Process for stabilizing a mixture of molten alkali metal nitrates and alkali metal nitrites usable particularly as a heat transfer fluid and stabilized mixture thus obtained

摘要

The present invention relates to a process for stabilizing a mixture of molten alkali metal nitrates and alkali metal nitrites usable particularly as a heat transfer fluid and to the stabilized mixture thus obtained. The process comprises adding to the mixture a quantity of alkali metal hydroxide such that the value of the logarithm of the ratio P(H2O)/|OH-|2 (where P(H2O) denotes the partial pressure of water vapor expressed in atmospheres and |OH-| the hydroxide ion concentration expressed in moles/kg) is between a value b corresponding to the disproportionation of the nitrites into nitrate and nitric oxide and a value a corresponding to the appearance of peroxides, the values a and b being determined for a given nitrate/nitrite ratio, a given temperature and given partial pressures of the gases blanketing the mixture.