Assessing the reactivity of magnesium oxide calcinated at different temperatures for understanding its role in degradation processes

2020 ◽  
Author(s):  
Tobias Bader ◽  
Anja Diekamp
Keyword(s):  
Magnesium Oxide ◽  
Calcium Oxide ◽  
Raw Material ◽  
X Ray Diffraction ◽  
Development Fund ◽  
Degradation Processes ◽  
European Regional Development Fund ◽  
Different Temperatures ◽  
Historic Mortars ◽  
Dolomite Rock

<p>In Tyrol, Austria, dolomite rock was commonly used as raw material for historic mortars and plasters. During calcination of dolomite rock, almost equal amounts of calcium oxide and magnesium oxide are produced. While the reactivity of calcium oxide is well known, the reactivity of magnesium oxide is still not completely understood. Within this study, the reactivity of magnesium oxide obtained from calcination at different temperatures (600 - 1000 °C) will be examined. For this purpose, natural magnesite (Hochfilzen, Tyrol) will be used instead of natural dolomite rock in order to minimise the influence of calcium oxide on the wet slaking curves. Both, calcination and slaking of magnesite will be studied with the help of X-ray diffraction analysis and thermogravimetric analysis. The gained knowledge is believed to be beneficial for improving the understanding of degradation processes. The study was performed within the Interreg V-A Italy-Austria project named DOLOMIA (ITAT 2036) with the funding by INTERact and the European Regional Development Fund (ERDF) being grateful acknowledged.</p>

scholarly journals The Effects of Temperature on the Hydrothermal Synthesis of Hydroxyapatite-Zeolite Using Blast Furnace Slag

Materials ◽  
2019 ◽  
Vol 12 (13) ◽  
pp. 2131 ◽  
Author(s):  
G.U. Ryu ◽  
G.M. Kim ◽  
Hammad R. Khalid ◽  
H.K. Lee
Keyword(s):  
Blast Furnace ◽  
Hydrothermal Synthesis ◽  
Blast Furnace Slag ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Type Zeolite ◽  
Effects Of Temperature ◽  
Furnace Slag

Blast furnace slag, an industrial by-product, is emerging as a potential raw material to synthesize hydroxyapatite and zeolite. In this study, the effects of temperature on the hydrothermal synthesis of hydroxyapatite-zeolite from blast furnace slag were investigated. Specimens were synthesized at different temperatures (room temperature, 50, 90, 120, or 150 °C). The synthesized specimens were analyzed qualitatively and quantitatively via X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), BET/BJH, and scanning electron microscopy/energy dispersive using X-ray analysis (SEM/EDX). It was found that the hydroxyapatite phase was synthesized at all the reaction temperatures, while faujasite type zeolite appeared in the specimens synthesized at 90 and 120 °C. Moreover, faujasite was replaced by hydroxysodalite in the specimens synthesized at 150 °C. Additionally, the crystals of the hydroxyapatite tended to become larger and total crystallinity increased as the reaction temperature increased.

X-ray diffraction Warren–Averbach mullite analysis in whiteware porcelains: influence of kaolin raw material

Clay Minerals ◽  
2018 ◽  
Vol 53 (3) ◽  
pp. 471-485 ◽  
Author(s):  
Angel Sanz ◽  
Joaquín Bastida ◽  
Angel Caballero ◽  
Marek Kojdecki
Keyword(s):  
Crystallite Size ◽  
Firing Temperature ◽  
Microstructural Analysis ◽  
Stoichiometric Composition ◽  
Raw Material ◽  
Size Distributions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Different Temperatures ◽  
Crystallite Sizes

ABSTRACTCompositional and microstructural analysis of mullites in porcelain whitewares obtained by the firing of two blends of identical triaxial composition using a kaolin B consisting of ‘higher-crystallinity’ kaolinite or a finer halloysitic kaolin M of lower crystal order was performed. No significant changes in the average Al2O3 contents (near the stoichiometric composition 3:2) of the mullites were observed. Fast and slow firing at the same temperature using B or M kaolin yielded different mullite contents. The Warren–Averbach method showed increase of the D110 mullite crystallite size and crystallite size distributions with small shifts to greater values with increasing firing temperature for the same type of firing (slow or fast) using the same kaolin, as well as significant differences between fast and slow firing of the same blend at different temperatures for each kaolin. The higher maximum frequency distribution of crystallite size observed at the same firing temperature using blends with M kaolin suggests a clearer crystallite growth of mullite in this blend. The agreement between thickening perpendicular to prism faces and mean crystallite sizes <D110> of mullite were not always observed because the direction perpendicular to 110 planes is not preferred for growth.

scholarly journals The Interaction of Water Suspension Incarbonic Dolomite with Sulfuric Acid and Carbon Dioxide

