scholarly journals Synthesis and Properties of Red Mud-Based Nanoferrite Clinker

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Hongfang Sun ◽  
Chuyu Chen ◽  
Li Ling ◽  
Shazim Ali Memon ◽  
Zhu Ding ◽  
...  
Keyword(s):  
Red Mud ◽  
Environmental Concern ◽  
Raw Materials ◽  
Average Diameter ◽  
Synthesis Temperature ◽  
Raw Material ◽  
Stoichiometric Ratio ◽  
Surrounding Water ◽  
Optimum Synthesis ◽  
Combustion Technology

Red mud, an industrial waste obtained from alumina plants, is usually discharged into marine or disposed into a landfill polluting the surrounding water, atmosphere, and soil. Thus, disposal of red mud is an environmental concern and it should be recycled in an effective way. Since red mud consists of iron- and aluminum-rich phases, it can potentially be processed into cementitious material and can be used for a construction purpose. This research investigated the synthesis of nanoferrite (NF) clinker by using red mud as a raw material through chemical combustion technology for potential use in cement-based composite. Before the synthesis of NF, red mud was characterized by using XRF, XRD, and SEM techniques. From characterization results, the stoichiometric ratio of raw materials was calculated and experimentally optimized. The sample was then tested at various temperatures (815, 900, 1000, and 1100°C) to find the optimum synthesis temperature. Finally, the hydraulic activity of NF was verified and the contribution to mechanical properties was determined by replacing cement with NF at various substitution levels (0, 5, 10, and 20 wt%). Test results showed that the optimum condition for the synthesis of NF was found when the ratio of CaCO3/red mud was 1.5 and the sintering temperature was 815°C. The synthesized NF had an average diameter of 300 nm, and the main composition was brownmillerite (C4AF) with distinct hydraulic reaction. When NF was used as a substitute of Portland cement in mortar, the flexural strength with a 5% replacement level improved by 15%. Therefore, it can be concluded that the synthesis of NF provides an alternative approach to recycle red mud and could significantly help in reducing environmental pollution.

Preparation of Self-Releasing Glaze Ceramic Materials Utilizing Red Mud

2011 ◽  
Vol 383-390 ◽  
pp. 3366-3373
Author(s):  
Shuo Qin ◽  
Bo Lin Wu ◽  
Shiao Zhao ◽  
Cong Chang Ma ◽  
Zu Sheng Hu
Keyword(s):  
Mechanical Properties ◽  
Red Mud ◽  
Barium Carbonate ◽  
Raw Materials ◽  
Normal Pressure ◽  
Ceramic Materials ◽  
The Self ◽  
Raw Material ◽  
Radiation Level ◽  
Red Sandstone

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).

Synthesis of Lignin-Based Epoxy Resin in Ionic Liquid [BMIm]Cl

2015 ◽  
Vol 740 ◽  
pp. 51-54
Author(s):  
Wen Ting Li ◽  
Ming Qiang Chen ◽  
Zhong Lian Yang
Keyword(s):  
Ionic Liquid ◽  
Epoxy Resin ◽  
Synthesis Temperature ◽  
Raw Material ◽  
Value Analysis ◽  
Alkali Lignin ◽  
Optimum Synthesis ◽  
Ft Ir ◽  
Modified Lignin ◽  
Epoxy Value

Industrial alkali lignin (LG) was used as raw material and ionic liquid 1-butyl 3-methylimidazolium chloride ([BMIm]Cl) was used as solvent. Alkali lignin was dissolved into the [BMIm]Cl and modified as propyl ether lignin(HLG). Then the HLG modified lignin was used to synthesizing the lignin-based epoxy resin (LGEP) with epoxy chloropropane. The structure of LG, HLG and LGEP were characterized with FT-IR, the results indicated that the propyl group was introduced to the LG and the reaction activity was improved. The expoxy value analysis results showed that the optimum synthesis temperature was 80°C and the epoxy value was 0.218.

scholarly journals Physicochemical, mineralogical and radiological properties of red mud samples as secondary raw materials

