As usual, I agree with LittleInch ..
Slurry transport piping design and operation is a little tricky.... Usually, what the engineering challenge involves is finding the best velocity required to efficiently transport solids. The minimum transport velocity is usually important.
This min velocity depends on the percentage solids, density, particle size and several other criteria.
Pipe routing is also very important. There are entire books written about slurry piping design and the study of Rheology
Maximum velocity ??... I would guess that you are looking at erosion/corrosion issues ...
Is the transported material hard ground garnet or talcum powder ?
MJCronin
Sr. Process Engineer