Abstract This study focused on identifying the differences in a clay quarry that is used in brick production to understand the variation between samples based on two kinds of clays: the first kind was suitable for brick production, but the second one did not show good production efficiency. Various samples were characterized by physical and chemical methods. In addition, free iron extraction by a CBD method and calcination at various temperatures were performed. The clay samples were then structurally characterized by XRD, FTIR and 27Al NMR spectroscopy and thermally characterized using dilatometry. Finally, these results were correlated to the SEM investigation. These results revealed variations in the Si/Al molar ratio (1.4 to 3.3) due to the mineralogy variation within the quarry. Indeed, the non-secondary phase and clay phase contents differed according to the location in the quarry. NMR analysis also revealed that some iron atoms were located in a kaolinite structure, whereas other iron phases, in goethite form, interacted with clay minerals only on the surface of, e.g., kaolinite and muscovite and were not in their structures. From the thermal characterization, the influence of this structural iron in the kaolinite was also evidenced by an increase in the total shrinkage. In conclusion, this work determined the structural differences and their impact on brick production.

中文翻译：

---

通过各种方法确定砖工业中使用的粘土之间的差异：铁提取和核磁共振光谱

摘要 本研究的重点是确定用于制砖的粘土采石场的差异，以了解基于两种粘土的样品之间的差异：第一种适合制砖，但第二种没有表现出良好的生产效率。 . 通过物理和化学方法对各种样品进行表征。此外，通过CBD法提取游离铁并在不同温度下进行煅烧。然后通过 XRD、FTIR 和 27Al NMR 光谱对粘土样品进行结构表征，并使用膨胀计进行热表征。最后，将这些结果与 SEM 调查相关联。这些结果表明，由于采石场内的矿物学变化，Si/Al 摩尔比发生了变化（1.4 到 3.3）。确实，非次生相和粘土相的含量因采石场的位置而异。核磁共振分析还表明，一些铁原子位于高岭石结构中，而针铁矿形式的其他铁相仅与高岭石和白云母等表面上的粘土矿物相互作用，不在它们的结构中。从热表征来看，高岭石中这种结构铁的影响也可以通过总收缩率的增加来证明。总之，这项工作确定了结构差异及其对砖生产的影响。高岭石和白云母，不在它们的结构中。从热表征来看，高岭石中这种结构铁的影响也可以通过总收缩率的增加来证明。总之，这项工作确定了结构差异及其对砖生产的影响。高岭石和白云母，不在它们的结构中。从热表征来看，高岭石中这种结构铁的影响也可以通过总收缩率的增加来证明。总之，这项工作确定了结构差异及其对砖生产的影响。