A modified method of preparing active alumina, and

The invention relates to a modified activated aluminum oxide and a preparation method thereof. The modified activated aluminum oxide consists of lanthanum nitrate La, aluminum nitrate Al, polyethylene glycol solution and ammonia water. The preparation method comprises the following steps of: 1, dissolving the lanthanum nitrate and the aluminum nitrate in water in a mass ratio of (3.0-10.0):100 toform mixed solution a; 2, adding 40-percent polyethylene glycol solution into the mixed solution a to form mixed solution b; 3, stirring the mixed solution b quickly, adding 8 mol/L of ammonia water,and mixing and reacting until the pH value is 8.5 to obtain semitransparent pasty suspension c; 4, conveying the semitransparent pasty suspension c to a centrifugal machine, and separating to obtain a precipitate d; 5, conveying the precipitate d to a microwave drying chamber, and drying for 5 to 30 minutes; and 6, loading a dried material e into a crucible, conveying to a high-temperature furnace, and calcining at the temperature of between 850 and 1,200 DEG C for 2 to 6 hours to obtain the modified activated aluminum oxide. The invention has the advantages that: the modified activated aluminum oxide has a large specific surface area, can exist stably at high temperature, and is high in dispersibility and purity; the cost is reduced by 30 to 40 percent; and the yield is improved by over 20 percent.