Effect of Na₂SO₄ on the Embedding Direct Reduction of Beach Titanomagnetite and the Separation of Titanium and Iron by Magnetic Separation

Abstract

A novel process for separating iron and titanium from Indonesian beach titanomagnetite (TTM) concentrates is proposed. This process involves several steps, including mixing the TTM concentrate and additive, pressing the mixture into pellets, embedding direct reduction of the pellets, and magnetic separation. Given that coal and additives are the main factors influencing the coal-based direct reduction of beach TTM, this study employed embedding reduction, where pellets are embedded under the coal to be reduced, and Na 2 SO 4 was used as an additive. The best result was obtained when the Na 2 SO 4 dosage was 4%, and the direct reduction iron powder (DRI powder) with an iron grade of 94.45%, iron recovery of 85.18%, and TiO 2 content of 0.44% were obtained. Titanium concentrate assay yielded 40.43% TiO 2 containing main titanium minerals of ilmenite and ferrous pseudobrookite. The results showed that a suitable Na 2 SO 4 addition (4-6%), DRI powder and titanium concentrate presented better iron recovery and TiO 2 grade as compared without addition, while this advantage disappeared as Na 2 SO 4 addition increased ( > 6%). The characteristics of roasted pellets were analyzed through X-ray diffraction, scanning electron microscopy, and energy dispersive spectrometry. Results showed that FeS and nepheline are formed by addition of Na 2 SO 4 , thereby benefiting the migration and growth of metallic iron particles in the redox system and separation of titanium and iron. While a suitable dosage of Na 2 SO 4 could promote porosity and induce a reducing atmosphere, but more liquid phase formed by an excessive Na 2 SO 4 was unfavorable and caused expansion of the pellets.

Utilization of coal sludge as reductant in the direct reduction of titanomagnetite ore

“…The slurry was separated in a CXG-99 Davies Magnetic Tube. The methods of grinding and magnetic separation have been described elsewhere [11,12].…”

Selective Enrichment and Separation of Ti–Fe Enriched Mineral from Ti-bearing Electric Furnace Slag with Metallic Iron as Carrier

“…Moreover, the magnetic Ti-Fe enriched mineral particle could be easily separated from other nonmagnetic gangues by magnetic separation which is simple and environmentally friendly. 23) Furthermore, pseudobrookite could be obtained through the melting process as using the thermal energy of hot molten slag separated in the electric smelting process. In the reduction process of pseudobrookite, hydrogen was chosen as reductant due to its high reductive efficiency in the low temperature range.…”

Effects of Preheating Temperature and Time of Hongge Vanadium Titanomagnetite Pellet on Its Gas-Based Direct Reduction Behavior with Simulated Shaft Furnace Gases

“…6) Compared with the BF process, several new processes on the basis of direct reduction containing coal of HVTM or other minerals have been widely studied. [7][8][9][10][11][12][13][14][15][16][17] Zhao et al 8) surveyed the reduction behaviors of FeO·V 2 O 3 and FeO·Cr 2 O 3 during coal-based direct reduction of HVTM and the effects on the elements distribution in the subsequent magnetic separation. Hu et al…”