What is the purpose of washing in the filtration process?

There are two types of washing in nutsche filtration.

First, displacement washing, serves several purposes – it removes the liquid and its impurities while keeping the cake intact and it replaces the previous liquid with fresh liquid. There is also the opportunity prior to this step to try and close cracks if the cake has any via smoothing. The re-slurry process is an optional wash that can be used when a long contact time is needed between the wash fluid and the solids or the displacement wash does not provide the required wash quality.