The Synthesis Of Zeolites With Circulating Fluidized Bed Fly Ashes And Treatment Of Fluoride Wastewate And Regeneration Of Zeolites

Fly ash is a kind of quality mixture material as volcano ash by combustion, which is the solid discard comes from the smelt, chemical engineering and coal-fire power plant, it is one of the biggest materials of proportion in the industrial solid discard. A great deal of the ash open-air heap put, if don not add a processing, not only take up large land, and serious pollute environment. But, the fly ash also is a well active material in industy. So, regardless save or use resources, still from protection the Earth environment, the valid use of ash is very urgent. The technique of fly ash utilizing is considered as a national policy in some developed nations, such as the United States, England, Germany, the former Soviet and Japan etc. The utilizing of fly ash is also an important factor in development of economic construction, the processing of ash and the recycling become an urgently problem for resolve in our country.There has been many reports concerning fly ash synthesize the zeolites internal and abroad currently. This paper studied directly synthesizing zeolites by using fluidized-bed combustion fly ash that is low crystal and active , and overleap the heating and pretreatment. This paper also studied the feasibility and superiority of synthesizing zeolites utilizing industral waste residues circulating fluidized bed (CFB) fly ashes.The source of industry waste water contains fluorine is extensively and endanger huge, and it is difficultly to process. Currently, the mainly method to defluorine has mixed precipitate and ion exchange etc domestic and international. But all the above mothods have some disadvantages, such as mix precipitates, expensive, can not repeat exploitation, and also produce a great of discard; ion exchange has a low defluorition ratio. The zeolites method adopt by this experiment has the dual functions of adsorption and ion exchange, compare with other methods have cheap, regeneration, great capacity and a high defiuorition ratio. At the same time, the zeolites are loud by Fe³⁺ to rise the removal rate, the isotherm line of the zeolites before loud by Fe³⁺ and the zeolites loud by Fe³⁺ also be studied to esplore the effects of adsorption.The results of the experiment showed that 98.97%, 98.3% and 85% of fluoride can be removed from low, middle and high concentration liquid of flourid and the absoring capacity is up to 26.7mgF^-/g when the zeolites carried by the best Fe³⁺ concentrationThis paper also does some primary researches about zeolite regeneration, studied the effects of regeneration, make sure the best regenerative time and the best concentration of the regenerative liquid and recovery rate. The recovery rate of the zeolites loud by Fe³⁺ is high up to 93.4% under the condition of one hour dipping and 5% HCl liquid.