This paper reports the results of a comparison of the qualitative physicochemical simulations (by the Winsel program complex) of the composition of the reacting fluid with experimental data on the water-electrolyte (NaCl, HCl, NaOH, and KOH)-mineral (quartz, corundum, microcline, and plagioclase) system and the water-electrolyte-rock (granite and pelite) system at 400-800 degrees C and 1-10 kbar. Constraints are proposed for the temperature, pressure, and the composition of the electrolyte at which the simulation results are consistent with the experimental data.