Estimation of the hindered settling function R(φ) from batch-settling tests

The hindered settling function R(phi) is a material function that quantifies the interphase drag of colloidal suspensions for all solids volume fractions phi. A method is presented to estimate R(phi) from batch-settling tests for solids volume fractions between the initial solids volume fraction, phi(0), and the solids volume fraction at which the suspension forms a continuously networked structure, phi(g), known as the gel point. The method is based on an analytic solution of the associated inverse problem. Techniques are presented to address initialization mechanics observed in such tests as well as experimental noise and discrete data. Analysis of synthetic and experimental data suggests that accurate estimates of R(phi) are possible in most cases. These results provide scope for characterization of suspension dewaterability from batch-settling tests alone. (c) 2005 American Institute of Chemical Engineers