Experimental study of epidote dissolution rates from pH 2 to 11 and temperatures from 25 to 200 °C

The dissolution rates of Green Monster Mine epidote at temperatures 25, 100 and 200 °C, over the pH range 2–11, were determined from far-from equilibrium experiments performed in both batch mixed-flow reactors. Epidote based on silicon release decrease with increasing to ? 8, then increase response further increases. apparent relative metal chemical steady-state found vary temperature, part due secondary phase formation. At Al is preferentially released Si alkaline pH, but retained by solid 2 < 8. This behaviour interpreted stem precipitation re-dissolution oxy-hydroxides such as boehmite, diaspore, gibbsite, observed solids recovered after experiments. Calcium tends be compared acidic near neutral pH. Iron was prompt formation Fe minerals. Nevertheless, neither 20 wt% initial mass nor phases surface substantially changed rates. As (i) almost three times more Ca-rich than a typical basaltic glass, (ii) releases Ca CO2-charged water injections, (iii) exhibits increases conditions, it seems likely that presence altered basalts may beneficial for calcite other Ca-carbonates during mineral carbonation efforts. In addition, relatively rapid conditions suggest has significant role weathering mafic rocks.