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Thermally treated granite slurry waste as a mitigating agent for sisal fiber mineralization in fiber-cement composites

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International Journal of Applied Ceramic Technology 2025年

作者： Gutiérrez, Maximo A. U. da Silveira, Thamires A. Ribeiro, Felipe V. Aramburu, Arthur B. Gomes, Cristian C. Gonçalves, Margarete R. F. Delucis, Rafael A. Post-Graduate Program in Materials Science and Engineering Federal University of Pelotas Pelotas Brazil Wood Industry Engineering Federal University of Pelotas Pelotas Brazil Post-Graduate Program in Mining Metallurgical and Materials Engineering Federal University of Rio Grande do Sul Porto Alegre Brazil

This study explores the use of thermally treated granite slurry waste to mitigate the mineralization of sisal fibers in fiber-cement composites. Granite waste was thermally treated at 600°C and 900°C, and the treated materials were analyzed using X-ray fluorescence (XRF), Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Sisal fibers, alkali-treated with 1.7% NaOH, were incorporated into fiber-cement composites, where 15% and 30% of the cement was replaced by treated and untreated granite. Composites with 15% of granite treated at 600°C and 900°C showed improvements in compressive strength of up to 12% and 18%, respectively, compared to the control. The flexural strength increased by 10% with 15% granite treated at 900°C. However, the untreated granite at 30% replacement increased porosity by 25% and water absorption by 18%, negatively affecting the mechanical properties. Aging tests showed a 40% loss in compressive strength, while composites with 30% granite treated at 900°C maintained their flexural strength, making them more durable. These findings highlight the potential of thermally treated granite waste to enhance the sustainability and performance of fiber-cement composites in construction. © 2025 The Author(s). International Journal of Applied Ceramic Technology published by Wiley Periodicals LLC on behalf of American Ceramics Society.

关键词： Machinability

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Study of gasification reactivity of some Indonesian coals using thermogravimetry–mass spectrometry (TG-MS) approach

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International Journal of Coal Preparation and Utilization 2025年

作者： Widayat, Agus Haris Anggayana, Komang Halim, Nurulhuda Muslim, Abrar Al Hamda, Aisyah Rifaldi, Mirza Dian Dwiantoro, Mulyono Hariyadi, Sundek Research Group of Earth Resources Exploration Mining and Petroleum Engineering Faculty Institut Teknologi Bandung Bandung Indonesia Research Group of Metallurgical Engineering Mining and Petroleum Engineering Faculty Institut Teknologi Bandung Bandung Indonesia Department of Chemical Engineering Engineering Faculty Universitas Syiah Kuala Darussalam Indonesia Graduate Program of Mining Engineering Mining and Petroleum Engineering Faculty Institut Teknologi Bandung Bandung Indonesia Engineering Faculty Universitas Kutai Kartanegara Kalimantan Timur Tenggarong Indonesia

Four coal samples from the Upper Kutai, South Sumatra, and Meulaboh basins were analyzed using chemical, petrographic, and thermogravimetric–mass spectrometry (TG-MS) methods to characterize their composition and thermal behavior during pyrolysis and gasification. Chemical and petrographic analyses revealed that the samples vary in rank, ranging from sub-bituminous C to high-volatile A bituminous coal (vitrinite reflectance, Rr, between 0.34% and 0.86%). Vitrinite is the predominant maceral, comprising 71.90% to 86.30% by volume. Thermal decomposition during both pyrolysis and gasification was found to be more strongly influenced by coal rank than by maceral composition. During pyrolysis, higher-rank coals exhibited lower thermal decomposition rates. CO₂ was the first gas released during thermal cracking, followed sequentially by CH4, H₂O, and H₂. The latter becoming the dominant gas in the later stages of pyrolysis. In CO₂-driven gasification, the sub-bituminous C coal exhibited a maximum char reactivity of 0.61 mg/min, compared to just 0.01 mg/min for the high-volatile A bituminous coal. Carbon monoxide (CO) was the primary syngas produced during the gasification process. © 2025 Taylor & Francis Group, LLC.

