Magnesium oxide flue-gas desulfurisation is built around a simple reaction: MgO hydrated in the scrubber reacts with sulfur dioxide to form magnesium sulfite, which can be oxidised to soluble magnesium sulfate. The process is compact, tolerant of load changes and avoids the scaling and plugging that limestone systems often fight.
Why magnesium rather than calcium
Magnesium sulfite and sulfate are far more soluble than their calcium equivalents. That means the absorber can run at a lower liquid-to-gas ratio, with smaller towers and less recirculation energy, and the spent liquor can be handled as a recoverable stream rather than a solid waste.
What the oxide grade changes
- Activity. A lightly calcined, high-activity MgO hydrates faster and reaches target SO₂ removal with less reagent.
- Particle size. Fine, consistent powder disperses in the slurry and reduces unreacted carry-over.
- Assay and acid-insolubles. Inert residue accumulates in the loop; low acid-insolubles keep the circuit clean.
Specifying for a scrubber
Ask for the hydration rate and activity data alongside the standard assay. Our laboratory can supply a trial lot so you can measure SO₂ removal and reagent consumption on your own gas stream before committing to a contract volume.
Need the measured values for a specific grade? Ask our technical team for the data sheet and a trial sample.