Air Atomization of Titania Slag – Characterization and Upgrading Using a Hydrometallurgical Route
Presenter: Shayan Shahini (MASc Candidate)
Supervisor: G. Azimi
Titanium is the second transition metal in the periodic table, and the ninth most abundant element in the earth’s crust. The most widely used titanium product is titanium dioxide (TiO2), which is used as pigment because of its brightness and very high refractive index. There are two technologies for the production of pigment grade TiO2, i.e., the sulfate and the chloride processes. To make titanium minerals, in particular ilmenite, a suitable feed for these processes, a beneficiation step is required to produce synthetic rutile (90-95%TiO2) or titania slag (70-86% TiO2). While the former is suitable for both processes, the latter can only be used in the sulfate process and an additional upgrading step is required to make it suitable for the chloride process. One of commercial processes for this purpose is called UGS, which is based on oxidation-reduction roasting and it requires multiple step processes including crushing, grinding, oxidation, reduction, leaching, washing, and calcination. In the current study, a new process is proposed based on air atomization that can substitute the UGP process and eliminates crushing and reduction steps. Here, a thorough characterization of the original (slow cooled) and atomized slags was performed utilizing various spectroscopy and microscopy techniques. It was shown that atomization process forms two phases, one rich in titanium and other rich in iron. Here, systematic leaching experiments were performed using HCl as the leaching agent and iron was successfully leached from the atomized slag, leaving behind a an upgraded titanium phase. The results of this study provides the proof-of-concept that air atomization is a potential substitute for the UGS process, eliminating the need for crushing, grinding, oxidation, and reduction in separate units, which could significantly benefit the TiO2 pigment industry.
Thursday, April 20, 2017 | 12:00 p.m. | Room TBD