Green synthesis of zeolites from a natural aluminosilicate mineral rectorite: Effects of thermal treatment temperature
Green synthesis of zeolites from a natural aluminosilicate mineral rectorite: Effects of thermal treatment temperature
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DOI：
10.1016/j.clay.2014.01.006
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发表时间：
2014-03
影响因子：
5.6
通讯作者：
Haiyan Liu;Tong Shen;Tiesen Li;Pei Yuan;Gang Shi;Xiaojun Bao
中科院分区：
文献类型：
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作者：
Haiyan Liu;Tong Shen;Tiesen Li;Pei Yuan;Gang Shi;Xiaojun Bao
本文报道了热处理温度对累托石矿物的物理化学性质以及用于沸石合成目的的活化累托石产物的化学反应性和结晶行为的影响。采用XRF、XRD、FTIR、29 Si和27 Al MAS NMR等技术对累托石原料及其热活化产物进行了系统表征，并对合成的累托石沸石进行了XRD表征。结果表明，累托石在25-1300 °C热处理后，经历了150-300 °C脱水、600-700 °C脱羟基、1000 °C结构坍塌和1100 °C以上新相形成4个阶段。在1000 °C热处理后，累托石中的SiO 4四面体单元发生畸变，AlO 6八面体单元发生分解，从而使活性SiO2和Al 2 O3含量同时达到最大值，以1000 °C热处理累托石为原料合成了P型沸石。研究结果进一步表明，累托石与高岭土一样，在适宜的温度下热活化后可用于沸石合成，是一种很有前途的直接由天然硅铝酸盐合成绿色沸石的原料。
This article reports the effects of thermal treatment temperature on the physicochemical properties of a rectorite mineral and the chemical reactivity and crystallization behavior of the activated rectorite products for zeolite synthesis purposes. The raw rectorite mineral and its thermal activation products were systematically characterized by XRF, XRD, FTIR and29Si and27Al MAS NMR techniques and the resultant zeolites were characterized by XRD technique. The results showed that after being thermally treated in the temperature range of 25–1300 °C, the rectorite experienced the following four stages: dehydration at 150–300 °C, dehydroxylation at 600–700 °C, structure collapse at 1000 °C, and new phase formation at above 1100 °C. Moreover, it was found that after being thermally treated atca.1000 °C, the SiO4tetrahedral units in the rectorite mineral are distorted, while the AlO6octahedral units are decomposed and thus the maximum contents of active SiO2and Al2O3can be simultaneously achieved, and as a result, zeolite P is obtained when using the rectorite calcined at 1000 °C as the starting material for fabricating zeolites. Our results further revealed that like kaolin rectorite after thermal activation at a suitable temperature can be used for zeolite synthesis and thus demonstrates itself a promising feedstock for the green synthesis of zeolites directly from natural aluminosilicates without experiencing intermediate chemicals.