An Experimental Study Of Limestone Dissolution At High Temperature And High Pressure In Liquid-Flow Reaction Set

Rock-water reaction plays an important role in many aspects of geology science. Scientists spend a lot on studying dissolution kinetics . It is a hot spot. Limestone covers nearly 15% of the whole area of earth surface.In this paper we studied the solubility of limestone in HCl-H2O system respectively at 250℃,300℃,350℃,400℃at a stable pressure of 25 MPa . They are 24.12,65.07,60.84,53.21 mg/l. The experimental study thus indicates that it is a rapid process that limestone dissolutes in HCl-H2O system. On the base of this, we then changed HCl-H2O into NaCl-H2O system of 0.6mol/ to determine the limestone dissolution kinetics at 50℃,100℃,150℃,200℃,250℃,300℃,350℃,400℃,450℃,500℃of 25 MPa . The experimental study thus indicates the process of limestone dissolution in NaCl-H2O system is regularity. When temperature is not changed , the concentration of Ca2+ decrease with the increase of the velocity of flow in a nilpotent way. The rate constant and the reaction progression are different at different temperature. The rate constant increase with the increasing of the temperature blow 300℃which is the highest, than it is fall. These dates are very important . It is necessary in uncovering and solving some relative geological matters.