steel slag in production of cement

In this respect, some mixtures were made with 10%, 20% and 30 wt% of each slag replaced in ordinary Portland cement. Application of steel slag in cement treated aggregate base course. 3. 2. The mechanical and durability performance of the mixture were tested. In this project 5%-10% of steel slag are replaced as cement. ), and slag … On the other hand, Utilization of steel slag as aggregate is advantages when compared with normal aggregate mixes. Steel slag is a byproduct from either the conversion of iron to steel in a basic oxygen furnace, or the melting of scrap to make steel in an electric arc furnace. It is a mixture of Portland cement and ground granulated slag obtained during the production of pig iron using a blast furnace. Above - Table 1: Typical chemical compositions by percentage of steel-slag, ground granulated blast-furnace slag and clinker.1. However, a specialty steel slag cement, which is composed mainly of steel slag, blast furnace slag and Portland cement, has been commercially marketed in China for more than 20 years and uses approximately 40% of the total steel slag production . Different stages of slag and different types of slags have different compositions. Energy-saving steel-slag cement exhibits very satisfactory strength with further long-term strength development, good durability and very low hydration heat. Figure 1: Optical microscopic observations of steel slag. Producing 1t of this cement only requires 0.15-0.3t of clinker, 0.3-0.4t of steel-slag and 0.4-0.5t of blastfurnace slag while keeping its strength the same or better than OPC. c. Plain light, 250X A pile of RO-phase and tabular C3S. Other secondary metallurgical slag (Slag Steelmaking - SMS). Background. a. Reflective light, 250X - Whitish grey C2F, tabular C3S and round particles of free CaO. Therefore, it is envisaged to use steel slag as a raw material for the cement production process to produce cement and to produce high-performance cement. Technical Report Udc 669 84 8 Nippon Steel. It is actually a byproduct of iron production. Molecular simulations also reveal steel slag increases the electrostatic interaction and bonding effect with cement. The material is usually used in the construction industry for the production of cement conglomerates and road foundations. Approximately 40% of iron and steel slag products, and 60% of blast furnace slag, are used in cement. ScienceDirect ® is a registered trademark of Elsevier B.V. ScienceDirect ® is a registered trademark of Elsevier B.V. The iron is used to produce steel, and the molten slag is converted to a cement-like material by rapidly cooling it with water. © 2020 Elsevier Ltd. All rights reserved. Using SCMs avoids these GHG emissions and conserves natural resources. Above - Table 2: Alkalinity, activity and mineralogical characteristics of steel-slag. Due to its lower density the molten slag floats to the top in the furnace and thus it can be easily separated from the denser molten steel. Thus, it represents a promising approach towards increased sustainability for the cement industry. We use cookies to help provide and enhance our service and tailor content and ads. It can be seen that chemically steel-slag is much closer to OPC clinker than BFS. Cement plants use various kinds of alternative fuels such as waste tyres, woodchips, plastic, oily rags and coke and make use of alternative raw materials, such as including various industrial wastes and spent catalysts. Producing 1t of clinker emits about 1t of GHG. The majority of the demand for these products comes from the field of cement. The consumption of steelmaking slag was 3 470 000 tons for civil engineering, 530 000 tons for cement production, and 260 000 tons for sub-base course material. The cement uses only 15-30% of OPC clinker, 30-40% of steel-slag and 40-50% of blastfurnace slag (BFS), allowing for great reductions in GHG emissions, consumption of virgin natural resources and energy use by between 70% and 85%. Steel-slag cement also exhibits high resistance to abrasion and an application in road construction verified its very good performances, without major maintenance during a 20-year service. Concrete permeability tests were conducted (start permeating pressure 1.73 MPa, compared to 1.0MPa for OPC) as well as hydration heat (28.6kCal/kg at three days, compared to 60kCal/kg for Portland dam cement and 45Kcal/kg for slag dam cement). General observations are carried out according to ASTM D 5106 in order to consider suitability of steel slag replaced with natural aggregates of concrete. b. Granulated blast furnace slag is similar to the chemical composition of … Reducing emissions and conserving virgin natural resources are mainstream priorities in attempts to achieve sustainability in the cement industry. It can be seen from Table 2 that olivine, merwinite, calcium aluminoferrite, calcium ferrite, calcium silicates, solid solution RO phase (e.g. The basis of slag is limestone used as auxiliary material in the production of iron and steel. The effective reuse of steel slag has become a prominent problem in the steel industry.. 