Study on the Absorption of Carbon Dioxide by Zeolite transformed from Coal Fly Ash

这项研究是作为开发一种新的二氧化碳物理吸收方法的基础研究。本研究以工业废渣中的飞灰为原料，通过碱处理将其转化为沸石。而沸石(我们称之为沸石煤飞灰)被用来吸收空气-二氧化碳混合气体中含有的二氧化碳，被认为是烟道气。用天然沸石和市售人造沸石作为吸气剂进行了气体吸附实验，将粉煤灰与氢氧化钠水溶液反应约90℃，反应16h，得到黄铁矿类型的沸石。用X-射线粉末衍射仪和阳离子交换容量法检测了飞灰的沸石化程度。以粘土为粘结剂，将粉状沸石飞灰低温固化成直径为7 mm×6 mm的颗粒。由于沸石飞灰高温受热后使非沸石型沸石熄灭，沸石性质消失。天然沸石的气体吸收速率比沸石飞灰快4倍以上。天然沸石由大孔径大于磷灰石的丝光沸石组成。实验证明，利用煤粉飞灰可以有效地吸附二氧化碳。提出了一种新的二氧化碳吸收方法，作为工业废渣中煤飞灰回收利用的一种新方法。

This study was conducted as a basic research for the development of a new physical absorption method of carbon dioxide. In this study, coal fly ash of industrial waste was transformed into zeolite by alkali treatment. And the zeolite (we call it "zeolitized coal fly ash") was used to absorb carbon dioxide contained in air-carbon dioxide mixing gas considered as flue gases. Natural zeolites and artificial zeolite being on sale were also used for absorbent to compare the absorptivity in the gas absorption experiments.Phillipsite type zeolites were formed through reaction of coal fly ash with IN NaOH aqueous solution by heating about 90℃ for 16 hours. The zeolitization of coal fly ash was checked by X-ray powder diffraction analysis and cation exchange capacity measurement. Powdery zeolitized coal fly ash was solidified to pellet(7mm in diameter×6mm in height) by heating at low temperature with 'kibushi'clay for binder. Because, upon being heated at high temperature, zeolitized coal fly ash was extinguished the phillipsite type zeolites and disappeared properties of zeolite.The rate of gas absorption by natural zeolite was four times faster or more than zeolitized coal fly ash. Because natural zeolite was composed of mordenite with larger macropore radius than phillipsite.It was clarified experimentally that coal fly ash could be applied to absorbent of carbon dioxide effectively.A new absorption method of carbon dioxide was proposed as a technology for recycling of coal fly ash of industrial waste.