Activated clay is a clay (mainly bentonite) as raw material, the inorganic acid treatment, and then rinsed by water, dry made of adsorbent, the appearance of milky white powder, odorless, tasteless, non-toxic, strong adsorption, adsorption Colored material, organic matter. Easy to absorb moisture in the air, placed too long will reduce the adsorption performance. However, heating to 300 degrees Celsius above began to lose crystal water, is the structure changes, affecting the fading effect. Activated clay is insoluble in water, organic solvents and a variety of oils, almost completely soluble in hot caustic soda and hydrochloric acid, the relative density of 2.3 to 2.5, in the water and oil swelling is minimal. Widely used in mineral oil, animal and vegetable oils, wax and organic liquid decolorization refining. It can also be used as raw material for water desiccant, internal medicine drug alkali antidote, vitamin A, B adsorbent, lubricating oil superficial contact agent, gasoline and gas phase refining agent, etc. It can also be used as medium temperature polymerization catalyst, high temperature polymerization agent and raw material for making granular clay The
In the past, people only knew that bentonite was the raw material of activated clay. In fact, mineral materials with clay properties could be used as raw materials for activated clay, such as kaolinite clay, montmorillonite clay, sepiolite clay, attapulgite clay Wait.
Kaolinite kaolin is a kind of kaolinite mineral as the main component, the texture of pure fine clay, the appearance of white, light gray and other colors, with impurities when the yellow, gray, black and so on. Dense block or loose soil-like, a creamy feeling, hardness is less than nails. The proportion of 2.4-2.6, after drying with water absorption. Refractoriness up to 1770-1790 ℃. Low plasticity, low adhesion, good insulation and chemical stability.
Pure kaolin calcined white, white up to 80% -90%. Montmorillonite clay, also known as bentonite, bentonite, porphyrite, is a montmorillonite as the main mineral composition of fine clay. Appearance is generally white, pink, light gray, light yellow, when the impurities can be gray-green pollution, purple brown and other darker colors. Loose soil-like shiny dim, dense block were waxy luster. Hardness 1-2, soft and soft. Block or soil, with a slippery feel. Specific gravity 2-3. After the volume of water swelling, water absorption of its volume of 8-15 times. With high plasticity and good adhesion, in the aqueous solution was suspended and gelatinous, but also has the characteristics of cation exchange. The sepiolite clay is a clay containing sepiolite as the main ingredient. Appearance is yellow brown, dark gray, gray and other color, soil block, soft and light, hardness 1-2, the proportion of 2.4-2.65, with a sticky and plasticity, hand touch of a sense of sliding. Add water can be transferred into a paste, dry with a hammer can leave a hammer marks. Attapulgite clay is a kind of attapulgite as the main component of the clay, the appearance and the clay is the same, especially with the montmorillonite clay is very similar, and often symbiotic. Its field identification mark is the appearance of soil-like, was gray, gray, duck color, delicate soil, a sense of slippery, wet with a sticky and plasticity, dry after the light, shrink small. Put it into the water, hissing, and collapsing into pieces, but not swell. The properties of attapulgite clay, like sepiolite clay, are characterized by thermal stability, salt resistance, adsorption and high decolorization. Hunan made of activated clay with sepiolite, Zhejiang also found b-axis disorder of kaolin can also be activated clay, Shandong successful development of the residue with a water purifier for the active raw materials of clay. So that the raw material of activated clay is more extensive. But what we usually call active clay refers to activated clay with bentonite as raw material. The
Activated clay with sepiolite, to be selected, acid activation process can be made into activated clay. Selection is the use of water, liquid to solid ratio of 5 to 10. After the election of water after adding 0.5% sulfuric acid or 1.5% hydrochloric acid, boil 30min, and then filter, washed, dried, grinding is the product, decolorization rate of 93%, more than 90% of the national standard bleaching rate requirements. The attapulgite clay has the characteristics of high decolorization rate, no residual acid and so on.