Preparation method for rare earth oxide through jet pyrolysis of rare earth chloride solution

Abstract

The invention brings forward a preparation method for a rare earth oxide through jetting low-temperature rapid pyrolysis of a rare earth chloride solution. The method comprises the following steps: (1) combusting combustion gas and O2 according to certain flow so as to form high temperature mixed tail gas which is used as a heat source and a working fluid for a pyrolytic reaction; (2) allowing the rare earth chloride solution to enter into a jet device and be heated by the high temperature mixed tail gas so as to realize gasification and form tiny bubbles in dispersed distribution and carrying out the pyrolytic reaction so as to obtain rare earth oxide powder and high temperature pyrolysis tail gas containing HCl gas; and (3) introducing a gas-solid mixture of the rare earth oxide powder and the pyrolysis tail gas obtained after pyrolysis into a cyclone separator, carrying out gas-solid separation so as to obtain the rare earth oxide powder, introducing the pyrolysis tail gas into an absorbing tower for absorption by an absorbent so as to obtain a hydrochloric acid solution and totally discharging residual purified tail gas. The method can substantially reinforce mass transfer and heat transfer efficiency, reduces pyrolysis energy consumption and enables the rare earth chloride solution to be rapidly pyrolyzed; and the obtained rare earth oxide powder has small granularity, uniform particle distribution and high purity.

Description

technical field [0001] The invention belongs to the field of rare earth metallurgy, and in particular relates to a method for preparing rare earth oxides from rare earth chlorides. Background technique [0002] Rare earth oxides have a wide range of uses. For example, lanthanum oxide is widely used in the manufacture of special alloy precision optical glass, high-refraction optical fiber boards, suitable for cameras, cameras, microscope lenses and advanced optical instrument prisms, ceramic capacitors and reaction catalysts. Cerium oxide is widely used in oxidants, catalysts for organic reactions, color-changing glass and enamel glass, etc. Praseodymium oxide is used in architectural ceramics and daily-use ceramics. It is mixed with ceramic glaze to make colored glaze, and it can also be used alone as underglaze pigment. The pigment produced is light yellow, pure and elegant in tone. Neodymium oxide is mainly used as a colorant for glass and ceramics, as a raw material for ...

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Problems solved by technology

[0006] The present invention aims at the disadvantages of low pyrolysis efficiency, long high-temperature roasting cycle, large particle size and uneven distribution of rare earth oxide powder obtained by pyrolysis, and low product purity in the preparation of rare earth oxides by direct roasting and pyrolysis of rare earth chloride solution, and proposes A method for preparing rare earth oxides by jet injection of rare earth chloride solution at low temperature and rapid pyrolysis, the method can significantly enhance mass transfer and heat transfer efficiency, reduce pyrolysis energy consumption, and rapidly pyrolyze rare earth chloride solution to obtain rare earth oxides Oxide powder has small particle size, uniform particle distribution, and high purity

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