Preparation method of high-purity fused magnesia powder

Abstract

The application discloses a preparation method of high-purity fused magnesia powder, which comprises precursor granulation and pre-decontamination, wherein industrial light-burned magnesia powder with a mass percentage of magnesia of greater than or equal to 98.5% is selected as raw material, the light-burned magnesia powder is mixed with deionized water at a mass ratio of 1:1.5-2.5, and then is put into a strong kneader for normal-temperature stirring for 20-40 min to prepare uniform suspension slurry; 0.2%-0.5% of ammonium bicarbonate and 0.1%-0.3% of polyammonium acrylate, which account for the mass of the light-burned magnesia powder, are added into the slurry, and continuous stirring is carried out for 10-15 min until the additives are completely dispersed; the mixed slurry is sent into a pressure type spray granulation tower, the inlet air temperature is controlled to be 280-320 DEG C, the outlet air temperature is controlled to be 110-130 DEG C, and spray granulation is carried out to obtain spherical porous precursor particles with a particle size of 0.5-2 mm; the application solves the problems of poor convection, existence of smelting dead zones and uneven composition of a traditional smelting bath, and can drive directional enrichment and separation of trace metal impurity ions, without adding any external purification additives, and secondary impurity pollution is avoided.

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