School of Geoscience and Surveying Engineering, China University of Mining & Technology, Beijing 100083, China.
J Colloid Interface Sci. 2012 Jun 15;376(1):47-56. doi: 10.1016/j.jcis.2012.02.065. Epub 2012 Mar 14.
The thermal decomposition and dehydroxylation process of coal-bearing strata kaolinite-potassium acetate intercalation complex (CSKK) has been studied using X-ray diffraction (XRD), infrared spectroscopy (IR), thermal analysis, mass spectrometric analysis and infrared emission spectroscopy. The XRD results showed that the potassium acetate (KAc) have been successfully intercalated into coal-bearing strata kaolinite with an obvious basal distance increase of the first basal peak, and the positive correlation was found between the concentration of intercalation regent KAc and the degree of intercalation. As the temperature of the system is raised, the formation of KHCO(3), KCO(3) and KAlSiO(4), which is derived from the thermal decomposition or phase transition of CSKK, is observed in sequence. The IR results showed that new bands appeared, the position and intensities shift can also be found when the concentration of intercalation agent is raised. The thermal analysis and mass spectrometric analysis results revealed that CSKK is stable below 300°C, and the thermal decomposition products (H(2)O and CO(2)) were further proved by the mass spectrometric analysis. A comparison of thermal analysis results of original coal-bearing strata kaolinite and its intercalation complex gives new discovery that not only a new mass loss peak is observed at 285 °C, but also the temperature of dehydroxylation and dehydration of coal bearing strata kaolinite is decreased about 100 °C. This is explained on the basis of the interlayer space of the kaolinite increased obviously after being intercalated by KAc, which led to the interlayer hydrogen bonds weakened, enables the dehydroxylation from kaolinite surface more easily. Furthermore, the possible structural model for CSKK has been proposed, with further analysis required in order to prove the most possible structures.
采用 X 射线衍射（XRD）、红外光谱（IR）、热分析、质谱分析和红外发射光谱研究了含煤地层高岭石-乙酸钾插层复合物（CSKK）的热分解和脱羟过程。XRD 结果表明，乙酸钾（KAc）已成功插入含煤地层高岭石中，第一基底峰的基底间距明显增加，并且插层试剂 KAc 的浓度与插层程度之间存在正相关关系。随着体系温度的升高，依次观察到 CSKK 的热分解或相变生成的 KHCO₃、KCO₃和 KAlSiO₄。IR 结果表明，当插层试剂浓度升高时，出现了新的谱带，谱带的位置和强度也发生了变化。热分析和质谱分析结果表明，CSKK 在 300°C 以下稳定，质谱分析进一步证明了热分解产物（H₂O 和 CO₂）的存在。对原含煤地层高岭石及其插层复合物的热分析结果进行比较，发现不仅在 285°C 处观察到新的质量损失峰，而且含煤地层高岭石的脱羟和脱水温度降低了约 100°C。这是由于 KAc 插层后高岭石的层间空间明显增大，导致层间氢键减弱，使高岭石表面的脱羟更容易解释。此外，提出了 CSKK 的可能结构模型，需要进一步分析以证明最可能的结构。
