Novembre Daniela, Gimeno Domingo, Vecchio Alessandro Del
Dipartimento di Ingegneria e Geologia, Università di Chieti-Pescara, Via dei Vestini 30, 66013, Chieti, Italy.
Department Mineralogia, Petrologia i Geologia Aplicada, Universitat de Barcelona, 08028, Barcelona, Spain.
Sci Rep. 2020 Mar 31;10(1):5715. doi: 10.1038/s41598-020-62702-8.
Crystallization of zeolite Li-A(BW) from kaolinite (Standard Porcelain by the IMERYS Minerals Ltd) through a conventional hydrothermal treatment is here achieved for the first time with no additives as reported in the literature. Moreover lower kaolin calcination temperatures and lower synthesis temperatures are tested and verified in this work. The synthesis process is rather simple as the reaction of kaolinite with alkali occurs very readily after calcination of at 650 °C. Metakaolin is mixed with calculated amount of aluminum hydroxide and lithium hydroxide and the experiment is performed at ambient pressure and 180 ± 0.1 °C. Li-A(BW) is characterized by powder X-ray diffraction, high temperature X-ray diffraction, scanning electron microscopy, inductively coupled plasma optical emission spectrometry, thermal analysis and infrared spectroscopy. Calculation of cell parameters (through Rietveld Refinement) and density, specific surface and pore size are also achieved. The amount of amorphous phase in the synthesis powders is estimated with quantitative phase analysis using the combined Rietveld and reference intensity ratio methods. The results become notably attractive in view of a possible industrial transfer of the synthesis protocol.
首次在无文献报道的添加剂情况下，通过传统水热法从高岭土（IMERYS Minerals Ltd生产的标准瓷土）中成功制备出沸石Li-A(BW)。此外，本研究还测试并验证了更低的高岭土煅烧温度和更低的合成温度。合成过程相当简单，因为高岭土在650°C煅烧后很容易与碱发生反应。偏高岭土与计算量的氢氧化铝和氢氧化锂混合，实验在常压和180±0.1°C下进行。通过粉末X射线衍射、高温X射线衍射、扫描电子显微镜、电感耦合等离子体发射光谱法、热分析和红外光谱对Li-A(BW)进行表征。还通过Rietveld精修计算了晶胞参数、密度、比表面积和孔径。使用Rietveld方法和参考强度比方法相结合的定量相分析方法估算了合成粉末中非晶相的含量。鉴于合成方案可能进行工业转化，这些结果具有显著的吸引力。
