Resumen
White liquor used in cellulose digesters is produced by the causticizing process that employs a reactor system composed of two main parts: a mixing slaker reactor followed by causticizing reactors. At the slaker reactor, calcium hydroxide is produced, according to the reaction: CaO(s) + H2O(1) ? Ca(OH) 2(s). Simultaneously a causticizing reaction occurs with the formation of sodium hydroxide: Na2CO3(aq) + Ca(OH) 2(s) ? 2 NaOH(aq) + CaCO3(s). The latter takes place along several mixing reactors connected in series. An initial step towards building this dynamic mathematic model was taken and tested for the Klabin Paraná Papéis mill slaker reactor, established in Brazil, for modeling purposes. Simulations of the dynamic model at process conditions show that it was able to reproduce the main characteristics of the process. Close agreement with plant measurements was obtained by adjusting one kinetic parameter.