A structural model for the time-dependent recovery of mineral suspensions

A thixotropic recovery model has been developed that is based on considerat ion of the microstructural interactions that occur between particles within a suspension particle network. The model is based on Smoluchowski coagulat ion rate theory, utilizing second order kinetics to describe the thixotropi c recovery behavior. The model is applied to Na-montmorillonite-based coal tailings suspensions and is also shown to be applicable to brown coal and b auxite residue suspensions. The model describes all the recovery data well. , especially at intermediate to large recovery times. The recovery of the m ontmorillonite suspensions at short times was faster than predicted, indica ting the existence of additional factors in early-time structure developmen t. The discrepancy may have also been due to the highly anisotropic nature of the clay platelets. The recovery rate constant, Kr, increases with incre asing solids concentration (for constant surface chemical conditions) as wo uld be expected from the basis of the model.