scholarly journals Progress on the Industrial Applications of Red Mud with a Focus on China

Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 773
Author(s):  
Hua Zeng ◽  
Fei Lyu ◽  
Wei Sun ◽  
Hai Zhang ◽  
Li Wang ◽  
...  
Keyword(s):  
Red Mud ◽  
Building Materials ◽  
Bauxite Residue ◽  
Industrial Applications ◽  
Utilization Rate ◽  
Oil Well ◽  
Alumina Production ◽  
Industrial Utilization ◽  
Develop Technology ◽  
Well Cement

Red mud (RM), also called bauxite residue, is a strong alkaline industrial waste generated during the alumina production process. The annual production of RM in China is large, but its average utilization rate is low (only 4%). High generation and low consumption make the disposal of RM mainly by stockpiling, which has caused serious heavy metal pollution and radioactive contamination. In this paper, the various industrial utilization methods of RM in China during the past 60 years have been introduced. Moreover, some recent industrial progresses were referred. The results show that RM can be widely used in building materials, valuable metals extraction, and some novel utilization methods, such as silica-calcium fertilizer, inorganic polymer material and desulfurizer. Most of the industrial utilization methods of RM have been used until now and some successfully applied to other aluminum plants, providing some feasible routes for a large amount utilization of RM. Some industrial utilization methods (such as oil well cement and calcium silicon fertilizer) have not been used due to some problems that cannot be ignored, but it provided a lot of valuable experience and was helpful for the subsequent RM utilization. Moreover, some novel and feasible RM utilization methods were proposed and successfully industrialized, which showed that RM has a broader application prospect. Many actual practices showed that the best way to safely dispose of RM was to develop technology that could consume large amounts of RM or transform it into secondary resources, which may need more time and effort.

scholarly journals An Alternative to Clay in Building Materials: Red Mud Sintering Using Fly Ash via Taguchi’s Methodology

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Suchita Rai ◽  
Dilip H. Lataye ◽  
M. J. Chaddha ◽  
R. S. Mishra ◽  
P. Mahendiran ◽  
...  
Keyword(s):  
Fly Ash ◽  
Construction Industry ◽  
Red Mud ◽  
Morphological Analysis ◽  
Building Materials ◽  
Sintering Temperature ◽  
Bauxite Residue ◽  
Significant Parameter ◽  
Alkaline Waste ◽  
Free Caustic Soda

“Red mud” or “bauxite residue” is a highly alkaline waste generated from alumina refinery with a pH of 10.5–12.5 which poses serious environmental problems. Neutralization or its treatment by sintering in presence of additives is one of the methods for overcoming the caustic problem as it fixes nearly all the leachable free caustic soda present in red mud. In the present study, feasibility of reducing the alkaline nature of red mud by sintering using fly ash as an additive via Taguchi methodology and its use for brick production, as an alternative to clay, is investigated. The analysis of variance (ANOVA) shows that sintering temperature is the most significant parameter in the process. A pH of 8.9 was obtained at 25–50% of red mud and 50–75% fly ash with water and temperature of . Alternatively 50% of red mud can be mixed with 50% of fly ash with water at temperature of to get a pH of about 8.4. The mechanism of this process has been explained with also emphasis on chemical, mineralogical, and morphological analysis of the sintered red mud. The results would be extremely useful in utilization of red mud in building and construction industry.

Bayern`s Method of Al2O3 Production – Possibilities of Red Mud Disposal and Utilization

2011 ◽  
Vol 176 ◽  
pp. 11-20 ◽  
Author(s):  
Mariola Saternus
Keyword(s):  
Chemical Composition ◽  
Red Mud ◽  
Building Materials ◽  
Short Description ◽  
Iron Recovery ◽  
Alumina Production ◽  
Advantages And Disadvantages ◽  
Primary Aluminium

Bayern`s method is the first stage of obtaining primary aluminium. The product of this process is alumina. The paper presents how much alumina was produced in the last couple of years and who were its leading producers. As the main ore for alumina production is bauxite; it was necessary to describe its characteristics: chemical composition and types of bauxites. Short description of the method (digestion, precipitation and calcination) was presented. During this process a lot of pollution is usually emitted to the atmosphere, but mostly a lot of red mud is generated. This is the main waste of the process, which at the same time is very harmful to the environment. The ways red mud is disposed or utilized were reviewed. Two kinds of red mud disposal are known: wet and dry disposal. Both were characterized and their advantages and disadvantages were outlined. The possibilities of red mud utilization were shown. The focus was put on iron recovery or recovery of compounds such as Al2O3 or TiO2. The use of red mud in building materials was discussed. Radioactivity of such materials was also analyzed. Possibility of red mud utilization as a pigment and radiopaque material was also mentioned.

