Anti-adsorption mechanism of ion-adsorption type rare earth tailings

To investigate the process of RE^(3+)anti-adsorption on ion-adsorption type rare earth tailings,the thermodynamics,adsorption kinetics and infrared spectroscopy of these materials were investigated.The results indicate that the initial reaction rate of anti-adsorption of rare earth tailings is fast,but it reaches a balance in 6 min.The formula 1-2a/3-(1-a)2/3=k_2t(k represents rate constant of the reaction,a represents anti-adsorption rate of rare earth ore,t represents anti-adsorption time)of internal diffusion can be used to predict the kinetics of anti-adsorption in IATRE tailings.BecauseΔH<0,ΔG<0,ΔS>0(ΔH,ΔG,ΔS represent change of enthalpy,Gibbs free energy and entropy,respectively),the anti-adsorption of RE^(3+)on ion-adsorption type RE tailings is a spontaneous physical adsorption process.The effects of ligand exchange and strong chemical bond are not found in this process.Because the anti-adsorption process is exothermic,heating will inhibit the reaction and decrease the anti-adsorption performance.According to the infrared spectrum analysis,there are no significant changes in the mineral surface after anti-adsorption.Based on these findings,the anti-adsorption of rare earth tailings is physical adsorption.