Fly Ash Posted on 11th November 201531st August 2020 by ThePD (The Project Definition) Fly Ash is fine solid particles of ash, dust, and soot that is composed of the fine particles of burned fuel. Click to share on Twitter (Opens in new window)Click to share on Facebook (Opens in new window)Click to share on LinkedIn (Opens in new window) Related Posted in Substance and tagged environment, solid. ThePD (The Project Definition) ThePD has been developing the Preferred Project Definitions based on the actual project execution and operation experiences and knowledge with the Project Language, and sharing with you daily basis.