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 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 USE OF DUMPED RED MUD OF ALUMINA INDUSTRY AT GRANULATION OF THE MOLTEN SULFUR-CONTAINING BLAST FURNACE SLAG

2019 ◽  
Vol 16 (31) ◽  
pp. 837-845
Author(s):  
Andrey B LEBEDEV ◽  
Vladimir A UTKOV ◽  
Olga A KAYGORODOVA ◽  
Marsel A KADYROV
Keyword(s):  
Blast Furnace ◽  
Red Mud ◽  
Power Plants ◽  
Natural Waters ◽  
Thermal Power ◽  
Alumina Production ◽  
Industrial Gases ◽  
Red Muds ◽  
Alumina Industry ◽  
Sulfur Containing

There is a problem of using waste of alumina production from bauxite red mud. Warehousing of it is fraught with ecological catastrophes. Red muds constantly worsen the environment due to dusting and pollution of natural waters. Red mud is a product of bauxite processing. One ton of alumina accounts for 1 to 2.5 tons of red mud. Currently, it is not being processed, despite the availability of 3,000 publications and patents on this topic. One of them is justified by the ambiguity in the economic effectiveness of its use by consumers. In this paper, the options for economic and environmental efficiency of RM use are presented as substitutes for expensive lime and limestone used for purification of industrial gases emitted to the atmosphere in large quantities with toxic sulfur compounds. Laboratory and industrial tests revealed the sorption properties of red muds. When cleaning gases from sulfur emitted into the atmosphere by furnace gases, thermal power plants, sinter machines, and steelmaking furnaces. In addition, the ecological and technological efficiency of purification of sulfur-containing gases released in the areas of granulation of molten blast-furnace slags is shown.

scholarly journals Bulk Utilization of Red Mud in Geopolymer Based Products

2020 ◽  
Vol 12 (2) ◽  
pp. 86-91
Author(s):  
Abhisek Mohapatra ◽  
Prasanta Bose ◽  
Sagar S Pandit ◽  
Sanjay Kumar ◽  
T.C. Alex
Keyword(s):  
Red Mud ◽  
Ash Content ◽  
Target Strength ◽  
Alkali Concentration ◽  
Alumina Production ◽  
Ore Processing ◽  
Fine Size ◽  
Bauxite Ore ◽  
Alumina Industry ◽  
And Storage

Red Mud is the solid residue generated from Alumina refinery during the process of bauxite ore processing through Bayer’s process. Typical generation of red mud is 1.5 tons of red mud per ton of alumina produced. The disposal and storage of red mud has been a concern for the alumina industry since its inception, more than a hundred years ago. With the increase in alumina production, the magnitude of the problem is getting multiplied. Its alkaline nature (Na2O ~ 3-7%) and fine size make red mud unsuitable for many applications; a limited utilization is reported in cement industries as one of the raw mix components for cement. The present work deals with the utilization of red mud in geopolymer based paving blocks. Alumina, silica and alkali are the essential items required for geopolymer preparation. Having all these in red mud, the current study attempted to use the same in geopolymer based products. The focus has been on bulk utilization of red mud; target strength of 20 MPa after 28 days of curing (M20 grade) has been the goal as this strength is sufficient for many applications. The study focused on optimizing the red mud content, alkali concentration, fly ash content, etc. The samples are tested for its compressive strength and leachability. The study reveals that significant amount of red mud incorporation is possible with products conforming to USEPA 1311 norms.

Remediation of Bauxite Residue Through Integrated Approach of Microbes and Plantation

2021 ◽  
pp. 475-489
Author(s):  
Kumud Dubey ◽  
K. P. Dubey
Keyword(s):  
Tree Species ◽  
Red Mud ◽  
Industrial Waste ◽  
Bauxite Residue ◽  
Integrated Approach ◽  
Prosopis Juliflora ◽  
Acacia Auriculiformis ◽  
Physico Chemical ◽  
Cyanobacterial Species ◽  
Alumina Industry

Bauxite residue (red mud) is an industrial waste bye product of Alumina industry. It is toxic and highly alkaline in nature having heavy metals. Its disposal is the paramount environmental issue in Alumina industry. In the present study, bioremediation of red mud was carried out through cyanobacteria amendments and plantation. Two cyanobacterial species (viz. Phormidium and Oscillatoria) were found promising after studying their effect on physico-chemical characteristics of red mud. Seeds of selected tree species (viz. Dalbergia sissoo, Prosopis juliflora, Acacia auriculiformis, Pithecellobium dulce, Cassia siamia) were procured, and a nursery of these tree species was raised. Performances of two cyanobacteria (viz. Phormidium and Oscillatoria sps.) in combinations with PSB and VAM on red mud are very encouraging and hold considerable promise for bioremediation and revegetation of red mud. Inoculated seedlings of P. juliflora, P. dulce, A. auriculiformis, and C. siamia performed well for red mud revegetation.

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 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 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.

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 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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