Kinetics of Hydrothermal Crystallization of Quartz in Na_2CO_3 Solutions

摘要

The kinetics of crystallization of the {0001}_c, {01(1-bar)1}r, and {10(1-bar)1}R faces of quartz in 0.5 M Na_2CO_3 (M is molarity) aqueous solutions has been studied in the temperature range 200-450 ℃. It is established that the dependence f the crystal growth rate on temperature in the logV-1/T, K coordinates is of a parabolic nature. It is most probable that the nonlinearity of this dependence is associated with a deficiency in the solution of silica monomers, taking part in the elementary event of quartz crystallization. The causes of a jumpwise decrease in the activation energy of the growth of the c, r, and R faces at t > 280-325 ℃ are considered.