Study of the reduction mechanism of ironsands with addition of blast furnace bag dust

To improve the reduction properties of ironsands carbon-containing briquettes, the behavior of ironsand during reduction by the addition of blast furnace bag dust (BFBD) is studied using a high temperature resistance furnace, X-ray diffraction (XRD) analysis and scanning electron microscopy. Additionally, the reduction mechanism is discussed in this study. The results showed that the reduction level and compressive strength of ironsand carbon-containing briquettes could be promoted by increasing the proportion of BFBD. When the addition rate of BFBD was 31.25%, the metallization rate and compressive strength increased from 82.1% and 21.5 N/a to 91.4% and 172.5 N/a, respectively. Metallic iron reduced from BFBD particles favored the carbon gasification reaction, which enhanced the internal CO concentration, and then promoted the FeTiO3 reduction to Fe in ironsand. Meanwhile, a large amount of the liquid phase generated during the reduction process also favored Fe2+ diffusion, spread of iron joined crystals and the growth of crystals, which resulted in the improvement of the compressive strength of the ironsand carbon-containing briquettes.

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The Impact of Fly Ash after SNCR Treated with Tannin-Based Products on AAC Production

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.296.173 ◽

2019 ◽

Vol 296 ◽

pp. 173-179 ◽

Cited By ~ 1

Author(s):

Matěj Lédl ◽

Lucie Galvánková ◽

Rostislav Drochytka

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Bulk Density ◽

Catalytic Reduction ◽

Xrd Analysis ◽

Gaseous Ammonia ◽

X Ray Diffraction ◽

Consistency Test ◽

Effect Of Treatment ◽

The Impact

This paper is focused on the effect of treatment of fly ash after selective non-catalytic reduction (SNCR) with tannin on autoclaved aerated concrete (AAC) production in order to reduce or stop ammonia leakage from the fresh mixture due to its alkalinity. A pure form of tannin and a tannin-based product „Farmatan“ were used as a treatment in dosage ranging from 0,5 g – 3 g of agent per 1 kg of fly ash. Efficient dosage was determined at 2 wt.% of fly ash by the speed of an indicator change due to gaseous ammonia diluted in water. The rheological properties of fresh mixtures were observed by consistency test in Viskomat showing that Farmatan causes delay of hydration. The results of bulk density and compressive strength testing revealed that Farmatan causes an increase of bulk density and at higher amount decreases the compressive strength because of thermal crack formation due to combined effect of delayed hydration and thixotropy. Using x-ray diffraction (XRD) analysis there were no differences in phase composition observed.

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Effect of catalyst on tail gas during reduction of vanadium-titanium magnetite carbon-containing pellet

E3S Web of Conferences ◽

10.1051/e3sconf/202126702046 ◽

2021 ◽

Vol 267 ◽

pp. 02046

Author(s):

Bo Wang ◽

Xueyong Ding ◽

Xiaofei Zhang ◽

Tianhua Ju ◽

Shigang Li

Keyword(s):

Rotary Kiln ◽

Flue Gas ◽

Reduction Process ◽

Reduction Mechanism ◽

Gas Analyzer ◽

Metallization Rate ◽

Vanadium Titanium ◽

Reduction Effect ◽

Calcium Catalysts ◽

Titanium Magnetite

Catalyst can enhance the reduction effect and promote the reduction of vanadium titanomagnetite. In this paper, the carbon-containing pellets of vanadium titanomagnetite were prepared by using highly volatile coal as the reducing agent under the background of a novel process of pre-reduction in the rotary kiln. The effects of CaO, CaCO3, B2O3 and borax (Na2B4O7·10H2O) on the tail gas characteristics of carbon-containing pellets in the prereduction process were studied by using a simulated rotary kiln and flue gas analyzer. The results showed that the enhanced reduction effect of boron catalysts was slightly stronger than that of calcium catalysts, among which CaO catalyzed the least and borax the best. With the increase of metallization rate, the CO utilization in the tail gas is generally reduced, while when using CaCO3 as the catalyst, the CO utilization is significantly increased. Due to different reduction mechanism, the boron catalysts have little effect on the tail gas, and the calcium catalysts have a great effect on the tail gas. Based on the experimental results and the characteristics of the tail gas from the reduction process, we put forward the idea of using CaCO3 as the best catalyst and using CaO to absorb CO2 in the tail gas to form CaCO3.

