RHEOLOGICAL CHARACTERIZATION OF HANFORD NEUTRALIZED CURRENT ACID WASTE SIMULANT SLURRIES

Using a Couette viscometer, we investigated the dependence of the stea dy-shear viscosity of simulated neutralized current acid waste on pH a nd different acids. For a fixed weight percent of waste solids, the re lative viscosity decreased as pH was lowered. The magnitude of the rel ative viscosity varied for the different acids. The values of random m aximum packing for these different slurries were obtained using a floc -agglomerate structural model proposed by Tsutsumi et ol. (1994). As t he weight percent of waste solids is normalized by the value of maximu m packing, the relative viscosity data approximately fall onto a singl e master curve for a specific shear fate. A direct relationship betwee n the macroscopic rheological properties (steady shear viscosity) and the suspension microstructure was established through the packing beha vior of a suspension. A comparison of the strongly flocculated and non colloidal suspensions indicates that besides the normalized weight fra ction, the dependence of shear rate must be considered to estimate the relative viscosity for strongly flocculated suspensions. (C) 1996 Soc iety of Rheology.