scholarly journals Potential of red mud as raw material for alternative binders in concrete

Author(s):  
Ivana Vladić Kancir ◽  
Marijana Serdar
Keyword(s):  
Red Mud ◽  
2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.


2015 ◽  
Vol 14 (2) ◽  
pp. 90 ◽  
Author(s):  
K. L. M. Dos Passos ◽  
B. M. Viegas ◽  
E. N. Macêdo ◽  
J. A. S. Souza ◽  
E. M. Magalhães

The use of the waste of the Bayer process, red mud, is due to its chemical and mineralogical composition that shows a material rich in oxides of iron, titanium and aluminum. Some studies conducted show that this waste can be applied as a source of alternative raw material for concentration and subsequent recovery of titanium compounds from an iron leaching process, which is present in higher amounts, about 30% by weight. To obtain a greater understanding about the leaching kinetics, the information of the kinetic data of this process is very important. In this context, the main objective of this work is the development of a mathematical model that is able to fit the experimental data (conversion / extraction iron, titanium and aluminum) of the leaching process by which is possible to obtain the main kinetic parameters such as the activation energy and the velocity of chemical reactions as well as the controlling step of the process. The development of the mathematical model was based on the model of core decreasing. The obtained model system of ordinary differential equations was able to fit the experimental data obtained from the leaching process, enabling the determination of the controlling step, the rate constants and the activation energies of the leaching process.


2021 ◽  
Author(s):  
Yong Cheng ◽  
Longjun Xu ◽  
Chenglun Liu ◽  
Zao Jiang ◽  
Qiyuan Zhang ◽  
...  

Abstract In this work, red mud was used as raw material to extract Al and Fe with hydrochloric acid. The high-efficiency polyaluminum iron chloride (PAFC) flocculant was prepared via adjusting the pH of the leaching solution, the molar ratio of aluminum and iron, and the polymerization temperature. The effect of synthesis and flocculation conditions on the flocculation performance of aged landfill leachate was investigated. The results confirmed that the PAFC prepared at the polymerization pH of 2.5, the Al/Fe molar ratio of 8, and the polymerization temperature of 70 °C had the optimum flocculation effect. The flocculation consequences of PAFC and commercial polyaluminum iron chloride flocculant (CPAFC) under different flocculation conditions were compared. The chemical oxygen demand (COD), UV254, chroma and settlement height of PAFC at flocculant concentration of 60 g/L and solution pH of 6 were 72.2%, 79.2%, 82.9% and 9.5 cm (within 90 min), respectively. PAFC has excellent flocculation performance and can be used as a simple, potentially low-cost wastewater treatment agent in industrial applications.


2016 ◽  
Vol 31 (4) ◽  
pp. 877-882 ◽  
Author(s):  
Xiao Wang ◽  
Zhongtao Luo ◽  
Lei Zhang ◽  
Hui Rong ◽  
Jiujun Yang
Keyword(s):  
Red Mud ◽  

2011 ◽  
Vol 383-390 ◽  
pp. 3366-3373
Author(s):  
Shuo Qin ◽  
Bo Lin Wu ◽  
Shiao Zhao ◽  
Cong Chang Ma ◽  
Zu Sheng Hu

Red mud is the main solid residue generated during the production of alumina by means of the Bayer process. In order to expand the comprehensive utilization field of red mud and develop new ceramic products with low radioactivity utilizing red mud, the exploration of preparing self-releasing glaze ceramic materials using red mud as raw material was carried out. During the exploration, the self-releasing glaze ceramic materials with low radiation level were produced by normal pressure sintering process using the main ingredients of red mud, red sandstone, barium carbonate and ball clay. The properties of the self-releasing glaze ceramic samples were investigated by the measurements of mechanical properties, X-ray diffraction (XRD), scanning electron microscopy (SEM) and radiation measurement. The results show that the self-releasing glaze ceramic materials have good mechanical properties (the bulk density, 3.10 g/cm3; the compressive strength, 78.00 MPa). Adding barium carbonate to the raw materials and then calcine them to ceramics, which can extend the sintering temperature range and the radioactivity level of the self-releasing glaze ceramic materials can be reduced to that of the natural radioactive background of Guilin Area, Karst landform (the average 60 Total/Timer).


2021 ◽  
Vol 316 ◽  
pp. 673-677
Author(s):  
Irina V. Loginova ◽  
Aleksei V. Kyrchikov

In Russia, the main feedstock for producing aluminum is bauxite. During the processing of 1 ton of bauxite into alumina (Al2O3), up to 0.5–0.6 ton of techno-genic waste is formed, that is red mud. It is not currently disposed of and accumulated in mud tailing dumps. It contains valuable components: Al – 8 %; Fe – 25 %; Ti – 2.4 % and it can be considered as a potential raw material for ferrous metallurgy and as a source of vanadium, titanium, and rare-earth elements (REE) Sc, Y, La. The paper shows the possibility of obtaining red mud with an increased iron content of up to 36 %, with an additional extraction of aluminum. Red mud from the Ural Aluminum Plant (Russia) is considered. It is proposed to direct this mud to the production of pellets for the production of cast iron. To extract aluminum from red mud, it is proposed to process the mud in a highly alkaline medium by sintering in the temperature range 300–600 °C. The resulting sinter is leached with water or a slightly alkaline solution with the conversion of aluminum compounds into solution. The red mud, obtained this way, exhibits magnetic properties. A magnetic separation was carried out, and the yield of the magnetic fraction is 79.87 %. The iron content increases by 25 % and amounts to 51.88 % of Fe2O3.


