scholarly journals Study of Microbial Cultures for the Bioleaching of Scandium from Alumina Industry By-Products

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 951
Author(s):  
Kyriaki Kiskira ◽  
Theopisti Lymperopoulou ◽  
Lamprini-Areti Tsakanika ◽  
Charalampos Pavlopoulos ◽  
Konstantina Papadopoulou ◽  
...  
Keyword(s):  
Organic Acids ◽  
Bauxite Residue ◽  
Secondary Source ◽  
Alumina Production ◽  
Microbial Cultures ◽  
Global Environmental ◽  
Valuable Metals ◽  
One Step ◽  
Alumina Industry ◽  
Environmentally Friendly Approach

The disposal of voluminous, highly alkaline, bauxite residue (BR), the industrial by-product of alumina production by the Bayer process, constitutes an intricate global environmental problem. BR, containing valuable metals such as rare-earth elements (REEs)—in particular, scandium (Sc)—can be used as a secondary source for REE extraction. The scope of this study was the investigation of bioleaching as an innovative and environmentally friendly approach for the extraction of Sc from BR. The bioleaching parameters were studied on Greek BR and experiments were performed using different microbial cultures and solid to liquid ratios (S/L). The maximum extraction of Sc was 42% using Acetobacter tropicalis in a one-step bioleaching process at 1% S/L. The main organic acids produced were acetic, oxalic, and citric. The bioleaching data indicated a probable synergistic effect of the different organic acids produced by microorganisms along with a more targeted leaching mechanism.

Applications of bauxite residue: A mini-review

2017 ◽  
Vol 35 (10) ◽  
pp. 999-1012 ◽  
Author(s):  
Ajay S Verma ◽  
Narendra M Suri ◽  
Suman Kant
Keyword(s):  
Automobile Industry ◽  
Bauxite Residue ◽  
Glass Ceramics ◽  
Large Area ◽  
Alumina Production ◽  
Mineralogical Characteristics ◽  
Valuable Metals ◽  
High Alkalinity ◽  
Bauxite Ore

Bauxite residue is the waste generated during alumina production by Bayer’s process. The amount of bauxite residue (40–50 wt%) generated depends on the quality of bauxite ore used for the processing. High alkalinity and high caustic content in bauxite residue causes environmental risk for fertile soil and ground water contamination. The caustic (NaOH) content in bauxite residue leads to human health risks, like dermal problems and irritation to eyes. Moreover, disposal of bauxite residue requires a large area; such problems can only be minimised by utilising bauxite residue effectively. For two decades, bauxite residue has been used as a binder in cement industries and filler/reinforcement for composite materials in the automobile industry. Valuable metals and oxides, like alumina (Al2O3), titanium oxide (TiO2) and iron oxide Fe2O3, were extracted from bauxite residue to reduce waste. Bauxite residue was utilised in construction and structure industries to make geopolymers. It was also used in the making of glass-ceramics and a coating material. Recently bauxite residue has been utilised to extract rare earth elements like scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), neodymium (Nd) and dysprosium (Dy). In this review article, the mineralogical characteristics of bauxite residue are summarised and current progresses on utilisation of bauxite residue in different fields of science and engineering are presented in detail.

scholarly journals Removal of Phosphate Using Red Mud: An Environmentally Hazardous Waste By-Product of Alumina Industry

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Shivkumar S. Prajapati ◽  
P. A. Mohamed Najar ◽  
Vijay M. Tangde
Keyword(s):  
Aqueous Solutions ◽  
Red Mud ◽  
Selective Adsorption ◽  
Bauxite Residue ◽  
Selective Removal ◽  
Bet Surface Area ◽  
Size Analysis ◽  
Alumina Production ◽  
Heat Treated ◽  
Alumina Industry

The industrial waste, bauxite residue generated in the Bayer chemical process of alumina production, commonly known as red mud (RM) has been used as the adsorbent for selective removal of phosphate in aqueous solutions. RM collected from the storage area of alumina industry was characterized by chemical analysis and physical methods such as BET surface area, Scanning Electron Microscopy (SEM), particle size analysis, and X-ray diffraction (XRD) methods. Among the various red mud samples (0.2–200 μ) studied, the samples treated with 1 M HCl for 2 h were found better for the selective adsorption of phosphate in comparison with untreated and heat treated RM samples. The presence of phosphate in the aqueous samples collected after adsorption studies with red mud was determined by standard spectrophotometric procedure using ammonium molybdate and ascorbic acid in nitrate medium at λmax 880 nm. The studies reported significant adsorption of phosphate on acid treated red mud in comparison with adsorption of phosphate on untreated and heat treated red mud, respectively. The adsorption of phosphate on raw red mud and activated red mud was further investigated with respect to stirring time, pH of the solution, dose of adsorbent, and varying phosphate concentration. Acid treated RM is observed as an efficient and cost-effective adsorbent for selective removal of phosphate in aqueous solutions.