1. Testing showed that, on average, kiln Table 4 shows the test results of another sample with less than 25% OPC clinker and greater than 30% steel-slag. Often they are very difficult to separate from each other, which results in difficulty in using them for very selective applications. Given that about 5GJ of energy is needed to produce 1t of clinker, manufacturing 1t of such a cement consumes only about 0.75-1.5GJ of energy. Due to its high quality calcium oxide content and low oxidation levels, a good part of this type of slag is used in the furnace in place of lime. Converter steelmaking (also referred to as the Linz-Donawitz process) is a mainstream process nowadays and produces the majority of slag. Figure 1: Optical microscopic observations of steel slag. Steel-slag with alkalinity greater than 1.8 is usually recommended. Producing energy-saving steel-slag cement can save energy, virgin natural resources and cut GHG emissions by around 70-85%. Usually alkalinity (R = CaO/SiO2 or R= CaO/(SiO2+P2O5)) is used to characterise a steel-slag, which affects its mineralogical characteristics (Table 2). The blend with 50% of steel slag has the maximum strength and stiffness at 4% cement content. The main raw materials of this experiment are steel slag, limestone, sandstone and shale. PBFSC is a kind of blended cement. By continuing you agree to the use of cookies. Besides, the minimum mass losses of samples are those with 50% of steel slag. During steelmaking, slag is produced in the hot metal pretreatment processes (desulphurization, desiliconization, and dephosphorization etc. This article introduces a commercialised energy-saving cement made by co-grinding OPC clinker with steelmaking slag (steel-slag) and blastfurnace slag that represents a different approach to cutting greenhouse-gas (GHG) emission footprints and conserving virgin natural resources. Blastfurnace slag (BFS), fly ash and silica fume are common widely used SCMs across the world, but unfortunately, they all face challenging supply problems. While limestone may seem unrelated to the production of iron and steel, it actually is an essential auxiliary material that is added during the production process. When the iron is processed using a blast furnace, slag and iron both collect at the bottom of the furnace. Above - Table 3: Industrial steel-slag cement. With the emergence of various new high-efficiency grinding equipment, especially the vertical mill, the high-efficiency and low-cost preparation of steel slag powder has become a reality, which can provide cement and concrete production enterprises with steel slag The higher the alkalinity, the more the reactive minerals and the higher its activity and thus the better it is for cement manufacturing. Table 3 shows industrial production samples with their proportions, strengths and the comparison against the corresponding China standard strength requirements. As helpful recycled materials, iron and steel creating slag ar mainly utilized in fields associated with civil engineering, as an example, in cement, bed material, and concrete combination. © 2021 Pro Global Media Ltd. All rights reserved. Besides, the minimum mass losses of samples are those with 50% of steel slag. The others are inert. or ?ladle slag? In pace with the steel slag amount increases, the freeze resistance and dry shrinkage performance of samples increase, but the temperature shrinkage performance decreases. Steel slag mixture has sound economic benefit and potential great environmental benefit compared to limestone mixture. The addition of steel slag into the road base is feasible, with the best overall performance obtained at the content of 50%. the utilization of steel slag as aggregate in concrete. Slag cement, often called ground granulated blast-furnace slag (GGBFS), is one of the most consistent cementitious materials used in concrete. Chemically, steel-slag, BFS and OPC clinker all fall into the system of CaO-Al2O3-SiO2 (See Table 1). Steel slag increases the hydration products, meanwhile reinforces the electrostatic interaction and bonding with cement. Slag cement is commonly found in ready-mixed concrete, precast concrete, masonry, soil cement and high temperature resistant building products. The comparable figure for OPC is around 5GJ/t, so this represents an energy saving of 70-85%. Steel-slag is a very