scholarly journals A Combined Soda Sintering and Microwave Reductive Roasting Process of Bauxite Residue for Iron Recovery

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 222
Author(s):  
Chiara Cardenia ◽  
Efthymios Balomenos ◽  
Pritii Wai Yin Tam ◽  
Dimitrios Panias
Keyword(s):  
Metallic Iron ◽  
Bauxite Residue ◽  
Separation Process ◽  
Iron Recovery ◽  
Optimum Conditions ◽  
Microwave Furnace ◽  
Roasting Process ◽  
Alkali Leaching ◽  
Leaching Residue ◽  
Reductive Roasting

In this study an integrated process is presented as a suitable method to transform Fe3+ oxides present in bauxite residue into magnetic oxides and metallic iron through a microwave roasting reduction, avoiding the formation of hercynite (FeAl2O4). In the first step, all the alumina phases were transformed into sodium aluminates by adding sodium carbonate as a flux to BR and then leached out through alkali-leaching to recover alumina. Subsequently, the leaching residue was mixed with carbon and roasted by using a microwave furnace at the optimum conditions. The iron oxide present in the sinter was converted into metallic iron (98%). In addition, hercynite was not detected. The produced cinder was subjected to a wet high intensity magnetic separation process to separate iron from the other elements.

scholarly journals Optimization of Microwave Reductive Roasting Process of Bauxite Residue

Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1083
Author(s):  
Chiara Cardenia ◽  
Efthimios Balomenos ◽  
Dimitrios Panias
Keyword(s):  
Magnetic Properties ◽  
Metallic Iron ◽  
Irradiation Time ◽  
Bauxite Residue ◽  
Mass Ratio ◽  
Short Processing Time ◽  
Roasting Process ◽  
Reductive Roasting ◽  
Mineralogical Phase ◽  
Residue Mass

In this study, microwave-assisted heating is presented as a suitable method to transform the hematite and goethite contained in bauxite residue into magnetite, wüstite, and metallic iron, with a short processing time. The final target was the production of a sinter with strong magnetic properties, allowing the magnetic separation of Fe from the residue. The influence of microwave energy on the sample, the effect of irradiation time, and the carbon/bauxite residue mass ratio (C/BR) were the parameters that have been analyzed to optimize the process. Their optimized combination allowed transforming 79% of the iron present in the sinter into metallic iron. However, hercynite was also formed, and the presence of this mineralogical phase could be considered a possible drawback for its magnetic properties.

Greek “red mud” residue: A study of microwave reductive roasting followed by magnetic separation for a metallic iron recovery process

2013 ◽  
Vol 254-255 ◽  
pp. 193-205 ◽  
Author(s):  
Michail Samouhos ◽  
Maria Taxiarchou ◽  
Petros E. Tsakiridis ◽  
Konstantinos Potiriadis
Keyword(s):  
Magnetic Separation ◽  
Red Mud ◽  
Metallic Iron ◽  
Recovery Process ◽  
Iron Recovery ◽  
Reductive Roasting

Growth of metallic iron particles during reductive roasting of boron-bearing magnetite concentrate

2020 ◽  
Vol 27 (5) ◽  
pp. 1484-1494
Author(s):  
Xin Zhang ◽  
Guang-hui Li ◽  
Ming-jun Rao ◽  
Huan-peng Mi ◽  
Bin-jun Liang ◽  
...  
Keyword(s):  
Metallic Iron ◽  
Iron Particles ◽  
Magnetite Concentrate ◽  
Reductive Roasting

An effective separation process of arsenic, lead, and zinc from high arsenic-containing copper smelting ashes by alkali leaching followed by sulfide precipitation

2020 ◽  
Vol 38 (11) ◽  
pp. 1214-1221
Author(s):  
Yuhui Zhang ◽  
Xiaoyan Feng ◽  
Bingjie Jin
Keyword(s):  
Separation Efficiency ◽  
Separation Process ◽  
Copper Smelting ◽  
Solid Ratio ◽  
Effective Separation ◽  
Lead And Zinc ◽  
Valuable Metals ◽  
Alkali Leaching ◽  
Sulfide Precipitation ◽  
High Arsenic

Separation of arsenic and valuable metals (Pb, Zn, Cu, Bi, Sn, In, Ag, Sb, etc.) is a core problem for effective utilization of high arsenic-containing copper smelting ashes (HACSA). This study developed an effective separation process of arsenic, lead, and zinc from HACSA via alkali leaching followed by sulfide precipitation. The separation behaviors and optimum conditions for alkali leaching of arsenic and sulfide precipitation of lead and zinc were established respectively as follows: NaOH concentration 3.81 M; temperature 80°C; time 90 minutes; liquid-to-solid ratio 4:1; agitation speed 450 revolutions/minute (r/min) and 2.0 times of theoretical quantity of sodium sulfide (Na2S); temperature 70°C; and time 60 minutes. The results indicated that the leaching rates of As, Pb, and Zn were 92.4%, 36.9% and 13.4%, respectively. More than 99% of lead and zinc were precipitated from the alkali leachate. The scanning electron microscopy/energy dispersive X-ray spectroscopy study confirmed that arsenic was dissolved from HACSA into the alkali leachate. Furthermore, lead and zinc were precipitated as sulfides from the alkali leachate. The proposed process was a good technique for separation of arsenic and enrichment of valuable metals for further centralized treatment separately. It provided high separation efficiency of arsenic and valuable metals, as well as low environmental pollution.

