FITNIR Analyzers provide reliable, accurate and true compositions of green liquor as well as providing additional information not offered by any other techniques. Complete liquor compositions can be measured using FITNIR’s technology.

Optimization of Recovery Boiler Smelt Dissolving Tank
Traditional online measurements for the smelt dissolving tank operation include density, conductivity, differential pressure, and bubble tubes. All of these measurement techniques infer a concentration of EA, TTA, sulphide, and/or carbonate. All techniques suffer from drifts due to scaling of the probe. Online titrators have not yet been applied to raw green liquor measurements as the presence of solids complicates the accurate volume metering, which is critical to this wet chemical technique.

More reliable, accurate, and true concentrations of green liquor chemical compositions from FITNIR Analyzers provide the opportunity to perform TTA control, stabilizing the TTA feeding forward to the slaker and the rest of the recausticizing operation. Furthermore, FITNIR’s measurements of weak wash TTA and oxidized sulphur compositions also allow opportunities for monitoring and controlling the TTA in the dissolving tank.

Pulp Liquor Properties Measured by FITNIR Analyzers
> Green Liquor: TTA, EA, AA, Carbonate, Sulphide, Sulphate, Thiosulphate, Reduction Efficiency
> Weak Wash: TTA, Sulphate, Thiosulphate

Benefits of FITNIR Recovery Boiler Application
> Reduced TTA (and carbonate, EA, sulphide) variability
> Maximized TTA target while providing true TTA target
> Reduced deadload content (sulphate)
> Reduced lab tests

Contact FITNIR Analyzers Inc. and we can work together to optimize your recovery boiler operations.