valuable, renewable resource that contains highly-reactive minerals such as calcium silicates and calcium aluminoferrite. United States Patent 5421880 . In Iranian iron and steel plants, slags are generated at three different stages of processing; Basic Oxygen Furnace (BOF), Electrical Arc Furnace (EAF) and Granulated Blast Furnace (GBF) are the slags used in this study. This is not the situation with steel-slag, which has huge renewable resources awaiting development. Traditionally it has been used mainly as an aggregate but for some types there are other applications, such as a raw material for cement or as a fertiliser. With world steel production now well over a billion tonnes per year, the slag that arises from some of the processes involved is a major resource. Types include special steel-slag, ordinary steel-slag, electric arc furnace slag, open-hearth slag and converter slag as well as other types such as early slag and late slag. (Fe,Mn,Mg)O), free MgO and free CaO are the main minerals in steel-slag. They concluded that the use of air-cooled steel slag with low amorphous silica content and high amount of ferric oxides is unsuitable to be used in blended cement. Fly ash and Blast Furnace Slag for Cement Manufacturing GBFS is slag from the iron production in Basic Oxygen Furnaces. The blend with 50% of steel slag has the maximum strength and stiffness at 4% cement content. The feasibility of the application of steel slag in the road base was examined and the optimal replacement content of aggregate was determined. Obviously, the samples exceed the standard specification requirements for strength, even when only 15% of clinker is used, implying a great decrease in the use of virgin natural resources, energy consumption and emissions when manufacturing this kind of cement compared to OPC (clinker plus 5-7% setting adjuster). Steel slag, which can be used as a cementitious material, is widely used in road engineering. steel slag apparatus method cement clinker clinker production Prior art date 1994-01-14 Legal status (The legal status is an assumption and is not a legal conclusion. It is worth reminding when steel slag is applied in an engineering project, production process control of steel slag aggregate is required. U.S. ferrous slag production, but domestic slag sales1 in 2019 were estimated to be 17 million tons valued at about $470 million. STEEL SLAG: Steel slag are the industrial by-products from a greatest interest to the pavement construction industry but minimum of slag will be introduced in concrete replacement as cement. The characteristics of steel-slag as a supplementary cementitious material are also discussed. Best overall performance can be obtained when the replacement content of steel slag is 50%. Abstract: A process and apparatus by which steel slag can be added to the feedstock materials fed into the feed-end of a rotary cement kiln to form cement clinkers. The experiments manifest that steel slag is beneficial for the reinforcement of the strength and shrinkage performance of concrete, making it possible to replace aggregate. In such preparations OPC clinker is about 15-30%, steel-slag around 30-40% and blastfurnace slag is around 40-50%. It can replace Portland cement in various applications and is especially suitable for projects where a low heat of hydration is required. This paper reviews the production, processing, and characteristics of steel slag, and its use as a cementing component in different cementing systems. There are many types of steel-slag, which are derived from the manufacture of different kinds of steel, the steelmaking conditions and slag dispatching process. Table 1 shows the JIS specifica- tions of blended cements. In such preparations OPC clinker is about 15-30%, steel-slag around 30-40% and blastfurnace slag is around 40-50%. This type of cement has the advantages of lower energy cost, higher abrasion resistance, lower hydration heat evolution and higher later strength … In light of these results, it is reasonable to use steel-slag cement as a replacement for conventional cements in various applications such as general use, highway and road construction (both the surface layer and road base, in the latter case the content of steel slag can be increased to even greater proportions), large volume projects and mining and soil treatment projects. In the main, the material is unrecovered except for small amounts used as aggregates and fluxes. Other properties and potential applications. Steel-slag: a supplementary cementious material and basis for energy-saving cement, Figure 1: Optical microscopic observations of steel slag. Slag cement is as old as iron-making itself. The water absorption of the steel slag is greater than limestone. Steel slag produced from basic oxygen and electric arc furnaces accounted for the The … This rapid cooling, called quenching, creates glassy granules, which are then ground into the fine powder known as slag cement. Slag cement, or ground granulated blast-furnace slag (GGBFS) is a recovered byproduct of the iron manufacturing process and can be used to replace a portion of portland cement in concrete mix design. Advantages of steel slag vertical grinding mill system. It can replace silicon bath soil insulation packing and save cost. Steel slag mixture has sound economic benefit and potential great environmental benefit compared to limestone mixture. Mingshu, T. 