Study on non-saponification extraction process for rare earth separation

The purpose of this study was to overcome the disadvantages of ammonia-nitrogen wastewater pollution and high cost of sodium saponification in rare earth separation process. The study focused on the non-saponification extraction technology with magnesia. The influences of the content and particle size of magnesia, reaction time, reaction temperature, and O/A on cerium extraction rate were also discussed. The results showed that the hydrogen ions of extractant were exchanged by rare earth ions when organic extractant and rare earth solution were mixed with magnesia powder, and then the exchanged hydrogen dissolved magnesia to make the acidity of the system stable. The magnesium ions were not participated in the extraction reaction. Non-saponification extraction process of rare earth had been realized. The cerium extraction rate could reach up to 99% in single stage within the optimal reaction conditions.

Graphical AbstractEffect of time on extraction rate in different circumstances (No. 1: P507+MgCl2; No. 2: P507+CeCl3; No. 3: P507+MgO; No. 4: P507+MgCl2+ MgO; No. 5: P507+CeCl3+MgO; No. 6: P507+CeCl3+ MgO+MgCl2) (CMgO=0.270 mol/L, dMgO=−200 mesh, CP507=1.473 mol/L, T=25 °C, CCeCl3=0.180 mol/L, CMgCl2=0.270 mol/L, O/A=1)Figure optionsDownload full-size imageDownload as PowerPoint slide