Recent progresses on the boron species in aqueous solution: structure, phase equilibria, metastable zone width (MZW) and thermodynamic model

Abstract

The complexity of boron species in aqueous solution becomes the bottleneck in development of boron resources from brine. The concentrations of different boron species and transformation mechanism among boron species are mainly affected with the total boron concentration, temperatures, pH of the solution, and cations in the solution. The change trends for concentration of total boron in the complicated aqueous solution can be obtained with the phase equilibrium results, but the accurate concentration of boron species in the solution cannot be obtained. The metastable zone width (MZW) of borates and H3BO3 changed with the concentrations of impurity ions, the stirring rate, cooling rate, and original temperature for the saturated solution. The Pitzer model is the effective method to calculate the concentration of boron species. More thermodynamic data at temperatures below and above 298.15 K are needed for model parameterization. The main problems existed in the systems containing boron species were summarized, and the future development direction is also discussed. The progresses on boron species in the aqueous solution can provide fundamental data in the comprehensive exploitation of the brine boron resource.

Solid-Liquid Phase Equilibria of the Quaternary System (LiCl + LiBO2 + Li2B4O7 + H2O) at 308.15 K: Experimental and Theoretical Prediction

“…At the F 1 point, the maximum deviation between the mass fraction of w(LiCl), w(LiBO 2 ) and w(Li 2 B 4 O 7 ) and the theoretical value is 0,0.0466, 0.0005, respectively, and the , were used in this system for the calculation, but other boron species may be present in the brine, such as B(OH) 3 , B 3 O 3 (OH) 5 2− , and B 3 O 3 (OH) 4 − [6,27]. e results show that this assumption is not precise enough.…”

The geochemical role of B-10 enriched boric acid in cemented liquid radioactive wastes

“…The reason is the significant relative mass difference of the 10 B and 11 B isotopes, and the dependence of borate geometries on pH and boron concentration. The preference of the main borate geometries, which is typically trigonal for the heavier and tetrahedral for the lighter boron isotopes, also contributes to this phenomenon [29][30][31][32][33][34][35][36][37][38]. The so-called durability of the final waste forms is one of the most important quality parameters of the long-term waste disposals performance assessment analysis [4,12,[39][40][41][42][43].…”

Prediction of metastable zone widths of ammonium sulphate: modification of the nucleation potential model in an electrolyte system

“…9 Research suggests that MSZWs can be influenced by multiple factors, such as saturation temperatures, cooling rates, stirring rates, and additives or impurities. [10][11][12][13][14][15][16] There are empirical nucleation rate equations developed by Nývlt, 17,18 Kubota 19 and Sangwal 20 to analyze MSZWs. The nucleation free energy can be estimated by the classical nucleation theory (CNT), by determination of the induction time with an isothermal method at a constant temperature, when the solution is supersaturated.…”