2017 ◽  
Vol 32 (3) ◽  
pp. 261-266 ◽  
Author(s):  
Snezana Nenadovic ◽  
Gabor Mucsi ◽  
Ljiljana Kljajevic ◽  
Miljana Mirkovic ◽  
Milos Nenadovic ◽  
...  
Keyword(s):  
Red Mud ◽  
Building Materials ◽  
Raw Materials ◽  
Preliminary Investigation ◽  
Construction Materials ◽  
Hazard Index ◽  
Raw Material ◽  
Radiation Hazard ◽  
Absorbed Dose Rate ◽  
Radium Equivalent Activity

The main goal of the presented research was the preliminary investigation of possibility of red mud - Hungarian dump sites Almasfuzito (sample A) and Ajka (sample B) - application as a pigment or as a raw material for use in the construction materials industry. Also, the aim of this work was the characterization of red mud as industrial waste generated by the Bayer process in the aluminum industry - which may cause environmental problems if appropriate treatment is not carried out. The main mineral phases of both red mud are hematite (Fe2O3), calcite (CaCO3), gibbsite (Al(OH)3) and they consists of particles of median particle size 2.1 mm (sample A) and 2.5 mm (sample B) and have a characteristic red color, which was the reason for its testing for use in the industry of building materials as a pigment for standard concrete mixtures. The radionuclides content in the samples was determined by gamma spectrometry, and the radiological hazards originating from 238U, 232Th, 40K in the samples, were assessed through the radium equivalent activity, and the external radiation hazard index. The absorbed dose rate and the annual effective dose were calculated in accordance with the UNSCEAR 2010 report and the results are presented in this paper.

Synthesis of Stainless Steel/CNTs Nanocomposite Powders

2010 ◽  
Vol 93-94 ◽  
pp. 181-184 ◽  
Author(s):  
Duanghathai Kaewsai ◽  
Pisith Singjai ◽  
Pannada Niranatlumpong ◽  
Anucha Watcharapasorn ◽  
Sukanda Jiansirisomboon
Keyword(s):  
Carbon Nanotubes ◽  
Stainless Steel ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Average Diameter ◽  
Synthesis Temperature ◽  
Synthesis Time ◽  
Cvd Method ◽  
Optimum Synthesis ◽  
Nanocomposite Powders

Stainless steel/carbon nanotubes (CNTs) nanocomposite powders were synthesized by chemical vapor deposition (CVD) method with ethanol as a carbon source. The effects of synthesis temperature and time on microstructure and chemical composition of the powders were investigated. The as-received stainless steel powders were synthesized at temperature in between 550-800°C for 30-180 min at a pressure of 10 Torr. The optimum synthesis condition was found to be 800°C for 120 min. Average diameter of CNTs grown on stainless steel particles slightly increased with increasing growth temperature. The synthesis time, however, was found to have no effect on the size of CNTs.

Effect of CaO on SNCR Reaction with NH3 as Reducing Agent

2016 ◽  
Vol 847 ◽  
pp. 249-255 ◽  
Author(s):  
Yun Ning Zhang ◽  
Ya Li Wang ◽  
Su Ping Cui ◽  
Wei Wang ◽  
Yi Ning Zhao
Keyword(s):  
Catalytic Reduction ◽  
Raw Materials ◽  
Reduction Reaction ◽  
Raw Material ◽  
Reaction Process ◽  
Stoichiometric Ratio ◽  
Utility Boiler ◽  
Temperature Range ◽  
High Temperature Area ◽  
High Concentrations

Selective non-catalytic reduction (SNCR) is a denitration method in the high temperature area, and NH3 or urea is used for SNCR as reducing agents to react with NOX to produce N2 in the flue gas in the temperature ranged from 850°C to 1100°C. The SNCR deNOx technology has been well used in utility boiler, but compared with it, the lower denitration efficiency and the larger consumption of ammonia indicate a more complex process in cement pre-calciner. Unlike in utility boiler, the presence of high concentrations of cement raw materials may influence SNCR denitration reaction process in cement kilns. Therefore, studying the effect of CaO which occupy the major composition of cement raw material is very important in SNCR process. In this study the influence of CaO on the SNCR deNOx process was investigated by simulating SNCR reaction at temperature that ranges from 750°C to 1100°C with different normalized stoichiometric ratio. The experimental results demonstrate that the addition of CaO increases the optimum denitration temperature to 1100°C, but it has no effect on normalized stoichiometric ratio. In the whole reaction process NH3 not only restores NO to O2 but also reacts with O2 to NO. Since the adsorption of NH3 on CaO surface, in the temperature range of 750°C-850°C the addition of CaO promotes the reaction of NH3 and O2 and increases NOX concentration. However, in the temperature range of 850°C-1000°C it not only promotes NH3 oxidation but also inhibits the reduction reaction of NH3, thereby the denitration reaction is inhibited. In the temperature range of 1050°C-1100°C the denitration reaction is promoted due to the NH3 desorption from CaO surface.

