Upgrading of High-Aluminum Hematite-Limonite Ore by High Temperature Reduction-Wet Magnetic Separation Process

Abstract

Abstract:The huge consumption of iron ores in China has attracted much attention to utilizing low grade complex iron resources, such as high-aluminum hematite-limonite ore, which is a refractory resource and difficult to upgrade by traditional physical concentration processes due to the superfine size and close dissemination of iron minerals with gangue minerals. An innovative technology for a high temperature reduction-magnetic separation process was studied to upgrade a high-aluminum iron ore assaying 41.92% Fe total , 13.74% Al 2 O 3 and 13.96% SiO 2 . The optimized results show that the final metal iron powder, assaying 90.46% Fe total , was manufactured at an overall iron recovery of 90.25% under conditions as follows: balling the high aluminum iron ore with 15% coal blended and at 0.3 basicity, reducing the dried pellets at 1350˝C for 25 min with a total C/Fe mass ratio of 1.0, grinding the reduced pellets up to 95%, passing at 0.074 mm and magnetically separating the ground product in a Davis Tube at a 0.10-T magnetic field intensity. The metal iron powder can be used as the burden for an electric arc furnace (EAF). Meanwhile, the nonmagnetic tailing is suitable to produce ceramic, which mainly consists of anorthite and corundum. An efficient way has been found to utilize high-aluminum iron resources.

Synchronous Upgrading Iron and Phosphorus Removal from High Phosphorus Oolitic Hematite Ore by High Temperature Flash Reduction

“…Generally, with the addition of soft coal, the Boundouard reaction was accelerated to produce more CO, leading to a stronger reducing atmosphere and promoting hematite reduction. However, with a further increase in C/Fe, more apatite was reduced to P2 gas, and then the generated P2 could dissolve into metallic iron to form Fe-P solid solution [18]. As a result, the phosphorus content of magnetic product was increased, and the phosphorus removal rate of magnetic separation declined.…”

An Innovative Technique for Comprehensive Utilization of High Aluminum Iron Ore via Pre-Reduced-Smelting Separation-Alkaline Leaching Process: Part I: Pre-Reduced-Smelting Separation to Recover Iron

“…At an elevated temperature, the metallization rate of iron was reduced. This is probably due to the fact that rising temperature is beneficial to enhance the reduction of fayalite (Fe 2 SiO 4 ) and hercynite (FeAl 2 O 4 ), but more liquid phase would be formed if the reduction temperature is too high, which may be detrimental for diffusion of the reduction gas [13]. Therefore, the reduction temperature of 1000 • C was selected for subsequent experiments.…”

“…In addition, the alkaline leaching slag could potentially be used as raw material for construction purpose, which mainly consisted of SiO 2 and CaO.Metals 2020, 10, 57 2 of 17 remove aluminum from iron ore containing Fe total 52.94%, 9.95% Al 2 O 3 and 6.1% SiO 2 , and only 40% alumina was removed after 6 or 15 days of in situ leaching at 10% pulp density. Biological method could play a certain role in the separation of iron from alumina, but its effect may be poorer, especially the period is too lengthy compared to smelting processes.Smelting processes consist of coal-based direct reduction-magnetic separation, roasting-magnetic separation, and smelting separation [11][12][13]. It is effective to recover iron from low-grade refractory iron ore through coal-based direct reduction-magnetic separation.…”

“…However, there is a problem that exists in this process, low reduction rate [14,15]. Zhou et al [13] proposed a high temperature reduction followed by magnetic separation for high aluminum hematite-limonite ore treatment. Their findings indicated that approximately 90.25% of iron recovery was obtained, but the recovery of Al 2 O 3 was not considered.…”

“…Smelting processes consist of coal-based direct reduction-magnetic separation, roasting-magnetic separation, and smelting separation [11][12][13]. It is effective to recover iron from low-grade refractory iron ore through coal-based direct reduction-magnetic separation.…”