Reseach On Preparation Of New Alumina And Its Adsorption Property For Fluoride

In this paper, the preparation method of activated alumina was investigated .The influences of various processes pH value, concentration of raw materials, pore-expanding agent, calcining temperature and time on alumina structure and quality ware discussed. At the same time the scientific analytical methods of XRD, DTA and SEM-EDAX were used to analyze the activeness and micro-structure ofγ-Al₂O₃.Technic by gel plus reaming process was eventually identified in this paper and the amorphous activatedγ-Al₂O₃ were prepared by the technic. The adsorption properties of fluoride removal of this prepared amorphousγ-Al₂O₃ were researched, while the adsorption properties of finished activated alumina purchased from manufacturer was as the reference object.Static adsorption method had been used to study and compare adsorption performance for fluoride ions of the activated alumina prepared by using Sol-Gel technology and the reference aluminum and the best experimental conditions were determined. Their dynamic adsorption capacities were determined. The column height and flow rate on adsorption in dynamic adsorption experiments were examined and the dynamic adsorption capacity was determined. Static experiment and dynamic experimental results showed that the adsorption capacity for fluoride ion of the former was superior to the latter.The static saturated loading capacity of prepared amorphousγ-Al₂O₃ was 2.39 times compared to finished activated alumina; the dynamic saturated loading capacity of the former is 4.51mg/g, which was approximately 8 times compared to the latter's. The kinetic mechanism of alumina was explored .Results showed that adsorption process of activated alumina for F- could be well described by Pseudo second-order kinetics equation.