Influence of dispersed CaCO3 on the viscosity of montmorillonite suspensions containing NaCl

摘要

The plastic flow of concentrated polydisperse montmorillonite suspensions that contain sodium chloride and dispersed calcium carbonate and that are subjected to the action of atmospheric CO2 is studied. It is shown that small amounts of calcium carbonate (0.05-0.5 wt%), as an impurity, and added sodium chloride can lead to significant variations in the structural organization of suspensions. Anomalous behavior of suspensions is observed at NaCl concentrations of 2-3 g/dm(3). Mechanisms of structural transformation of concentrated clay suspensions are discussed. It is shown that the CaCO3 transformation can proceed by the mechanisms of the Ostwald ripening or chemical recondensation depending on the interaction of a disperse silicate system with the ambient medium and on the presence of NaCl.