scholarly journals Ecological resource availability: a method to estimate resource budgets for a sustainable economy

2020 ◽  
Vol 3 ◽  
Author(s):  
Harald Desing ◽  
Gregor Braun ◽  
Roland Hischier
Keyword(s):  
Resource Availability ◽  
Decision Makers ◽  
Annual Production ◽  
Earth System ◽  
Global Environmental ◽  
Sustainable Economy ◽  
Safe Limits ◽  
One Step ◽  
Environmental Limits ◽  
Environmental Burdens

Non-technical summary Resources are the basis of our economy and their provision causes major shares of the global environmental burdens, many of which are beyond safe limits today. In order to be sustainable, our economy needs to be able to operate within those boundaries. As resources are the physical ‘currency’ of our economy, we present a method that allows translating Earth system boundaries into resource budgets. This ecological resource availability determines the global annual production of a resource that can be considered absolutely sustainable. The budgets can be managed like financial budgets, bringing absolute environmental limits one step closer to decision-makers.

scholarly journals Preliminary Characterization of Three Metallurgical Bauxite Residue Samples

2021 ◽  
Vol 5 (1) ◽  
pp. 66
Author(s):  
Panagiotis Angelopoulos ◽  
Maria Georgiou ◽  
Paschalis Oustadakis ◽  
Maria Taxiarchou ◽  
Hakan Karadağ ◽  
...  
Keyword(s):  
Low Cost ◽  
Bauxite Residue ◽  
Raw Material ◽  
Morphological Observation ◽  
Critical Metals ◽  
Alumina Production ◽  
Preliminary Characterization ◽  
Fine Grained ◽  
Extraction And Separation ◽  
Bulk Chemical

Bauxite Metallurgical Residue (BR) is a highly alkaline and very fine-grained by-product of the Bayer process for alumina production. Its huge global annual production has resulted in increasing accumulation of BR, causing deposition problems and serious environmental issues. RM contains oxides and salts of the main elements Fe, Al, Ca, Na, Si, Ti, and rare earths—REEs (Sc, Nd, Y, La, Ce, Ds)—many of which have been categorised by EU as critical metals (CMs). The valorisation of BR as a low-cost secondary raw material and metal resource could be a route for its reduction, introducing the waste into the economic cycle. REEScue constitutes a research project that aims to instigate the efficient exploitation of European bauxite residues, resulting from alumina production from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA), containing appreciable concentrations of scandium and REEs, through the development of a number of innovative extraction and separation technologies that can efficiently address the drawbacks of the existing solution. The consortium consists of three alumina producers from Greece (MYTILINEOS SA), Turkey (ETI Aluminium), and Romania (ALUM SA) and two academic partners from Greece (National Technical University of Athens) and Turkey (Necmettin Erbacan University). We present preliminary characterization results of three different BR samples that originate from the three aluminium industries, in respect of bulk chemical analysis (XRF, ICP), mineralogical investigation (XRD), and morphological observation through microscopy.

scholarly journals The Future of Scandium Recovery from Wastes

2021 ◽  
Vol 5 (1) ◽  
pp. 55
Author(s):  
Olga Chernoburova ◽  
Alexandre Chagnes
Keyword(s):  
Rare Earth ◽  
Bauxite Residue ◽  
High Strength ◽  
Clean Energy ◽  
Industrial Wastes ◽  
Condensed State ◽  
No Production ◽  
Alumina Production ◽  
Energy Technologies ◽  
Critical Metal

With growing demand for renewable and clean energy technologies, the need in rare earth metals is increasing. Scandium, which is often considered a rare earth element (REE), is a critical metal mainly used in solid oxide fuel cells (SOFCs) and high strength aluminum alloys used in aerospace and 3D printing applications. Furthermore, scandium supply is limited due to its scarcity and the high cost of its production in Asia and Russia while Europe has no production of scandium. Therefore, scandium extraction from alternative resources such as secondary resources located in Europe is of great concern. Within this context, this work provides a condensed state-of-art review of the issue of scandium recovery from industrial wastes. Priority was given to addressing the technological and economic challenges associated with the recovery of scandium from the said residues, with particular emphasis on the bauxite residue from alumina production, which represents nearly 5 million tons on dry basis per year in Europe.

