Projects - Coal Fly Ash Remediation
At Yava, our sole focus is to develop and commercialize industrial processes that efficiently produce superior products,
while protecting the environment
Coal Fly Ash Remediation
A large amount of coal fly ash (CFA) is produced by coal combustion in thermal power plants and they are dotted around the globe. There has been an increasing environmental concern associated with the disposal of CFA because of the toxicity of metals present in this industrial by-product. Recently though, CFA has attracted a lot of attention as a potential secondary substitute for bauxite (aluminium ore) because of the increasing demand for alumina and decreasing bauxite reserves. However, the high level of silica (40-65%) in the CFA makes it very difficult to process them economically using conventional technologies.
When CFA is disposed in dry landfills or wet ponds, there are associated environmental effects. Wet surface impoundments account for a fifth of coal ash disposal. These wet impoundments can be an issue if they do not have proper liners for the landfill or pond to prevent leaking and leaching. Both leaking and leaching lead to groundwater contamination.
Yava has developed a low cost, environmentally friendly, hydrometallurgical technology to recover high purity alumina from hydrated alumina that can potentially be employed to process CFA to recover the same. Since CFA contains ~40-60% silica based on its source, Yava’s process concurrently recovers the contained silica as high purity precipitated silica for use in tires, rubbers and other filler applications. The overall process is expected to run as a closed-loop operation where most of the reagents are regenerated and recycled.