| 摘要 |
The invention relates to a method for processing ash from waste incineration plants by means of wet classification, wherein ash (1) is mixed with liquid (3) in a mashing tank (2) and, after a coarse fraction (4) has been screen out, is fed to a classifying stage (5) as a feed flow, which classifying stage comprises an upward-current classifier (6) and an upstream hydrocyclone installation (7). In the classifying stage (5), the feed flow is separated into a good fraction (8) free of harmful substances and a remaining fraction (9) containing harmful substances, wherein the remaining fraction (9) is drawn off as a suspension at the top side of a fluidized bed produced in the upward-current classifier and wherein the good fraction (8) drawn off at the bottom side of the fluidized bed is dewatered by means of a screening device (10). The pass-through fraction (13) of the screening device (10) is fed back into the hydrocyclone installation (7). In the hydrocyclone installation (7), at least one material flow containing essentially only particles that are smaller than the separation particle size of the screening process is removed as a cyclone overflow (15, 15'). In a second classifying stage (17), the cyclone overflow (15, 15') of the hydrocyclone installation (7) is separated into a fine-particle mineral fraction (18) and a remainder (19) containing harmful substances, wherein the remainder has a upper particle-size limit between 20 μm and 50 μm. |