关键词： Thermogravimetric analysis

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Analysis of cell evolution, solidification speed and microsegregation in upward directional solidification of hypoeutectic Al - 1 wt% Fe alloy: A study of predictive capacity of phase-field model

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Journal of Alloys and Compounds 2025年 1029卷

作者： Ferreira, Alexandre Furtado Garção, Wysllan Jefferson Lima Sales, Roberto Carlos Silva, Ágatha de Faria Sodré Baptista, Luis Antônio de Souza Júnior, Paulo Felipe Graduate Program on Metallurgical Engineering Federal Fluminense University RJ Volta Redonda27255-125 Brazil Federal Institute of Rio de Janeiro RJ Volta Redonda27213-100 Brazil Rio de Janeiro State University RJ Resende27537-000 Brazil

Hypoeutectic alloys ofAl - Fe, are known as casting alloys of low cost, good formability and characterized by its cell microstructure. The solidification sequence of hypoeutectic Al - 1 wt% Fe alloy is described in term of the cell microstructure formation and microsegregation profiles. This aluminum alloy was investigated in an upward directional solidification apparatus with transient heat flow conditions. Changes in the microsegregation profiles and thermal parameters, such as solidification speed and cooling rate along the casting, were observed and discussed. Experimental laws relating solidification speed, cooling rate and microsegregation profiles to the position along the casting have been determined, indicating that the increase in the position have induced a decrease in thermal parameters and microsegregation. The main goal of this work is focused on the predictions of cell morphology, solidification speed and microsegregation profile by phase-field model. The numerical results obtained by mathematical model were compared with experimental data observed through upward directional solidification experiment. Both cooling rate and effective partition coefficient determined during solidification experiment, were adopted during phase-field simulations. Firstly, two-dimensional simulation produced a cell microstructure morphology that is very similar to the ones found in solidification experiment. For solidification speed values obtained by phase-field model, the calculations results show a good agreement with experimental data. The results of microsegregation profiles calculated by phase-field model show excellent agreement with those observed during solidification experiment. Such excellent agreements are due to the fact that cooling rates, effective partition coefficient and back-diffusion of Fe solute are considered during the phase-field calculations. © 2025 Elsevier B.V.

关键词： Setting

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Vitrification of hazardous wastes from ship recycling: circular economy solutions for asbestos and synthetic vitreous fibers

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Environmental Science and Pollution Research 2025年第13期32卷 8183-8200页

作者： Pereira, Newton Narciso de Castro Bertagnolli, Denise da Silva, Ladário Faria, Eliel Eleutério Junior, José Mauro Moraes de Araujo de Monteiro Barros, Munique Eva Paiva Miranda, Tainara Alves de Oliveira Lima, Eduardo da Silva Almeida, Vitor Duarte Department of Production Engineering School of Industrial Engineering and Metallurgy at Volta Redonda - EEIMVR – Federal Fluminense University UFF Av. dos Trabalhadores 420 – Sala C77 Vila Sta. Cecília RJ Volta Redonda27255-125 Brazil Department of Chemistry Exact Sciences Institute Federal Fluminense University UFF Rua Desembargador Ellis Hermydio Figueira 783 RJ AterradoVolta Redonda27213-145 Brazil Department of Physics Exact Sciences Institute Federal Fluminense University UFF Rua Desembargador Ellis Hermydio Figueira 783 RJ AterradoVolta Redonda27213-145 Brazil Department of Physics Universidade Federal de Roraima Av. Cap. Ene Garcez N. 2413 Paricarana Roraima Boa Vista69310-000 Brazil Departament of Metallurgical Engineering Federal Fluminense University UFF Av. dos Trabalhadores 420 Vila Sta. Cecília RJ Volta Redonda27255-125 Brazil Physics Post-Graduate Program Brazilian Center for Physics Research Rua Doutor Xavier Sigaud 150 Urca RJ Rio de Janeiro22290-180 Brazil Physics Post-Graduate Program Physics Institute Federal Fluminense University UFF Av. Gal. Milton Tavares de Souza S/nº Praia Vermelha Campus RJ Niterói24210-346 Brazil

Ship recycling at the end of its useful life presents significant environmental and health challenges due to the presence of hazardous materials, such as asbestos and synthetic vitreous fibers (SVFs). This study aimed to convert SVFs and asbestos into safe, reusable co-products by incorporating them into a glassy matrix. The materials were melted at 1200 °C for 1 h with utilization of niobium pentoxide (Nb2O5) to lower fusion temperatures. Samples collected from an offshore vessel and platform being recycled in Rio de Janeiro, Brazil, were analyzed using energy-dispersive x-ray spectroscopy (EDS) and scanning electron microscopy (SEM), revealing the presence of SVFs but not asbestos. Seven types of glass were produced, with their non-crystalline, glassy nature confirmed by the presence of an amorphous halo in X-ray diffraction (XRD) and a glass transition observed in differential scanning calorimetry (DSC). These findings demonstrate the potential to transform hazardous waste into value-added products, advancing a circular economy in ship recycling operations. © The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature 2025.

