LAUSR

The solubility of NaHCO3 was determined in the NH4+–Na+–CO32––HCO3––Cl––H2O system with the concentration up to 6 mol·kg–1 by a dynamic method from 283.15 to 333.15 K. It was found that the solubility of NaHCO3 decreases with increasing concentration of Na2CO3, NH4HCO3, or NaCl. A speciation-based model was developed with mixed-solvent electrolyte interaction parameters newly obtained by regressing both the experimental and literature solubility data. The average relative deviations are less than 5.0%. The new model is able to predict the solubility of NaHCO3 at high pressures up to 6.0 MPa for the NH3–CO2–NaCl–H2O system at 313.15 and 323.15 K. This work can provide a theoretical basis for producing Na2CO3 with a better crystal form and higher productivity in the carbonation process.