Recovery of sludge from alumina production

Pyagai, I. N.; Pasechnik, L.А.; Yatsenko, A. S.; Скачков, В. М.; Yatsenko, S. P.

doi:10.1134/s107042721211002x

Cited by 15 publications

(4 citation statements)

References 3 publications

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“…The leachate is first treated with an organic flocculant to precipitate titania, is subsequently electrolysed to remove impurities, and finally scandium is precipitated by sodium zincate in combination with an organic flocculant. In a further improved version of the process, multiple leaching steps with mixtures of sodium carbonate and sodium hydrogencarbonate are carried out while a flow of flue gases from the bauxite sintering or calcination furnaces (containing CO 2 ) is passed through the solution (Yatsenko and Pyagai, 2010;Pyagai et al, 2012). Scandium is co-precipitated with zinc oxide.…”

Section: Recovery Of Rare Earths From Red Mudmentioning

confidence: 99%

Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review

Binnemans

Jones

Blanpain

et al. 2015

Journal of Cleaner Production

508

282

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The supply risk for some critical rare-earth elements (REEs), which are instrumental in many cleantech applications, has sparked the development of innovative recycling schemes for Endof-Life fluorescent lamps, permanent magnets and nickel metal hydride batteries. These waste fractions represent relatively small volumes, albeit with relatively high rare-earth contents.Nevertheless, rare earths are also present in lower concentrations in a multitude of industrial process residues, such as phosphogypsum, bauxite residue (red mud), mine tailings, metallurgical slags, coal ash, incinerator ash and waste water streams. This review discusses the possibilities to recover rare earths from these "secondary resources", which have in common that they contain only low concentrations of rare-earth elements, but are available in very large volumes and could provide significant amounts of rare earths. The success rate is set to increase if the rare-earth recovery from these industrial waste streams is part of a comprehensive, zero-waste, "product-centric" valorisation scheme, in which applications are found for the residual fractions that are obtained after removal of not only the rare earths but also other valuable (base) metals.

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Section: Recovery Of Rare Earths From Red Mudmentioning

confidence: 99%

Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review

Binnemans

Jones

Blanpain

et al. 2015

Journal of Cleaner Production

508

282

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“…The concentration of selected REEs in the RM-ESPD is shown in Table 3. It can be seen that the concentration of Sc (and other REEs) in this type of RM is very high: 240 mg kg −1 vs. 100 mg kg −1 for the RM obtained from the same bauxite by the Bayer process [32]. According to our previous research using electron probe microanalysis [28], Sc in the RM-ESPD is mainly associated with iron minerals.…”

Section: Red Mud Characterizationmentioning

confidence: 67%

High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4

et al. 2022

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Bauxite residue, also known as red mud (RM), from alumina production is the most promising technogenic material for the production of scandium (Sc) and other rare earth elements (REEs). Conveniently, RM is processed by using a strong acid (pH < 2.5), which lead to co-dissolution of iron and other undesirable major components. In this work, for the first time, the possibility of selective extraction of scandium from red mud by using highly diluted acid (pH > 4) in the presence of MgSO4 was shown. The effect of temperature (40–80 °C), time (0–60 min), pH (2–5), and the MgSO4 concentration (12–36 g L−1) on Sc extraction efficiency was evaluated. It was shown that Sc extraction was higher than 63% even at a pH of 4, at 80 °C, after 1 h, while more than 80% could be extracted at a pH of 2. Iron extraction reduced from 7.7 to 0.03% by increasing the pH from 2 to 4. The kinetics study using the shrinking core model (SCM) has shown that diffusion through a product layer is a rate-limiting stage of the process at high temperatures (>60 °C) and low pH (<3), whereas, at lower temperatures and higher pH values, the leaching rate is limited by diffusion through the liquid film.

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“…Through a statistical analysis of a large amount of the relevant literature on red mud, it was found that the utilization of red mud in China is mainly concentrated in three areas [12]: material preparation in the construction and chemical industries [13][14][15][16][17][18][19], environmental governance [20][21][22][23][24], and metal recovery in metallurgical fields [25][26][27][28][29][30][31][32]. Although RM has been widely used in these fields, its utilization rate is very low.…”

Section: Introductionmentioning

confidence: 99%

Resource Utilization Potential of Red Mud: A Study on the Micro-Mechanism of the Synergistic Effect of Multiple Solid Waste Filling Materials

Zhang,

Yan,

Bai

et al. 2023

Sustainability

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Red mud (RM) is a common industrial byproduct that is characterized by high alkalinity, high pollution, and difficult utilization. In this paper, gangue (CG), flue gas desulfurization gypsum (FGD), and silicate cement (PC) were used to assist red mud in the preparation of red mud-based composite filler material (RMC), aiming at the large-scale resource utilization of RM. The effects of the mass ratio of RM/CG, the mass ratio of FGD/(RM + CG), and the water–solid ratio (WCR) on the multi-angle properties of RMC were investigated and the optimal ratios were determined. The results showed that the RM/CG was 7:1, FGD/(RM + CG) was 4%, and WCR was 0.51 (RMC8), and the system could increase the RM content to 70%. The microstructural analysis of RMC using a specific surface area and porosity analyzer (BET), X-ray diffractometer (XRD), and scanning electron microscope (SEM) showed that its hydration products could remodel the pore structure, encapsulate and cement the coarse and fine particles into a dense matrix, and play a certain alkali reduction role, which revealed the microscopic synergistic mechanism between multiple solid wastes. The study shows that the comprehensive disposal of RM reduces the pollution released into the environment and provides new ideas for the green development of mines.

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Recovery of sludge from alumina production

Cited by 15 publications

References 3 publications

Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review

Towards zero-waste valorisation of rare-earth-containing industrial process residues: a critical review

High-Selective Extraction of Scandium (Sc) from Bauxite Residue (Red Mud) by Acid Leaching with MgSO4

Resource Utilization Potential of Red Mud: A Study on the Micro-Mechanism of the Synergistic Effect of Multiple Solid Waste Filling Materials

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