Preparation method of ultrafine magnesium-based rare earth hexaaluminate powder

Abstract

The invention relates to a preparation method of ultrafine magnesium-based rare earth hexaaluminate powder, which comprises the following steps: (1) preparation of precursor colloid: a, uniformly mixing an aluminum salt solution, a magnesium salt solution and a rare earth solution in a certain proportion; and b, adding the mixed solution obtained in the step a into ammonium hydroxide, stirring the obtained mixture, keeping the pH value of the obtained mixture not less than 12, and standing for ageing, so that the precursor colloid is obtained; (2) impurity removal: carrying out centrifugal solid-liquid separation on the obtained precursor colloid, washing and concentrating the obtained object, so that wet precursor gel is obtained; (3) drying: drying the wet precursor gel, so that precursor powder is obtained; and (4) heat treatment: calcinating the precursor powder, so that ultrafine magnesium-based rare earth hexaaluminate powder is obtained. The method is low in sintering temperature, the purity of the obtained powder is high, and the obtained powder can achieve nanoscale without being processed, the preparation process is simple, and required equipment is simple, therefore, the method is suitable for large-scale industrial production.

Description

technical field [0001] The invention relates to a preparation method of magnesium-based rare earth hexaaluminate ultrafine powder, which belongs to the field of preparation and application of inorganic non-metallic materials. Background technique [0002] Magnesium-based rare earth hexaaluminate with a hexagonal magnetoplumbite structure is a very important functional material at present, and has been widely studied in many fields, such as: superconducting materials, crystal matrix of fluorescent materials, laser materials, It can also be used in nuclear waste disposal and other aspects. At the same time, due to the high thermal stability of this material, it has also made some progress in the application research as a catalyst for high-temperature catalytic combustion reactions and thermal barrier coating materials in recent years. [0003] At present, the methods for synthesizing magnesium-based rare earth hexaaluminate powder mainly include: high-temperature solid-state ...

AI Technical Summary

Problems solved by technology

The supercritical drying method can obtain catalysts with better performance than oven drying. Under supercritical drying conditions, due to the disappearance of the gas-liquid interface, the capillary action is eliminated, so that the formed airgel maintains a relatively loose structure. The uniform mixing degree of the reactant molecular level is maintained, so the final sample has a high specific surface area, but the disadvantage of this method is high production cost and harsh reaction conditions

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