Rare earth high-salt wastewater has the characteristics of high salinity, high hardness and high content of heavy metal ions, and the inorganic salts such as sodium chloride and sodium sulfate contained in it are difficult to degrade in the natural environment, which will lead to soil salinization and groundwater pollution.
Rare earth high salt wastewater treatment process
Ion exchange method:
Rare earth ions in rare earth high-salt wastewater can be adsorbed and enriched by selective ion exchange resins, and regenerated by acid or alkali solution after resin saturation to achieve the highest quality of rare earth elements.
Solvent extraction:
The specific organic solvent is used to have a high solubility of rare earth ions in the wastewater, and the rare earth elements are effectively separated from the wastewater in the extraction tower, and then the pure rare earth compounds are obtained through the reverse extraction process.
Membrane Separation Technology:
The application of membrane separation technologies such as electrodialysis, nanofiltration, and reverse osmosis can effectively intercept the salt in the wastewater and partially extract rare earth elements, and produce two parts: fresh water and concentrated brine.
Advanced Oxidation Technology:
For example, electrocatalytic oxidation, fenton oxidation and other methods are used for oxidative decomposition of refractory organic matter that may exist in wastewater, and optimize wastewater water quality for subsequent treatment.
Crystallization separation method:
After the above pretreatment and separation steps, the remaining high-salt wastewater can be converted from the liquid phase to the solid phase by cooling crystallization and hot crystallization, which is convenient for further disposal or resource utilization.