I have drawn a diagram, and I still not sure how to calculate the composition of the first filtration,
The slurry that leaves the reactor on a plant manufacturing phosphoric acid contains 20% w/w solids together with a solution of phosphoric and sulphuric acids
In water. The solution consists of 38% w/w H3PO4 , 2.5% w/w H2SO4 , the
Remainder being water.
The slurry is filtered and all the solids are removed in the filter cake. The filter
cake that is produced contains 50% w/w solids and 50% w/w liquid. The filter
Cake is then re-slurried with water and subjected to a second filtration. The second
Filter cake contains 55% w/w solids and 45% w/w liquid. In this case also, all the
Solids are present in the filter cake.
If 1% of the phosphoric acid present in the initial slurry is retained in the liquid
Trapped in the second filter cake then, using a basis of 1000 kg initial slurry,
(a) The composition of the first filter cake,
(b) The composition of the second fillter cake,
(c) The amount of water used to reslurry the first filter cake.