scholarly journals A Review of the Influence of Steel Furnace Slag Type on the Properties of Cementitious Composites

2020 ◽  
Vol 10 (22) ◽  
pp. 8210
Author(s):  
Alexander S. Brand ◽  
Ebenezer O. Fanijo
Keyword(s):  
Microstructural Characterization ◽  
Mineralogical Composition ◽  
Basic Oxygen Furnace ◽  
Cementitious Composite ◽  
Supplementary Cementitious Material ◽  
Steel Furnace ◽  
Bof Slag ◽  
Free Cao ◽  
Furnace Slag ◽  
Composite Properties

The type of steel furnace slag (SFS), including electric arc furnace (EAF) slag, basic oxygen furnace (BOF) slag, ladle metallurgy furnace (LMF) slag, and argon oxygen decarburization (AOD) slag, can significantly affect the composite properties when used as an aggregate or as a supplementary cementitious material in bound applications, such as concretes, mortars, alkali-activated materials, and stabilized soils. This review seeks to collate the findings from the literature to express the variability in material properties and to attempt to explain the source(s) of the variability. It was found that SFS composition and properties can be highly variable, including different compositions on the exterior and interior of a given SFS particle, which can affect bonding conditions and be one source of variability on composite properties. A suite of tests is proposed to better assess a given SFS stock for potential use in bound applications; at a minimum, the SFS should be evaluated for free CaO content, expansion potential, mineralogical composition, cementitious composite mechanical properties, and chemical composition with secondary tests, including cementitious composite durability properties, microstructural characterization, and free MgO content.

scholarly journals Feasibility and Characterization Mortar Blended with High-Amount Basic Oxygen Furnace Slag

Materials ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 6 ◽  
Author(s):  
Wei-Ting Lin ◽  
Chia-Jung Tsai ◽  
Jie Chen ◽  
Weidong Liu
Keyword(s):  
Steel Industry ◽  
Setting Time ◽  
Basic Oxygen Furnace ◽  
Cementitious Material ◽  
Partial Replacement ◽  
Supplementary Cementitious Material ◽  
Basic Oxygen ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag ◽  
Weight Proportion

Basic oxygen furnace slag (BOFS) was ground to three levels of fineness as a replacement for cement at weight proportions of 10, 30, 50, and 70 wt.%. Fineness and weight proportion were shown to have significant effects on the flowability and setting time of the mortars. The expansion of BOFS mortars increased with an increase in the proportion of cement replaced, thereby exacerbating the effects of cracking. Optimal mechanical properties were achieved when 10 wt.% of the cement was replaced using BOFS with fineness of 10,000 cm2/g. The compressive strength of BOFS mortar is similar to that of ordinary Portland mortar, which makes BOFS suitable for the partial replacement of cement as a supplementary cementitious material. Scanning electron microscopy results revealed that the reaction of CaO with H2O results in the formation of C–S–H colloids, whereas the reaction of SiO2 with Al2O3 produces C–A–S–H colloids. The use of BOFS as a partial replacement for Portland cement could make a tremendous contribution to the steel industry and help to lower CO2 emissions.

scholarly journals Utilization of Basic Oxygen Furnace Slag in Geopolymeric Coating for Passive Radiative Cooling Application

2020 ◽  
Vol 12 (10) ◽  
pp. 3967 ◽  
Author(s):  
Chia-Ho Wu ◽  
Chih-Hong Huang ◽  
Yeou-Fong Li ◽  
Wei-Hao Lee ◽  
Ta-Wui Cheng
Keyword(s):  
Layer Structure ◽  
Research Work ◽  
Temperature Drop ◽  
Basic Oxygen Furnace ◽  
Radiative Cooling ◽  
Portland Cement Concrete ◽  
Basic Oxygen ◽  
Bof Slag ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

Basic oxygen furnace slag (BOFs) is difficult to reutilize because it contains excessive free lime, and thus causes serious expansion. For this reason, how to reuse BOF slag has turned out to be an imperative issue in order to meet the concept of a circular economy. The key intention of this research work is to develop a new way to reutilize BOF slag, which due to its high emissivity in the 8–13 µm wavelength range, can be used as a sustainable, passive radiative cooling material. Passive radiative cooling, without the consumption of any energy, achieves the cooling of a surface by reflecting the sunlight and radiating the heat throughout the outer space (not absorbed by the atmosphere). BOF slag is used as a radiative cooling material in geopolymeric coating. This coating possesses an emissivity of 0.95 within the range of 8–13 µm and also has high conductivity, but its gray appearance absorbs too much heat. Therefore, by improving the situation through a double-layer structure, a temperature drop of 5.9 °C was reached compared to non-coated concrete under simulated sunlight, simultaneously with a low heating rate and high cooling rate. Besides, the binding strength between the geopolymeric coating and Portland cement concrete is comparable to two commercial organic paints. It is highly probable that the utilization of BOF slag in geopolymeric coating is energy saving and also feasible for passive radiative cooling applications. Hence, it can greatly decrease indoor temperature and improve the comfort of people living in buildings.

