Process for preparing aluminate fluorescent powder by coprecipitation method

Abstract

A method for preparing aluminate phosphor by means of coprecipitation, belonging to the preparing process for phosphor, comprising: (1) weighing the nitrate, carbonate, acetate or oxidate relevant to the metal according to the chemical composition of the aluminate phosphor, preparing the metallic ion mixing solution; (2) preparing ammonium acid carbonate solution, the concentration is 1~3 mol / l, modifying the pH value to be 8~10; (3) adding additive to the ammonium acid carbonate solution; (4) heating the solution to 20~80 DEG C, adding the metallic ion mixing solution to the mixing solution; (5) stirring; (6) stopping stirring, stewing or carrying out centrifugal sedimentation, dewatering, drying and getting the puffy powder; (8) igniting the dried powder; (9) washing the ignited product with deionized water to be neutral, dewatering, drying, sifting with the mesh size being 400 and getting the needed phosphor.

Description

technical field [0001] The invention relates to a preparation method of aluminate fluorescent powder. It belongs to the preparation technology of phosphor powder in the fields of displays, fluorescent lamps, LEDs, and light-storing materials. Background technique [0002] The preparation of aluminate fluorescent powder generally adopts high-temperature solid-state reaction method, such as the method for preparing aluminate green fluorescent powder in US Patent No. Raw materials such as magnesium are mixed with an appropriate amount of flux, and then burned at a temperature of 1200-1600°C in a nitrogen / hydrogen weak reducing atmosphere, and then the burned product is dispersed by ball milling, washed with water, dried and sieved. The addition of fluxes such as boric acid can significantly reduce the synthesis temperature, but it also causes serious sintering of the phosphor powder. The particle size of the phosphor powder must be reduced by ball milling...

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Problems solved by technology

However, our experiment found that the phosphor particles prepared by the above method still have hard agglomeration phenomenon, and it is difficult to obtain fine and dispersed powder

[0005] When using the co-precipitation method to synthesize aluminate matrix phosphors, Al 3+ easy to form Al(OH) 3 It precipitates in the form of gel, and the primary particles of the precipitated product are extremely small (about 5-10nm), which will sinter or hard agglomerate after burning at high temperature, and the phosphor particles obtained by this method will also sinter, so the phosphor remains There are problems of coarse particles and serious agglomeration, and it is also difficult to prepare real ball-milling-free aluminate phosphors

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