2016 ◽  
Vol 17 (1) ◽  
pp. 76-80
Author(s):  
O.M. Duda ◽  
I.J. Kostiv
Keyword(s):  
Carbon Dioxide ◽  
Magnesium Oxide ◽  
Calcium Oxide ◽  
Aqueous Suspension ◽  
Inert Material ◽  
Calcium Compound ◽  
Different Temperatures ◽  
Active Calcium ◽  
Soluble Calcium ◽  
Active Magnesium Oxide

The interaction of aqueous suspension of calcium chloride has been studied at different temperatures and at the duration of natural dolomite and solutions of sulfate acid and also carbon dioxide. Studied composition of formed products. Established that the reaction rate of magnesium oxide with acid or carbon dioxide is lower than calcium oxide. The conditions of obtaining of active magnesium with content ballast calcium carbonate and sulfate, which is connected to soluble calcium. For 1023 K temperature forms the most active magnesium oxide, increasing it to 1123 K, magnesium oxide is passivated and increasing the number of active calcium oxide. Soluble calcium compound completely pass into insoluble sulfates or carbonates by passing through a suspension of carbon dioxide or solution of sulfate acid neutralization. Thermo activated dolomite which containing active magnesium oxide and various forms of inert material can be used for obtaining magnesia binders.

Effect of Temperature on the Phase Behaviors of Zircon by Carbothermal Reduction-Nitridation

2011 ◽  
Vol 492 ◽  
pp. 480-483 ◽  
Author(s):  
Li Yin ◽  
Zhao Hui Huang ◽  
You Guo Xu ◽  
Yue Tong Li ◽  
Yang Gai Liu ◽  
...  
Keyword(s):  
Energy Dispersive Spectroscopy ◽  
Carbothermal Reduction ◽  
Raw Material ◽  
Effect Of Temperature ◽  
X Ray Diffraction ◽  
Scanning Electronic Microscopy ◽  
Electronic Microscopy ◽  
X Ray ◽  
Different Temperatures ◽  
Phase Behaviors

Phase behaviors of zircon at different temperatures via carbothermal reduction-nitridation were investigated in this study. By using zircon as raw material, with carbon coke as reducing agent, the influence of reaction temperatures (1450, 1500, 1550 and 1600 °C, respectively) on phase behaviors and microstructure of the products was characterized by X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM) and energy dispersive spectroscopy (EDS). The results shows that by carbothermal reduction-nitridation, the main phases in the final products of zircon are m-ZrO2, c-ZrO2, β-SiC, ZrN and β-Si3N4at different temperatures for 4 hours.

Chemically Treated Submicron Illite Clays for Product with Improved Strength

2015 ◽  
Vol 1117 ◽  
pp. 152-155
Author(s):  
Liga Grase ◽  
Gundars Mezinskis ◽  
Inta Vitina
Keyword(s):  
Electron Microscopy ◽  
Raw Materials ◽  
Nitrogen Adsorption ◽  
Raw Material ◽  
Industrial Minerals ◽  
X Ray Diffraction ◽  
Adsorption Method ◽  
X Ray ◽  
Different Temperatures ◽  
Scanning Electron

A variety of industrial minerals, such as kaolinite, feldspars, and etc., have been used as solid raw materials in the geopolymerization technology. The illite-containing raw material in this study was obtained by the use of sedimentation method. Clay and dust fractions was subjected to the treatment with NaOH alkaline solution and afterwards treated at different temperatures. Results obtained by X-ray diffraction, Scanning electron microscopy, nitrogen adsorption method confirmed the usability of Liepas deposit homogenized gray and red clays for possible realization of geopolymer method.

Crystal Structure and Thermal Expansion of Ge-Doped Mn3CuN

2011 ◽  
Vol 412 ◽  
pp. 422-426
Author(s):  
Xue Yan ◽  
Z. Hua ◽  
J. Liu ◽  
Bin Li ◽  
X. Cheng
Keyword(s):  
Crystal Structure ◽  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Raw Material ◽  
X Ray Diffraction ◽  
X Ray ◽  
Thermal Expansion Coefficients ◽  
Refinement Method ◽  
Different Temperatures ◽  
N Powder

The Ge doped Mn3CuN powder was synthesized using gas-solid reaction method with manganese, copper, germanium powders and N2 gas as raw material. The phase constitute of the as-prepared powder was characterized using X-ray diffraction (XRD). The intrinsic and macro thermal expansion coefficients of the powder were measured by in-situ X-ray diffraction at different temperatures and TMA, respectively. The crystal structure of the powders was analyzed using Rietveld refinement method. The results show that the pure Mn3(Cu0.5Ge0.5)N powder can be prepared via the gas-solid method at 850 °C. The crystal structures of Mn3(Cu0.5Ge0.5)N and Mn3CuN both have the antiperovskite structures. The intrinsic and macro thermal expansion coefficient of Mn3(Cu0.5Ge0.5)N powder is-16.8×10-6K-1 and-17×10-6K-1, respectively. The temperature range with negative thermal expansion is from-80 °C to 50 °C.

