Optimization of Dissolution of Ulexite in Disodium Hydrogen Phosphate

The study aimed to investigate the optimization of the dissolution of ulexite minerals in disodium hydrogen phosphate solutions by using a factorial experimental design. The study used the solid-liquid ratio, reaction temperature, the concentration of disodium hydrogen phosphate solutions and reaction time as parameters. 2ⁿ factorial experimental design and orthogonal central composite experimental design methods were used. The optimum conditions for maximum ulexite dissolution were: Solid-liquid ratio of 1/8 g mL^-1, a reaction temperature of 65°C, a concentration of disodium hydrogen phosphate of 2M, and a reaction time of 4 hours. Under these optimum conditions, the dissolute B₂O₃ was 98.16% in disodium hydrogen phosphate solutions. The complete model, including all parameters, was obtained using the 2. degree variables of the model experiment and internal interactions was found to be as follows. Ŷk.model = 80,45 + 11,31X₁ + 5,70X₂ - 1,10X_{3 -} 7,29X_{4 -}11,27X₁₂ - 1,34X ₂₂ + 2,37X₃₂ - 4,33X₄₂ + 3,25 X₁X₂ - 7,45 X₁X₃ + 14,00 X₁ X₄ + 4,30 X₂X_{3 -} 7,80X₂X₄ + 7,17X₃X ₄