Sintering characteristics of titanium sands after grinding and its influence mechanism on the quality of sinter

Abstract

The size distribution,microstructure and high temperature properties of titanium sands after grinding were studied in the paper. The influence and mechanism of titanium sands on the sinter quality were identified by sinter pot test and scanning electron microscopy and energy dispersive spectrometry(SEM-EDS) test. It is found that the micromorphology of titanium sands becomes more irregular after grinding,and the granulation gets strengthened. Meanwhile,the high temperature characteristics of sintering are different with the common iron ore fines: when titanium sands become finer,the assimilation temperature improves by 21 ℃,and the liquid phase fluidity index decreases by 0.35 at 1280 ℃. The reason for these differences is that titanium sands after grinding react with Ca O to produce more perovskite,which can hinder the assimilation reaction and get the liquid phase stickier. In comparison with unground titanium sands,the reduction index(RI) of sinters produced with 8% of ground titanium sands in blends improves by 3.8%. The reasons are that titanium sands are distributed more uniformly in blends after grinding,resulting in the increase of phase particles containing titanium in sintered ores,and many microcracks emerge in the reduction reaction,which is in favor of reducing gas diffusion.

Keywords

• titanium sands
• sintering
• particle size distribution
• microstructure
• assimilation
• fluidity