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Characteristics and Design of Inong Balee Fort Binding Mortar For Restoration Purposes

Elkawnie ◽

10.22373/ekw.v6i2.6581 ◽

2020 ◽

Vol 6 (2) ◽

pp. 302

Author(s):

Muttaqin Hasan ◽

Teuku Budi Aulia ◽

Fido Yurnalis

Keyword(s):

Compressive Strength ◽

Chemical Composition ◽

Diffraction Pattern ◽

Xrd Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Indonesian Government ◽

Powder Samples

Abstract: Inong Balee Fort is one of the Islamic Kingdom of Aceh heritage built in 1599 by Admiral Malahayati but several parts of the fortress wall have currently been damaged and the stone removed. Indonesian Government plans to restore the fort and this makes it necessary to examine the characteristics of the fortress mortar with a focus on the chemical composition and mineralogical elements. Therefore, mortar powder samples obtained from the fort walls were tested through X-Ray Diffraction (XRD) and the results showed the main composition of mortar is CaCO3 and SiO2 from a mixture of lime and sand while the others are P2O5, MgCO3, and Al2O3. Meanwhile, two mortar mixtures including 1 lime: 2 sand and 1 cement: 2 lime: 3 sand were designed for restoration purposes and they were both found by the XRD analysis results to have a diffraction pattern similar to Inong Balee Fort mortar. However, mortar with 1 lime: 2 sand has a very low compressive strength subsequently it does not meet the specifications of the SNI 6882:2014 and ASTM C270-19a while mortar with 1 cement: 2 lime: 3 sand has a compressive strength that meets the specifications. Therefore, a mortar with 1 cement: 2 lime: 3 sand is recommended to be used for the restoration of Inong Balee Fort.Abstrak: Benteng Inong Balee merupakan salah satu peninggalan Kerajaan Islam Aceh yang dibangun pada tahun 1599 oleh Laksamana Malahayati. Saat ini banyak bagian dinding pasangan batu benteng tersebut sudah rusak dan batunya sudah terlepas dari ikatan mortar. Pemerintah Republik Indonesia berencana melakukan restorasi benteng tersebut. Oleh karena itu perlu diteliti karakteristik mortar pengikat dari pasangan batu benteng tersebut, berupa kandungan senyawa kimia dan mineralnya. Metode yang digunakan untuk karakterisasi adalah dengan melakukan pengujian X-Ray Diffraction (XRD) terhadap bubuk sampel mortar yang diambil dari dinding benteng. Hasil pengujian menunjukkan bahwa komposisi utama mortar pengikatnya adalah CaCO3 dan SiO2 yang menunjukkan bahwa mortar tersebut terbuat dari campuran kapur dan pasir. Disamping itu juga terdapat kandungan senyawa P2O5, MgCO3 dan Al2O3. Selanjutnya untuk keperluan restorasi didesain 2 campuran mortar, yaitu mortar dengan campuran 1 kapur : 2 pasir dan mortar dengan campuran 1 semen : 2 kapur : 3 pasir. Hasil analisis XRD menunjukkan bahwa kedua campuran tersebut mempunyai pola diffraksi yang mirip dengan Benteng Inong Balee. Akan tetapi mortar dengan campuran 1 kapur : 2 pasir mempunyai kuat tekan yang sangat rendah sehingga tidak memenuhi spesifikasi Standar SNI 6882:2014 dan ASTM C270-19a, sedangkan mortar dengan campuran 1 semen : 2 kapur : 3 pasir mempunyai kuat tekan yang memenuhi spesifikasi Standar SNI 6882:2014 dan ASTM C270-19a, sehingga mortar ini disarankan digunakan untuk keperluan restorasi Benteng Inong Balee.

