Acidity measurements at elevated temperatures. VI. Boric acid equilibriums

Boron isotope fractionation accompanying formation of potassium, sodium and lithium borates from boron-bearing solutions

“…This discrepancy is mostly due to the difference in the kind of polyborates supposed to exist in the solution phase and their stability constant values between this and the previous studies. In the present study, the work by Mesmer et al (1972) Spessard (1970) whose data were adopted in the previous paper (Oi et al, 1991) The latter tends in general to yield a larger K B value than the former for a given run. For L2B2O4, the estimation of the K B value for L4 and L11 is abandoned.…”

“…This assumption is actually not very bad one. Mesmer et al (1972). reported that no boron isotope fractionation was observed in cation exchange chromatography of B(OH) 3 within experimental errors.…”

“…There is only one boron species in the solid phase in each of the runs for which the isotopic measurements were made. are supposed to exist (Ingri et al, 1957;Spessard, 1970;Mesmer et al, 1972). Their concentrations depend on, among others, the total concentration of boron and pH of the solution.…”

“…10(a) and the corresponding distribution of the BO 3 and BO 4 units in Fig. 10(b), using the stability constants by Mesmer et al (1972). Under this assumption, Eq.…”

“…The total amount of boron (m tot ), the amount of deposited boron (m prec ), the volume of the solution phase (V sol ), the experimental pH of the solution, the assumed K B value and the initial boron isotopic ratio of the solution phase (( 11 B/ 10 B) sol ) are first given as initial inputs. The boron concentration and the BO 3 :BO 4 ratio of the solution are then calculated by using the input data and the stability constants of polyborates and the dissociation constant of boric acid cited from Mesmer et al (1972). Next, the boron isotopic ratios of the BO 3 and BO 4 units in the solution phase are calculated.…”