scholarly journals Concentration of Rare Earth Elements (Sc, Y, La, Ce, Nd, Sm) in Bauxite Residue (Red Mud) Obtained by Water and Alkali Leaching of Bauxite Sintering Dust

Minerals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 500 ◽  
Author(s):  
Leonid Chaikin ◽  
Andrei Shoppert ◽  
Dmitry Valeev ◽  
Irina Loginova ◽  
Julia Napol’skikh
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Red Mud ◽  
Electrostatic Precipitator ◽  
Bauxite Residue ◽  
X Ray ◽  
Before And After ◽  
Shrinking Core ◽  
Alkali Leaching ◽  
Rotary Kilns

One of the potential sources of rare-earth elements (REE) is the industrial waste known as red mud (bauxite residue), in which the majority of REE from the initial bauxite are concentrated via the Bayer process. Therefore, the studies of the subject, both in Russia and outside, focus almost exclusively on red mud processing. This article looks into the possibility of REE concentration into red mud by leaching an intermediate product of the bauxite sintering process at Russian alumina refineries, namely electrostatic precipitator (ESP) dust. The experimental works were performed by X-ray diffraction (XRD)and electron probe microanalysis (EPMA) of the sinter and sinter dust. The determination of major and rare-earth elements in the sinter from the rotary kilns and in the ESP dust before and after leaching was carried out by X-ray fluorescence (XRF) and plasma mass spectrometry (ICP-MS). The study showed that it is possible to obtain red mud that contains three times more REE than traditional waste red mud after two-stage leaching ESP dust in the water at 95 °C followed by leaching in an alkaline-aluminate liquor at 240 °C. The shrinking core model was used to study the kinetics of leaching of the original ESP dust and water-treated dust in alkaline-aluminate liquor. The study showed the change in the limiting stage of the alkaline leaching process after water treatment, with the activation energy growing from 24.98 to 33.19 kJ/mol.

Optimization of magnetic separation process for iron recovery from steel slag

2017 ◽  
Vol 24 (2) ◽  
pp. 165-170 ◽  
Author(s):  
Yuan-pei Lan ◽  
Qing-cai Liu ◽  
Fei Meng ◽  
De-liang Niu ◽  
Heng Zhao
Keyword(s):  
Magnetic Separation ◽  
Steel Slag ◽  
Separation Process ◽  
Iron Recovery

Effects of Activated Carbon in Microwave Induction of Lateritic Ore

2013 ◽  
Vol 372 ◽  
pp. 433-436 ◽  
Author(s):  
He Chen ◽  
Rui Guo ◽  
Na Su ◽  
Yue Hong Zhang ◽  
Xuan Wen Liu
Keyword(s):  
Activated Carbon ◽  
Microwave Irradiation ◽  
Stable Process ◽  
Heating Time ◽  
Heating Process ◽  
Roasting Process ◽  
Reductive Roasting ◽  
Lateritic Ore ◽  
Composition Of Products

Lateritic ore can be heated and deoxidized rapidly via microwave irradiation with activated carbon as deoxidizer. In this paper, we studied the reductive roasting behavior of carbon-containing lateritic ore in microwave field and the composition of products through different heating process with varying carbon content. The results show that the heating process of the lateritic ore is a thermally stable process. The reductive level of lateritic ore can be adjusted by changing the proportion of carbon powders and the heating time of microwave irradiation. During this reductive roasting process, the quality of the added carbon powders will make a great impact on the phase composition of the product and then affect the heating rate. The reductive calcite product mainly consists of magnetite and wastage. With the rising of the content of reducing agent, the reductive level of lateritic ore will increase, which cause Ni and a small quantity of Fe to be deoxidized and forms Ni-Fe alloy.

Process Mineralogy and Concentrating of Hematite-Limonite Ore in Southern China

2011 ◽  
Vol 201-203 ◽  
pp. 2749-2752
Author(s):  
Shu Xian Liu ◽  
Li Li Shen ◽  
Jin Xia Zhang
Keyword(s):  
Southern China ◽  
Close Association ◽  
Separation Process ◽  
Reverse Flotation ◽  
Iron Recovery ◽  
Flotation Process ◽  
Iron Concentrate ◽  
Process Mineralogy ◽  
Concentrate Grade ◽  
Reverse Floatation

The grade of the crude hematite-limonite ore is 39.79%. The main metallic minerals are hematite-limonite. Hematite has disseminated structure distributed in the gangue. Limonite was inlayed as stars in hematite. Due to their fine dissemination and close association with gangue minerals, the hematite and limonite particles are hard to be fully liberated, bringing difficulty in their separation. Staged grinding-separation process consisting of high intensity magnetic separation and reverse floatation wag adopted in the beneficiation test on the regionally representative hematite—limonite ore resource. At a grind of 70.0% -200 mesh for the primary grinding and 98.7% -200 mesh for the secondary grinding, the final iron concentrate grade 58.26% and having an iron recovery of 8.33% can be achieved after reverse flotation process test on magnetic concentrate.

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