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Effect of Cobalt on Nickel Oxide Toward Reduction Behaviour in Hydrogen and Carbon Monoxide Atmosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1010.373 ◽

2020 ◽

Vol 1010 ◽

pp. 373-378

Author(s):

Norliza Dzakaria ◽

Maratun Najiha Abu Tahari ◽

Salma Samidin ◽

Tengku Shafazila Tengku Saharuddin ◽

Fairous Salleh ◽

...

Keyword(s):

Carbon Monoxide ◽

Nickel Oxide ◽

Reduction Process ◽

Xrd Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Reduction Behaviour ◽

One Step ◽

Temperature Programmed ◽

Co Doped

The reduction behaviour of cobalt doped with nickel oxide and undoped nickel oxide (NiO) by hydrogen (H2) in nitrogen (20%, v/v) and carbon monoxide (CO) in nitrogen (40%, v/v) atmospheres have been investigated by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Co doped and undoped nickel oxide in both reductants proceed in one step reduction (NiO → Ni) without intermediate. TPR results also suggested that by adding Co metal into NiO, the reduction to metallic Ni by both reductant gaseous give different intensity of the peak. The reduction process of Co and undoped NiO become faster when H2 was used as a reductant. Furthermore, in H2 atmosphere, Co-NiO give complete reduction to metallic Ni at 700 °C. Meanwhile, XRD analysis indicated that NiO without Co composed better crystallite phases of NiO with higher intensity.

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Experimental Study on Strengthening Carbothermic Reduction of Vanadium-Titanium-Magnetite by Adding CaF2

Minerals ◽

10.3390/min10030219 ◽

2020 ◽

Vol 10 (3) ◽

pp. 219 ◽

Cited By ~ 1

Author(s):

Xiangdong Xing ◽

Yueli Du ◽

Jianlu Zheng ◽

Yunfei Chen ◽

Shan Ren ◽

...

Keyword(s):

Carbothermic Reduction ◽

Reduction Rate ◽

Reduction Process ◽

Complex Compounds ◽

Carbon Gasification ◽

Promotive Effect ◽

Mass Fractions ◽

Vanadium Titanium ◽

Gasification Reaction ◽

Titanium Magnetite

The effects and reduction mechanisms of carbothermic reduction of vanadium–titanium–magnetite were studied by adding various mass fractions of CaF2 ranging from 0%, 1%, 3%, 5% to 7%. The results showed that the proper CaF2 addition could strengthen the carbothermic reduction of vanadium–titanium–magnetite while the excessive amounts will weaken the promotive effect, hence the appropriate dosage was determined to be 3 mass%. The CaF2 was favorable for the carbon gasification reaction, where it increased the partial pressure of CO inside briquette and caused the lattice distortion of vanadium–titanium–magnetite. The reaction improved the reduction process and accelerated the reduction rate. The appearance of 3CaO·2SiO2·CaF2 and other complex compounds with low melting point facilitated the aggregation and growth of the slag and the iron, which increased the concentration of iron grains and the aggregation level of the slag.

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Microstructure, Mechanical Properties, and Corrosion Behavior of Boron Carbide Reinforced Aluminum Alloy (Al-Fe-Si-Zn-Cu) Matrix Composites Produced via Powder Metallurgy Route

Materials ◽

10.3390/ma14154315 ◽

2021 ◽

Vol 14 (15) ◽

pp. 4315

Author(s):

M. Meignanamoorthy ◽

Manickam Ravichandran ◽

Vinayagam Mohanavel ◽

Asif Afzal ◽

T. Sathish ◽

...