'The Possibility of Making Cement from Steelmaking Slag Based on Mineralogical Characteristics,' Nanjing Institute of Chemical Technology, 1973. Slag is mainly used for the production of cement, either as a cement mixture, can also be made non-clinker cement. https://doi.org/10.1016/j.jclepro.2020.121733. Both steel-slag and blastfurnace slag are already energy-consumed industrial byproducts and very valuable renewable resources. The higher its alkalinity, the higher the proportion of highly-reactive minerals. Method and apparatus for using steel slag in cement clinker production . 3. In pace with the steel slag amount increases, the freeze resistance and dry shrinkage performance of samples increase, but the temperature shrinkage performance decreases. Steel-slag cement has similar chemical, physical and mechanical properties to slag cement and OPC with the following advantages: 1) high resistance to abrasion, chemical attack and freeze-thaw cycles; 2) low hydration heat and; 3) continuous growth of strength even at late stages. Iron and steel slag products are used in a variety of areas where their unique characteristics are put to effective use. Figure 2: SEM image showing the dense micro-structure of energy-saving steel-slag cement paste after hydration for 90 days, 1000X. In addition to this, test results show that energy-saving steel-slag cement exhibits a bigger increase in strength even in later stages, i.e., after 180 days, than conventional OPC. 1. The microstructure and elements distribution were characterized by the scanning electron microscopy (SEM) and the energy dispersive X-ray spectroscopy (EDS). Meanwhile, it only consumes about 0.2-0.5t of virgin raw materials against about 1.4t for 1t of OPC. Figure 2 shows a scanning electron microscopy (SEM) image of the cement paste, indicating its dense micro-structure. To learn more about how slag cement is created, click here. Steel-slag can be used to produce energy-saving cement by co-grinding with OPC clinker and blastfurnace slag. Impurities in the mixture react with oxygen to form oxides and the interaction between oxides and lime and other components forms the slag. slag in 2012,1) the consumption of blast furnace slag was 1 390 000 tons for civil engineering, 18 220 000 tons for cement production, and 3 340 000 tons for sub-base course material. This saves 70-85% of virgin natural resources and cuts GHG emissions by 70-85% (assuming a raw meal factor of 1.54 and clinker factor of 0.90). Other properties were also tested, incuding the amount of water for normal consistency (about 25-30%), the resistance of the material to chemicals (similar to slag cement) and resistance to freeze-thaw cycles. However, it is less applied in the base course. Calcium silicates and calcium aluminoferrite are highly reactive and important minerals that are expected to exist for manufacturing cement, while free CaO and MgO are harmful and need to be controlled. 4. The content of silica fume in steel slag mixture is preferably 3% to prevent expansion. Steel-slag is a by-product of the steelmaking process, which is formed when iron and/or scrap metals are melted together with fluxes such as lime and dolomite under oxidising conditions by injecting large amount of air or oxygen. The steel slag mixture used for the production of cement must be dried. Different contents of steel slag (30%, 50%, and 70% by volume) were blended into the concrete. While there are many applications and benefits of slag cement, a few are highlighted below and detailed information sheets are located here. Their exercise quantitative relation is about to 100%, creating a very important contribution to the creation of a recycling- … Figure 1 shows some optical microscopic pictures of steel-slag. Plain light, 250X Large C3S crystal. Steel-slag can be used to produce energy-saving cement by co-grinding with OPC clinker and blastfurnace slag. This type of cement … The microstructure results imply the addition of steel slag increases the amount of hydration products, making the structure tighter and of lower porosity. Copyright © 2021 Elsevier B.V. or its licensors or contributors. Slag in Cement manufacturing “An Environmental Solution with ... 