2020 ◽  
Vol 991 ◽  
pp. 144-149
Author(s):  
Arif Hidayat ◽  
Galih Kholifatu Roziq ◽  
Faiz Muhammad ◽  
Winarto Kurniawan ◽  
Hirofumi Hinode

The problem associated with biodiesel production is economic feasibility. The biodiesel cost will reduce when the low cost feedstock was used as feedstock. Used Cooking Oil (UCO) is a promising candidate as raw material for biodiesel synthesis. In this study, the investigation of biodiesel synthesis from UCO was studied using red mud as heterogeneous catalysts. The catalyst was prepared by impregnating Potassium metals on red mud. The catalyst physico-characteristics were determined using Nitrogen gas adsorption, FT-IR, XRD, and XRF. The catalyst was tested to synthesize biodiesel from UCO. The reaction temperatures, methanol to oil mass ratio, and amount of catalyst were varied to examine their effects on biodiesel synthesis. The optimum reaction conditions were obtained at 60°C of reaction temperature, 10:1 of methanol to oil mass ratio, and 10% of catalyst amount. The highest biodiesel yield of 94.4% was obtained.


2014 ◽  
Vol 540 ◽  
pp. 225-228 ◽  
Author(s):  
Long Ma ◽  
Guo Zhong Li ◽  
Ji Rui Hu

The red mud lightweight insulation brick was prepared by the sintering process as red mud, fly ash, bentonite as the main raw material, adding a certain amount of pore forming agent and fluxing agent. The sintering heat preservation time of red mud insulation brick on the properties was studied. The red mud lightweight insulation brick damage fracture microstructure was analyzed using scanning electron microscope (SEM) and the sintering mechanism was discussed preliminarily. The results show that with sintering temperature of 1100°C heating for 180 minutes, the performance of thermal insulation brick is better. When the heat preservation time extends to continue, the performances of sample remain stable basically.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Franziska Klimpel ◽  
Michael Bau ◽  
Torsten Graupner

AbstractScandium is a critical raw material that is essential for the EU economy because of its potential application in enabling technologies such as fuel cells and lightweight materials. As there is currently no secure supply of Sc, several projects worldwide evaluate potential Sc sources. While elsewhere in Europe emphasis is placed upon secondary resources such as red mud, we investigated the potential of industrial garnet sand and its waste products. Since Sc readily substitutes for Mg and Fe in the crystal lattice of garnet, the garnet minerals almandine and pyrope, in particular, may show high Sc concentrations. Garnet sand, after being used as an abrasive in the cutting and sandblasting industry, is recycled several times before it is finally considered waste which eventually must be disposed of. Extraction of Sc (and rare earth elements, REE) from such garnet sand may generate added value and thereby reduce disposal cost. The studied garnet sands from different mines in Australia, India and the U.S., and industrial garnet sands commercially available in Germany from different suppliers show average Sc concentrations of 93.7 mg/kg and 90.7 mg/kg, respectively, i.e. similar to red mud. Our data also show that “fresh” and recycled garnet sands yield similar Sc concentrations. Within the framework of a minimum-waste approach, it may be feasible to utilize the industrial waste-product “garnet sand” as an unconventional source of Sc and REE, that reduces disposal cost.


Author(s):  
Светлана Александровна Бибанаева ◽  
Владимир Михайлович Скачков

Работа посвящена изучению влияния моно- и сложносоставных металлических добавок на процесс переработки бокситов гидрощелочным способом. Изучен химический качественный и количественный состав, морфология красных шламов (КШ) полученных в условиях автоклавного высокотемпературного выщелачивания. Проведены рентгенофазовые исследования, направленные на определение состава и структуры соединений в красном шламе. Показана перспективность метода автоклавного выщелачивания трудновскрываемых бокситов с одновременным извлечением глинозема и конверсии гематита в магнетит газообразным водородом. Установлено, что способ позволяет переработку бокситов с высокой степенью извлечения глинозема и позволяет получать красные шламы с различным содержанием магнитной фракции и низким содержанием натрия. Полученный магнетизированный красный шлам пригоден для переработки с помощью магнитной сепарации и делает перспективным сырьем для черной металлургии. Определена зависимость степени конверсии гематита в магнетит от вида восстанавливающего агента. По результатам исследований был получен патент на изобретение. The work is devoted to the study of the influence of mono - and composite metal additives on the process of processing bauxite by the hydro-alkaline method. The chemical qualitative and quantitative composition, morphology of red mud (RM) obtained under conditions of autoclave high-temperature leaching were studied. X-ray phase studies aimed at determining the composition and structure of compounds in red mud were carried out. The prospects of the method of autoclave leaching of hard-to-open bauxites with simultaneous extraction of alumina and conversion of hematite to magnetite by hydrogen gas are shown. It was found that the method allows the processing of bauxite with a high degree of alumina extraction and allows to obtain red mud with different magnetic fraction content and low sodium content. The resulting magnetized red mud is suitable for processing by magnetic separation and makes it a promising raw material for the ferrous metallurgy. The dependence of the degree of conversion of hematite to magnetite on the type of reducing agent is determined. According to the results of the research, a patent for the invention was obtained.


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