Grinding reduces the particle size to cement fineness. Yet from the available heat in the hearth point of view,1 the blast furnace slag should be neither very. The chemical composition of slag is usually expressed in terms of simple. Such a slag acquires liquid mobility and trickles down the furnace away from the site where it starts distorting plastically, as soon as possible. Slag handling is an important aspect of modern blast furnace operation. Blastfurnace slag article about blastfurnace slag by. The dust obtained from the lead baghouse assays about 5052 per cent lead and 2023 per cent zinc and is returned to the lead smelting system.
The slag shall contain no additions and shall conform to the sulfide sulfur and sulfate chemical composition requirement. Blast furnace slag is a coproduct of the iron making process. Other components of blast furnace slag include alumina alsub2 o 3 and magnesium oxide mgo, as well as a small amount of sulfur s, while steelmaking slag contains iron oxide feo and magnesium oxide mgo. The raw materials iron ore, coke and fluxes are fed into the top of the furnace.
Steel slag material description user guidelines for waste and. Significant influence for steel desulphurization has content of. While there are many applications and benefits of slag cement, a few are highlighted below and detailed information sheets are located here. The mineralogical phase composition of the pozzo lan was determined by the use of powder xray. Significant influence for steel desulphurization has content of easily reducible oxides in slag. Portland blastfurnace slag cement is a mixture of ordinary portland cement and not more than 65 wt. The rapid cooling of molten slag by large quantities of water produces sandlike granule aggregate.
The mortar flow diameter decreased with increasing slag content, this means that the workability decreased with increasing slag content. When the metallurgical smelting process is complete, the lime in the flux has been chemically combined with the aluminates and silicates of the ore and coke ash to form a nonmetallic product called blast furnace slag. Composition and microstructure of 20yearold ordinary. The slag composition that has the minimum corrosion ability is obtained. Properties of hardened concrete with blast furnace slag.
Blast furnace control using slag viscosities and liquidus. Development of engineered cementitious composites with. The latent hydraulic property of the blast furnace slag gives excellent longterm strength. The paper presents the results of experimental research that dealt with the substitution of fi nely ground blast furnace slag for portland cement in the course of simple concrete manufacturing.
The molten slag, which absorbs much of the sulfur from the charge, comprises about 20 percent by. There are two distinct types of slag produced at the bluescope steel port kembla site. Effect of blast furnace slag powder on compressive. These slags are combined with any carryover of furnace slag and assist in absorbing. It is a recovered industrial byproduct of an iron blast furnace. Blast furnace slag an overview sciencedirect topics. It is then processed and used for various iron and steel slag converter applications. Hiraskar and chetan patil abstractthe iron industries produce a huge quantity of blast furnace slag as byproduct, which is a nonbiodegradable waste material from that only a small percentage of it is used by. The primary components of iron and steel slag are limestone cao and silica sio 2.
Microwave roasting of blast furnace slag for carbon dioxide. After solidi fication, cooling may be accelerated by applications. It consists of nonferrous components contained in the iron ore together with limestone as an auxiliary materials and ash from coke. Groundgranulated blastfurnace slag ggbs or ggbfs is obtained by quenching molten iron slag a byproduct of iron and steelmaking from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder. Ground granulated blast furnace slag is commonly used in combination with portland cement in concrete for many applications10,11 7. Cdic can now conduct more than 100 mechanical tests, out of which, 55 tests come under the nabl accreditation. Effect of blast furnace slag powder on compressive strength. It is removed from the blast furnace and allowed to cool. As a product of calcinated fluxstone and the alumina and silica phases present in iron ore, the four major oxide phases present in acbfs are oxides of calcium cao, silica. Approximately 110 kg of slag is generated for each ton of converter steel. In the same way as aircooled blast furnace slag, converter slag is cooled slowly by natural cooling and water spray in a cooling yard. Today, blast furnace slag is a saleable product granulated slag sand used as co 2friendly substitute of clinker in cement production rather than a difficult and costly waste material.
In carbon steelmaking it is important to ensure foaming slag conditions, which increases energy efficiency of the eaf. The elemental composition of bf slag was investigated by xray fluorescence spectrometry xrf1800, shimadzu, japan, with a rh target used as the target. A portland cement mixed with a designated amount of ground granulated blast furnace slag. Analysis of slag flow in blast furnace during the extraction. Astm c989 c989m 18a standard specification for slag. The physical structure and gradation of granulated slag depend on the chemical composition of the slag, its temperature at the time of water quenching, and the. Groundgranulated blast furnace slag ggbs or ggbfs is obtained by quenching molten iron slag a byproduct of iron and steelmaking from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder.
The ground granulated blast furnace slag is a byproduct of iron manufacturing industry. Properties significant chemoresistance, and suppression of alkaliaggregate reaction type b and c. Use of aircooled blast furnace slag as coarse aggregate. Recent developments in slagfuming process 7 0 2n b 0 10 29 30 40 50 60 70 80 90 100 110 120 ti ne,s,inute 2 ovetal eliminative curve chambers. Other components of blast furnace slag include alumina alsub2o3 and. Aluminachrome brick is the suitable refractory to freeze lining in submerged arc furnace. Such fact indicates a possibility to produce portland cement, since decrease the bofs basicity caosio2. Nonportland cement activation of blast furnace slag anne elizabeth oberlink university of kentucky, anne. Groundgranulated blast furnace slag is highly cementitious and high in csh calcium silicate hydrates which is a strength enhancing.
