Preparation of Rare Earth Metals
Rare earth metal production, also known as rare earth fire metallurgical production. Rare earth metals are generally divided into mixed rare earth metals and single rare earth metals. The composition of the mixed rare earth metal is close to that of the rare earth in the ore, and the single metal is the rare earth separation and purification of the metal. Rare earth oxide (in addition to samarium, europium, ytterbium and thulium oxide) as raw materials with the general metallurgical method is difficult to restore a single metal, because of its great heat generation, high stability. Therefore, the current production of rare earth metals commonly used raw materials are their chlorides and fluoride.
Industrial mass production of mixed rare earth metals are generally used in molten salt electrolysis. This method is rare earth chloride and other rare earth compounds heated and melted, and then electrolysis, in the cathode precipitation of rare earth metals. Electrolysis of chloride electrolysis and oxide electrolysis in two ways. The preparation of single rare earth metals varies from element to element. Samarium, europium, ytterbium, thulium due to high vapor pressure, not suitable for electrolysis preparation, and the use of reduction distillation. Other elements can be prepared by electrolysis or metal thermal reduction.
Chloride electrolysis is the most common method of producing metal, especially mixed rare earth metal process is simple, cheap, small investment, but the biggest drawback is the chlorine release, pollute the environment.
Oxygen electrolysis without harmful gas release, but the cost is slightly higher, the general production of higher prices of a single rare earth such as neodymium, praseodymium and so on with the oxide electrolysis.read more: