The solidification of a multicomponent stainless steel slag and dust composite has been studied by thermodynamic calculations using Factsage and analyses of samples using EPMA and Rietveld refinement of synchrotron X-ray powder diffraction after various cooling rates. At an apparent cooling rate of 1 K/min, the content of spinel (10.6 wt%) was less than thermodynamically calculated (16.6 wt%), largely because of difficulties in the diffusion of depleted ions (including Cr, Mn, and Ni) in the liquid with very gradual compositional gradients. Melilite showed a uniform but distorted crystal structure of P21212 and its content (48.9 wt%) was larger than the calculated result (32.3 wt%). At apparent cooling rates of 10 K/min and 50 K/min, a slight decrease in spinel and a significant decrease in melilite were observed, and the spinel was divided into two regions with an identical space group of Fd (Formula presented.) m but with distinguished composition and lattice parameters. However, the amorphous proportion consistently increased with the cooling rate from 29.4 wt% at 1 K/min to 69.6 and 92.9 wt% at 10 K/min and 50 K/min respectively.
Bibliographical noteFunding Information:
This study was supported by the Brain Korea 21 (BK21) Project of the Ministry of Science, ICT and Future Planning grant no. 2016-11-0010 and the Ministry of Trade, Industry and Energy grant no. 10044705.
All Science Journal Classification (ASJC) codes
- Ceramics and Composites
- Materials Chemistry