Interaction of sulphuric acid solutions with carbonates and feldspar during underground uranium leaching

The interaction of sulphuric acid solutions with calcite, dolomite and alkali feldspar at room temperature is experimentally studied. The mineral ground up to 0.63-1 mm has been mixed with crushed quartz glass and poured over by sulphate solution. The time required for sulphate solution neutralization by these minerals is determined. The interaction of sulphuric acid with calcite occurs very quickly, the solution has a neutral reaction in some days, the process with dolomite proceeds at first quickly up to total neutralization, then its rate sharply drops, the H2SO4 interaction with alkali feldspars proceeds very slowly. To estimate the extent of equilibrium between the solution and carbonates the experimental data are compared with the results of computer calculations of partial equilibria at various degrees of main reaction course. The results can be used in supplement to the processes occurring at underground uranium leaching as well as processes in oxidation and cementation zones of sulphide deposits