scholarly journals Structure Formation Processes and Green Ceramics Manufacturing from Hazardous Bauxite Red Mud and Ferrous Slag

2021 ◽  
Author(s):  
Vsevolod Mymrin ◽  
Kirill Alekseev ◽  
Walderson Klitzke ◽  
Monica A. Avanci ◽  
Paulo H.B. Rolim ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Structure Formation ◽  
Red Mud ◽  
Raw Materials ◽  
Ceramic Materials ◽  
Linear Shrinkage ◽  
Industrial Wastes ◽  
Raw Material ◽  
Material Base ◽  
Traditional Natural

Abstract This paper reports the development and characterization of some new ceramic materials from hazardous bauxite red mud (50 to 100 wt.%) and blast furnace slag (10 and 50%). This research aimed to demonstrate the possibility of expanding the raw material base for ceramics production, completely replacing the traditional natural raw materials (clay and sand) by hazardous industrial wastes composites with increasing local and global sustainability. Studies on the physicochemical processes of the ceramic structure’s formation were conducted by the XRF, XRD, AAS, SEM with EDS, and LAMMA methods. Changes in flexural strength, linear shrinkage, water absorption, and density were determined during the sintering process at 1000°, 1050°, 1100°, 1150°, 1200°, and 1225°C. The ceramics` flexural strength after sintering at 1225°C reached 19.78 MPa due to the syntheses of the mainly glass-like structure formation, confirmed by SEM, EDS and isotopes LAMMA methods with the complete binding of the heavy metals.

Preparation of a Novel Cement from Red Mud and Limestone

2022 ◽  
Vol 58 ◽  
pp. 171-182
Author(s):  
Hoc Thang Nguyen ◽  
Quang Minh Do
Keyword(s):  
Red Mud ◽  
Environmental Concern ◽  
Cementitious Material ◽  
Cement Clinker ◽  
The Novel ◽  
Surrounding Water ◽  
Hydraulic Cement ◽  
Portland Cement Clinker ◽  
Calcium Aluminoferrite ◽  
Mineralogical Compositions

Red mud (RM) is an industrial waste obtained from the Bayer process which is usually discharged into marine or disposed into a landfill causing pollution for the surrounding water, air, and soils. Thus, disposal of RM is an environmental concern, and it should be recycled effectively. Because RM consists of iron- and aluminum-rich phases, it is possible to be processed into cementitious material and utilized for construction purposes. This research fabricated a type of cement from the mixture of RM and limestone. The mixture was sintered at temperature of 1180 °C to obtain the clinker of the novel hydraulic cement with C2S, C3A, and C4AF minerals. In which, C2S, C3A, and C4AF are respectively belite, alite, and tetra-calcium aluminoferrite compounds that are characteristic hydraulic minerals of Portland cement clinker. The specifications of this cement were tested and evaluated in this study such as chemical and mineralogical compositions, fineness, specific surface area, mechanical strength after 3, 7, and 28 days.

Study on Preparation of Ceramic Material and its Properties

2014 ◽  
Vol 686 ◽  
pp. 57-60
Author(s):  
Ya Li Liu
Keyword(s):  
Fly Ash ◽  
Red Mud ◽  
Bending Strength ◽  
Sintering Temperature ◽  
Raw Materials ◽  
Porous Ceramic ◽  
High Strength ◽  
Porous Ceramics ◽  
Raw Material ◽  
High Porosity

This paper introduces the classification, properties and application of porous ceramic materials, reviewed preparation of porous ceramics. Taking fly ash and red mud as the main raw material to generate porous ceramics, the paper study the influence of different proportions of raw materials, sintering temperature, porosity of porous ceramic sample rate, bending strength, and microstructure. The results show that, fly ash and red mud proportioning and sintering temperature are the main factors that influence the structure and properties of samples. The 4# sample is a kind of high porosity and high strength quality of porous ceramics.

scholarly journals Needleless electrospun polyacrylonitrile/konjac glucomannan nanofiber mats