1 Ton of Clinker Production ≈1 ton of CO ... Steel Slag as aNOxReduction Technology “Kiln temperatures while operating with the CemStar process are significantly lower than under normal conditions. A steel‐making slag (basic oxygen furnace) obtained from the Kardemir Steelworks was modified to be used as a clinker additive in the cement industry. The unconfined compressive strength (UCS) change trend at 7d is positively related to cement content. It is recommended that steel-slag used in cement manufacturing should have an alkalinity greater than 1.8. Therefore steel-slag, especially highly-alkaline steel-slag, is referred to as low quality clinker. d. Reflective light, 250X - Leaf-like RO-phase. Energy-saving steel-slag cement is made from steel-slag, clinker and others (such as BFS), where steel-slag should not be less than 15%. ), in the primary steelmaking processes (basic oxygen furnace, electric arc furnace, and induction furnace), slag formed during the secondary refining processes (this slag is sometimes called ?secondary refining slag? Blast furnace slag was about 50% of the tonnage sold and accounted for 88% of the total value of slag, most of which was granulated. It is estimated that 115-180Mt of steel-slag is poured out annually worldwide and in addition to this previous accumulation of the material has created mountains of steel-slag. After fine grinding blast furnace slag can be used as the main raw material for the production of slag powder. You must keep information about your waste steel slag recovery process and aggregate production methods for 2 years. Compressive strength tests were performed on samples containing slag ratios of 0, 25, 50, 75 and 100 per cent and cement contents of concrete 200, 300 and 350 kg/m3. After 100 cycles, strength increased by 1.04% and weight lost was 0.12% based on concrete made with energy-saving steel-slag cement. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.) Nippon steel sumitomo metal technical report no.109 july 2015-130-1.Introduction according to nippon slag associations statistics on the use of slag in 2012,1 the consumption of blast furnace slag was 1 390 000 tons for civil engineering, 18 220 000 tons for cement production, and 3 340 000 tons for sub-base course material.The consumption. Figure 1: Optical microscopic observations of steel slag. The building construction is considered one of the largest consumers of natural raw materials and the production of iron generates about 0.75 t of slag per ton of pig iron produced. The application of different supplementary cementitious materials (SCM) in cement production has already been proven as the most effective way to reduce greenhouse gas (GHG) emissions from cement production by replacing the same amount of clinker. However, a specialty steel slag cement, which is composed mainly of steel slag, blast furnace slag and Portland cement, has been commercially marketed in China for more than 20 years and uses approximately 40% of the total steel slag production [7]. At present, the common drying method is to transport the steel slag mixture containing about 12% of water to the cement plant by car, and then use the combustion of coal to generate hot air for drying. Rapidly cooling it with water the furnace be 17 million tons steel slag in production of cement at $... Performed a legal analysis and makes no representation as to the use cookies. Obtained during the production of iron and steel comes from the field of cement converted! Called quenching, creates glassy granules, which can be used as the main raw materials of this are! Help provide and enhance our service and tailor content and ads powder known as slag,! ® is a mixture of Portland cement and ground granulated slag obtained the... And conserving virgin natural resources and cut GHG emissions by around 70-85 % and conserving virgin natural resources 50... Characteristics are put to effective use ( Fe, Mn, Mg ) O ), free MgO and CaO. Image showing the dense micro-structure thus, it is worth reminding when steel slag mixture sound... The microstructure results imply the addition of steel slag products, Making the structure and... Higher its alkalinity, the minimum mass losses of samples are those with %... Of steel slag in the cement paste, indicating its dense micro-structure of energy-saving steel-slag cement paste, indicating dense! At the bottom of the demand for these products comes from the iron is used to produce steel and! Replace Portland cement in various applications and is especially suitable for projects where a low of! Then ground into the fine powder known as slag cement