bauxite residue separation

The scope of this work is to develop and optimize a reductive roasting process followed by wet magnetic separation for iron recovery from bauxite residue (BR). The aim of the roasting process is the transformation of the nonmagnetic iron phases found in BR (namely hematite and goethite), to magnetic ones such as magnetite, wüstite, and …

Using physical methods, iron-rich bauxite residue can be separated and may be utilized as low-grade iron ore. In the paper, advanced physical recovery techniques such as multistage magnetic ...

The present study investigates the properties of H2-reduced calcium-added bauxite residue, self-hardened pellets, and the feasibility of iron recovery through electrostatic and magnetic separa...

The particle size distribution of bauxite residues depends on the separation of sand size particles after the alumina extraction step. Menzies et al. (2004), for example, show that red sand from Gove has a particle size distribution between 10 and > 1000 μm with more than 50% of the particles being larger than 250 μm.

Also called red sludge or bauxite residue, this highly alkaline (pH 10–13) slurry contains a complex mixture of various oxides, traces of valuable metals (for example, Sc and Y), as well as ...

Acid selection for REEs leaching from bauxite residue. To choose the best leaching agent and optimum operating conditions, a systematic investigation was performed using HNO 3, HCl, and H 2 SO 4 ...

Bauxite residue (BR) contains substantial concentrations of rare-earth elements (REEs), but their recovery is a challenge. Acidic BR leachates typically comprise much higher concentrations of base elements (g L −1) than those of the REEs (ppm). Thus, adsorbents that are highly selective for the REEs over the base elements are required for the ...

The strong surface charge of bauxite residue (BR) and its high fineness have made its rapid and high-efficiency solid–liquid separation an urgent problem to be solved. The proposed two-step procedure involving charge neutralization and flocculation through the synergy of lime and polyacrylamide (PAM) was carried out.

Iron and alumina can be separated from bauxite residue and calcite self-hardened reduced pellets through simultaneous magnetic separation and alkali leaching. Bauxite residue and calcite self-hardened pellets were reduced non-isothermally by hydrogen gas to obtain metallic iron. Thereafter, the fine grounded reduced pellet powder was leached with a …

Bauxite residue (BR) is a well promising resource for critical metals, especially scandium (Sc), a rare and expensive metal with increasing applications in advanced technology. Greek BR seems to significantly favor a commercially viable recovery of Sc combining optimized leaching and advanced separation techniques. Leaching with mineral acids …

1. Recovery of the alumina from the residue at the early stage facilitates the iron and other metal recovery in the smelting reduction processes. That is because alumina increases the slag viscosity and high slag viscosity hinders efficient metal-slag separation. Therefore, alumina recovery prior to volatilization of other.

Complex surface properties and high fineness of bauxite residue (BR) make it hard to compact and settle, which reduces the solid content of the BR cake and solid–liquid separation efficiency. The proposed three-step procedure involving surface wettability adjustment, charge neutralization, and flocculation through the synergy of …

1. Introduction. Bauxite residue is an industrial solid waste with high alkalinity produced in the alumina refining process, which contains a variety of elements such as iron, aluminum, sodium, titanium, silicon, calcium, and magnesium (Fu et al., 2022; Shao et al., 2021).With the rapid development of the alumina industry, China has been …

Advanced separation techniques used for recovery of iron from bauxite residue. •. Coal dust, most effective reducer amongst sugar cane bagsse, spent spot lining. •. Reduction roasting is not a good alternative. •. Best option is Hydrocyclone & magnetic separation with 70% Fe2 O 3 and 80% recovery.

Reduction roasting reduces hematite in bauxite residue to magnetite, and subsequent magnetic separation results in a magnetic concentrate. The magnetic separation product is not ideal and provides low separation efficiency (47–60% Fe grade, 70–80% Fe recovery) due to the formation of mixed oxides (fayalite, hercynite) [ 19, 20 ].

The bauxite ore residue used in this study was a byproduct of the Bayer process. The main compositions of bauxite ore residue sample and the non-magnetic material prepared by reductive roasting-magnetic separation process of bauxite ore residue are shown in Table 1.The reductive roasting and magnetic separation process …

In summary, this study introduced a feasible means of strengthening solid–liquid separation of bauxite residue (BR) by charge neutralization and flocculation. Lime was effectively adsorbed on the surface of BR particles for charge neutralization in the form of Ca-OH but at high dosages.