Effect of red mud addition on oil well cement at high temperatures

2019 ◽  
pp. 1-11 ◽  
Author(s):  
Xiaowei Cheng ◽  
Xuezheng Yang ◽  
Chi Zhang ◽  
Xianshu Gao ◽  
Yongjin Yu ◽  
...  
Keyword(s):  
High Temperatures ◽  
Red Mud ◽  
Oil Well ◽  
Oil Well Cement ◽  
Well Cement

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.

scholarly journals Approaches Regarding Red Mud Valorization for a Green Future and Sustainable Environment

2020 ◽  
Vol 71 (1) ◽  
pp. 51-56
Author(s):  
Adriana Cuciureanu ◽  
Georgiana Cernica ◽  
Bogdan Adrian Stanescu ◽  
Ioana Alexandra Ionescu
Keyword(s):  
Red Mud ◽  
Building Materials ◽  
Current Practice ◽  
Pollutant Removal ◽  
Complex Composition ◽  
Mine Waters ◽  
Alumina Production ◽  
Sustainable Environment ◽  
Experimental Parameters ◽  
Removal Efficiencies

Today the red mud generated from alumina production is a resource, a material that can be valorized, an opportunity. The current practice in waste management in some parts of the planet has to be revised. We need to change technologies and become more aware and thoughtful on our footprint on Earth. Red mud is the main waste generated from the bauxite Bayer process. Having a complex composition with predominantly Al2O3 (14-27%), Fe2O3 (19-56%) contents, viable solutions were sought for the reuse of the red mud. A number of applications have resulted in the recovery of metallic components, chemical industry, and building materials industry. A field of red mud applicability, which has enabled the development of innovative and sustainable techniques, is that of the environment. The paper presents the results of the researches carried out in order to valorize the red mud in the treatment of two categories of wastewater: phosphates waters and mine waters. The influence of the experimental parameters on the pollutant removal efficiencies in these wastewaters is highlighted.

Carbonization processing of bauxite residue as an alternative rare metal recovery process

2020 ◽  
pp. 56-63
Author(s):  
I. N. Pyagay ◽  
◽  
E. A. Kremcheev ◽  
L. A. Pasechnik ◽  
S. P. Yatsenko ◽  
...  
Keyword(s):  
Red Mud ◽  
Raw Materials ◽  
Bauxite Residue ◽  
Target Component ◽  
Acid Activation ◽  
Rare Metals ◽  
Residual Moisture ◽  
Alumina Production ◽  
Carbonization Process ◽  
Pregnant Solution

A prerequisite for commercial production of rare metals is a continuous effort given to developing knowledge-intensive recovery and refining techniques. Commonly known natural raw materials and conventional processing techniques, which are based on initial acid activation and recovery of minerals, as well as selective recovery of the target component (i.e. by sorption and extraction) cannot always ensure sufficient productivity or cost-effectiveness. This paper considers certain aspects of continued research in this area, which would require novel techniques. Such techniques should be based on new approaches allowing for the use of alternative raw materials to produce valuable rare metals on a cost-effective basis. It is demonstrated that red mud, i.e. waste material generated by bauxite industry and rich in scandium and other rare metals, can serve as such alternative source material. The paper describes the results of a study that looked at finding an optimum carbonization process for red mud that would ensure a consistent and predictable complexing process with regard to certain components. The paper also examines the environment in which soluble carbonate complexes can be stabilized and concentrated in the pregnant solution before the primary scandium-bearing concentrate can be recovered. The authors identified target parameters that determine enhanced filtration properties of carbonized slurry to ensure complete separation of the pregnant solution from the dehydrated (to the residual moisture content of 18%) carbonized residue. The paper highlights some positive factors of the carbonization process which enable a comprehensive utilization of alumina production waste. They include a long-term sequestration of carbon dioxide in the air and modified physical and chemical properties of red muds. This makes carbonized muds more compactable and thus more suitable for transportation and minimizes waste disposal hazards. The experimental research was carried out in conformance with the governmental assignments of the Institute of Solid State Chemistry of the Ural Branch of the Russian Academy of Sciences and Saint-Petersburg Mining University.

scholarly journals Hydrothermal Resource-saving Processes in Complex Processing of Bauxite and Red Mud

