Combustion chamber and method for synthesizing ultrafine lanthanum oxide powder through combustion

Abstract

The invention relates to the technical field of rare earth oxide powder, and provides a combustion chamber and a method for synthesizing ultrafine lanthanum oxide powder through combustion. A combustion chamber comprising four atomizing nozzles is adopted to synthesize superfine lanthanum oxide powder, a first atomizing nozzle and a third atomizing nozzle are symmetrically distributed, and a second atomizing nozzle and a fourth atomizing nozzle are symmetrically distributed; the method comprises the following steps: feeding a flammable solvent into the combustion chamber from the first atomizing nozzle and the third atomizing nozzle under the action of a first carrier gas for ignition, feeding a lanthanum salt solution into the combustion chamber from the second atomizing nozzle and the fourth atomizing nozzle under the action of a second carrier gas for combustion, combusting more than 85% of lanthanum salt to generate lanthanum oxide in the combustion process, and subjecting the combustion product to microwave oxidation calcination to convert a small amount of residual lanthanum salt into lanthanum oxide. The method provided by the invention is simple in process, short in flow, easy to operate and low in cost, and the obtained ultrafine lanthanum oxide powder is good in dispersity, high in purity and uniform in particle size.

Description

technical field [0001] The invention relates to the technical field of rare earth oxide powders, in particular to a combustion chamber and a method for combusting and synthesizing ultrafine lanthanum oxide powders. Background technique [0002] Lanthanum oxide (La 2 o 3 ) is one of the important products in light rare earths. Because of its good physical and chemical properties, it has been widely used in civil, military and commercial science and technology fields. At present, it has been used in glass, ceramics, catalysts, phosphors, lasers , Heating body, cathode material and electrical contacts and other fields are widely used. Superfine La 2 o 3 Due to the characteristics of small size effect, surface effect, quantum size effect and macroscopic quantum tunneling effect, the powder has different thermal, magnetic, electrical, optical and other sensitive characteristics and surface stability, which are different from traditional powders and show more excellent perform...

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Problems solved by technology

[0003] At present, the existing methods for producing ultrafine lanthanum oxide powder mainly include vacuum condensation method, physical pulverization method, mechanical ball milling method, precipitation method, hydrothermal synthesis method, sol-gel method, supercritical fluid method and solvent evaporation method, etc. However, the above-mentioned methods for preparing ultrafine lanthanum oxide powder all have the problems of complex preparation process, difficult control, and high input cost, and it is difficult to obtain ultrafine lanthanum oxide powder with high purity, good dispersibility, and uniform particle size.

D of lanthanum oxide powder prepared by conventional oxalate precipitation 50 Between 2.5 and 6.0 μm, the particle size is large and the distribution is wide; methods such as ammonium bicarbonate precipitation, ultrasonic uniform precipitation, and solid-phase synthesis are all used in the preparation of ultrafine La 2 o 3 Agglomeration is easy to occur in the powder process, resulting in uneven particle size; the sol-gel method has the disadvantages of slow gelation process, large shrinkage during drying, and uneven particle size.

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