Several strategies (e.g. direct magnetic separation, pyro‐ and hydrometallurgical processes) have been investigated to recover the main elements present in the residues (Al, Fe and Ti). ... One approach for the future of bauxite residue management may be its use in soil remediation and improvement to degraded soils.120, …

To investigate the separation performance of bauxite residue obtained under different digestion processes (LTD, HTD and RBD), the gravity separation experiments on the red mud samples were conducted and the results are shown in Table 5. Experiment 1 in Table 5 shows that the iron minerals in red mud from the LTD process cannot be …

The separation of scandium from the solution generated in acid leaching is one of the main challenges for the hydrometallurgical processing of bauxite residue. Several organic extractants were evaluated, being the most prominent phosphine acids, while amine-based compounds have shown great results for separating metallic ions.

On the other hand, the fine particle size of bauxite residue limits the performance of the magnetic separation (i.e., a specific form of physical beneficiation). Direct Leaching of Bauxite Residue Table 4 …

Bauxite residue, calcite and quick lime mixtures were pelletized and the pellets properties regarding CaO/CaCO 3 variation were studied. One of the produced pellets were further reduced by H 2 gas and it was processed by alkali leaching and magnetic separation for alumina and iron recovery.

Bauxite residue is a type of high-alkaline material that is discharged during the alumina production process [ 1 ]. Due to its complex mineral composition and lack of comprehensive utilization technology, it is mostly disposed of in landfills.

The amount of moisture in bauxite residue is determined by the solid-liquid separation process of individual Bayer refinery and impacts the storage conditions and requirements. The primary technology in Bayer refineries for solid-liquid separation is counter-current decantation which results in red mud slurry with >40% solid content ...

Bauxite residue is the industrial solid waste discharged from the production of alumina by bauxite, which contains a certain amount of ferric oxide in a reddish-brown color, so it is also called "red mud", and is a typical non-ferrous metallurgical solid waste (Wang et al. 2018; Xue et al. 2022).The varieties of bauxite residue depend on the …

Introduction. Bauxite residue is a highly alkaline waste discharged from the process of alumina production. In recent years, the global industrial inventory is approximately 5 billion tons, with an annual increase of 200 million tons (Wu et al., 2020).Due to its high saline-alkalinity, and potential environmental risk, the …

Bauxite residue is the industrial solid waste discharged from the production of alumina by bauxite, which contains a certain amount of ferric oxide in a reddish-brown color, so it is also called "red mud", and is a typical non-ferrous metallurgical solid waste (Wang et al. 2018; Xue et al. 2022).The varieties of bauxite residue depend on the …

Some investigate the sintering or melting of bauxite residue in combination with C or H 2 gas (as a reducing agent), in some cases in a microwave reactor, followed by magnetic separation, if ...

During the stacking of bauxite residue, a layer of white "frost" is often coated on the surface; this layer is mainly the soluble sodium precipitating from the bauxite residue, which is mainly NaOH, Na 6 CaAl 6 Si 6 (CO 3)O 24 ·H 2 O and Na 2 CO 3, etc., accounting for approximately 20–25% of the sodium content [3], [4]. The precipitation of ...

Aluminum and iron can also be removed from bauxite residue by reduction roasting in the presence of alkali followed by water leaching and magnetic separation [12–14]. However, it is difficult to achieve high recoveries of iron during magnetic separation after roasting because of the fineness and complex mineralogy of the bauxite residue.

Complex surface properties and high fineness of bauxite residue (BR) make it hard to compact and settle, which reduces the solid content of the BR cake and solid-liquid separation efficiency.

Bauxite residue (BR) contains substantial concentrations of rare-earth elements (REEs), but their recovery is a challenge. Acidic BR leachates typically comprise much higher concentrations of base elements (g L −1) than those of the REEs (ppm).Thus, adsorbents that are highly selective for the REEs over the base elements are required for the …

Reagents. Sulfuric acid of analytical grade were used in the experiments. Methods. As the main titanium-bearing minerals in the bauxite ore residue were titanomagnetite, kassite, and sodium tri-titanate (Fig. 2), magnetic separation process can be conducted to recover iron and titanium due to the magnetic character of …

The chapter on bauxite residue (red mud) comprehensively reviews all aspects of bauxite residue from separation, management and disposal through to the ever-increasing use of the Material. Mud washing and the optimum recovery of soda and alumina values is presented.

Red mud, also referred to as bauxite residue, is the largest process waste produced during alumina production from bauxite ore by the Bayer method. Approximately 1–2 tons of red mud are produced ...

Abstract. The scope of this work is to develop and optimize a reductive roasting process followed by wet magnetic separation for iron recovery from bauxite residue (BR). The aim of the roasting process is the transformation of the nonmagnetic iron phases found in BR (namely hematite and goethite), to magnetic ones such as magnetite, wu ̈stite ...