scholarly journals The role of thermal analysis in the development of high-iron-content kaolinite-based photocatalysts

2020 ◽  
Vol 142 (1) ◽  
pp. 289-299
Author(s):  
Veronika Vágvölgyi ◽  
Katalin Győrfi ◽  
Balázs Zsirka ◽  
Erzsébet Horváth ◽  
János Kristóf
Keyword(s):  
Iron Content ◽  
Adsorbed Water ◽  
Acid Base ◽  
High Iron Content ◽  
High Iron ◽  
Defect Sites ◽  
Heating Water ◽  
Coordinated Water

Abstract Dynamic and controlled-rate thermogravimetric analyses have been carried out on acid-treated (11 and 5.8 M HCl), high-iron-content kaolinites as potential photocatalysts. The mineral contaminants were determined by XRD, while the defect sites of reduced coordination number obtained by surface treatments were identified with 27Al MAS NMR spectroscopy. Upon heating, water is evolved from the surface-treated samples in three main stages: (1) removal of adsorbed water up to ~ 200 °C, (2) goethite dehydroxylation between 200 and 350 °C and (3) dehydroxylation of the clay in the 300–700 °C temperature range. Identification of water released from the above mass loss steps is difficult due to the significant overlap of steps 2 and 3, as well as to the presence of coordinated water at broken edges and defect sites (–OH2+ groups). As a result, the thermal behavior of surface-treated kaolinites should be taken into account both in the preparation of hybrids/composites and in the acid–base characterization of the catalytic surface.

CHARACTERIZATION OF GEOPOLYMERS OBTAINED BY ALKALINE ACTIVATION OF METAKAOLIN WITH HIGH IRON CONTENT

2014 ◽  
Vol 1 (1) ◽  
Author(s):  
Erica A.S. Vassalo ◽  
Adriana G. Gumieri ◽  
Maria Teresa P. Aguilar
Keyword(s):  
Iron Content ◽  
Construction Material ◽  
Alkaline Solutions ◽  
Activation Process ◽  
High Iron Content ◽  
Alkaline Activation ◽  
High Iron ◽  
Precursor Material ◽  
Dsc Analyses

The use of activated alkali aluminosilicate has been shown to be an economically-viable alternative that decreases the environmental impact of building construction material. Geopolymers are a type of activated alkali aluminosilicate that are rich in SiO2 and Al2O3, and harden within alkaline solutions. In this study, geopolymers obtained by alkaline activation of metakaolin with high iron content were characterized. The activation process used sodium hydroxide solutions at molarities of 12, 15, and 18 mol. The geopolymers were oven-dried at 85°C and at room temperature. The results identified the physicochemical and microstructural properties of the geopolymers and elucidated the activation process using the techniques: XRF, XRD, DTA, TG, DTG and DSC analysis. The results of the dynamic recrystallization indicated the presence of quartz, kaolinite, hematite, and muscovite in the samples. The DSC analyses showed an immediate reaction between the precursor material and the activator. The DTA results showed that the reactions began at low temperatures, where the dissolution of Si and Al occurred. The peaks that appear between 45°C and 60°C indicate that polymerization occurred through the condensation of Si and Al.

ON THE PROCESSING OF HEMATITE RAW MATERIALS AT THE KRYVOROZHSK MINING AND PROCESSING PLANT OF OXIDIZED ORE ON TECHNOLOGY OF DIRECT RECOVERY ITmk3

2018 ◽  
pp. 32-37
Author(s):  
P.I. Loboda ◽  
Younes Razaz ◽  
S. Grishchenko
Keyword(s):  
Magnetic Properties ◽  
Cast Iron ◽  
Iron Content ◽  
Raw Materials ◽  
Direct Reduction ◽  
Processing Plant ◽  
High Iron Content ◽  
High Iron ◽  
Direct Restoration ◽  
First Time

Purpose. To substantiate the efficiency of processing hematite raw materials at the Krivoy Rog Mining and Processing Plant of Oxidized Ores using the direct reduction technology itmk3®. Metodology. Analysis of the results of the itmk3® direct restoration technology developed by Kobe Steel Ltd., Japan and Hares Engineering GmbX, Austria, with a view to using it to process Krivbass hematite ores into granulated iron (so-called “nuggets”). Findings. The involvement in the production of hematite ores (oxidized quartzite) of Krivbass with high iron content, but with low magnetic properties for their processing into granular cast iron is grounded. Originality. The use of itmk3® direct reduction technology from Kobe Steel Ltd., Japan and Hares Engineering GmbH, Austria for the processing of Krivbass hematite ores into granular cast iron is justified for the first time. Practical value. The efficiency of the use of hematite ores (oxidized quartzite) has been substantiated, which can significantly reduce the costs in the mining cycle for the economical production of metallurgical products.

