Adsorption Characteristics and Optimal Dosage of Flocculants in the Solid Separation of Suspensions

A new, simple model for flocculation of suspended particles was proposed taking into account the bridging between a flocculant-adsorbed surface on a particle and a bare surface on another particle. Experimental data on the adsorption of flocculants onto particles were fitted to a Langmuir-type adsorption isotherm, and two adsorption parameters were obtained by the fitting. Flocculation experiments were conducted for quartz suspensions with two types of polymer flocculants that had been developed in our previous studies. The flocculation efficiency of the flocculant was evaluated by turbidimetry. An attempt was made to apply the proposed model to the experimental flocculation efficiency, and it was shown that the model can well explain the experimental results. As a result, it was revealed that one of the model parameters, (alpha), plays the most important role in flocculation phenomena, and it gives the fraction of particles surface covered by flocculant at an optimum flocculation.