How to identify bentonite
2022-03-11
In the naked eye identification, high-quality bentonite is pure white, generally gray or light yellow white, often due to water absorption or containing impurities and light green, light green, rose red and other colors. It is still pure white, gray or light yellow white after air drying. After being broken by hand, the section is uneven and jelly-like. There is grease luster, hand touch with slippery feeling. Can absorb water expansion, good can become colloidal. If the water is lost after long-term air drying, it can become loose again. Bentonite has a strong ion exchange force, so it can absorb or absorb a variety of colors. Mix it with grease to make the grease smoother. Its fine powder is added to the water suspension, dispersion (divergence) is very good, not easy to precipitate. Natural bentonite type, mainly according to the relative content of the type of cation montmorillonite is divided into calcium, sodium, hydrogen, hectorite, etc., which is mainly calcium montmorillonite clay called calcium bentonite. Most of the bentonite ore in China to produce calcium-based bentonite, calcium-based bentonite is cheaper than sodium-based bentonite, and easy to get, so we in the broiler and laying hens test, are using calcium-based soil. Feed the chicken with bentonite additive, because the palatability is good, the chicken loves to eat.
But only by the above introduction of the naked eye and other sensory identification is not accurate enough. There is no unified national standard for identification of bentonite in China. Most mines implement the "Ministry of Bentonite and Clay for Foundry" (1997) and enterprise standards. The main determination of blue absorption, moisture, colloid medium, through rate, wet pressure strength, expansion coefficient, pH value, etc., determination methods and standards are omitted here.