The Chemical Durability of SiO_2-Na_2O-Oxide of Transition Element System Glasses (1st Report) : SiO_2-Na_2O-V_2O_5 Syetem

The chemical durability of glasses to water was studied in this paper. Sixteen kinds of glasses in SiO_2-Na_2O-V_2O_5 system were fused in electric furnace. The fused glasses were powdered into particles of 35-60 meshes and 2g of them were immersed in 50cc water of 30,50 and 70℃ while being stirred during 10,20,40 and 80 minutes respectively. Then the amounts of vanadium dissolved into water were measured by chelatometric titration. The results were as follows. 1) The experimental data were tested by analysis of variance and it was proved that log of dissolved amounts was linear function of log of dissolving time and reciprocal of absolute temperature. 2) The dissolved amounts increased with increasing VO_<2.5> mol and decreased with increasing Na_2O mol in constant SiO_2 mol, and they increased with increasing Na_2O mol and decreased with increasing SiO_2 mol in constant VO_<2.5> mol. 3) In glasses of SiO_2 60 and 65mol, there were minimum value of dissolved amounts at certain composition, and in VO_<2.5> 15 mol, there were also minimum value at certain composition.

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