Abstract: Carbothermic chlorination reaction is made on the tailings of BaoSteel Concentrator with SiCL₄ as the de-fluorine agent.The effect of the reaction time, reaction temperature and de-fluorine agent on the yield of rare-earth chloride is investigated.The results indicate that at the presence of de-fluorine agent and at a temperature between 700~800℃, the chlorination reaction time is 2h and the chlorination rate is as high as above 95%.The X-ray diffraction of the acid-insoluble substance of the chloride product shows that the acid-insoluble content includes rare-earth fluoride, SiO₂, Fe₂O₃ and monazite between 450~500℃; SiO₂ and a small amount of monazite at 700℃; and SiO₂ and a small amount of monazite and rare-earth fluoride at 900℃.

Key words: Tailings, Rare earth, Carbothermic chlorination, De-fluorine agent