Synthesis of pure potassium pentaborate (KB₅) from potassium dihydrogen phosphate (KH₂PO₄) and colemanite

Abstract

In this study, after specifying theoretical reaction conditions required for the chemical reaction, potassium pentaborate (KB₅) was synthesized from the potassium dihydrogen phosphate (${\text{KH}}_{2} {\text{PO}}_{4}$) solution and raw colemanite (${\text{Ca}}_{2} {\text{B}}_{6} {\text{O}}_{{11}} \cdot 5{\text{H}}_{2} {\text{O}}$) ore. The slow evaporation solution method was used at 25 °C. The effect of time (6–18 h) on crystallization was studied. Synthesized minerals were characterized by X-ray diffraction (XRD), Fourier transform infrared (FT-IR), RAMAN spectroscopy, and scanning electron microscopy (SEM). The results according to XRD, FT-IR, RAMAN, and SEM analyses proved that the synthesized product was potassium pentaborate (${\text{KB}}_{5} {\text{O}}_{8} \cdot 4{\text{H}}_{2} {\text{O}}$) mineral with ICSD: 96-026-1927 pdf code. As a result, the cost was reduced by using raw boron ore, colemanite, and KB₅ was obtained in a shorter time and at a lower temperature.