Abstract
Preparation of relative stable slurries from waste calcium carbonate, resulted from the NPK fertilizers industry, and their testing as buffering agent, are reported. Characterization of the waste calcium carbonate was carried out by IR spectra, chemical analysis and thermal behavior, in comparison with two natural limestones, taken out from two Romanian deposits, i.e. Sandulesti and Vata de Jos. In order to establish the main physical properties of the slurries prepared by dry and wet milling, measurements of their particle size composition, settling number and rheology were performed. The buffering capacity against some acid solutions, determined in a batch reactor with stirring and provided with conductometrical sensitive elements was utilized as a measure of their reactivity.