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采用共沉淀法制备用于除氟的羟基氧化锆吸附剂,研究碱的滴加速度、沉淀终点pH值、烘干时间和焙烧温度4个制备条件对吸附剂除氟性能的影响.结果表明,制备羟基氧化锆吸附剂的优选工艺参数为:碱的滴加速度2mL/min,沉淀终点pH值7.0,烘干时间72h和焙烧温度低于100℃.对所制备的羟基氧化锆进行表征,SEM结果表明它是由一些小颗粒团聚而成,粒径为20～30μm左右的粉末材料,XRD和TG/DTA说明羟基氧化锆具有无定形结构,并在焙烧温度达到600℃时转化为四方相结构,同时氮气吸附脱附法测定其具有高比表面积约138.4m2/g,孔隙结构以中孔为主,平均孔径2nm左右.本研究还对羟基氧化锆的再生性能进行了分析,结果显示吸附剂吸附饱和后,经过再生技术处理,可基本恢复原有除氟性能.
Hydroxyzirconia adsorbents for fluoride removal were prepared by co-precipitation method, and the effects of the dropping time of alkali, the final pH value of the precipitate, the drying time and the calcination temperature on the de-fluoridation performance of the adsorbents were investigated. The optimum technological parameters of zirconia adsorbent are as follows: the dropping rate of alkali is 2mL / min, the final pH value is 7.0, the drying time is 72h and the calcining temperature is lower than 100 ℃. The prepared zirconium oxyhydroxide is characterized by SEM. XRD and TG / DTA show that the zirconia has an amorphous structure and transformed into a tetragonal phase structure when the calcination temperature reached 600 ℃. Meanwhile, the nitrogen gas Adsorption-desorption method has a high specific surface area of about 138.4m2 / g, the pore structure is mainly mesoporous, the average pore size of about 2nm.In this study, the regeneration performance of hydroxy zirconia was also analyzed, the results show that the adsorbent saturation , After regeneration technology processing, can basically restore the original fluoride performance.