Study On Synthesis And Application Of 4A Zeolite Using Coal Fly Ash

In recent years,the rapid increase in population and economic growth have led to an increase in energy demand. To our country, the coal is now known to be the most stable and available energy source. However, utilization of coal as an energy source involves the generation of a great amount of coal ash, and the recycling rate of the ash is rather low. It is mainly used for producing the civil construction material at present,and there is a limit to the demand for coal ash by construction industries. The use of the fly ash is low technological content. At present, the utilization ratio of the fly ash of our country is still less than 1/2, therefore, the amount of coal fly ash is increasing and different applications should be considered.This study is to synthesize the excellent performance 4A molecular sieve using inexpensive industrial waste material fly ash as basic raw materials by two methods.One method consists of a hydrothermal technique at different conditions of alkali source, the other comprises a combination of alkaline fusion of fly ash with NaOH prior to a hydrothermal treatment at different conditions of guide agent. In addition, we have utilized synthetic zeolite products to get rid of heavy metal ions in the wastewater, which may provide experimental base for environmental friendly industrialization and find a new approach for the use of fly ash with subtly.Through XRD expertizing phase, SEM observing appearance, TG-DTA analyzing heat stability,IR analyzing structure, laser analyzing granularity and measuring the uptake of heavy metal ions in the wastewater by atomic absorption spectrophotometry .The results show that excellent performance 4A zeolite can be synthesized at conditions: calcined at 850℃ and for 2.0hours,then hydrothermal reacted with composition of reaction mixture 3Na₂O:1Al₂O₃:2SiO₂:185H₂O at temperature90℃, crystallization time 6h. In both cases, the synthetic zeolite products display significantly increased adsorption capacities compared tothe raw material. And that the fusion method yield better results in terms of shorter times necessary to obtain a product with high crystallinity and excellent performance as cation exchanger, the saturation adsorption capacity of Cu2+ up to 10.72 mg/g.