Method for preparing micro-nano lanthanum oxide through combustion-calcination

Abstract

The invention relates to the field of preparation methods of materials, in particular to a method for preparing micro-nano lanthanum oxide through combustion-calcination, which comprises the following steps: uniformly mixing a lanthanum source, a dispersing agent and a solvent to obtain a first mixture, atomizing the mixture and spraying the mixture into a rotary kiln for combustion, generating hot flue gas and solid materials in the combustion process, recycling solid particles in the hot flue gas, adding the solid particles into the rotary kiln, calcining the solid particles and the solid materials through part of heat released by the hot flue gas to obtain a second mixture, and cooling and grinding the second mixture to obtain the micro-nano lanthanum oxide. The lanthanum source and the liquid organic fuel are mixed into the solution or the slurry, the solution or the slurry is atomized and burnt in the rotary kiln and calcined into the lanthanum oxide, the lanthanum oxide powder of different sizes can be prepared by adjusting the variety and the concentration of the lanthanum source, the using amount of the dispersing agent, the variety of the fuel, the calcining time, the grinding time and the like, the production process is continuous, and the lanthanum oxide powder can be prepared on a large scale.

Description

technical field [0001] The invention relates to the field of materials preparation methods, in particular to a method for preparing micro-nano-scale lanthanum oxide by combustion-calcination. Background technique [0002] Lanthanum oxide (La 2 o 3 ) is an important light rare earth product, which is widely used in the manufacture of catalysts, precision optical glass and optical fibers, and is also used in the manufacture of ceramic capacitors, piezoelectric ceramic doping agents and X-ray luminescent materials such as lanthanum oxybromide powder. Lanthanum oxide is used in petrochemical and automobile exhaust purification, such as catalyzing the oxidation reaction of carbon monoxide when doped with cadmium oxide; in the field of optomagnetic materials, it can be used to improve barium titanate (BaTiO 3 ), strontium titanate (SrTiO 3 ) The temperature dependence and dielectric properties of ferroelectrics, the micro-nano-level lanthanum oxide has the characteristics of la...

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Problems solved by technology

[0003] At present, the preparation methods of micro-nano lanthanum oxide mainly include precipitation method, sol-gel method, hydrothermal method and microemulsion method, etc. The emerging methods mainly include electrospinning method, molten salt method, low-temperature combustion method, etc. The above-mentioned methods Most of them are based on laboratory synthesis, or the sources of raw materials are narrow, expensive, or the process is complicated, the conditions are harsh, or it is difficult to achieve large-scale and industrial production

[0004] Literature (Wang Lihua, Yi Xiaodong. Preparation and properties of nano-lanthanum oxide [J]. Journal of Fujian Normal University (Natural Science Edition), 2012 (04): 60-63.) Using sol-gel method to prepare tens of nanometer The lanthanum oxide; literature (Li Li. Synthesis and application research of micro / nano lanthanum oxide [D]. Xi'an Polytechnic University.) using hydrothermal method to synthesize spherical lanthanum oxide from hundreds of nanometers to several microns, and found micro-nano Grade lanthanum oxide can improve the dyeing effect of polyester; the patent (Rare earth oxide particles and method for preparation thereof US6387339B1) uses the precipitation method to prepare nano-lanthanum oxide powder, which has many steps and is difficult to produce continuously; the patent (Process for preparing nanosized powder US5698483A) prepared a spherical nano-lanthanum oxide by adding a soluble rare earth salt to alkali precipitation, but the method has a long process and high energy consumption; the patent (a method for preparing uniformly dispersed nano-lanthanum oxide CN 102161498A) prepared by precipitation A uniformly dispersed nano-lanthanum oxide, but the method uses many types of raw materials, and some raw materials are expensive; the patent (a preparation method of high-purity nano-lanthanum oxide material CN 111017980 A) is a method of precipitation, rotary evaporation, drying, and calcination A high-purity nano-lanthanum oxide material is obtained, but the method is complex in process, high in cost, and difficult to produce on a large scale. For this reason, the present invention proposes a method for preparing micro-nano-scale lanthanum oxide by combustion-calcination

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