Keyword(s):

Compressive Strength ◽

Powder Metallurgy ◽

Corrosion Behavior ◽

Xrd Analysis ◽

Matrix Composites ◽

Energy Dispersive Analysis ◽

X Ray Diffraction ◽

X Ray ◽

Time Period ◽

Mechanical Properties And Corrosion

In this paper, Al-Fe-Si-Zn-Cu (AA8079) matrix composites with several weight percentages of B4C (0, 5, 10, and 15) were synthesized by powder metallurgy (PM). The essential amount of powders was milled to yield different compositions such as AA8079, AA8079-5 wt.%B4C, AA8079-10 wt.%B4C, and AA8079-15 wt.%B4C. The influence of powder metallurgy parameters on properties’ density, hardness, and compressive strength was examined. The green compacts were produced at three various pressures: 300 MPa, 400 MPa, and 500 MPa. The fabricated green compacts were sintered at 375 °C, 475 °C, and 575 °C for the time period of 1, 2 and 3 h, respectively. Furthermore, the sintered samples were subjected to X-ray diffraction (XRD) analysis, Energy Dispersive Analysis (EDAX), and Scanning Electron Microscope (SEM) examinations. The SEM examination confirmed the uniform dispersal of B4C reinforcement with AA8079 matrix. Corrosion behavior of the composites samples was explored. From the studies, it is witnessed that the rise in PM process parameters enhances the density, hardness, compressive strength, and corrosion resistance.

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Utilization of Waste Glass in Autoclaved Silica–Lime Materials

Materials ◽

10.3390/ma15020549 ◽

2022 ◽

Vol 15 (2) ◽

pp. 549

Author(s):

Katarzyna Borek ◽

Przemysław Czapik

Keyword(s):

Compressive Strength ◽

Water Absorption ◽

Bulk Density ◽

Quartz Sand ◽

Reference Sample ◽

Xrd Analysis ◽

Waste Glass ◽

X Ray Diffraction ◽

X Ray ◽

Waste Container

This paper aims to investigate the possibility of using waste glass of different colours as a complete substitute for quartz sand in autoclaved silica–lime samples. On the one hand, this increases the possibility of recycling waste glass; on the other hand, it allows obtaining autoclaved materials with better properties. In this research, reference samples with quartz sand (R) and white (WG), brown (BG), and green (GG) waste container glass were made. Parameters such as compressive strength, bulk density, and water absorption were examined on all samples. The samples were examined using a scanning electron microscope with an energy dispersive spectroscopy detector (SEM/EDS) and subjected to X-ray diffraction (XRD) analysis. The WG samples showed 187% higher compressive strength, BG by 159%, and GG by 134% compared to sample R. In comparison to the reference sample, volumetric density was 16.8% lower for sample WG, 13.2% lower for BG, and 7.1% lower for GG. Water absorption increased as bulk density decreased. The WG sample achieved the highest water absorption value, 15.84%. An X-ray diffraction analysis confirmed the presence of calcite, portlandite, and tobermorite phases. Depending on the silica aggregate used, there were differences in phase composition linked to compressive strength. Hydrated calcium silicates with varying crystallisation degrees were visible in the microstructure image.

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Thermally Treated Waste Silt as Filler in Geopolymer Cement

Materials ◽

10.3390/ma14175102 ◽

2021 ◽

Vol 14 (17) ◽

pp. 5102

Author(s):

Abbas Solouki ◽

Alireza Fathollahi ◽

Giovanni Viscomi ◽

Piergiorgio Tataranni ◽

Giovanni Valdrè ◽

...

Keyword(s):

Compressive Strength ◽

Total Solid ◽

Xrd Analysis ◽

Second Phase ◽

X Ray Diffraction ◽

Limestone Aggregate ◽

Calcination Temperatures ◽

Alkali Solutions ◽

Geopolymer Cement ◽

European Standards

This study aims to investigate the feasibility of including silt, a by-product of limestone aggregate production, as a filler in geopolymer cement. Two separate phases were planned: The first phase aimed to determine the optimum calcination conditions of the waste silt obtained from Società Azionaria Prodotti Asfaltico Bituminosi Affini (S.A.P.A.B.A. s.r.l.). A Design of Experiment (DOE) was produced, and raw silt was calcined accordingly. Geopolymer cement mixtures were made with sodium or potassium alkali solutions and were tested for compressive strength and leaching. Higher calcination temperatures showed better compressive strength, regardless of liquid type. By considering the compressive strength, leaching, and X-ray diffraction (XRD) analysis, the optimum calcination temperature and time was selected as 750 °C for 2 h. The second phase focused on determining the optimum amount of silt (%) that could be used in a geopolymer cement mixture. The results suggested that the addition of about 55% of silt (total solid weight) as filler can improve the compressive strength of geopolymers made with Na or K liquid activators. Based on the leaching test, the cumulative concentrations of the released trace elements from the geopolymer specimens into the leachant were lower than the thresholds for European standards.

