Design a CSTR reactor for the production of phosphoric acid

the main reaction is :

Ca$3$PO$4+3$H$2$SO$4+6$H$2$O $-------->2$H$3$PO$4+3($CaSO$4\mathrm{.}2$H$2$O$)$

I want the volume of the reactor

$($Continuous state$)$

X $=0\mathrm{.}9$

Fao $=10000$ kg$/$hr

$-$k$=1\mathrm{.}1627$ e$-3742/$ T

T $=353$ k $,$ U can calculate the

concentration or get from any reference $($if so right the refrence $)$