关键词： Asbestos

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Modeling the mini blast furnace process based on self-reducing agglomerates

Modeling the mini blast furnace process based on self-reduci...

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3rd International Meeting on Ironmaking and 2nd International Symposium on Iron Ore

作者： De Castro, José Adilson De Souza, Franciene Teixeira Da Silva, Alexandre José Federal Fluminense University Post Graduate Program on Metallurgical Engineering Mechanical Engineering Department Volta Redonda-RJ Brazil

ISBN: (纸本)9788577370320

The blast furnace process is the main supplier of hot metal in the steel industry. This process is massive user of carbon source materials as fuel and reducing agent. Recently the development of self-agglomerates has open the possibility of its direct use in mini blast furnace. This investigation aims to numerically simulate a mini blast furnace process operating with self-reducing agglomerates with low slag rate and high rates of pulverized biomass combined with oxygen injection and small coke as solid fuels. The model describes the mini blast furnace process as a counter current reactor of five phases interacting with one another. The solid phase considers small sinter, self-reducing pellets and briquettes as iron bearing materials and small coke as solid fuel charged from the top. The modeling is based on transport equations of momentum, energy and chemical species of each phase and the chemical reactions are modeled by semi-empirical equations. Model results are presented for global parameters and spatial distributions for temperature and composition for solid and gas phases. Smooth operational conditions were obtained for about 20% of self-reducing pellets combined with small sinter and coke in the burden materials. In addition, up to 100 kg/t of pulverized biomass could be injected in the mini blast furnace tuyeres.

关键词： Biomass

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Numerical Simulation of Microstructural Evolution via Phase-Field Model Coupled to the Solutal Interaction Mechanism

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Materials Sciences and Applications 2015年第10期6卷 907-923页

作者： Alexandre Furtado Ferreira Ingrid Meirelles Salvino Tomaskewski Késsia Gomes Paradela Dimas Moraes da Silva Roberto Carlos Sales Graduate Program on Metallurgical Engineering Graduate Program on Mechanical Engineering Federal Fluminense University Volta Redonda Brazil

A phase-field model coupled to the multiphase/multiscale model is used to simulate the microstructural morphology and predict the CET during solidification. The considered mechanism for the CET is based on interactions of solute between the equiaxed grains and the advancing columnar front. The results for the solute concentration in liquid region, dendrite tip velocity, volume fraction of the liquid and solid are presented and discussed. The phase-field model is used to simulate the dendritic morphology of an alloy directionally solidified, by imposing a constant temperature gradient. The simulation of the equiaxed grains growth requires a further important element, the growth of grains with different crystallographic orientations. The grain orientations are generated randomly for each nucleus introduced in computational domain. Finally, the coupling results between the multiphase/multiscale model and phase-field are presented and discussed. For higher nuclei density present in the melt, a shorter distance between mold wall and the equiaxed zone in the solidification process can be observed. A solute concentration boundary layer exists in the liquid along the columnar grain contour. The concentrations in the solid indicate the presence of a microsegregation pattern. The simulated results show that the solidification features are consistent with those observed based on the metallographic examinations of cast microstructures reported in the literature.

关键词： Columnar-to-Equiaxed Transition Directional Solidification Al-Cu Alloy

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Combustion of high ash pulverized coal and biomass in fluidized bed reactor for thermoelectricity generation

Combustion of high ash pulverized coal and biomass in fluidi...

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5th International Congress on the Science and Technology of Ironmaking, ICSTI 2009

作者： Adilson, Castro Jose De Souza, Baltazar Anderson William Post Graduate Program on Metallurgical Engineering Federal Fluminense University Av. Dos Trabalhadores Volta Redonda RJ Brazil

A fluidized bed based process is proposed to produce gas for thermoelectric applications. The process variables are modeled based on transport equations and the finite volume numerical approach is applied to discretise the differential equations. Rate equations for momentum, energy and chemical species exchanges are proposed to model the interphase interactions. The model is tested to investigate the combustion of biomasses and high ash Brazilian coals. A dessulfurising bed is used to control the gas product and keep thermal stability of the reactor. Numerical and experimental results from a pilot scale reactor indicated that is possible to produce gas with quality compatible with the requirements of those for thermal generation with high combustion rates.

关键词： Coal combustion

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Temperature prediction at the blow end of the converter via control model 2014

Temperature prediction at the blow end of the converter via ...

