| 摘要 |
PROBLEM TO BE SOLVED: To prevent secondary pollution such as heavy metal elution by suspending the fly ash in a water phase, blowing a gas containing carbon dioxide to carbonate a heavy metal salt in the fly ash to make insoluble, filtering, drying and charging the heavy metal carbonate in a melting furnace to decompose the heavy metal carbonate to make a slag having vitreous structure. SOLUTION: The fly ash and water are charged into a fly ash dissolving tank 1 and are stirred by a stirrer 2 to prepare a suspension, the suspension is transferred to a gas reaction tank 3 and a waste gas of an incineration furnace is blown to the suspension to cause carbonation reaction. Next, the reaction solution is transferred to a thickener 4, a slurry concentrated by sedimentation is filtered by a filter 5 while being washed, the cake is dried by a dryer 6 and melted in an ash melting furnace 8. And the molten stag after melting is cooled in a dry slag discharging device 9 and discharged as an annealed slag. On the other hand, the waste gas of the dryer 6 and the waste gas of the melting furnace 8 are dust-removed in a dust collector 10 and discharged as a waste gas and the molten fly ash recovered by the dust collector 10 is fed to a fly ash melting furnace 1 and treated again. |
