Method for preparing zirconium mullite brick with ultralow apparent porosity at low temperature by using microporous zirconium mullite multiphase material

The invention relates to the technical field of refractory materials, in particular to a method for preparing an ultra-low apparent porosity zirconium mullite brick at low temperature by using a microporous zirconium mullite multiphase material, which comprises the following steps: mixing the microporous zirconium mullite multiphase material, zirconium silica fume, active rho-Al2O3 and a dextrin solution to obtain mixed slurry, wherein d1 is more than or equal to 3mm and less than 5mm, d1 is more than or equal to 1mm and less than 3mm, and d1 is more than or equal to 0.074 mm and less than 1mm; the preparation method comprises the following steps: sequentially mixing a zirconium mullite composite material with d1 greater than 0 mm and less than 0.074 mm, and a mixture of a microporous zirconium mullite composite material with d1 greater than 0 mm and less than 0.074 mm, calcined a-Al2O3 powder, metal silicon and Suzhou soil, pressing, carrying out low-temperature firing to obtain a zirconium mullite brick, so