The prediction of the filtration rate for a flocculated kaolin system in a plant filter is achieved using a compressional rheological model. This model requires two important rheological functions, namely the compressive yield stress and a hindered settling function, which relate to the compressibility and permeability of the filter cake. For our flocculated kaolin suspension, these functions are determined from laboratory experiments. The model results compare well with the data collected in an industrial scale plate and frame pressure filtration device. This allows predictions to be made from the model when the plant operations such as the applied pressure are changed.