Central Institute of Mining and Fuel Research, Dhanbad-826015, Jharkhand, India.
Environ Technol. 2012 Jan-Feb;33(1-3):37-50. doi: 10.1080/09593330.2010.548532.
In the present study, samples of coal fly ash were obtained from seven major Indian thermal power plants. These samples were transformed into fly ash zeolite (FAZ) using hydrothermal activation by treatment with NaOH. All experiments were carried out at 100 degrees C, but with different solid:liquid ratios, different concentrations of alkali and different incubation times. The chemical composition, mineralogy and morphology of the fly ash and FAZ were determined by wet chemical method after Na2CO3 fusion, x-ray diffraction and scanning electron microscopy. The cation exchange capacity of fly ash and FAZ was determined using the ammonium acetate method (IS:2720). The ammonium exchange capacity was determined by the titrimetric method. The experiments demonstrate that zeolite can be synthesized at 100 degrees C using alkali. The cation exchange capacity and ammonium adsorption capacity of FAZ (up to 250 meq/100 g and 22.93 mg NH4+/g respectively) indicate that the FAZ may be potentially useful to reduce heavy metals and other pollutants from contaminated environments. Therefore, zeolitization at low temperature potentially allows waste fly ash to be used in an economically advantageous way.
在本研究中，从印度七个主要火力发电厂采集了煤飞灰样品。这些样品通过 NaOH 的水热活化转化为飞灰沸石（FAZ）。所有实验均在 100°C 下进行，但采用不同的固液比、不同浓度的碱和不同的孵化时间。采用碳酸钠熔融后的湿化学法、X 射线衍射和扫描电子显微镜法对粉煤灰和 FAZ 的化学成分、矿物学和形态进行了测定。采用乙酸铵法（IS：2720）测定粉煤灰和 FAZ 的阳离子交换容量。采用滴定法测定铵交换容量。实验表明，在 100°C 下可以用碱合成沸石。FAZ 的阳离子交换容量和铵吸附容量（高达 250 meq/100g 和 22.93mg NH4+/g）表明，FAZ 可能有助于减少污染环境中的重金属和其他污染物。因此，低温沸石化可能使废粉煤灰以经济有利的方式得到利用。
