Preparation of organic bentonite montmorillonite minerals are: montmorillonite is a unique properties of aluminosilicate minerals, by the two layers of SiO tetrahedral sheet sandwiched a layer of AIO (OH) octahedral sheet composed of lamellar minerals. The Si + in the montmorillonite structural unit layer can be replaced by A13 +, and the AP + in the octahedral layer is often replaced by polyvalent ions such as Mg2 +, Fe3 + and Zn2 +, so that the charge in the lattice is unbalanced and the residual negative charge is generated. It has the ability to adsorb cations and exchange anions. With high hydration energy, the oxygen layer and the oxygen layer between the crystal layers in the C axis (lamellar stacking direction) are smaller and can form good dissociation Surface, easy to immerse in water molecules or other polar molecules, causing the expansion of the C-axis direction.
This is the performance that other non-expansive clays do not have. Because of this property, the montmorillonite layers are filled with nH: O interbedded water and exchangeable cations, which are the motivations that cause the expansion of montmorillonite.
However, the types of interchangeable cations between montmorillonite and bentonite with different mineralization conditions are very different from exchange capacity (CEC). (Ca2 +, Mg2 +, etc.) montmorillonite double layer hydration film is thin, the expansion ratio is low; low-cost cation (Na +, K +, etc.) hydration film thickness, high expansion factor. Thus, Na + montmorillonite reacts with the organic coating agent.