Activated clay is a clay (mainly bentonite) as raw material, the inorganic acid, followed by water rinsing, drying adsorbent made of, look for the milky white powder, odorless, tasteless, non-toxic, strong adsorption, can adsorb colored material, organic matter. Easy to absorb moisture in the air, place too long will reduce the adsorption properties. However, heated to 300 degrees Celsius above began to lose water of crystallization, is the change in structure, effects of fading effect. Senior activated clay products, products for the gray white, pink or white powder or granular, non-toxic and tasteless, insoluble in water, easy to absorb moisture; with larger specific surface area and more active acid center, so the catalytic and adsorptive ability strong, so not only have decolorization ability better, at the same time activity the degree is high, the low rate of oil, filtering speed, is the most ideal bleaching agent.
Use of activated clay widely, in animal and vegetable oil refining industry for the decolorization and purification; in the petroleum industry, used for petroleum resin, wax, paraffin oil, kerosene decolorization and purification; paper industry for paper dyes, dye, fill oil. As a fire extinguisher powder in forestry and water and soil conservation, binder hond elimination of oil in water; used as a catalyst and catalyst carrier in chemical industry, carrier insecticides, pesticides and fungicides, rubber and plastic filler, desiccant and filtering agent, adsorbent radioactive waste; in water purification and sewage treatment as absorbent and flocculant. The use of appropriate heating (80 to 100 degrees) resurrection, if heated to 300 degrees above began to lose water of crystallization, structure change, affecting decolorization.
CA bentonite as raw material, using sulfuric acid as activator, on activated clay production process was studied by orthogonal experiment, and the optimum technological conditions are determined according to the performance of activated product activation. The results show that, the main factors affecting the decolouring ratio as the acidity, liquid to solid ratio, temperature and activation time. Under the optimum conditions, the decolorization of activated clay rate can reach more than 90%.
Key acid clay variable Activated Bleaching Clay is activation of bentonite:
Activation operation 1, bentonite, generally used in sulfuric acid as activator, sulfuric acid consumption in the range 5-25%, liquid to solid ratio in 2-5:1, activation temperature of around 95, the activation time of 4-8 hours.
2, washing acid: bentonite slurry activated containing excess acid, the impact of product use, must be washed to remove, acid reaches the standard. Generally use the rinsing solution acid, each time the amount of water is about 10 times as large as the material, fully stirring settlement) 1-2 hours, the supernatant was removed, rinse 3-5 times, so that the final rinse solution of pH of 4-5.
3, solid-liquid separation and drying
Contain a lot of water slurry after washing, filtration or centrifugal way by dehydration, electric heating drying oven drying, the general temperature at around 105, 2-3 hours.
4, crushing and classification
The dried material agglomeration is more, has a certain hardness, need grinding sieve, obtained for activated clay products, sealing packing.