SUPPRESSION OF BORON VOLATILIZATION FROM A HYDROFLUORIC-ACID SOLUTION USING A BORON-MANNITOL COMPLEX

Volatilization and mass fractionation of boron during evaporation of the hydrofluoric and hydrochloric acid solutions were investigated with varying mannitol/boron ratios. The degree of volatilization and mass fractionation decreases with increasing mannitol/boron mole ratio, and the boron volatilization is completely suppressed when the ratio is more than unity. These results indicate that the final stable compound is an equimolar complex of boron and mannitol. The formation of this complex in the acid solutions allows the use of hydrofluoric and hydrochloric acids for the dissolution of silicate rock samples and for the subsequent chemical separation of boron from the samples adopting anion-exchange chromatography in F− form. © 1990, American Chemical Society. All rights reserved.