关键词: 煤矸石, 酸浸, 氧化铝, 动力学

Abstract: Coal gangue in Panxian, Guizhou Province, was used to extract alumina by leaching with concentrated sulfuric acid. The single factor and orthogonal experiments were conducted to examine the factors influencing the leaching rate of alumina such as the mass ratio of acid to gangue, reaction time and reaction temperature. The optimal conditions and leaching kinetics of this process were also studied. The results show that under the optimal conditions of mass ratio of acid to gangue 1.4(w), reaction time 4 h, and reaction temperature 170℃, the leaching rate of alumina reaches 98.47%. The leaching kinetic study shows that the acid leaching process of alumina form coal gangue can be described with the unreacted shrinking core model of particle unchanged shrinking core model, and the leaching reaction is controlled by interface chemical reaction. The corresponding equation of reaction kinetics can be expressed as 1-(1-x)1/3=kt, and the activation energy of leaching reaction is 61.32 kJ/mol.

Key words: coal gangue, acid leaching, alumina, kinetics