METHOD AND APPARATUS FOR REDUCING THE CARBON CONTENT OF COMBUSTION ASH AND RELATED PRODUCTS

摘要

A method for reducing the carbon content of a combustion ash mixture (1) containing siliceous ash particles and carbon particles. The combustion ash mixture (1) is subjected to comminution (2) to reduce the particle size of the siliceous ash particles and of the carbon particles, followed by the separation (4) of a portion of the carbon particles from the siliceous ash particles by subjecting the comminuted ash to a flow of gas effecting the separation (4). The method is preferably performed by employing autogenous grinding to effect the comminution (2) of the particles and by employing a classifying rotor (40) to separate the comminuted particles into a high-carbon product (6) and a low-carbon product (8) based on the density differential between the siliceous ash particles and the carbon particles. A method of creating a concrete mix is also provided, whereby a reduced-carbon-content portion of a combustion ash mixture (1) is admixed with an aggregate material and cement to create the concrete mix. A combined grinder/classifier unit (32) for reducing the carbon content of combustion ash is also provided, wherein air supplied via air jet nozzles (36) is used for autogenous grinding as well as for particle classification and separation in conjunction with a classifying rotor (40).