scholarly journals Alumina Extraction from Red Mud by Magnetic Separation

2018 ◽  
Vol 18 (2) ◽  
pp. 331 ◽  
Author(s):  
Suprapto Suprapto ◽  
Zahrotul Istiqomah ◽  
Eko Santoso ◽  
Ahmad Anwarud Dawam ◽  
Didik Prasetyoko
Keyword(s):  
Magnetic Separation ◽  
Red Mud ◽  
Inductively Coupled Plasma ◽  
Aluminum Content ◽  
Magnetic Phase ◽  
Second Step ◽  
Mass Ratio ◽  
Carbon Reduction ◽  
Inductively Coupled ◽  
Roasting Process

Alumina extraction from red mud has been investigated by magnetic separation with three-step treatment. First, the addition of red mud with Na2CO3 (12 wt%) and heated at 110 °C for 4 h. The second step was carbon reduction using coal with mass ratio of (red mud+Na2CO3) : coal was 1:3 then roasted at temperature of 850, 950, and 1050 °C for 1, 2, and 3 h. The third step was magnetic separation. The magnetic separation was carried out in order to remove magnetite produced during roasting process. Magnetic and non-magnetic phases obtained were characterized by XRD and SEM-EDX techniques. The non-magnetic phase obtained was leached using HCl 6 M, and then aluminum content was determined by Inductively Coupled Plasma (ICP). The result revealed that the highest aluminum oxide extracted from the red mud was 20.66 wt% obtained by roasting at temperature of 1050 °C for 2 h.

scholarly journals Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 433
Author(s):  
Andrei Shoppert ◽  
Irina Loginova ◽  
Julia Napol’skikh ◽  
Aleksey Kyrchikov ◽  
Leonid Chaikin ◽  
...  
Keyword(s):  
Red Mud ◽  
Inductively Coupled Plasma ◽  
Bauxite Residue ◽  
Product Layer ◽  
Raw Material ◽  
X Ray ◽  
Inductively Coupled ◽  
Leaching Process ◽  
Alkali Fusion ◽  
Shrinking Core

Bauxite residue, known as “red mud,” is a potential raw material for extracting rare-earth elements (REEs). The main REEs (Sc, Y, La, Ce, Nd, Nb, and Sm) from the raw bauxite are concentrated in RM after the Bayer leaching process. The earlier worldwide studies were focused on the scandium (Sc) extraction from RM by concentrated acids to enhance the extraction degree. This leads to the dissolution of major oxides (Fe2O3 and Al2O3) from RM. This article studies the possibility of selective Sc extraction from alkali fusion red mud (RMF) by diluted nitric acid (HNO3) leaching at pH ≥ 2 to prevent co-dissolution of Fe2O3. RMF samples were analyzed by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and inductively coupled plasma mass spectrometry (ICP-MS). It was revealed that Sc concentration in RMF can reach up to 140–150 mg kg−1. Sc extraction was 71.2% at RMF leaching by HNO3 at pH 2 and 80 °C during 90 min. The leaching solution contained 8 mg L−1 Sc and a high amount of other REEs in the presence of relatively low concentrations of impurity elements such as Fe, Al, Ti, Ca, etc. The kinetic analysis of experimental data by the shrinking core model showed that Sc leaching process is limited by the interfacial diffusion and the diffusion through the product layer. The apparent activation energy (Ea) was 19.5 kJ/mol. The linear dependence of Sc extraction on magnesium (Mg) extraction was revealed. According to EPMA of RMF, Sc is associated with iron minerals rather than Mg. This allows us to conclude that Mg acts as a leaching agent for the extraction of Sc presented in the RMF in an ion-exchangeable phase.

scholarly journals Integration of Statistical Models and Computer Simulation in Environmental Accidents: A Study on Leakage of Red Mud in the Pará River, Amazon, Brazil

2021 ◽  
Author(s):  
Pedro de Sousa Jr. ◽  
Simone Pereira ◽  
Ronaldo Rocha ◽  
Mateus Alves ◽  
Luciana Pinheiro ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Red Mud ◽  
Inductively Coupled Plasma ◽  
Chemical Elements ◽  
Principal Component ◽  
Optical Emission ◽  
Simulation Models ◽  
Inductively Coupled ◽  
Environmental Accidents ◽  
Computer Simulation Models

The introduction of potentially toxic elements (PTEs) from industrial activities in water bodies, highlights the vulnerability of the environment and the need for actions focused on the implementation of mechanisms that help in the control and remediation of these impacts. The objective of the study was based on the integration of instrumental analytical methods, multivariate statistics, and computer simulation models, with the proposal of implementing realistic scenarios of the red mud plume behavior in the Pará River. The selected location was the municipality of Barcarena-PA, where is located an important alumina/aluminum industrial center. With the aid of the inductively coupled plasma optical emission spectrometer (ICP OES), the chemical elements Al, B, Cr, Fe, Mn, P, Ti, and Zn were quantified and the principal component analysis (PCA) allowed to select Al, B, Fe, P, and Zn as the most relevant with 98.68% of the accumulated variance. Some scenarios were proposed by the simulated hydrodynamic model, which evidenced that the Trambioca community would be the most affected in the first 13 h after the effluent overflowed, and the other locations in domino effect. The main scientific gain of the proposal is the possibility of the predictive scenarios to help the actions of containment and mitigation of environmental damages by public control agencies, institutions involved, and other competent bodies.

