Activated alumina desiccant is a porous, highly dispersed, and large specific surface area alumina with adsorption properties and catalytic activity. It is suitable for drying various gases and liquids and is used as an adsorbent, desiccant, catalyst, and carrier in many reaction processes in the petroleum, fertilizer, and chemical industries. This product is made from high-purity alumina through scientific formulation and catalytic fine processing. It has high compressive strength, a long service life, and can be reused repeatedly through regeneration methods.

The principle of defluorination is that fluorine is adsorbed on the surface of the adsorbent to form insoluble fluorides, while SO42– on the adsorbent can exchange with other anions such as F- and HCO3ˉ in water. The adsorbent can be placed in a filter bed, with a thickness typically between 700~1000mm and a particle size of 0.5~2.5mm, and a filtration speed of 1.5~2.5m/n. The supporting layer uses pebbles, with a thickness of 400~700mm, and the pH of the raw water is adjusted to 5.5~6.5 with acid.

Using small particle activated alumina increases the specific surface area, which can enhance the defluorination effect and reduce water production costs. When the defluorination capacity of the activated alumina adsorbent does not meet standards, an aluminum solution of 1%~2% can be prepared and passed through the filter column at a flow rate of 0.6m/n for 6~8 minutes to regenerate it, after which it can be reused. This method has strong defluorination capacity and is an excellent technology for removing fluorides and various inorganic ions.

Typically, activated alumina is produced by calcining hydrated alumina at 400℃~600℃ or by burning ordinary alumina with alkaline metal ions at 400℃~500℃ to form white granular porous adsorbents.

//// Adsorption Function of Activated Alumina Desiccant

Activated alumina desiccant is a multi-microporous spherical material with strong adsorption capabilities, large specific surface area, high compressive strength, and long service life, and can be reused repeatedly through regeneration methods. This product is a white, spherical porous substance that is non-toxic, odorless, does not powder, and is insoluble in water. It is widely used in the instrument air drying in industries such as petrochemicals, chemicals, textiles, and metallurgy, and in pressure swing adsorption air separation devices, where the dew point can reach above -41 degrees. It can also be used for deep drying of liquid and gas phases in steel, petroleum cracking gas, ethylene, and propylene.

Activated alumina, also known as reactive alumina, has the English name Activated Alumina or Reactive alumina; activated alumin(i)um oxide. The term “activated alumina” is typically used to refer to alumina used in catalysts. It is a porous, highly dispersed solid material with a large surface area, and its microporous surface possesses the characteristics required for catalytic activity, such as adsorption properties, surface activity, and excellent thermal stability. Therefore, it is widely used as a catalyst and catalyst carrier in chemical reactions. Spherical activated alumina pressure swing oil adsorbent is a white spherical porous particle, with uniform particle size, smooth surface, high mechanical strength, strong hygroscopicity, and retains its original state without swelling or cracking after absorbing water. It is non-toxic, odorless, and insoluble in water. Activated alumina is an efficient desiccant for deep drying of trace water, making it very suitable for non-thermal regeneration devices.

//// Main Factors Affecting the Adsorption Performance of Activated Alumina:

⑴ Particle Size: The smaller the particle size, the higher the adsorption capacity, but the lower the particle strength, which affects its service life.

⑵ Raw Water pH Value: When the pH value is greater than 5, the lower the pH value, the higher the adsorption capacity of activated alumina. ⑶ Initial Fluoride Concentration of Raw Water: The higher the initial fluoride concentration, the greater the adsorption capacity.

⑶ Alkalinity of Raw Water: A high concentration of bicarbonate in raw water will reduce the adsorption capacity.

⑷ Chloride Ions and Anions. ⑸ Influence of Arsenic: Activated alumina has an adsorption effect on arsenic in water, and the accumulation of arsenic on activated alumina reduces the adsorption capacity for fluoride ions and makes it difficult to elute arsenic ions during regeneration.