关键词: 粉煤灰;湿法加碱煅烧;4A分子筛;吸附;六价铬

Abstract: Through wet method alkalinizing calcination , 4A Zeolite can be synthesized based on fly ash as main raw material.The effects of fly ash/alkali, calcination temperature and alcination time on 4A Zeolite were investigated .The results showed that 4A zeolite had been synthesized under fly ash/alkali of 1.0:0.8, calcination temperature of 700 ℃, calcination time of 1 h.At the same time, the removal efficiency of 4A zeolite adsorbing hexavalent chromium in water was studied .The experiments showed that 4 A zeolite had higher removal efficiency for hexavalent chromiumion in water , when 4 A zeolite dosage was 0.3 g, solution pH value was 6-7, adsorption time was 80 min and adsorption temperature was 10-25 ℃.The adsorption behavior of 4 A zeolite to sixvalent chromium accorded with Freundlich isotherm adsorption , mainly with physical absorption .Regeneration of 4 A zeolite was also studied , the results showed that , after 2 cycles, its adsorption capacity can still maintain more than 90％of the initial adsorption capacity .

Key words: fly ash;wet method alkalinizing calcination;4 A zeolite;adsorption;hexavalent chromium