Dissolution of Rare Earth Elements from Zanjan Morvarid Iron ore tailings by leaching and acid digestion method

In this research, the leaching of REEs from the tailing of the apatite-iron ore processing unit of Morvarid mine (NW Iran), has been investigated using nitric, hydrochloric and sulfuric acids. This tailing contains rare earth elements (REEs) specifically Ce, La, Nd, Y and its accompanying minerals are magnetite, apatite, monazite, hematite, quartz. The appropriate dimensions for apatite release are 80-75μm. Leaching tests were performed for all three acids, and digestion process was also used for sulfuric acid. The leaching in the presence of sulfuric acid, under a temperature of 90°C, an acid concentration of 40% and a time of 60 minutes, leads to the total recovery of REE equal to 40.23%, and in acid sulfuric acid digestion at 200°C, equal to 61.21%. became. The recovery of REE when using hydrochloric acid at 72.64°C, concentration of hydrochloric acid 36.21% and time 56.28 minutes, was equal to 60.57%. In the presence of nitric acid, under the optimal conditions of temperature 61.51°C, acid concentration 40% and time 72.92 minutes. Furthermore, the maximum recovery of total REE equal to 51.9% was obtained. Due to the higher recovery and the lower price of sulfuric acid, this method is suggested for extracting for the extraction of REEs from the tailings.