Adsorption of sodium polyacrylate in high solids loading calcium carbonate slurries

The adsorption of sodium polyacrylate (NaPAA) in slurries with up to 75 wt.% calcium carbonate was investigated with the use of attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) and adsorption of probe molecules. Analysis of the IR spectra demonstrated that the carboxylate groups of NaPAA adsorbed onto ground calcium carbonate (GCC) in three different modes. These modes were shown to be dependent on the solids loading and age of the slurry. Further investigation lead to the determination of the chelating ability of NaPAA at high solids loading.

The fate of high solids loading slurries (>55 wt.%) are different from low solids loadings. The bridging state for bonds is increased with solids loading and age of slurry. These phenomena seem not to occur in dilute conditions.Figure optionsDownload as PowerPoint slide