Increasing Iron Recovery from High-Iron Red Mud by Surface Magnetization

Zhou, Xiao-Nong; Liu, Guihua; Qi, Tiangui; Zhao, Jiasheng; Peng, Zhihong; Wang, Yilin; Shen, Leiting

doi:10.1007/s40831-023-00686-1

Cited by 7 publications

(3 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The mechanism of the magnetite formation can be described by Equations ( 1)- (3). The source of the Fe 2+ can be different: iron [19] and aluminum [20] that reacts with the alkaline solution with the formation of H 2 and following the reduction of Fe 3+ to Fe 2+ ; the addition of FeSO 4 [21,22] and the addition of organic matter [23]. The presence of Fe 2+ ions also helps to decrease the amount of Na and Al that is lost with the BR, which is connected to the formation of other desilication products [24].…”

Section: Introductionmentioning

confidence: 99%

Low-Temperature Treatment of Boehmitic Bauxite Using the Bayer Reductive Method with the Formation of High-Iron Magnetite Concentrate

et al. 2023

View full text Add to dashboard Cite

The Bayer process is the main method of alumina production worldwide. The use of low-quality bauxites for alumina production results in the formation of a significant amount of technogenic waste—bauxite residue (BR). The Bayer reductive method is one possible way to eliminate BR stockpiling, but it requires high-pressure leaching at temperatures higher than 220 °C. In this research, the possibility of boehmitic bauxite atmospheric pressure leaching at both the first and second stages or high-pressure leaching at the second stage with the simultaneous reduction of hematite to magnetite was investigated. Bauxite and solid residue after NaOH leaching were characterized using XRD, SEM-EDS, and Mössbauer spectroscopy methods. The first stage of leaching under atmospheric pressure with the addition of Fe(II) species in a strong alkali solution (330–400 g L–1 Na2O) resulted in a partial reduction of the iron minerals and an extraction of more than 60% of Si and 5–25% of Al (depending on caustic modulus of solution) after 1 h. The obtained desilicated bauxite was subjected to atmospheric leaching at 120 °C in a strong alkali solution (350 g L−1) or high-pressure leaching at 160–220 °C using the Bayer process mother liquor in order to obtain a concentrate with a magnetite content higher than 83 wt. %.

show abstract

Section: Introductionmentioning

confidence: 99%

Low-Temperature Treatment of Boehmitic Bauxite Using the Bayer Reductive Method with the Formation of High-Iron Magnetite Concentrate

et al. 2023

View full text Add to dashboard Cite

show abstract

“…The leaching process results in the formation of a solid residue, commonly referred to as a bauxite residue, which consists of iron minerals, hydrous aluminosilicates, which are formed through the interaction of aluminium and silicon compounds in a solution, and other impurity minerals [4][5][6]. Some of the aluminium in bauxite is present in the form of refractory at standard leaching alumogoethite (Algoethite) and alumohematite (Al-hematite) [7][8][9]. The study of Li et al [10,11] showed that reductive leaching can increase the Al extraction through the magnetization of Algoethite and Al-hematite.…”

Section: Introductionmentioning

confidence: 99%

“…The magnetite formed through the reduction of hematite can also be reduced to iron (Equation (9)) and dissolved to form hydroxocomplexes (Equation ( 10)):…”

Section: Introductionmentioning

confidence: 99%

Novel Method of Bauxite Treatment Using Electroreductive Bayer Process

Shoppert,

Valeev,

Loginova

2023

Metals

View full text Add to dashboard Cite

Reductive leaching in the Bayer cycle using iron (2+) allows for Al extraction to be significantly increased through the magnetization of Al-goethite and Al-hematite. However, the use of expensive iron (2+) salts or iron powder as a source of iron (2+) leads to a significant increase in production costs. In this work, the feasibility of a new method, the reductive leaching of bauxite using an electrolysis process, was investigated. The reduction of iron minerals of boehmitic bauxite in both the Bayer solution and purely alkaline solutions was carried out. Experiments were performed using a plate cathode and a bauxite suspension in an alkaline solution, as well as using a bulk cathode with a stainless-steel mesh at the bottom of a cell as the current supply. During the electrolysis process, the potential of the cathode relative to the reference electrode was measured as a function of the current at different concentrations of solid (100–300 g L−1) and suspension temperatures (95–120 °C). It was shown that the current efficiency using the suspension and plate cathode with the predominant deposition of Fe did not exceed 50% even with the addition of magnetite to increase the contact of the solid phase with the current supply. With the use of a bulk cathode, the reduction of iron minerals led predominantly to the formation of magnetite with the efficiency of using the electric current at more than 80%. As a result of the preliminary desilication and electroreduction, it was possible to extract more than 98% of Al from bauxite and to increase the iron content in the bauxite residue to 57–58%.

show abstract