Wei Wang,

are you really looking for "equilibrium" data between dolomite and
phosphoric acid, or are you interested in the reaction kinetics.
If equilibrium (???): what are the pressures you state: total P or CO2
partial pressure?

The influence of reaction temperature on 18O/16O fractionation upon
reaction of dolomites with phosphoric acid has
been investigated, for instance, by Rosenbaum (GCA, 1986), Lynton
Land (1980) ...

Michael