Lehigh Cement markets and distributes fly ash in British Columbia. For information please call our Fly Ash Division at 604-946-3842.

Description of Product

What is Fly Ash?

Fly ash for use in concrete is defined by the Canadian Standards Association (CSA) in its document CSA-A3000 (Cementitious Materials Compendium) as:

"The finely divided residue that results from the combustion of pulverized coal .... which is carried from the combustion chamber of a furnace by exhaust gases."

What about other "Fly Ashes"?

Any "ash" which is carried away from a "burning mass" in the exhaust gases is a fly ash. However, only ash from the combustion of pulverized coal, as defined by CSA-A3000 above, can be used in the concrete specified on most construction projects in Canada.

What does Fly Ash look like?

Portland cement and fly ash look similar and are handled in virtually the same way. Centralia fly ash from Washington state tends to be a tan or beige tone versus cement's gray colour. Genesee fly ash from Alberta is light gray in colour.

Where does Fly Ash come from?

Fly ash is a by-product of coal fired thermal power generation. The following schematic shows a simplified Coal Fired Generating Station process layout. The schematic shows that fly ash comes out of the process at the bottom of the "Electrostatic Precipitators".

Electrostatic precipitators are equipment which were installed on most "smoke" producing industrial process in the late 1960's. Their purpose is to eliminate the particulate or smoke coming from our industries thus, reducing air pollution. Fly ash is essentially the particulate that used to make up the "smoke" coming from coal powered generating stations.

                           Examples of Coal Fired Generating Stations