The solubility of kraft recovery boiler precipitator ash.

摘要

Precipitator ash typically contains sodium sulfate (Na 2SO4), sodium carbonate (Na2CO3), sodium chloride (NaCl) and potassium salts. The solubility of precipitator ash in water is important information for ash treatment processes to maximize the removal efficiency of chloride and potassium while minimizing the losses of sodium and sulfur. Various techniques have been proposed to treat the precipitator ash due to its enrichment in Cl and K that play an important role on fouling and corrosion problems in recovery boilers.;This thesis concerns a study on the solubility data of the system Na +, K+, Cl, CO32- and SO 42- in water using a thermodynamic model, OLI. The study results show that Cl concentration in the liquid increases with and increase in ash concentration, while sulfate concentration decreases. Temperature has little effect on the composition of the liquid phase for temperatures between 30 and 100°C, but has significant effect below 30°C.