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The Reduction Behaviour of Cerium Doped Iron Oxide in Hydrogen and Carbon Monoxide Atmosphere

Materials Science Forum ◽

10.4028/www.scientific.net/msf.840.381 ◽

2016 ◽

Vol 840 ◽

pp. 381-385

Author(s):

Tengku Shafazila Tengku Saharuddin ◽

Alinda Samsuri ◽

Fairous Salleh ◽

Rizafizah Othaman ◽

Mohammad Kassim ◽

...

Keyword(s):

Carbon Monoxide ◽

Iron Oxide ◽

Metallic Iron ◽

Reduction Process ◽

Xrd Analysis ◽

Temperature Programmed Reduction ◽

X Ray Diffraction ◽

X Ray ◽

Reduction Behaviour ◽

Temperature Programmed

The reduction behaviour of 3% cerium doped (Ce-Fe2O3) and undoped iron oxide (Fe2O3) by hydrogen in nitrogen (10%,v/v) and carbon monoxide in nitrogen (10%,v/v) atmospheres have been investigate by temperature programmed reduction (TPR). The phases formed of partially and completely reduced samples were characterized by X-ray diffraction spectroscopy (XRD). TPR results indicate that the reduction of Ce doped and undoped iron oxide in both reductants proceed in three steps reduction (Fe2O3 → Fe3O4 → FeO → Fe) with Fe3O4 and FeO were the intermediate. TPR results also suggested that by adding Ce metal into iron oxide the reduction to metallic Fe by using both reductant gaseous give better reducibility compare to the undoped Fe2O3. The reduction process of Ce and undoped Fe2O3 become faster when CO was used as a reductant instead of H2. Furthermore, in CO atmosphere, Ce-Fe2O3 give complete reduction to metallic iron at 700 0C which about 200 0C temperature lower than other samples. Meanwhile, XRD analysis indicated that Ce doped iron oxide composed better crystallite phases of Fe2O3 with higher intensity and a small amount of FeCe2O4.

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Biocement Fabrication and Design Application for a Sustainable Urban Area

Sustainability ◽

10.3390/su10114079 ◽

2018 ◽

Vol 10 (11) ◽

pp. 4079 ◽

Cited By ~ 4

Author(s):

Chungmin Lee ◽

Hyesun Lee ◽

Ok Kim

Keyword(s):

Compressive Strength ◽

Sustainable Design ◽

Xrd Analysis ◽

X Ray Diffraction ◽

Calcite Precipitation ◽

Conventional Concrete ◽

Water Percolation ◽

Living Organisms ◽

Two Parameters ◽

Optimized Conditions

Recently, designers have begun to pursue sustainability through the fabrication of materials from living organisms such as bacteria, fungi, and algae in order to address environmental issues. Based on the potential of materials from living organisms, this study has explored a sustainable design application using biocement formed thorough microbially-induced calcite precipitation (MICP), which produces minerals by bacterial metabolic activity. Since most of the studies on MICP thus far have focused on limited fields such as engineering, biotechnology, and geo-technology, this study has focused more on improving the application of biocement in design. We optimized MICP conditions using two parameters (i.e., concentration of urea-CaCl2 and bacterial cell density) through water percolation testing, compressive strength testing, and X-ray diffraction (XRD) analysis. Then, based on the optimized conditions, material compatibility testing and scalability testing were performed, and design application research was conducted as well. As a result, biocement has been identified as a potential sustainable design material, based on its 40% compressive strength compared to conventional concrete, improved material finish, aesthetic aspects, and environmental impact. This paper contributes to the development of biocement applications in the environmental design field through multidisciplinary research ranging from biological experiments to design applications.

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