required Soil Treatment Systems Ltd to install additional equipment at the Soil Washing Plant to facilitate the production of the material.

A full testing regime was carried out in the laboratory at Aitkenhead Road to ensure that the product, when used in the natural environment, would not have a negative impact on the structures being infiltrated.

The target was to produce a product that would be acceptable in a potable water environment.

This R&D project also generated a methodology for the production of hydraulic bound mixtures, which was very successful, and a volume of material was produced for a utilities company from the trench arisings that they had to dispose of and replace with virgin product.

Attached photographs show the results from the testing carried out by Soil Treatment Systems Ltd on the finished product.

The thermal plant is a key component in the production of both the HBMs and the modified clays, as it is imperative that all organic elements are removed from the material prior to entering the wash and production cycle through the Soil Treatment Systems Ltd wash plant.

Soil Treatment Systems Ltd now has the ability to reuse 100% of all material arriving at the remediation centre for treatment.