scholarly journals Characterization of Ladle Furnace Slag from Carbon Steel Production as a Potential Adsorbent

2013 ◽  
Vol 2013 ◽  
pp. 1-6 ◽  
Author(s):  
Ankica Rađenović ◽  
Jadranka Malina ◽  
Tahir Sofilić
Keyword(s):  
Surface Area ◽  
Coming Out ◽  
Steel Slag ◽  
Steel Production ◽  
Mineralogical Composition ◽  
Basic Oxygen Furnace ◽  
Bet Surface Area ◽  
Ladle Furnace ◽  
Secondary Refining ◽  
Furnace Slag

A promising type of steel slag for applications is the ladle furnace (LF) slag, which is also known as the basic slag, the reducing slag, the white slag, and the secondary refining slag. The LF slag is a byproduct from further refining molten steel after coming out of a basic oxygen furnace (BOF) or an electric arc furnace (EAF). The use of the LF slag in further applications requires knowledge of its characteristics. The LF slag characterization in this paper has been performed using the following analytical methods: chemical analysis by energy dispersive spectrometry (EDS), mineralogical composition by X-ray diffraction (XRD), surface area properties by the Brunauer-Emmett-Teller (BET) and the Barrett-Joyner-Halenda (BJH) methods, surface chemistry by infrared absorption (FTIR) spectroscopy, and morphological analysis by scanning electron microscopy (SEM). The results showed that the main compounds are calcium, silicon, magnesium, and aluminium oxides, and calcium silicates under their various allotropic forms are the major compounds in the LF slag. Surface area properties have shown that the LF slag is a mesoporous material with relatively great BET surface area. The ladle furnace slag is a nonhazardous industrial waste because the ecotoxicity evaluation by its eluate has shown that the LF slag does not contain constituents which might in any way affect the environment harmfully.

scholarly journals Stabilization of a Clayey Soil with Ladle Metallurgy Furnace Slag Fines

Materials ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 4251 ◽  
Author(s):  
Alexander S. Brand ◽  
Punit Singhvi ◽  
Ebenezer O. Fanijo ◽  
Erol Tutumluer
Keyword(s):  
Soil Stabilization ◽  
Clayey Soil ◽  
Kaolinite Clay ◽  
Suitable Candidate ◽  
Ladle Metallurgy ◽  
Steel Furnace ◽  
Free Cao ◽  
Civil Engineering Infrastructure ◽  
Dispersive Soils ◽  
Furnace Slag

The research study described in this paper investigated the potential to use steel furnace slag (SFS) as a stabilizing additive for clayey soils. Even though SFS has limited applications in civil engineering infrastructure due to the formation of deleterious expansion in the presence of water, the free CaO and free MgO contents allow for the SFS to be a potentially suitable candidate for clayey soil stabilization and improvement. In this investigation, a kaolinite clay was stabilized with 10% and 15% ladle metallurgy furnace (LMF) slag fines by weight. This experimental study also included testing of the SFS mixtures with the activator calcium chloride (CaCl2), which was hypothesized to accelerate the hydration of the dicalcium silicate phase in the SFS, but the results show that the addition of CaCl2 was not found to be effective. Relative to the unmodified clay, the unconfined compressive strength increased by 67% and 91% when 10% and 15% LMF slag were utilized, respectively. Likewise, the dynamic modulus increased by 212% and 221% by adding 10% and 15% LMF slag, respectively. Specifically, the LMF slag fines are posited to primarily contribute to a mechanical rather than chemical stabilization mechanism. Overall, these findings suggest the effective utilization of SFS as a soil stabilization admixture to overcome problems associated with dispersive soils, but further research is required.

scholarly journals ALKALI SILICA REACTION OF BOF AND BFS WASTES COMBINATION IN CEMENT

2013 ◽  
Vol 19 (1) ◽  
pp. 113-120 ◽  
Author(s):  
Ömer Özkan ◽  
Mehmet Sarıbıyık
Keyword(s):  
Experimental Study ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Basic Oxygen Furnace ◽  
The Other ◽  
Alkali Silica Reaction ◽  
Basic Oxygen ◽  
Bof Slag ◽  
Composite Cements ◽  
Furnace Slag

