Al-TiO2-C grain refiner, preparation method thereof and commercial-purity aluminum refining method

The invention discloses an Al-TiO2-C grain refiner, a preparation method thereof and a commercial-purity aluminum refining method. The Al-TiO2-C grain refiner is composed of Al powder, TiO2 powder and C powder. The preparation method of the Al-TiO2-C grain refiner comprises the steps that 1, the Al powder, the TiO2 powder and the C powder are mixed and then processed on a star type ball mill through ball milling for 0.5-2 h; 2, a precast block with the diameter phi being 30 is pressed on a universal tester, wherein 85 KN pressure is used for block pressing; 3, the precast block is wrapped by aluminum foil, and air between the precast block and the aluminum foil is extruded for storage; 4, the precast block is sintered in a high-temperature sintering furnace; and 5, furnace cooling is carried out, then the sintered precast block is taken out, and therefore the prepared Al-TiO2-C grain refiner is obtained. Precipitated phases of the prepared Al-TiO2-C grain refiner are TiC, Al2O3 and Al3Ti phases. The Al-TiO2-C grain refiner has the good grain refining effect. By adjusting the ratio of C to TiO2, the TiO2 addition, pressure needed for precast block preparation and the like, Al2O3 with the appropriate amount is contained in the Al-TiO2-C grain refiner structure and distributed in a relatively dispersed mode, and the better grain refining effect is achieved.