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2014 International Conference on Advanced Materials, Structures and Mechanical engineering, ICAMSME 2014

作者： Ferreira, Alexandre Furtado Graduate Program in Metallurgical Engineering Universidade Federal Fluminense Av. dos Trabalhadores 420 Volta RedondaRJ Brazil

ISBN: (纸本)9783038352549

In the present work, a technique and model for temperature prediction at the blow end are briefly discussed, along with their limitations and perspectives for application. As a result of this analysis, a mathematical model based in heat and mass balances has been developed with a view to evaluating the possibility of improving this prediction capability. The study here presented focuses the development of a semi-dynamic control model in the LD-KGC converter (Linz-Donawitz- Kawasaki Gas Control Converter). The control model enables one to predict the temperature of the blow end by solving both the energy and mass equations. The inputs to the control model are the load data of the LD-KGC converter at the blow beginning and the collected data by the lance to 89% of oxygen blow. The results obtained in the present work were compared to the data measured in steelmaking. The semi-dynamic control model results agree well with data for LD-KGC converters. © (2014) Trans Tech Publications, Switzerland.

关键词： Steelmaking

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Low Temperature Plasma Nitriding of H13 Steel for Improved Surface Hardness

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稀有金属材料与工程 2012年第S1期41卷 69-73页

作者： J Pongsopa P Visuttipitukul W Bhanthumnavin B Paosawatyanyong Nanoscience and Technology Program Graduate SchoolChulalongkorn UniversityBangkok 10330Thailand Department of Metallurgical Engineering Faculty of EngineeringChulalongkorn UniversityBangkok 10330Thailand Faculty of Science Chulalongkorn UniversityBangkok 10330Thailand ThEP Center Commission on Higher EducationBangkok 10330Thailand

AISI H13 steel samples were plasma nitrided to improve their surface hardness using a locally developed combined ***-ionized RFICP plasma was employed in combination with DC glow discharge and thermal emission source to achieve the nitride precipitates in iron-matrix under low sample *** nitride layers over 150 microns could be realized with low RF power of 100 W under the processing time between 1-20 h and low sample temperature of 300℃.The gas mixtures of H2 and N2 were utilized while the processing pressure and the DC bias to the sample were maintained at 0.5 torr and 300 V,*** electron microscope(SEM),energy dispersive X-ray spectroscopy(EDS),glancing incident angle X-ray diffractometer(GIXD)and Vickers hardness test were employed to characterize the properties of sample *** increases of surface hardness to over 1,000 HV were observed after treatment.

关键词： H13 tool steel plasma nitriding surface hardness

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Analysis of synthetic natural gas injection into charcoal blast furnace

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Journal of Materials Research and Technology 2013年第3期2卷 255-262页

作者： Rocha, Elisa Pinto Da Guilherme, Vagner Silva De Castro, José Adilson Sazaki, Yasushi Yagi, Jun-Ichiro Post-Graduation Program in Metallurgical Engineering Universidade Federal Fluminense Volta Redonda RJ Brazil Environmental Metallurgy Laboratory Graduate Institute of Ferrous Technology Pohang University of Science and Technology Pohang Korea Republic of Tohoku University Sendai Japan

Recently, the synthetic natural gas (SNG) has been available for large consumers in the Brazilian domestic market. The SNG is a suitable fuel with potential use to several processes and facilities of the steel industry. This paper investigates the injection of SNG into charcoal blast furnaces as a substitute for granular charcoal charged from the top and pulverized charcoal injections with potential increase of productivity and decrease of specific CO2 emissions. In order to study the effect of replacement of granular charcoal and injection of pulverized charcoal the well known Blast Furnace Five Fluid Model (BF-FFM) is applied to describe detailed phenomena within the process. This model treats the blast furnace as a five-phase reactor, accounting for gas, lump solids (raw iron ore, sinter, pellets and granular charcoal), hot metal, pulverized charcoal, and molten slag. The model is based on conservation equations for mass, momentum, energy and chemical species numerically solved based on the finite volume method (FVM). The SNG has high amount of H2 and strongly affects the inner conditions of the reactor and only a comprehensive model with detailed chemical reaction rates can properly predict the inner parameters of the process and hence furnish useful information to design smooth operational conditions. The simulation results obtained in this study indicated that smooth operations using SNG up to 25 N m3/t of pig iron could be achieved simultaneously by increasing the productivity up to 58% and with a decrease of 40 kg/thm on the granular charcoal charged. © 2013 Brazilian metallurgical, Materials and Mining Association.

关键词： Steelmaking

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