Ingeniería e Investigación
Print version ISSN 0120-5609
RUIZ MADRONERO, Christhy Vanessa and RODRIGUEZ PAEZ, Jorge Enrique. Sodium aluminates obtained from the Al(NO3)3 • 9H2O - NaOH system using the controlled precipitation method. Ing. Investig. [online]. 2010, vol.30, n.2, pp. 16-24. ISSN 0120-5609.
Sodium aluminate, NaAlO2• xH2O, is an important comercial chemical used in water treatment, as a source of aluminium in the preparation of zeolites and other catalytic materials and as an additive in paper manufacturing. Sodium aluminates were synthesised in this work by using the Al(NO3)3 • 9H2O- NaOH system's controlled precipitation method. Using the controlled precipitation method enabled identifying the process's different stages from potentiometric titration of Al(NO3)3 • 9H2O dissolved in water and using NaOH as precipitating agent to ensure control and reproducibility and also identify final product characteristics. Powders were characterised by infrared spectroscopy (FTIR), X-ray diffraction (XRD) and gravimetric and differential thermal analysis (GDTA). The results indicated that NaAlO2 crystallised well at 1,000°C (obtained as the main crystalline sodium aluminate phase) and that β-alumina treatment began to form at 1,500°C.
Keywords : sodium aluminate; synthesis; controlled precipitation method.