Carbonate Salts — properties & hazards overview
Physical form
Solid crystals / dissolved salts
Solubility (20 °C)
Na₂CO₃: high · CaCO₃: low
Decomposition temp.
600–900 °C → CO₂ + oxide
Reactivity
Mild alkali (neutralizes acids)
Flammability
Non-flammable
Toxicity
Low / negligible
Chronic risk
Dust irritation
Environmental
Elevates alkalinity
| Property | Value / Note |
|---|---|
| Appearance | White crystalline solid or dissolved alkaline salt; may precipitate as scale on cool surfaces. |
| pH (1 % soln) | ≈ 11 – 11.5 (Na₂CO₃ / K₂CO₃); 9 – 9.5 (CaCO₃ suspension) |
| Formation in scrubbers | Results from neutralization of acid gases (SO₂, HCl, H₂S) with alkaline liquor (NaOH, Na₂CO₃); excess CO₂ leads to carbonate buildup. |
| Scaling tendency | High for CaCO₃ at elevated temperature or pH > 9; periodic cleaning required. |
| Best analytical detection | Ion chromatography (IC) for carbonate/bicarbonate ions — highly accurate and selective for quantifying carbonate species in scrubber liquor or wastewater samples. |
*Analytical results typically expressed as mg CO₃²⁻ /L or as alkalinity (mg CaCO₃ /L).