The adsorption and desorption behavior and mechanism research of cobalt, nickel and copper in nitrite - sulfuric acid system

In this paper, we studied the adsorption and desorption characteristics of cobalt, nickel, and copper in nitrite–sulfuric acid system, and their adsorption mechanism was also explored. The results showed that the adsorption capacity of cobalt and copper on the anion exchanger is 206 and 175 mg/g, respectively. However, the nickel adsorption capacity was very weak, exhibiting almost no adsorption. When the concentration of sodium nitrite was 1 mol/L, IRA-900 resin showed the best adsorption selectivity to cobalt. The FT-IR, UV absorption spectrometry, and XPS analysis results indicated that the adsorption mechanism of cobalt and copper could be attributed to the formation of anionic nitro-complexes in the solution, which could be exchanged with the anions on the resin to achieve the adsorption of metal ions. After a series of investigations, 1 mol/L sulfuric acid and ammonia were selected as desorption agents for cobalt and copper.