Fabrication of bisferrocenyl derivative grafted HTPB with high iron content and its application in dopamine detection

2021 ◽  
pp. 121789
Author(s):  
Alireza Aghaiepour ◽  
Shabnam Rahimpour ◽  
Elmira Payami ◽  
Reza Mohammadi ◽  
Reza Teimuri-Mofrad
Keyword(s):  
Iron Content ◽  
High Iron Content ◽  
High Iron ◽  
Dopamine Detection

High iron content of Ankaferd hemostat as a clue for its hemostatic action of red blood cell origin

2015 ◽  
Vol 26 (2) ◽  
pp. 233-234 ◽  
Author(s):  
Nejat Akar ◽  
Yasemin Ardçoğlu ◽  
Zeki Öktem ◽  
Nuran Erduran ◽  
Ibrahim C. Haznedaroglu
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Iron Content ◽  
High Iron Content ◽  
High Iron

scholarly journals Studies on high iron content in water resources of Moradabad district (UP), India

Water Science ◽  
2017 ◽  
Vol 31 (1) ◽  
pp. 44-51 ◽  
Author(s):  
Vipin Kumar ◽  
Pawan Kumar Bharti ◽  
Meenu Talwar ◽  
Ajay K. Tyagi ◽  
Pamposh Kumar
Keyword(s):  
Water Resources ◽  
Iron Content ◽  
High Iron Content ◽  
High Iron

Ductile Fe-based amorphous alloys with high iron content

2010 ◽  
Vol 17 (2) ◽  
pp. 199-203
Author(s):  
Feng-juan Liu ◽  
Tao Zhang ◽  
Shu-jie Pang ◽  
Ke-fu Yao
Keyword(s):  
Iron Content ◽  
Amorphous Alloys ◽  
High Iron Content ◽  
High Iron

scholarly journals In Situ Control of Thermal Activation Conditions by Color for Serpentines with a High Iron Content

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6731
Author(s):  
Tatiana K. Ivanova ◽  
Irina P. Kremenetskaya ◽  
Andrey I. Novikov ◽  
Valentin G. Semenov ◽  
Anatoly G. Nikolaev ◽  
...  
Keyword(s):  
Iron Content ◽  
Large Scale ◽  
Color Change ◽  
Reference Sample ◽  
Chemical Activity ◽  
High Iron Content ◽  
Color Palette ◽  
High Iron ◽  
Serpentine Minerals ◽  
Heat Treated

Serpentine heat treatment at temperatures of 650–750 °C yields magnesium–silicate reagent with high chemical activity. Precise and express control of roasting conditions in laboratory kilns and industrial aggregates is needed to derive thermally activated serpentines on a large scale. Color change in serpentines with a high iron content during roasting might be used to indicate the changes in chemical activity in the technological process. This study gives a scientific basis for the express control of roasting of such serpentines by comparing the colors of the obtained material and the reference sample. Serpentines with different chemical activity were studied by X-ray diffraction, Mössbauer spectroscopy, and optical spectroscopy. The color parameters were determined using RGB (red, green, blue), CIELAB (International Commission on Illumination 1976 L*a*b), and HSB (hue, brightness, saturation) color models. The color of heat-treated samples was found to be affected by changes in the crystallochemical characteristics of iron included in the structure of the serpentine minerals. The color characteristics given by the CIELAB model were in good coherence with the acid-neutralizing ability and optical spectra of heat-treated serpentines. Thus, in contrast to the long-term analysis by these methods, the control by color palette provides an express assessment of the quality of the resulting product.

Catalytic Polymerization of Anthracene in a Recyclable SBA-15 Reactor with High Iron Content by a Friedel-Crafts Alkylation

2012 ◽  
Vol 51 (12) ◽  
pp. 2859-2863 ◽  
Author(s):  
Jeonghun Kim ◽  
Chokkalingam Anand ◽  
Siddulu N. Talapaneni ◽  
Jungmok You ◽  
Salem S. Aldeyab ◽  
...  
Keyword(s):  
Iron Content ◽  
Catalytic Polymerization ◽  
High Iron Content ◽  
High Iron
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