Regular Article

Non-isothermal crystallization behavior of spinel crystals in FeO-SiO₂-TiO₂-V₂O₃-Cr₂O₃ slag

¹ College of Materials Science and Engineering, Chongqing University, 400044 Chongqing, P.R. China
² Department of Science and Technology, Chongqing University of Education, 400065 Chongqing, P.R. China

^* Corresponding author: diaojiang@163.com.

Received: 23 January 2018
Accepted: 24 April 2018

Abstract

The growth behaviour of spinel crystals in vanadium slag with high Cr₂O₃ content was investigated and clarified by statistical analyses based on the Crystal Size Distribution (CSD) theory. The results indicate that low cooling rate and Cr₂O₃ content benefit the growth of spinel crystals. The chromium spinel crystals firstly precipitated and then acted as the heterogeneous nuclei of vanadium and titanium spinel crystals. The growth mechanisms of the spinel crystals at the cooling rate of 5 K/min consist two regimes: firstly, nucleation control in the temperature range of 1873 to 1773 K, in which the shapes of CSD curves are asymptotic; secondly, surface and supply control within the temperature range of 1773 to 1473 K, in which the shapes of CSD curves are lognormal. The mean diameter of spinel crystals increases from 3.97 to 52.21 µm with the decrease of temperature from 1873 to 1473 K.