CARBONATE CAPACITIES OF NA2O-SIO2-B2O3 MELTS

CO2 solubilities of Na2O-SiO2-B2O3 melts were determined by the thermo gravimetric method in the overall temperature range of 1 000-1 250-deg rees-C after correction for loss of weight due to volatilization from the melts as well as drag force of flowing gas. The melts had mostly 5 0 mol%. Na2O, with SiO2 and B2O3 contents varying from 0 to 50 mol%. T he values of CO2 solubilities for 50Na2O-50SiO2 melts were within the ranges reported in literature. For 50 mol% Na2O, the solubility decrea sed with increasing B2O3 content in the melt and with increase in temp erature. Also linear dependence of logarithm of carbonate capacity wit h theoretical optical basicity were obtained at constant temperatures.