Inside a conical acid hydrolysis tank lined with two layers of tiles. According to the ratio of mineral acid ratio of 1:1.5～1:1.7 (mass ratio, sulfuric acid is calculated as 100%), make the pre-adjusted process concentration of 88%-90% sulfuric acid and pre-pulverize to 325 mesh and mix 0.2% antimony oxide The dried ilmenite powder is subjected to acidolysis reaction. The acid hydrolysis reaction can only take place when the reactants are preheated to above 90°C. Under the stirring of compressed air, with the progress of the reaction, the heat of reaction increases, and the temperature gradually rises to 180-200 °C, and a violent reaction occurs. Afterwards, a porous solid-phase acid hydrolysis reaction product is formed. After cooling, leaching is carried out in a precipitation tank at 55-65 °C. A flocculant is added to the obtained leachate, and the unseparated matter and mechanical impurities suspended in the leachate are separated by sedimentation. The obtained leachate mainly contains titanium sulfate, but also contains many divalent and trivalent ferric sulfates. The ferric iron is reduced by adding iron filings, and then frozen to 3-5°C. The ferrous sulfate can be crystallized out by a frozen brine refrigeration device or a vacuum adiabatic evaporative refrigeration device, the by-product ferrous sulfate is removed by filtration, and the pure titanium liquid is concentrated to 190-210gTiO2/L solution by vacuum evaporation, and sent to hydrolysis under stirring Reactor, adding pre-specialized seed crystals in the seed crystal tank for hydrolysis to generate hydrated Titanium Dioxide Ema (commonly known as metatitanic acid). There are two methods to realize the hydrolysis process in industry: normal pressure and pressurization, and the temperature is different. There are also many methods for making seed crystals, which vary with product requirements and manufacturers. The metatitanic acid generated by hydrolysis is repeatedly washed with a leaf filter to remove soluble iron salts, and then sent to a rotary furnace for calcination at 800-850 °C. Before calcination, salts should be added to the salt treatment tank for salt treatment. The purpose of the salt treatment is to reduce the calcination temperature and promote the transformation of the crystal form, and to improve the grinding wettability of the pigment. The calcined Titanium Dioxide Ema does not yet have pigment properties and requires post-processing. The post-processing is to dry-pulverize the calcined Titanium Dioxide Ema with a Raymond mill or a universal pulverizer, and then use a spray dryer (or a belt dryer, boiling Fluidized dryer, drying room, etc.) drying, and then superfine pulverization with a jet mill to ensure that the particle size of the product is below 1 μm.