Cerium

After cerium is separated from other rare earth elements through ion exchange or solvent extraction technology, metallic cerium can be prepared by the metal thermal reduction method. Lithium thermal reduction of rare earth chlorides is different from calcium thermal reduction of rare earth chlorides. The reduction process of the former takes place in the gas phase. The lithium thermal reduction reactor is divided into two heating zones, and the reduction and distillation processes are carried out in the same equipment. Anhydrous cerium chloride is placed in the titanium reactor crucible at the top (also the CeCl3 distillation chamber), while the reducing agent metallic lithium is placed in the crucible at the bottom. Then, the stainless steel reaction tank is evacuated to 7Pa and heating begins. When the temperature reaches 1000℃, it is maintained for a certain period of time to allow the CeCl3 vapor to fully react with the lithium vapor. The solid cerium metal particles reduced out fall into the crucible at the bottom. After the reduction reaction is completed, only the lower crucible is heated and the LiCl is distilled to the upper crucible. The reduction reaction process usually takes about 10 hours. To obtain relatively pure metallic cerium, the reducing agent metallic lithium should be 99.97% high-purity lithium, and anhydrous CeCl3 obtained through secondary distillation should be used.