Recovery Boiler reduction efficiency: 93 - 95% in smelt (typical 97%)

Production: about 0.4 kg / 1 kg of black liquor DS

Typical Composition:
Sodium Carbonate Na₂CO₃: 65 - 75%
Sodium Sulfide Na₂S: 20 - 25%
Sodium Sulfate Na₂SO₄: 0.5 - 1.5%

Melting Point: 800 - 900 ^oC

Smelt spouts are used to help remove the smelt from the recovery boiler.