Effects of AlN hydrolysis on fractal geometry characteristics of residue from secondary aluminium dross using response surface methodology

Abstract

The effects of aluminium nitride (AlN) hydrolysis on fractal geometry characteristics of residue from secondary aluminium dross were studied using response surface methodology. The results show that the fractal dimensions of the residue can be significantly influenced by the AlN hydrolysis from secondary aluminium dross. The hydrolysis of AlN in the dross was spontaneous under temperatures of 303–373 K. The actual fractal dimensions of residue were significantly affected by the liquid–solid ratio (p<0.05) and changed from 1.16 to 1.80, which accurately aligned with those from the calculations. Moreover, the fractal dimensions of residue were significantly affected by the interactions between hydrolysis temperature and hydrolysis time, liquid–solid ratio and hydrolysis time, respectively (p<0.01). The minimum fractal dimensions of the residue reached 1.15 under the optimized conditions, which included a hydrolysis temperature of 30 °C, liquid–solid ratio of 5 mL/g and hydrolysis time of 10 min. The results suggest that response surface methodology can guide in optimizing the conditions of AlN hydrolysis in order to obtain the minimum fractal dimensions of residue for improving the reutilization of the dross.