This study reports the results of an experimental study conducted to determine composite cements manufactured with the combination of Basic Oxygen Furnace (BOF) Slag and Blast Furnace Slag (BFS). The overall objective of this work is to determine whether a combination of BOF slag and BFS can be used as a cementations material to produce Composite Portland Cement (CPC). Three groups of cement are produced for testing. The first group contains BOF slag, the second group contains BFS and the last group contains the mixture of BOF slag and BFS together. Physical properties and Alkali Silica Reaction (ASR) of these groups are also evaluated in this study. Maximum ASR expansion is observed from the sample of CPC created with BOF slag. On the other hand minimum ASR expansion value is located in the sample of CPC created with BFS only.

scholarly journals Recycling of Basic Oxygen Furnace Slag as a Raw Material for Autoclaved Aerated Concrete Production

2020 ◽  
Vol 12 (15) ◽  
pp. 5896
Author(s):  
Ying-Liang Chen ◽  
Chun-Ta Lin
Keyword(s):  
Basic Oxygen Furnace ◽  
Essential Elements ◽  
Raw Material ◽  
Basic Oxygen ◽  
Autoclaved Aerated Concrete ◽  
Concrete Production ◽  
Bof Slag ◽  
Aerated Concrete ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

The purpose of this study was to recycle basic oxygen furnace (BOF) slag in the production of autoclaved aerated concrete (AAC), and to examine the influence on the properties of AAC products. The magnetic substances in the BOF slag accounted for about 15 wt.% and the magnetic proportion increased as the particle size decreased. The nonmagnetic portion of the BOF slag was acquired by a magnetic separation process and its major constituents were Ca (~42 wt.% as CaO) and Si (~35 wt.% as SiO2), which are the essential elements of AAC. When using the BOF slag for AAC production, the bulk density and compressive strength of the specimens decreased as the amount of slag increased. The results of the performance analysis revealed that at appropriate water–solids ratios, using 15 wt.% or less of the BOF slag was beneficial to the properties of the AAC products. In general, it should be feasible to recycle the BOF slag in the production of AAC. However, the foreign elements introduced by the BOF slag can alter the formation and structure of hydrates, including tobermorite, and thus affect the properties of the AAC product, a potential issue that needs to be addressed.

The Improve of Accelerated Carbonation on Engineering Properties of Basic Oxygen Furnace Slag

2016 ◽  
Vol 709 ◽  
pp. 42-45
Author(s):  
Cheng Chung Chen ◽  
Chao Shi Chen ◽  
Jyun Yong Jhan ◽  
Ming Sheng Ko
Keyword(s):  
Physical And Mechanical Properties ◽  
High Hardness ◽  
Basic Oxygen Furnace ◽  
Engineering Properties ◽  
Accelerated Carbonation ◽  
Engineering Applications ◽  
Basic Oxygen ◽  
Bof Slag ◽  
High Roughness ◽  
Free Cao

Basic oxygen furnace (BOF) slag is characterized by high hardness, low abrasion, and high roughness. It is suitable as graded aggregate for engineering applications. However, the conversion process generated a great amount of unreacted free CaO, resulting in expansion and thus making the slag inconvenient for use in engineering applications. Accelerated carbonation of BOF slag is equivalent to natural weathering. Moreover, it can effectively shorten the weathering time. This study found that accelerated carbonation not only reduce expansion behaviors but also strengthen physical and mechanical properties. According to test results, the abrasion resistant, soundness, California bearing ratio, shear strength, and compressive strength have increased after carbonation.

scholarly journals Geopolymer Technologies for Stabilization of Basic Oxygen Furnace Slags and Sustainable Application as Construction Materials

2020 ◽  
Vol 12 (12) ◽  
pp. 5002
Author(s):  
Wei-Hao Lee ◽  
Ta-Wui Cheng ◽  
Kuan-Yu Lin ◽  
Kae-Long Lin ◽  
Chia-Cheng Wu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Construction Materials ◽  
Value Added ◽  
Pilot Scale ◽  
Basic Oxygen Furnace ◽  
Basic Oxygen ◽  
Expansion Test ◽  
Free Cao ◽  
Basic Oxygen Furnace Slag ◽  
Furnace Slag