2020 ◽  
Vol 15 ◽  
pp. 155892502096480
Author(s):  
Al Mamun ◽  
Marah Trabelsi ◽  
Michaela Klöcker ◽  
Jan Lukas Storck ◽  
Robin Böttjer ◽  
...  
Keyword(s):  
Raw Materials ◽  
Average Diameter ◽  
Konjac Glucomannan ◽  
Raw Material ◽  
Oxidative Stabilization ◽  
Carbon Nanocomposites ◽  
Amorphophallus Konjac ◽  
Wide Range ◽  
The Cost ◽  
Nanofiber Mats

In this study we report for the first time about the preparation of polyacrilontrile (PAN)/konjac glucomannan (KGM) nanofiber mats, needleless electrospinning from the low-toxic solvent dimethyl sulfoxide (DMSO) and the formation of carbon nanocomposites. Konjac glucomannan is a biopolymer and renewable, environmentally friendly raw material and a well-known polysaccharide, which is non-toxic and biocompatible material and is extracted from the Amorphophallus konjac plant. The addition of poloxamer in electrospinning PAN/KGM solution resulted in the reduction of membrane areas and decrease of beads in nanofibers. The concentration of 1.5% or 0.5% of konjac glucomannan in PAN/KGM nanofiber mats was not detected to affect the morphology of the nanofiber mats. The PAN/KGM nanofiber mats received oxidative stabilization and subsequent carbonization. It could be observed that after the oxidative stabilization process the average diameter of PAN/KGM nanofibers increased and after carbonization decreased compared to stabilized nanofibers. Alternative renewable raw materials such as KGM electrospun with synthetic polymers offer the possibility to reduce the environmental impact and are the alternative to new technical materials and lowers the cost of carbon materials. The combination of PAN with konjac glucomannan and the properties of both polymers open up a wide range of applications for the PAN/KGM nanofiber mats and carbon nanocomposites produced in this study, for example, for pharmaceutical and biomedical applications, as absorbents for the removal of pollutants in wastewater and as filter media for air purification, as well as for optical and chemical sensors.

RHEOLOGICAL PROPERTIES OF CERAMIC MASSES: IMPROVEMENT BY COMPLEX MATERIAL ACTIVATION

2019 ◽  
Vol 16 (3) ◽  
pp. 334-351
Author(s):  
A. S. Mavlyanov ◽  
E. K. Sardarbekova
Keyword(s):  
Rheological Properties ◽  
Raw Materials ◽  
Sensitivity Coefficient ◽  
Raw Material ◽  
Clay Material ◽  
Fibrous Materials ◽  
Chemical Production ◽  
Production Wastes ◽  
Pass Through ◽  
The Masses

Introduction. The objective of the research is to study the effect of the complex activation of the alumina raw material on the rheological properties of the ceramic mass. In addition, the authors investigate solutions for the application of optimal coagulation structures based on loams and ash together with plastic certificates.Materials and methods. The authors used the local forest like reserves of clay loams at the BashKarasu, ash fields of the Bishkek Central Heating Centre (BTEC) and plasticizer (sodium naphthenate obtained from alkaline chemical production wastes) as fibrous materials. Moreover, the authors defined technological properties of raw materials within standard laboratory methodology in accordance with current GOSTs.Results. The researchers tested plastic durability on variously prepared masses for the choice of optimal structures. The paper demonstrated the plastic durability of complexly activated compounds comparing with non-activated and mechanically activated compounds. The sensitivity coefficient increased the amount of clay loams by mechanically and complexly activated, which predetermined the possibility of intensifying the process of drying samples based on complexly activated masses.Discussion and conclusions. However, mechanical activation of clay material reduces the period of relaxation and increases the elasticity coefficient of ceramic masses by 1.8–3.4 times, meanwhile decreases elasticity, viscosity and the conventional power during molding, which generally worsens the molding properties of the masses. Сomplex activation of ash-clay material decreases the period of relaxation and provides an increase in elasticity, plasticity of ceramic masses by 46–47%, reduction in viscosity by 1.5–2 times, conventional power on molding by 37–122% in comparison with MA clay loams. Ceramic masses based on spacecraft alumina raw materials belong to the SMT with improved rheological properties; products based on them pass through the mouthpiece for 5–7 seconds.

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