Preparation method of low-cost ultra-white porcelain tile

The invention relates to a preparation method of a low-cost ultra-white porcelain tile. The preparation method comprises the following steps of (1) weighing materials, mixing the materials, adding water, a bonding agent and a dispersing agent, carrying out ball milling to prepare slurry, wherein sieving the slurry by 250 meshes with the weight percent of residues being less than 0.5%; carrying out ageing for 24-72 hours for spare use, wherein the materials comprise the following components by weight percent: 25-40% of kaolin, 40-50% of low-cost whitening mineral, 9-15% of feldspar and 6-11% of quartz sand, and the low-cost whitening mineral is mixture of black talc and diopside; (2) feeding the slurry into a spraying and drying tower to carry out spraying granulation so as to obtain body powder; (3) pressing the body powder to obtain a green body, feeding the green body into a drying kiln for drying so as to obtain the dried green body; and (4) applying transparent glaze on the dried green body, entering a roller kiln for firing so as to obtain the low-cost ultra-white porcelain tile. The preparation method has the advantages that the cost is lower, the prepared porcelain tile is high in whiteness and good in mechanical property and thermal stability property.