The basic oxygen furnace slag is a major waste by-product generated from steel-producing plants. It possesses excellent characteristics and can be used as a natural aggregate. Chemically, the basic oxygen furnace slag encloses free CaO and free MgO, which is the main reason for the expansion crisis since these free oxides of alkaline earth metals react with water to form their hydroxide yields. The objective of the present research study is to stabilize the basic oxygen furnace slag by using innovative geopolymer technology, as their matrix contains a vast quantity of free silicon, which can react with free CaO and free MgO to form stable silicate compounds resulting in the prevention of the basic oxygen furnace slag expansion predicament. Lab-scale and ready-mixed plant pilot-scale experimental findings revealed that the compressive strength of fine basic oxygen furnace slag-based geopolymer mortar can achieve a compressive strength of 30–40 MPa after 28 days, and increased compressive strength, as well as the expansion, can be controlled less than 0.5% after ASTM C151 autoclave testing. Several pilot-scale cubic meters basic oxygen furnace slag-based geopolymer concrete blocks were developed in a ready-mixed plant. The compressive strength and autoclave expansion test results demonstrated that geopolymer technology does not merely stabilize the basic oxygen furnace slag production issue totally, but also turns the slags into value-added products.

scholarly journals Time-Dependent Strength Behavior, Expansion, Microstructural Properties, and Environmental Impact of Basic Oxygen Furnace Slag-Treated Marine-Dredged Clay in South Korea

2021 ◽  
Vol 13 (9) ◽  
pp. 5026
Author(s):  
Gyeong-o Kang ◽  
Jung-goo Kang ◽  
Jin-young Kim ◽  
Young-sang Kim
Keyword(s):  
Particle Size ◽  
Environmental Impact ◽  
South Korea ◽  
Mechanical Characteristics ◽  
Basic Oxygen Furnace ◽  
Microstructural Properties ◽  
Compression Tests ◽  
Basic Oxygen ◽  
Strength Behavior ◽  
Bof Slag

The aim of this study was to investigate the mechanical characteristics, microstructural properties, and environmental impact of basic oxygen furnace (BOF) slag-treated clay in South Korea. Mechanical characteristics were determined via the expansion, vane shear, and unconfined compression tests according to various curing times. Scanning electron microscopy was conducted to analyze microstructural properties. Furthermore, environmental impacts were evaluated by the leaching test and pH measurements. According to the results, at the early curing stage (within 15 h), the free lime (F-CaO) content of the BOF slag is a significant factor for developing the strength of the adopted sample. However, the particle size of the BOF slag influences the increase in the strength at subsequent curing times. It was inferred that the strength behavior of the sample exhibits three phases depending on various incremental strength ratios. The expansion magnitude of the adopted samples is influenced by the F-CaO content and also the particle size of the BOF slag. Regarding the microstructural properties, the presence of reticulation structures in the amorphous gels with intergrowths of rod-like ettringite formation was verified inside the sample. Finally, the pH values and heavy metal leachates of the samples were determined within the compatible ranges of the threshold effect levels in the marine sediments of the marine environment standard of the Republic of Korea.

scholarly journals Component Modification of Basic Oxygen Furnace Slag with C4AF as Target Mineral and Application

2021 ◽  
Vol 13 (12) ◽  
pp. 6536
Author(s):  
Yanrong Zhao ◽  
Pengliang Sun ◽  
Ping Chen ◽  
Xiaomin Guan ◽  
Yuanhao Wang ◽  
...  
Keyword(s):  
Intermediate Phase ◽  
Raw Materials ◽  
Activity Index ◽  
Basic Oxygen Furnace ◽  
Hydration Products ◽  
Basic Oxygen ◽  
Bof Slag ◽  
Mineral Compositions ◽  
Slag Component ◽  
Basic Oxygen Furnace Slag

In this paper, a new method of basic oxygen furnace (BOF) slag component modification with a regulator was studied. The main mineral was designed as C4AF, C2S and C3S in modified BOF slag, and the batching method, mineral compositions, hydration rate, activation index and capability of resisting sulfate corrode also were studied. XRD, BEI and EDS were used to characterize the mineral formation, and SEM was used to study the morphology of hydration products. The results show that most inert phase in BOF slag can be converted into active minerals of C4AF and C2S through reasonable batching calculation and the amount of regulating agent. The formation of C4AF and C2S in modified BOF slag is better, and a small amount of MgO is embedded in the white intermediate phase, but C3S is not detected. With the increase in the CaO/SiO2 ratio in raw materials, the CaO/SiO2 ratio of calcium silicate minerals in modified BOF slag increases, the contents of f-CaO are less than 1.0%, and the activity index improves. Compared with the BOF slag, the activity index and exothermic rate of modified BOF slag improved obviously, and the activity index of 90 days is close to 100%. With the increase in modified BOF slag B cement, the flexural strength decrease; however, the capability of resisting sulfate corrode is improved due to the constant formation of a short rod-like shape ettringite in Na2SO4 solution and the improvement of the structure densification of the hydration products.

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