Greetings,

I am looking for advice from anyone with knowledge or experience on bricks made from fly ash. Fly ash bricks are new type of 'green' bricks made from waste coal ash from coal power stations. It is starting to gain popularity in some parts of Asia such as India. Apparently they have properties as good as or even better than conventional clay bricks. And more importantly, it uses a lot less energy to make. My question is whether it is possible to make fly ash bricks from fly ash derived from combustion of vegetative material such as oil palm fronds or palm fibres. Our company is currently investigating a possibility of incinerating widely abundant oil palm fronds and palm fibres, for purpose of generation of carbon credits. And our by-products will be plentiful of left over fly ash. However, fly ash derived from such sources will consists of a significantly greater amount of alkali metals, due to the greater existence of potassium in non-woody biomass such as the palm fronds that I mentioned. Can anyone let me know whether it is still possible to make fly ash bricks from such a source, and whether their strength or properties will be inferior or equal compared with fly bricks made from conventional coal ash?

Any input on this will be highly appreciated. Thank you.

There is historical precedence for what you are suggesting. We have used this approach in developing nations. Our work is with geopolymers which is the inorganic chemistry required to accomplish what you are wanting to do [email protected]

My understanding is that these are more like concrete blocks than fired bricks.

Yes and no. there are ceramic cements that set at room temperature and are still ceramic. There are geopolymers that set at ambient or there are geopolymers that benefit from a little added heat ( 60 C ) From the standpoint of how they are mixed and poured or extruded they do perform like portland based cements From a performance and a crystallographic structure standpoint they are ceramic. Some geopolymers--especially alkalai activated metakaolin based--are amorphous structure which is even better! So, they are like concrete blocks in how they can be made, they are like fired ceramics in their chemistry and performance