Molecular dynamics study on the DOP evolution of slags during recycling nickel slag by aluminum dross

Recycling nickel slag by aluminum dross can realize the 'utilization of waste heat' and the 'recovery of waste into resource'. Based on the molecular dynamics study, the influences of w('FeO')/w(Al2O3) and w(Al2O3)/w(SiO2) on the degree of polymerization (DOP) evolution have been discussed. As w('FeO')/w(Al2O3) decreases from 1.69 to 0.48, the first peak of the Si -O pair in radial distribution functions (RDFs) shifts from 1.65 to a lower abscissa value of 1.63, and the mean square displacement (MSD) distributions of both Ca and Si atoms decrease. Similarly, w(Al2O3)/w(SiO2) induces a higher slag DOP. Under different w('FeO')/w(Al2O3) and w(Al2O3)/w(SiO2), DCa, DFe, DO, DA1 and DSi of each atom are between 7.74-12.80 x 10-11, 6.08-11.78 x 10-11, 2.88-9.56 x 10-11, 2.05-3.78 x 10-11 and 1.58-3.37 x 10-11 m2 s- 1, respectively. The increasing predicted viscosities keep a good accordance with the experimental data, signifying the increasing DOP of slags from the macro level.