Modeling and experimental study on limestone dissolution in wet desulphurization
湿法脱硫中石灰石溶解特性的模型及实验研究

The limestone dissolution affects the slurry absorbability of SO2 and the volume of the slurry pool in the wet limestone-gypsum FGD (flue gas desulphurization). Based on theories of the mass transfer and the chemical ion balance, the model to describe the limestone dissolution is built and the experiment is carried out in this paper. Results show that modeling data are basically consistent with the experimental value and the model can perfectly describe the dissolution process. To increase the stirring intensity will obviously increase the dissolution rate in the lower pH slurry, but to increase the stirring intensity has a little influence on the rate in the higher pH slurry. The dissolution index, which is related with the Ca2+ concentration, pH and CO2 pressure in gas phase, and dissolution coefficient which is related with temperature, are defined in this paper. The condition of limestone dissolution is that the dissolution index must be less than dissolution coefficient.