Case Studies >Energy from Waste – Incinerator bottom ash plant


Year: 2018
Ash Processing
c. 5,000 hrs p.a.
40 tonnes p.h.
200,000 tonnes p.a.

Country: GB
Project Type: Turnkey

The facility, located in England is responsible for managing the County’s municipal waste to benefit the local community, economy and environment, under contract with County Council.

Their mission is to “massively reduce the county’s dependence on landfilling, whilst recovering value from waste in the form of electricity, recyclable metals and aggregate”.

The project is currently under construction and, when completed, the plant will have the capacity to process up to 200,000 tonnes of residual waste per year, spread over a 12.6-acre site.

The Challenge

For this project, the client’s main requirement was to create an efficient and bespoke system for the collection and transportation of the ash underneath the bottom incinerator, as well as the treatment plant that the ash would then pass through after.

This called for Turmec to design and build the entire system, including a bespoke shuttling conveyer belt, which could discharge the ash in any section of the dry bay.

Turmec was also to design and construct the treatment plant, with conveyor belts able to withstand the high temperatures from the hot ash.


Turmec was selected to take on the project due to its extensive knowledge and experience in this field.

The intricate project, currently being commissioned, will include the following:

  • Conveyors
  • Scalping screens
  • Independent feeders
  • Trommel screen
  • Magnets
  • Eddy Current
  • Multiple bay storage conveyor system

The process used a complex conveyor shuttling system so that the ash can be kept in any one of 5 storage bays. Being unique to the project, the belt was reinforced to transport hot ash, withstanding heat up to 500 degrees, and a different scraper was also needed for the abrasive material.

Materials are passed from feeder to the trommel screen before the oversize is scalped off, which is anything 35mm plus & magnet, ferrous recovery & non-ferrous recovery.

Fine fraction falls through a trommel and is passed under an electromagnet to remove the ferrous fraction and this is collected in a storage bin underneath.

Once the ferrous fraction is removed, the ash is passed over an eddy current separator, where the non-ferrous is ejected and collected in another storage bin underneath. The remainder of the ash continues towards maturation bays, which use the same shuttling system as over drying bays.