Primary Measures:
• Higher temperatures at pre-heater outlet, better absorption of released sulphur.
• If sulfidic bound sulphur is part of a minor raw mix component, than it is recommendable to add this raw material portion directly to the calciner.
• Good management of raw mill run time. Raw mill is a very good SO2 scrubber. Depending on gas moisture scrubbing rates from 30% (low moisture) to 70% (high moisture, e.g. waste fuel combustion) are possible.
Secondary Measures:
• Dry sorption process：Ca(OH)2 + SO2 + ½ O2 ↔ CaSO4 + H2O
• Formation of solid CaSO4. Removal of CaSO4 in bag filter or ESP.
• Low investment costs, proven technology in cement plants.
• SO2 clean gas concentration 50 – 400 mg/Nm³ @ 10 Vol-% O2, depending on SO2 raw gas concentration. Reduction efficiency approx. 60 – 80%.
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