Activated clay is an adsorbent made from clay (mainly bentonite) as raw material, treated with inorganic acidification, salt or other methods, and then rinsed and dried with water. It has a milky white powder appearance, is odorless, odorless, non-toxic, and has strong adsorption performance. It can adsorb colored and organic substances. It is easy to absorb moisture in the air, and placing it for too long will reduce the adsorption performance. When using, it is advisable to heat (preferably at 80-100 degrees Celsius) to revive. However, heating above 300 degrees Celsius begins to lose crystalline water, causing structural changes and affecting the fading effect. Activated clay is insoluble in water, organic solvents, and various oils, almost completely soluble in hot caustic soda and hydrochloric acid, with a relative density of 2.3-2.5, and minimal swelling in water and oil.

The naturally occurring white clay with inherent bleaching properties is a white, white gray clay mainly composed of montmorillonite, albite, and quartz, and is a type of bentonite.

Mainly the product of the decomposition of glassy volcanic rocks, which do not expand after absorbing water, and the pH value of the suspension is different from that of alkaline bentonite; Its bleaching performance is worse than that of activated clay. The colors generally include light yellow, green white, gray, olive color, brown, milk white, peach red, blue, etc. There are very few pure white ones. Density 2.7-2.9g/cm. The apparent density is often low due to its porosity. The chemical composition is similar to that of ordinary clay, with the main chemical components being aluminum oxide, silicon dioxide, water, and a small amount of iron, magnesium, calcium, etc. No plasticity, with high adsorption capacity. Due to its high content of hydrous silicic acid, it is acidic to litmus. Water is prone to cracking and has a high water content. Generally, the finer the fineness, the higher the decolorization power.

When conducting quality evaluation during the exploration phase, it is necessary to measure its bleaching performance, acidity, filtration performance, oil absorption, and other items.