Commercialization rights for a technology to manufacture ceramic lightweight aggregate from high carbon ash have been secured for the United States by Boral Resources. The resulting aggregate can be used in construction applications.
The technology, which has been deployed in Europe, utilizes a proprietary dryer and a high temperature rotary kiln to convert the raw materials, typically fly ash, into sintered spherical pellets. The excess heat production capacity also may be converted into hot water or electricity and sold to generate revenue. The lightweight aggregate that results from the process is a ceramic, chemically neutral product that has potentially wider application than natural aggregates.
High carbon ash generated from coal-fueled electricity production or recovered from landfills or ponds can be used as feed material to manufacture the aggregate. As a result, the technology can help reduce or avoid costs associated with the transportation and storage of coal ash in a landfill or surface impoundment.