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.

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.

New composite material, with neutralized red mud

2021 ◽  
pp. 156-169
Author(s):  
А.А. Баринкова ◽  
В.Ю. Пиирайнен ◽  
В.М. Баринков
Keyword(s):  
Composite Material ◽  
Portland Cement ◽  
Red Mud ◽  
Building Materials ◽  
Experimental Studies ◽  
Theoretical Studies ◽  
Advantages And Disadvantages ◽  
Promising Area ◽  
New Material ◽  
Direct Use

В статье предложено решение по утилизации красного шлама в больших количествах с перспективой создания цикла его полной переработки. Для определения области работы были проведены аналитические исследования по уже известным технологиям переработки, описаны их основные преимущества и недостатки. В процессе анализа была определена наиболее перспективная область - непосредственное использование отхода, а именно производство строительных материалов. Были проведены экспериментальные исследования в лабораторных условиях, которые показали конкурентоспособность полученного композита относительно традиционных бетонов на основе портландцемента и выявлены возможные области применения нового материала. This paper proposes a solution for utilization of red mud in large amounts with the prospect of creating a complete recycling cycle. In order to determine the area of work, theoretical studies of already known recycling technologies were conducted, their main advantages and disadvantages were described. In the process of analysis, the most promising area was determined - the direct use of waste, namely the production of building materials. Experimental studies have been conducted in laboratory conditions, which showed the competitiveness of the resulting composite relative to the traditional Portland cement and identified possible applications of the new material.

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 Influence of Sodium Sulfate Addition on Iron Grain Growth during Carbothermic Roasting of Red Mud Samples with Different Basicity

Metals ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 1571
Author(s):  
Pavel Grudinsky ◽  
Dmitry Zinoveev ◽  
Denis Pankratov ◽  
Artem Semenov ◽  
Maria Panova ◽  
...  
Keyword(s):  
Magnetic Separation ◽  
Grain Growth ◽  
Red Mud ◽  
Sodium Sulfate ◽  
Phase Distribution ◽  
Solid Phase ◽  
Alumina Production ◽  
Metallic Particles ◽  
Iron Phase ◽  
High Alkalinity

Red mud is an iron-containing waste of alumina production with high alkalinity. A promising approach for its recycling is solid-phase carbothermic roasting in the presence of special additives followed by magnetic separation. The crucial factor of the separation of the obtained iron metallic particles from gangue is sufficiently large iron grains. This study focuses on the influence of Na2SO4 addition on iron grain growth during carbothermic roasting of two red mud samples with different (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21, respectively. Iron phase distribution in the red mud and roasted samples were investigated in detail by Mössbauer spectroscopy method. Based on thermodynamic calculations and results of multifactorial experiments, the optimal conditions for the roasting of the red mud samples with (CaO + MgO)/(SiO2 + Al2O3) ratio of 0.46 and 1.21 were duration of 180 min with the addition of 13.65% Na2SO4 at 1150 °C and 1350 °C followed by magnetic separation that led to 97% and 83.91% of iron recovery, as well as 51.6% and 83.7% of iron grade, respectively. The mechanism of sodium sulfate effect on iron grain growth was proposed. The results pointed out that Na2SO4 addition is unfavorable for the red mud carbothermic roasting compared with other alkaline sulfur-free additives.

A Contribution to the Treatment of Salt Damage in Historical Buildings

2015 ◽  
Vol 824 ◽  
pp. 127-132
Author(s):  
Iñigo Antepara ◽  
Igor Medveď ◽  
Jaromír Žumár ◽  
Robert Černý
Keyword(s):  
Building Materials ◽  
Historical Buildings ◽  
Research Teams ◽  
Porous Building Materials ◽  
Salt Damage ◽  
Advantages And Disadvantages ◽  
Historical Masonry

Salts and water may cause serious damage to historical masonries. Therefore, numerous conservation treatments have been developed by research teams for the consolidation and protection of porous building materials affected by salt attack. Here the focus is on methods for obtaining an effective desalination of historical masonry, indicating their advantages and disadvantages. It is pointed out that cellulose is a favourite material added to poultices used in desalination.

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.

