To evaluate their potential uses in ceramic compositions, two different types of abundant clays from Kindia (Guinea Conakry), denoted ABD and ARD, were characterized with the chemical and mineralogical compositions, the specific surface area, the plasticity index, the particle size distribution, and the thermal behavior. Kaolinite and muscovite are the main clay minerals that are identified. Besides, non‐plastic minerals are large amount of quartz with a small particles size, goethite, hematite, anatase, and a small quantity of gibbsite. The two clays have a high plasticity index that is consistent with the small particle size and the broad size distribution. During heating, the fluxing behavior of the two clays induces a significant densification that is favored by the muscovite mineral combined with the reactive fine quartz. Besides, the firing shrinkage is limited to values of 4.5% and 3.5% for ABD and ARD respectively. In the objective of manufacturing ceramics, the two clays present the required properties. They present a sufficient plastic index in the green state, and after firing they lead to dense ceramics with an interesting bright color. The limited firing shrinkage is favorable to maintain the dimensional stability of vitrified ceramics as porcelain.

中文翻译：

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理化特性对金迪亚（几内亚）粘土在陶瓷组合物中的使用的影响

为了评估其在陶瓷组合物中的潜在用途，通过化学和矿物学组成，比表面积，可塑性指数，粒度分布，和热行为。高岭石和白云母是确定的主要粘土矿物。此外，非塑料矿物是大量具有小粒径的石英，针铁矿，赤铁矿，锐钛矿和少量的菱铁矿。两种粘土具有较高的可塑性指数，这与较小的粒径和较宽的粒径分布是一致的。在加热过程中，两种粘土的助熔剂行为引起明显的致密化，白云母矿物与反应性细石英相结合有利于这种致密化。除了，对于ABD和ARD，烧成收缩率分别限制为4.5％和3.5％。在制造陶瓷的目的中，两种粘土具有所需的性能。它们在绿色状态下表现出足够的塑性指数，并且在烧制后会形成致密的陶瓷，并具有有趣的鲜艳颜色。有限的烧成收缩有利于保持作为瓷器的玻璃化陶瓷的尺寸稳定性。