The Dissolving Behavior of Vanadium and Calcium Ion Dissolved into Water from The Glasses of B_2O_3-V_2O_5-CaO System

The dissolving behavior of vanadium and calcium ions dissolved into water from glasses of B_2O_3-V_2O_5-CaO system was studied in this paper. Nineteen kinds of glasses in this system were melted in electric furnace, about 1300℃, four hours. The melted glasses were powdered into particles of 35-60 meshes and 2 g of them were immersed in 50 ml water of 30,50 and 70℃ while being stirred for 10,20,40 and 80 minutes respectively. Then the amounts of vanadium and calcium ions dissolved into water were measured by chelatometric titration. The results are as follows. 1) The experimental data were tested by analysis of variance and it is found that log of dissolved amounts was linear function of log of dissolving time and reciprocal of dissolving temperature and has no interaction term of time and temperature. That is, the dissolving amounts are proportional to t1/2 and apparent average dissolving energy is 1.60×10^3K for vanadium ion and the dissolving amounts are proportional to t1/2 and dissolving energy is 1.51×10^3K for calcium ion. 2) The glass of 40 B_2B_3-20 V_2Q_5-40 CaO (mol %) was the most durable one and 30 B_2O_3-50 V_2O_5-20 CaO (mol %) was the weakest in this system and roughly the composition of good resistant glasses was in the center of this system.