Such as copper, magnesium, sodium and potassium. However, the interaction between these cations and montmorillonite cells is very unstable and easy to be exchanged by other cations, so they have good ion exchange. Abroad, it has been applied in more than 24 fields of industrial and agricultural production 100 departments, with more than 300 kinds of products, so people call it "universal soil".
nature
The main chemical components are silica, alumina and water, and also contain elements such as iron, magnesium, calcium, sodium and potassium. The contents of Na2O and CaO have great influence on the physical and chemical properties and technological properties of bentonite. Montmorillonite minerals belong to monoclinic system, which is usually earthy and white, sometimes with light red, light green, light yellow and other colors. Gloss is dull.
The hardness is 1 ~ 2 and the density is 2 ~ 3g/cm3. Bentonite can be divided into sodium bentonite (alkaline earth), calcium bentonite (alkaline earth) and natural bleaching soil (acid soil or acid clay) according to the type, content and interlayer charge of montmorillonite, among which calcium bentonite includes calcium sodium bentonite and calcium magnesium bentonite. Bentonite has strong hygroscopicity and expansibility, which can absorb 8 ~ 15 times its own volume of water, and its volume expansion can reach several times to 30 times.