Recycling unit MAR®

The MAR® (Magaldi Ash Recycling) is an improvement of the MAC® (Magaldi Ash Cooler) system for dry extraction, cooling and handling of bottom ash from solid fuel fired boilers. That innovative process used to recycle both “dry” bottom ash and economizer (ECO) ash in the combustion chamber aims at converting them into fly ash. After the MAC® system, dry bottom ash along with ECO ash can be diverted to the MAR® system and then injected into the boiler through the coal pulverisers. Dry bottom ash, extracted and cooled by the MAC® system, and ash from ECO hoppers are pneumatically conveyed and stored in small reception bins, located at the coal bunkers level. The finest particles, along with conveying air, are directly drafted into the combustion chamber or the flue gas ducts. Ash is extracted from the reception bins by tubular vibrating feeders and dosed to the coal mill feeding hoppers. Then ash is milled by coal pulverisers along with coal before being injected into the boiler through coal burners. As a result, bottom ash and ECO ash are turned into fly ash, a more valuable by-product of the coal combustion (CCP) in compliance with international standards: in the EU these are EN 197-1 for cement and EN 450-1 for concrete T he MAR® system ensures the valorisation both of bottom ash and ECO ash. Using CCPs, in cement or concrete production rather than disposing of them, conserves natural resources and reduces greenhouse gas emissions.