Abstract:The modified equation of AlN content in aluminium dross was put forward by studying the change of each component and its content in the process of aluminium dross hydrolysis reaction. The effects of hydrolysis parameters such as time, temperature and rotational speed on the hydrolysis rate of aluminium dross were investigated according to the measure of AlN content and pH of suspension. The hydrolysis parameters and the modified content of AlN in aluminium dross were analyzed by multivariate nonlinear regression analysis. The results show that the AlN content in the aluminum dross and the pH value of the suspension reduce with the increase of temperature. The hydrolysis of AlN can be effectively promoted with the prolongation of time, and the pH value of the suspension is simultaneously raised to a high level within 2 h. The rotational speed has no obvious effect on the hydrolysis rate of AlN and the pH value of suspension. Generally speaking, the way of the content of AlN is more objective than the pH value of suspension to characterize the hydrolysis rate of AlN in aluminum dross. Multivariate nonlinear regression analysis and secondary simplification on the hydrolysis parameters and the modified content of AlN in aluminium dross show that the relative error between the theoretical value and the experimental value is within ±8.65%, which has a certain guiding significance for the prediction and control of the modified content of AlN in aluminum dross during the hydrolysis process.

Key words: aluminum dross; AlN; hydrolysis; multivariate nonlinear regression analysis; temperature; rotational speed; time