U resin Strongly basic anion exchange resin

What is an ion exchange resin? 
Ion exchange resins are a type of high-molecular functional material. They usually appear as spherical particles in appearance, and have a porous network structure inside. The high-molecular framework of these resins is connected with active groups that can undergo exchange reactions with ions in the solution. When a uranium-containing solution flows through the resin, the active groups on the resin will undergo exchange with uranium ions, "capturing" the uranium ions, thereby achieving the enrichment and separation of uranium. 
According to the different active groups, ion exchange resins can be classified into two major categories: cation exchange resins and anion exchange resins. 
In the extraction of uranium, uranium mainly exists in the alkaline leaching solution in the form of the carbonate uranyl anion ([UO₂(CO₃)₃]⁴-). 
In the acidic leaching solution, uranium exists mainly in the form of uranyl ions (UO₂²⁺) and the uranyl sulfate complex anion formed by it and sulfate ions (UO₂(SO₄)₃]⁴⁻). 
Therefore, strong basic anion exchange resins with positively charged groups have become an ideal choice for uranium extraction.

Uranium extraction resin: The outstanding "uranium catcher" 
The uranium-containing resin is precisely designed based on the above principle. It is a strong basic anion exchange resin with quaternary ammonium groups attached to a macroporous styrene-divinylbenzene copolymer, belonging to the styrene-based resin. 
From the perspective of chemical structure, the uranium extraction resin is a cross-linked copolymer of styrene and divinylbenzene as the framework, and the functional group -N+(CH3)3 is introduced through chemical modification. These quaternary ammonium groups carry positive charges and can form electrostatic attraction and ion exchange with the carbonate uranyl anion/trisulfate uranyl ion in the solution, thereby achieving the selective adsorption of uranium ions. 
The chemical essence of the uranium extraction process is the synergy of ion exchange and coordination: 
Electrostatic traction: 
The R-N⁺(CH₃)₃ fixed on the resin framework forms a strong Coulombic attraction with [UO₂(CO₃)₃]⁴⁻ / [UO₂(SO₄)₃]⁴⁻ in the solution. (This causes the uranium complex carrying -4 charge to be strongly attracted to the adsorption sites carrying +1 or +4 charge.) 
Ion substitution: 
When the resin leaves the factory, it usually carries chloride ions (Cl⁻ type). When the uranium-containing solution passes through, the uranium oxyanion/trisulfate uranium ion will replace the Cl⁻ on the resin, enter the resin phase and be firmly fixed. 
The chemical equation for this process can be simplified as:

Alkali:

Acid: