Are montmorillonite and kaolin the same?
Montmorillonite, also known as microcrystalline kaolinite, is a silicate aluminate whose main component is octahedral montmorillonite particles. Kaolinite, illite, and montmorillonite are the three most common clay minerals that makeup clay soil. Montmorillonite is the main component of bentonite. Most of the industrially valuable montmorillonite deposits in my country are produced in the Mesozoic volcanic rock system.
Montmorillonite has a dull luster. Hardness 2 to 2.5. Relative density 2 to 2.7, very soft. The water content of montmorillonite varies greatly with environmental humidity, and it has a high ability to absorb and expand water. After absorbing water, its volume expands and increases several to dozens of times, and it has a strong adsorption capacity. Montmorillonite monolayers can relatively firmly adsorb 4 monomolecular water layers
Generally speaking, the appearance of montmorillonite refers to the original bentonite ore, which is often in the form of earthy cryptocrystalline blocks. Montmorillonite is usually white, sometimes slightly red or green, and sometimes light gray. The scaly cleavage is complete. Montmorillonite mineral crystals are flaky, flocculent, or felt-like. In addition to the main mineral component montmorillonite, bentonite also contains other clay minerals, such as illite, kaolinite, chlorite, sepiolite, allophane, and attapulgite. The particle size of the montmorillonite clay particles contained in bentonite is generally less than 2μm. The physical and chemical properties of bentonite are mainly determined by the properties of the montmorillonite it contains.
Montmorillonite has excellent physical and chemical properties, such as water absorption and swelling, adsorption, dispersion and suspension, cation exchange, thixotropy, adhesion, lubricity, etc. It can be used as a binder, suspending agent, reinforcing agent, plasticizer, thickener, thixotropic agent, flocculant, stabilizer, purifying and decolorizing agent, filler, catalyst, carrier, filler, etc. It is used in building materials, metallurgy, petroleum, chemical industry, agriculture, medicine, machinery, light industry, food, environmental protection, and other fields.