Crystallisation kinetics of calcite in the presence of magnesium ions

Abstract

The kinetics of calcite growth from Ca(HCO₃)₂ solutions containing Mg(HCO₃)₂ up to a magnesium to calcium ratio of ca. 1 has been measured at 25 °C using a seeding technique. The growth data are analysed using a mechanistic model and the results show the inhibiting influence of magnesium on the growth process. The extent of the inhibition action is found to depend on the state of supersaturation of the mixed solution at the time of the calcite seed addition and the total dissolved magnesium concentration. Analysis using the parabolic rate law was found to be less successful.