Abstract:The effects of a nonionic surfactant on the seeded precipitation rate of sodium aluminate solution, the particle size and morphology of the products were studied. The results show that when the added amount of the nonionic surfactant ranges from 100 mg/L to 150 mg/L, the seeded precipitation rate can be raised by about 6%, and its accelerating effects on the agglomeration of Al(OH)3 crystals and inhibiting secondary nucleation are also found in terms of the particle size distribution and SEM, which results in the increase of the average radius of products by 16 μm. The mechanism of the surfactant behavior was discussed. The results indicate that the Zeta potential of Al(OH)3 particle is changed and surface tension of sodium aluminate solution decreases by 20−30 mN/m with the addition of surfactant, which makes the stability of sodium aluminate solution greatly decline. Therefore, the nonionic surfactant can effectively intensify the seeded precipitation process of sodium aluminate solution.

Key words: sodium aluminate solution; surfactant; intensification; seeded precipitation