scholarly journals Crystallization and preliminary X-ray diffraction analysis of nepenthesin-1

2014 ◽  
Vol 70 (a1) ◽  
pp. C446-C446
Author(s):  
Karla Fejfarová ◽  
Petr Man ◽  
Hynek Mrázek ◽  
Alan Kádek ◽  
Petr Halada ◽  
...  
Keyword(s):  
Ministry Of Education ◽  
X Ray Diffraction ◽  
Aspartic Proteases ◽  
Development Fund ◽  
X Ray ◽  
Cell Parameters ◽  
European Regional Development Fund ◽  
Diffusion Technique ◽  
Grant Agency

Carnivorous pitcher plants of the genus Nepenthes secrete their own aspartic proteases, nepenthesins, to digest prey. Nepenthesins differ significantly in sequence from other plant aspartic proteases. This difference, which brings more cysteine residues into the structure of nepenthesins, in conjunction with putative N-glycosylation, can contribute to uniquely high temperature and pH stabilities of these proteases [1, 2]. In continuation of our previous study of the expression and biochemical and enzymatic characterization of a recombinant form of nepenthesin-1 (rNep-1) from Nepenthes gracilis [3], we report its crystallization and preliminary X-ray analysis. Crystals of rNep-1 in complex with the pepstatin A inhibitor have been grown using the hanging-drop vapour-diffusion technique. Diffraction data were collected to 2.9 Å resolution using synchrotron radiation at Bessy II of HZB, Berlin. The crystals belong to space group P21, with unit-cell parameters a = 54.4 Å, b = 86.6 Å, c = 95.8 Å, β = 1060. The self-rotation function combined with solvent-content calculations and Matthews coefficient suggest the presence of two molecules of rNep-1 in the asymmetric unit. This work was supported by the Ministry of Education, Youth and Sports of the Czech Republic (grants No. EE2.3.30.0029 and No. LG14009), by BIOCEV CZ.1.05/1.1.00/02.0109 from the European Regional Development Fund, and by the Grant Agency of the Czech Technical University in Prague, grant No. SGS13/219/OHK4/3T/14.

scholarly journals Structural and electrical studies on zinc added magnesium oxide nanoparticles

2020 ◽  
Vol 31 (3) ◽  
pp. 73-86
Author(s):  
Sumithraj Premkumar P. ◽  
Keyword(s):  
Magnesium Oxide ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Mgo Nanoparticles ◽  
X Ray ◽  
Electrical Studies ◽  
Magnesium Oxide Nanoparticles ◽  
Different Temperatures ◽  
Crystalline Nature ◽  
Scanning Electron

Magnesium oxide (MgO, pure) and zinc added MgO nanoparticles were synthesised by a simple microwave assisted solvothermal method. The concentrations of impurity used in the present work were 0.25 M and 0.50 M. All samples were annealed at 400°C for 1 h to improve the ordering. The prepared pure and zinc added magnesium oxide nanoparticles were characterised by powder X-ray diffraction (PXRD), energy dispersive spectroscopy (EDS) and scanning electron microscopy (SEM). PXRD studies of pure and zinc added MgO nanoparticles showed that all samples belong to crystalline nature with cubic structure. The grain size of all samples were determined from the XRD results and it belongs to nano meter scale. The EDS confirmed the presence of zinc, magnesium and oxide elements in the respective prepared samples. The scanning electron microscope images confirmed that the prepared samples possess nanometer dimensions. The electrical properties such as AC conductivity, dielectric constant and dielectric loss were measured at different temperatures in the different frequency range by involving the impedance analyser of all the prepared samples.

scholarly journals Micro-Change Process of Calcium–Magnesium Double Expansive Agent and Its Performance Characterization in Cement-Based Materials

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3269
Author(s):  
Yihang Ding ◽  
Zhongyang Mao ◽  
Yu Wang ◽  
Min Deng ◽  
Mingshu Tang
Keyword(s):  
Compressive Strength ◽  
Magnesium Oxide ◽  
Calcium Oxide ◽  
Cement Paste ◽  
Change Process ◽  
Development Trend ◽  
Different Temperatures ◽  
Calcium Magnesium ◽  
Microscopic Change ◽  
Microscopic Morphology

