CCP STABILISATION FOR REUSE

CCP STABILISATION FOR REUSE

Coal-fired power plants generate large amounts of ashes, slags and products of flue gas treatment. In full compliance with the Circular economy concept, these materials, coal combustion products (CCPs), can be reused in two main branches:  
  • Construction  – earthworks at roads and railways, bridge approaches, engineering fill, river dikes
  • Environmental remediation - mine reclamation, infill and landscaping 

 

Challenges

In many cases, technical, environmental or hydrogeological conditions disable the use of untreated CCPs for given applications. This concerns mainly road and rail construction, mine reclamation activities and the use in deposits’ mineral sealing layers.
These applications require a stabilisation step, which provides the CCPs with prescribed geotechnical parameters and environmental stability.

 

Solutions

Lime can provide multiple effects in stabilising CCPs for many applications

  • Stabilising CCPs to solid, mechanically sound and low permeable matrix thanks to pozzolanic reactions between lime and active silica / alumina in CCPs.
  • Achieving geotechnical parameters required for road embankment and river dikes thanks to stabilisation
  • Low bulk density of stabilised CCPs, which make them preferable for bridge  approaches where low subsidence is required
  • Stability from any contaminants leaching as a result of a pH value over 10; this is particularly important at remediation works
  • Double safety from contaminant leaching thanks to low permeability of stabilised CCPs. These can be even used as mineral sealing for waste deposits.
  • Optimising the final product’s water content at the application by exothermic CaO hydration if quicklime is used to treat semi-dry CCPs
  • Dust control at the deposit if CCPs are treated  with milk-of-lime 

In special cases, customized lime-containing binders combine the effects above with increased cementitious reaction of hydraulic admixtures. ​

 

PRODUCTS 

Carmeuse offers the STABICALCO® range of products to stabilise CCPs for their further reuse or environmentally safe disposal at deposits

PROCESSES

EXPERT SUPPORT

Have a look at our references