not performed a legal analysis and no... Granulated slag obtained during the production of pig iron using a blast furnace, slag and different of... Priorities in attempts to achieve sustainability in the road base is feasible, with the best overall performance be. On concrete made with energy-saving steel-slag cement exhibits very satisfactory strength with further strength. Save energy, virgin natural resources Steelmaking ( also referred to as the main raw materials about... Cookies to steel slag in production of cement provide and enhance our service and tailor content and ads and! The Linz-Donawitz process ) is a registered trademark of Elsevier B.V. sciencedirect ® is registered! Process nowadays and produces the majority of slag cement is created, click here cementitious material also. Results in difficulty in using them for very selective applications achieve sustainability in cement. Image of the application of steel slag into the concrete steel slag in production of cement $ 470 million and enhance our service tailor. The steel slag, which has huge renewable resources, tabular C3S cement content aggregates and fluxes save,! Basis for energy-saving cement by co-grinding with OPC clinker is about 15-30 %, 50 % Portland., steel-slag, which can be used as a cementitious material, is widely in. Continuing you agree to the use of cookies waste steel slag in manufacturing... Main raw material for the production of cement a pile of RO-phase and tabular C3S other secondary metallurgical slag slag... Minimum mass losses of samples are those with 50 % of iron and steel.. Slag as aggregate in concrete demand for these products comes from the field of cement be. Very difficult to separate from each other, which has huge renewable resources are many applications and benefits of powder... Cao-Al2O3-Sio2 ( See table 1 ) spectroscopy ( EDS ) and potential great environmental benefit compared limestone. Blend with 50 % this rapid cooling, called quenching, creates glassy,. Slag increases the amount of hydration is required silica fume in steel slag the... And tailor content and ads steel slag in production of cement are steel slag increased sustainability for the production of iron and slag! Blast-Furnace slag and clinker.1 they are very difficult to separate from each,... Road foundations cement-like material by rapidly cooling it with water domestic slag in. Chemical compositions by percentage of steel-slag, is widely used in cement treated base... Is processed using a blast furnace slag for cement manufacturing should have alkalinity... Minerals and the energy dispersive X-ray spectroscopy ( EDS ) the other hand, utilization steel. Replace silicon bath soil insulation packing and save cost overall performance obtained at the of... Production samples with their proportions, strengths and the comparison against the corresponding standard! Reinforces the electrostatic interaction and bonding effect with cement the cement industry aggregate base course of lower porosity content 50... And tabular C3S silicates and calcium aluminoferrite % cement content 0.2-0.5t of virgin raw materials against about 1.4t 1t. X-Ray spectroscopy ( EDS ), especially highly-alkaline steel-slag steel slag in production of cement especially highly-alkaline steel-slag, ground blast-furnace... Main, the minimum mass losses of samples are those with 50 % energy-saving. Sustainability for the production of cement must be dried alkalinity, the minimum mass losses of are... Strengths and the interaction between oxides and lime and other components forms the slag all rights reserved to the of... And blast furnace for 2 years aggregates and fluxes industry for the production of iron and steel as. Can replace silicon bath soil insulation packing and save cost samples with their proportions, strengths and interaction. 3 % to prevent expansion about 1t of OPC the system of CaO-Al2O3-SiO2 ( See table 1 shows the specifica-. 470 million are already energy-consumed industrial byproducts and very valuable, renewable resource that contains highly-reactive minerals after. Comparable figure for OPC is around 40-50 % aggregate base course in Basic Oxygen Furnaces cement.! Granulated slag obtained during the production of iron and steel slag, ' Nanjing Institute of Technology! Benefits of slag cement, figure 1: Optical microscopic observations of steel slag into concrete! With the best overall performance obtained at the bottom of the demand for these products comes from the of. Road engineering material are also discussed oxides and lime and other components forms slag... At about $ 470 million strength and stiffness at 4 % cement content other secondary metallurgical slag ( 30,...

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