scholarly journals The beginning and the end of the aluminium value chain

2020 ◽  
Vol 108 (5-6) ◽  
pp. 506
Author(s):  
Leiv Kolbeinsen
Keyword(s):  
Value Chain ◽  
Bauxite Residue ◽  
Bayer Process ◽  
International Institute ◽  
Silicon Iron ◽  
Alumina Production ◽  
The World ◽  
Scrap Recycling ◽  
Negative Environmental Impact ◽  
Electric Cables

Metallic aluminium does not naturally occur in nature, and it was largely unknown, virtually a mystery, until 200 years ago. The modern aluminium production using a hydrometallurgical refining process for making alumina followed by electrolysis of this mineral was first developed in 1886 and, in principle, the same technology is still used to this day. About 90% of alumina refineries in the world use the Bayer process for refining Bauxite ore. It is very efficient, but it can only be used on high quality bauxite with low content of admixtures, especially silicon. The Bayer process also generates a Bauxite Residue (BR), maybe better known as Red Mud (RM) which is a thick red-brown, high-basicity paste consisting of silicon, iron, aluminium, titanium and others. The International Institute of Aluminium estimates that since 1886 almost a billion tonnes of aluminium were produced around the world with three fourths of this amount still being in use today, of which about 35% is located in buildings and structures, 30% in electric cables and equipment and 30% in transport. Aluminium scrap is collected all over the world. In the home, it mostly consists of aluminium beverage cans. It is claimed that 1 ton of recycled empty beverage cans save 8 tons of bauxite, 4 kg of various fluorides and 14 kWh of electricity. Additionally, recycling aluminium significantly reduces the negative environmental impact of ever-expanding RM landfills. As the idea of environmental responsibility is gaining more and more traction, separate household scrap recycling is becoming more and more popular around the world. How challenges related to such activity can be met will be the main topic of this paper alongside discussing new developments for alumina production without RM generation.

scholarly journals CO2 conversion by high-dose rate electron beam irradiation: one-step, metal-free and simultaneous production of H2, CO, CH4, C2H6 and organic acids from an acid-decomposed CaCO3/additive EtOH mixture

2019 ◽  
Vol 21 (11) ◽  
pp. 3091-3098 ◽  
Author(s):  
Yoichi Hosokawa ◽  
Shuji Kajiya ◽  
Ayako Ohshima ◽  
Nobuhiro Ishida ◽  
Masakazu Washio ◽  
...  
Keyword(s):  
Electron Beam ◽  
Organic Acids ◽  
Electron Beam Irradiation ◽  
High Dose Rate ◽  
High Dose ◽  
Co2 Conversion ◽  
Beam Irradiation ◽  
Simultaneous Production ◽  
Metal Free ◽  
One Step

The reduction in CO2 emissions is an important issue across many industries.

scholarly journals Extraction of Valuable Elements from Red Mud with a Focus on Using Liquid Media—A Review

Recycling ◽  
2021 ◽  
Vol 6 (2) ◽  
pp. 38
Author(s):  
Dmitry Zinoveev ◽  
Liliya Pasechnik ◽  
Mikhail Fedotov ◽  
Valery Dyubanov ◽  
Pavel Grudinsky ◽  
...  
Keyword(s):  
Red Mud ◽  
Bauxite Residue ◽  
Environmental Risks ◽  
Environmental Damage ◽  
Acid Solutions ◽  
Liquid Media ◽  
Alumina Production ◽  
Advantages And Disadvantages ◽  
Complex Methods ◽  
Biological Organisms

Bauxite residue, known as red mud, is a by-product of alumina production using the Bayer process. Currently, its total global storage amounts to over 4.6 billion tons, including about 600 million tons in Russia. The total global storage of red mud occupies large areas, leading to environmental damage and increasing environmental risks. Moreover, it contains a significant amount of sodium, which is easily soluble in subsoil water; therefore, a sustainable approach for comprehensive recycling of red mud is necessary. The bauxite residue contains valuable elements, such as aluminum, titanium, and scandium, which can be recovered using liquid media. In recent years, many methods of recovery of these elements from this waste have been proposed. This paper provides a critical review of hydrometallurgical, solvometallurgical, and complex methods for the recovery of valuable components from red mud, namely, aluminum, titanium, sodium, and rare and rare-earth elements. These methods include leaching using alkaline or acid solutions, ionic liquids, and biological organisms, in addition to red mud leaching solutions by extraction and sorption methods. Advantages and disadvantages of these processes in terms of their environmental impact are discussed.

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