Boral offers a technology and service for the manufacture of ceramic lightweight aggregate (LWA) from coal combustion products generated by current production or recovered from landfills or ponds. The resulting aggregate can be sold and beneficially purposed in a variety of construction, agricultural, and related applications.
The technology, which has already been successfully deployed in Europe, utilizes a proprietary dryer and a high-temperature/high-efficiency rotary kiln to convert the raw materials, typically high-carbon fly ash, into sintered spherical pellets. The sintering operation is autogenous, as it does not require external fuel beyond the coal remaining in the feed material itself. The excess heat production capacity may also be converted into hot water or electricity and sold to generate revenue.
The production facility is automated, can be overseen by as few as four people, and allows for setup as a separate stand-alone installation to process raw material harvested from a pond/landfill or as an integrated installation incorporated into a power plant for processing production ash and providing heat recovery. The lightweight aggregate that results from the process is a safe, chemically neutral product with a high strength-to-weight ratio and a resistance to freeze-thaw/fire as well as animal and plant pests.