Formation of boron-mannitol complex in the hydrofluoric acid solution and a possibility of the use of acids in the separation of boron from the natural rock samples

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 mol ratio and the boron volatilization is completely suppressed when the ratio is more than unity. These results indicate that the final stable compound of boron-mannitol complex is an equimolar complex of boron and mannitol. The formation of this complex allows the use of hydrofluoric and hydrochloric acids for the dissolution of silicate rock samples and for separation of boron from the samples adopting anion exchange chromatography in F- form. (author)