scholarly journals Adsorptive removal of phosphate from aqueous solutions using different types of red mud

2018 ◽  
Vol 2017 (2) ◽  
pp. 570-577 ◽  
Author(s):  
Tengfei Guo ◽  
Haiquan Yang ◽  
Qingyou Liu ◽  
Hannian Gu ◽  
Ning Wang ◽  
...  
Keyword(s):  
Adsorption Capacity ◽  
Red Mud ◽  
Inductively Coupled Plasma ◽  
Atomic Emission ◽  
Sintering Process ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Surface Areas ◽  
Plasma Mass Spectrometry ◽  
Pseudo Second Order

Abstract Red mud (RM) is an industrial waste generated during production of alumina from using the Bayer process or the sintering process. Four types of red mud from China were characterized for their diverse chemical and mineral compositions using inductively coupled plasma–atomic emission spectroscopy (ICP-AES), inductively coupled plasma–mass spectrometry (ICP-MS) and X-ray diffraction (XRD). Acid treatment was employed to obtain activated red mud (ARM), posing increased surface areas from 10–28 m2/g to 220–350 m2/g. RMs and ARMs were used to adsorb phosphate in solution to compare the adsorption capacity. Sample GZ3, a red mud from the sintering process, presented the highest adsorption capacity among the four raw RMs, posing an adsorption capacity of 0.37 mg P/g in the solution of 1 mg P/L with a solid/solution ratio of 0.5 g: 1 L. Whereas, activated GX (AGX), a high iron Bayer red mud from diaspore bauxite, showed the highest adsorption capacity of all the ARMs, with an adsorption capacity of 1.92 mg P/g in the same condition. The dynamic studies indicate that the adsorption mainly followed the pseudo second-order model. The models of Freundlich and Langmuir were used to simulate the sorption equilibrium on GZ3 and AGX. It suggests that the Freundlich model had a better correlation with GZ3 while the Langmuir model fitted well with AGX.

scholarly journals Selective Scandium (Sc) Extraction from Bauxite Residue (Red Mud) Obtained by Alkali Fusion-Leaching Method

2021 ◽  
Author(s):  
Andrei Shoppert ◽  
Irina Loginova ◽  
Julia Napol’skikh ◽  
Aleksey Kyrchikov ◽  
Leonid Chaikin ◽  
...  
Keyword(s):  
Red Mud ◽  
Inductively Coupled Plasma ◽  
Bauxite Residue ◽  
Product Layer ◽  
X Ray ◽  
Inductively Coupled ◽  
Leaching Process ◽  
Alkali Fusion ◽  
Shrinking Core ◽  
Alumina Industry

One of the potential sources of rare-earth elements (REEs) is the solid waste from alumina industry - bauxite residue, known as “red mud” (RM). The main REEs from the raw bauxite are concentrated in RM after the Bayer leaching process. The earlier worldwide studies were focused on the scandium (Sc) extraction from RM by concentrated acids to enhance the extraction degree. This leads to the dissolution of major oxides (Fe2O3 and Al2O3) from RM. This article studies the possibility of selective Sc extraction from alkali fusion red mud (RMF) by diluted nitric acid (HNO3) leaching at pH ≥ 2 to prevent co-dissolution of Fe2O3. RMF samples have been analyzed by X-ray fluorescence spectrometry (XRF), X-ray diffraction (XRD), electron probe microanalysis (EPMA), and inductively coupled plasma mass spectrometry (ICP-MS). Sc extraction has been found to be 71.2 % at RMF leaching by HNO3 at pH=2 and at 80 °C during 90 min. The kinetic analysis of experimental data by the shrinking core model has shown that Sc leaching process is limited by the interfacial diffusion and the diffusion through the product layer. The apparent activation energy (Ea) was 19.5 kJ/mol. We have established that according to EPMA of RMF, Sc is associated with iron minerals; it could act as the product layer. The linear dependence of Sc extraction of magnesium (Mg) extraction has been revealed. This fact indicates that Mg can act as a leaching agent of Sc presented in RMF by ion-exchangeable phase.

Determination of aluminum soaps in pitch deposits by gas chromatography

TAPPI Journal ◽  
2010 ◽  
Vol 9 (10) ◽  
pp. 19-22
Author(s):  
BRUCE SITHOLÉ ◽  
PAUL ABBYAD
Keyword(s):  
Gas Chromatography ◽  
Acid Hydrolysis ◽  
Inductively Coupled Plasma ◽  
Aluminum Content ◽  
Plasma Spectroscopy ◽  
Acid Digestion ◽  
Inductively Coupled

Aluminum soaps can be determined by formation of aluminum-acetylacetonate chelates that are volatile enough to be analyzed by gas chromatography. Application of the technique to pitch deposits containing aluminum soaps entails acid hydrolysis to break down the aluminum soaps, chelation of the aluminum with acetylacetonate at pH >6, and analysis of the aluminum chelates by gas chromatography. The technique offers results that are comparable to those obtained by a traditional, much longer method that requires acid digestion of aluminum soaps and analysis of aluminum content by inductively coupled plasma spectroscopy.

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