2020 ◽  
Author(s):  
Liliya A. Pasechnik ◽  
Sergey P. Yatsenko ◽  
Vladimir M. Skachkov ◽  
Svetlana A. Bibanayeva
Keyword(s):  
Saturation Magnetization ◽  
Red Mud ◽  
Bauxite Residue ◽  
Bulk Sample ◽  
Resource Saving ◽  
Alumina Production ◽  
Bayer Liquor ◽  
Rare Elements ◽  
Cleaner Technology ◽  
Promising Source

The Bayer bauxite residue (red mud, RM) is environmentally hostile and hazardous to human health. Red mud can be viewed as an important and promising source of scandium, yttrium, zirconium and other elements rather than a solid waste. Due to a high content of iron in bauxites and especially in RM, the conversion of hematite into magnetite in Bayer liquor plays a key role in the exploration of a cleaner technology of alumina production. Thus, RM and raw bauxite were used for hydrothermal digestion in an original one-stage method of magnetite production during co-recovery of alumina. The yield of alumina reaches 80% from RM and more from bauxites during digestion with addition of lime and Fe(II) or Fe . The saturation magnetization of a bulk sample of magnetized bauxite is 40.5 emu/g, two orders of magnitude higher than that of a raw red mud sample. Moreover, magnetite containing a residue has a high crystallinity, which contributes to better deposition and magnetic separation in the development of an overall flowsheet for RM utilization. Keywords: Red mud, bauxite, hydrothermal treatment; enrichment, extraction, magnetization, hematite, magnetite, rare elements

scholarly journals Fundamental study of red mud based fluxes for desulphurization and dephosphorization of hot metal

2021 ◽  
Author(s):  
Abdolkarim Danaei
Keyword(s):  
Red Mud ◽  
Characteristic Temperature ◽  
Bauxite Residue ◽  
Mineral Resources ◽  
Melting Behavior ◽  
Hot Metal ◽  
Fundamental Study ◽  
Alumina Production ◽  
Phosphorus Distribution ◽  
Microscopy Technique

Bauxite residue, also known as red mud, is generated during alumina production and is an abundant industrial waste material. Continuously increasing environmental concerns, together with scarcity of traditional mineral resources, have created a thrust to re-use the material. Red mud contains significant amounts of iron oxide and sodium hydroxide, hence a highly basic (pH > 10) slurry. In this research, the use of red mud as starting material for preparation of iron refining fluxes was evaluated. Red mud based fluxes and hot metal were equilibrated in graphite crucibles at the temperature range of 1300 ºC to 1400 °C and oxygen partial pressures range of 10-2 atm to 10-6 atm. It was found that the sulphide capacity increases with lime addition to a maximum 32 wt% CaO and decreases with increasing A12O3, TiO2 and SiO2 content in the fluxes saturated with lime. An iron foil equilibrium technique was employed to obtain precise measurements of phosphorus distribution between carbon saturated iron and red mud based fluxes. The measurements indicate that the equilibrium phosphorus distribution ratio initially increases with rise in FeO or CaO concentration of the fluxes and then drops. The melting behavior of the fluxes was also studied by visualizing the deformation of flux pellets as they were heated using a high temperature microscopy technique. Measurements of characteristic temperature for different fluxes indicated the melting property is a function of slag basicity. Therefore, optical basicity was used to establish a correlation between basicity of the red mud based fluxes and their melting properties.

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 Manufacture of ceramics with high mechanical properties from red mud and granite waste

2019 ◽  
Vol 69 (333) ◽  
pp. 180 ◽  
Author(s):  
I. Gonzalez-Triviño ◽  
J. Pascual-Cosp ◽  
B. Moreno ◽  
M. Benítez-Guerrero
Keyword(s):  
Mechanical Properties ◽  
Red Mud ◽  
Bauxite Residue ◽  
Hardness Test ◽  
X Ray Diffraction ◽  
Alumina Production ◽  
X Ray ◽  
Test Electron ◽  
Electron Scanning Microscopy ◽  
Global Inventory

Red mud (bauxite residue) is an alkaline suspension that is the by-product of alumina production via the Bayer process. Its elevated annual production and the global inventory of red mud determine its valorisation. Granite can be used as a source of fluxing oxides for the ceramic industry, as can the flake-shaped waste generated during the flaming of granite. In this work, a set of ceramic pieces made of red mud and granite waste are prepared and characterised via X-ray diffraction, a hardness test, electron scanning microscopy, a leaching test, and determining open porosity, water absorption, bulk density and flexural strength of the samples. The main crystalline phases in the high-temperature fired products are hematite, pseudobrookite and anorthite; the presence of magnetite reveals their ferrimagnetic character. All samples present high mechanical properties. Leaching results are below critical levels established by regulations.

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