The Research of Iron Containing Wastes Modification Process of Leninabad Rare Metals Plant

2021 ◽  
Vol 410 ◽  
pp. 778-783
Author(s):  
Pavel V. Matyukhin ◽  
Daler I. Mirzoev
Keyword(s):  
Chemical Composition ◽  
Building Materials ◽  
Raw Material ◽  
Filling Material ◽  
Rare Metals ◽  
X Ray ◽  
Modification Process ◽  
Before And After ◽  
The Republic ◽  
Enrichment Process

The paper presents the results of ferriferous wastes modification process research carried on the basis of JCS “Leninobad rare metals Plant” located in the Republic of Tajikistan. The wastes for the study were taken from the western tailing. The article presents the justification of the chosen wastes as a filling material in the development of new radiation protective composite building materials. The data on the initial ferriferous chemical composition of the tailing wastes and the chemical composition of the material that passed the enrichment process is presented. The study contains microphotos of ferriferous haematite raw material particles surface before and after completing the modifying process. The paper presents and describes the study of X-ray phase analysis diffractograms of enriched iron-containing wastes before and after the modification process. The current research proves that the enrichment ferriferous wastes particles modification process is possible and as a result it can be used as a filling for the development of new kinds of radioprotective composite materials.

Interfacial interactions between urea formaldehyde and cellulose nanofibrils (CNFs) of varying chemical composition and their impact on particle boards manufacture (PBs)

2021 ◽  
Author(s):  
Maria C. Iglesias ◽  
Philip S. McMichael ◽  
Osei A. Asafu-Adjaye ◽  
Brian K. Via ◽  
Maria S. Peresin
Keyword(s):  
Chemical Composition ◽  
Building Materials ◽  
Colloidal Stability ◽  
Low Cost ◽  
Urea Formaldehyde ◽  
Cellulose Nanofibrils ◽  
Global Market ◽  
Modulus Of Rupture ◽  
Superior Performance ◽  
Interfacial Interactions

Abstract Wood-based panels are commonly used as building materials for interior and exterior purposes. Their production and utilization have increased over the past decades due to the useful properties they present. Adhesive-bonded products make up to 80% of the wood alternatives on the global market, and of that, urea-formaldehyde (UF) makes up approximately 81% of the resins used. Formaldehyde-based resins are used due to their effectiveness and low cost, as well as their ease of application and lack of color. Nevertheless, their main disadvantages are the lack of tackiness and the emission of formaldehyde over time. To improve UF performance, the utilization of microfibrillated cellulose, has been demonstrated to be effective. However, more understanding on the mechanisms of the interactions is of relevant importance. In this work, we studied interfacial interactions between UF with bleached (BCNF) and unbleached (LCNF) cellulose nanofibrils using Quartz Crystal Microbalance with dissipation monitoring (QCM-D) technique observing the superior performance of lignin-containing CNF. Additionally, the surface free energies were investigated using Contact Angle Measurements (CA) showing a decrease of the values mainly when utilizing LCNF, which was later correlated with the wettability properties of the particle boards (PBs). PBs with different adhesive/CNF formulations were produced showing larger improvements when adding LCNF in terms of modulus of elasticity (MOE), modulus of rupture (MOR), and internal bonding (IB). To gain a better understanding on the interactions between CNF and UF, CNF was fully characterized in terms of morphology, chemical composition, charge density, as well as thermal and colloidal stability.

scholarly journals A Study of the Potential Use of Red Mud to Obtain Compositions Based on Portland Cement

2020 ◽  
Author(s):  
Ekaterina Gerasimova ◽  
Elizaveta Gumirova
Keyword(s):  
Portland Cement ◽  
Red Mud ◽  
Waste Product ◽  
Cement Stone ◽  
Mathematical Planning ◽  
Alumina Production ◽  
Mineral Additive ◽  
Composition Properties ◽  
Planning Of Experiments ◽  
Potential Use

The paper deals with the problem of utilization of red mud which is a waste product from alumina production using the Bayer method. The principal possible use for the red mud of JSC “Bogoslovsky aluminum plant” (Sverdlovsk region) for the compositions based on Portland cement is shown. It was found that the mud introduction accelerates beginning of the cement paste setting and thickens the paste reducing its mobility. It is concluded that the introduction of red mud up to 30 % is justified in terms of strength indicators. The work is carried out using mathematical planning of experiments. Keywords: red mud, Portland cement, active mineral additive, composition, properties, bauxite, chemical composition, cement stone strength, mathematical planning of experiments

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