Prediction of chemical speciation in stabilized solidified wastes using a general chemical equilibrium model Part I. Chemical representation of cementitious binders Academic Article uri icon

abstract

  • Chemical equilibrium models are useful to evaluate stabilized/solidified waste. A general equilibrium model, SOLTEQ, a modified version of MINTEQA2 for S/S, was applied to predict the chemical speciations in the stabilized/solidified waste form. A method was developed to prepare SOLTEQ input data that can chemically represent various stabilized/solidified binders. Taylor's empirical model was used to describe partitioning of alkali ions. As a result, SOLTEQ could represent chemical speciation in pure binder systems such as ordinary Portland cement and ordinary Portland cement + fly ash. Moreover, SOLTEQ could reasonably describe the effects on the chemical speciation due to variations in water-to-cement, fly ash contents, and hydration times of various binder systems. However, this application of SOLTEQ was not accurate in predicting concentrations of Ca, Si, and SO4 ions, due to uncertainties in the CSH solubility model and Ksp values of cement hydrates at high pH values.

published proceedings

  • CEMENT AND CONCRETE RESEARCH

author list (cited authors)

  • Park, J. Y., & Batchelor, B.

citation count

  • 19

complete list of authors

  • Park, JY||Batchelor, B

publication date

  • March 1999