With the increase of cement output, the demand for cement expansion agents increases, and composite expansion agents have become the development trend. The purpose of this study is to study the microscopic change process and expansion effect of calcium oxide and magnesium oxide double expansion agents. After calcination at different temperatures, the change process of microscopic morphology of calcined products was observed. Through calcining dolomite at 900 °C, the mixture D900 of calcium oxide and magnesium oxide was obtained. To prepare mixed cement, 10 wt %, 20 wt %, and 30 wt % of D900 were added into cement to prepare mixed cement. At the same time, the compressive strength, deformation, and porosity of mixed cement were measured. The results show that adding D900 improves the expansion rate of early cement paste and reduces the compressive strength. After 120 days, the compressive strength of 20 wt % cement paste is higher than that of blank cement paste, and the porosity of 20 wt % cement paste is the lowest among the three mixed cements. This shows that 20 wt % is a more suitable substitute.

scholarly journals AB0012 ROLE OF IRF5 GENE ON THE PATHOGENESIS OF IMMUNOGLOBULIN-A VASCULITIS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1309.1-1310
Author(s):  
S. Remuzgo Martinez ◽  
F. Genre ◽  
V. Pulito-Cueto ◽  
D. Prieto-Peña ◽  
B. Atienza-Mateo ◽  
...  
Keyword(s):  
Inflammatory Diseases ◽  
Disease Onset ◽  
Immunoglobulin A ◽  
Type I ◽  
Research Support ◽  
Development Fund ◽  
European Regional Development Fund ◽  
Social Fund ◽  
Relevant Role ◽  
Immunoglobulin A Vasculitis

Background:Interferon signaling pathway plays a relevant role in autoimmunity. Genetic variants in theinterferon regulatory factor (IRF) 5gene, that encodes the major regulator of the type I interferon induction [1], have been related to the development of several inflammatory diseases [2].Objectives:To determine the influence ofIRF5on Immunoglobulin-A vasculitis (IgAV), an inflammatory vascular disease.Methods:ThreeIRF5polymorphisms (rs2004640, rs2070197 and rs10954213) representative of 3 different haplotype blocks were genotyped in 372 Caucasian patients with IgAV and 876 sex and ethnically matched healthy controls.Results:No statistically significant differences between patients with IgAV and controls were observed when eachIRF5polymorphism was analyzed independently. Similarly, no statistically significant differences between patients with IgAV and controls were found whenIRF5polymorphisms were evaluated combined conforming haplotypes. Additionally, there were no statistically significant differences in genotype, allele and haplotype frequencies ofIRF5when patients with IgAV were stratified according to the age at disease onset or to the presence/absence of gastrointestinal or renal manifestations.Conclusion:Our results do not support an influence ofIRF5on the pathogenesis of IgAV.References:[1]Nat Immunol 2011; 12: 231-8;[2]Arthritis Res Ther 2014; 16: R146.Acknowledgments:This study was supported by European Union FEDER funds and “Fondo de Investigaciones Sanitarias” (grant PI18/00042) from ‘Instituto de Salud Carlos III’ (ISCIII, Health Ministry, Spain). RL-M is a recipient of a Miguel Servet type I programme fellowship from the ISCIII, co-funded by the European Social Fund (ESF, `Investing in your future´) (grant CP16/00033). SR-M is supported by funds of the RETICS Program (RD16/0012/0009) (ISCIII, co-funded by the European Regional Development Fund (ERDF)). VP-C is supported by a pre-doctoral grant from IDIVAL (PREVAL 18/01). LL-G is supported by funds of PI18/00042 (ISCIII, co-funded by ERDF).Disclosure of Interests:Sara Remuzgo Martinez: None declared, Fernanda Genre: None declared, Verónica Pulito-Cueto: None declared, D. Prieto-Peña: None declared, Belén Atienza-Mateo: None declared, Belén Sevilla: None declared, Javier Llorca: None declared, Norberto Ortego: None declared, Leticia Lera-Gómez: None declared, Maite Leonardo: None declared, Ana Peñalba: None declared, María Jesús Cabero: None declared, Luis Martín-Penagos: None declared, Jose Alberto Miranda-Filloy: None declared, Antonio Navas Parejo: None declared, Javier Sanchez Perez: None declared, Maximiliano Aragües: None declared, Esteban Rubio: None declared, MANUEL LEON LUQUE: None declared, Juan María Blanco-Madrigal: None declared, E. Galindez: None declared, Javier Martin Ibanez: None declared, Santos Castañeda: None declared, Ricardo Blanco Grant/research support from: Abbvie, MSD and Roche, Consultant of: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen and MSD, Speakers bureau: Abbvie, Pfizer, Roche, Bristol-Myers, Janssen, Lilly and MSD, Miguel A González-Gay Grant/research support from: Pfizer, Abbvie, MSD, Speakers bureau: Pfizer, Abbvie, MSD, Raquel López-Mejías: None declared

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