THE INFLUENCE OF ADDING EMULSION FLOCCULANTS ON THE EFFECTS OF RED-MUD SEDIMENTATION

The main objective of this investigation was to define, based on an industrial probe, the influence of emulsion flocculants on the effects of red-mud precipitation. The precipitation velocity of the red mud as well as the transparency of the liquid phase create the basis for the comparison of the efficiency between the conventional flocculants and the emulsion flocculants. The investigation was also focused on the characteristics of the precipitated mud presented as the content of dry particles as well as the granulation of red mud. The influence of the suspension viscosity on the loading of the mixer inside the decantation vessels was also investigated. All of the precipitation experiments were carried out within the automatic Cytec unit for the preparation and dosage of the liquid flocculants. The parallel investigation of the efficiency of two different flocculants was performed in separate decantation vessels. The results show that the red-mud precipitation velocity during the experiment with the emulsion flocculants is several time higher than the precipitation velocity obtained with synthetic flocculants. The emulsion flocculants also enable a better solution transparency with a clear and distinct boundary between the two phases (liquid and solid). Besides that, the consequence of the emulsion flocculants' dosage is a higher content of dry particles in the suspension as well as an increased granulation and a lower viscosity. Using emulsion flocculants increased the decantation vessels' productivity, improved the quality of the aluminate's solution and improved the effects of red-mud rinsing.