| 摘要 |
The present invention relates to a fly ash utilization process or system for the removal of sulfur dioxide from the flue gas of coal fired boilers.
<??>In one embodiment, a high ionic concentration is maintained in a closed loop, water balanced system which is operated at a low pH, i.e. less than 4 and preferably less than 3. The ionic concentration of the scrubber slurry is maintained at at least 5,000 parts per million of alkali metal cations, preferably over 10,000 parts per million, at least a substantial portion of which has been leached from fly ash.
<??>The ionic concentration of the scrubber slurry is maintained at a high level by providing small diked areas (38, 42) in a waste pond (34) for settling of undissolved solids wherein the returned supernatant has a high ionic concentration.
<??>A principal advantage of the system is that there is a substantially reduced liquid-to-gas ratio required for scrubbing SO2, with substantial savings in pumping and power requirements for the system. |