Effect of ground granulated blast furnace slag as partial. Blast furnace slag concrete can be reliably pumped when the slag is supplied to the readymix production in a saturated condition. Pyrometallurgy, blast furnace, slag viscosity, slag liquidus temperature, phase equilibria abstract the viscosity of molten slag in blast furnace operations is an important process variable, influencing the rate and location of reactions inside the furnace, as well as the ease with which the final slag could be removed from the. Slag cement is a hydraulic cement formed when granulated blast furnace slag ggbfs is ground to suitable fineness and is used to replace a portion of portland cement. It is generally recognized that the rate of hardening of slag cement is somewhat slower than that of ordinary portland cement during the first 28 days but thereafter increases so that at 12 months the strengths become close to or even exceed those of. Iron is extracted from iron ore in a blast furnace by a process known as reduction. They showed that slag of the following composition 35% al 2 o 343. Hamazaki, properties of granulated blastfurnace slag cement concrete, in proceedings of the fly ash, silica fume, slag, and natural pozzolans in concrete fourth international conference, istanbul, turkey, 1992. At the present, most industrial slags are being used without taking full advantage of their properties or disposed rather than used. Today, blast furnace slag is a saleable product granulated slag sand used as co 2 friendly substitute of clinker in cement production rather than a difficult and costly waste material. The latent hydraulic property of the blastfurnace slag gives excellent longterm strength. Blast furnace slag material description user guidelines for.
Ld slag has a series of advantages over natural rock in the field of road construction. Blastfurnace slag cement article about blastfurnace slag. Ground granulated blast furnace slag ggbfs is designated in astm c 989 and consists mainly of silicates and aluminosilicates of calcium. Online slag composition analysis for electric arc furnaces. Use of the cementatious properties of ground granulated blast furnace ggbf slag was reported as early as 1774.
Blast furnace slag as a concrete aggregate mf 1638 a. The chemical composition of a slag varies considerably depending on the composition of the raw materials in the iron production process. A technical advisory group tag was set up to bring together representatives from the environment agency, wrap and industry. The composition of the slag glass was determined by electron microprobe analysis of powder, embedded in resin, ground and polished flat. It is a nonmetallic product, consisting of silicates and aluminosilicates of.
Blast furnace slag is recovered by melting separation from blast furnaces that produce molten pig iron. Grain size effect in elution test of electric arc furnace slag mdpi. Appendix a contains a list of tag members and appendix b gives its terms of reference. The chemical composition of a slag varies considerably depending on the composition of the raw materials in the. Using slag cement in concrete can greatly decrease the amount of portland cement typically used for a specific mixture of concrete. In the case of steelmaking slag, the slag contains metal elements such as iron in oxide form. Influence of curing time on the drying shrinkage of. The results of chemical analysis determined according to astm standard c311 12 are shown in table 1. However, this statement can be considered only partially correct. Blastfurnace slag is the glassy granular material formed when molten blastfurnace slag is rapidly chilled, as by immersion in water virgalitte et al. The blast furnace slag should be a freeflowing one at the operating temperatures to ensure efficient slag metal separation. Rinse eyes thoroughly with water for at least 15 minutes, including under lids, to remove all particles.
Ggbfs is divided into three classifications based on its activity index. Wash with cool water and a ph neutral soap or a mild skin detergent. A portland cement mixed with a designated amount of ground granulated blastfurnace slag. Blast furnace slag is a nonmetallic coproduct produced in the process. Granulated blast furnace slag is a glassy granular material that varies, depending on the chemical composition and method of production, from a coarse, popcornlike friable structure greater than 4. Hiraskar and chetan patil abstractthe iron industries produce a huge quantity of blast furnace slag as byproduct, which is a nonbiodegradable waste material from that only a small percentage of it is used by cement industries to manufacture cement. Jan 10, 2014 ld slag has a series of advantages over natural rock in the field of road construction. Hamazaki, properties of granulated blast furnace slag cement concrete, in proceedings of the fly ash, silica fume, slag, and natural pozzolans in concrete fourth international conference, istanbul, turkey, 1992.
Blastfurnace slag cement article about blastfurnace. This specification covers three strength grades of finely ground granulated blastfurnace slag grades 80, 100, and 120 for use as a cementitious material in concrete and mortars. Blast furnace slag material description user guidelines. This paper studies the blast furnace slag glass phase structure by a series of analysis methods. Mechanochemical modification of cement with high volumes of. Viscosity decreases with basicity for high alumina blast furnace slags with increase in basicity and caf 2.
Effects of fineness and chemical composition of blast furnace. Because of the disputes over the composition of the cement, the manufacturers of cements containing blast furnace slag founded the association of german iron. The overall conclusion is that with a more reliable composition of hot metal and slag from the taps, the distribution coefficients could be calculated with. Solution compositions were measured from the very first minutes of. Iron ore, coke and limestone are fed into the furnace and the resulting molten slag floats above the molten iron at a temperature of about 15000c to 16000c. While blast furnace slag has a long history of use as an industrial byproduct, going back almost 100 years in the united states and 150 years in europe 8, steel slag was less popular. Early stage dissolution characteristics of aluminosilicate glasses. This group of materials is characterized by high ductility in the range of 37%, tight crack width of around 60. Blast furnace slag granulation ironmaking our activities. Use of aircooled blast furnace slag as coarse aggregate in. Asms then further process the blast furnace slag into useful products for the construction industry such as concrete aggregates and road base products. Generally the products produced from this type of slag are known as air. Molten slag diverted from the iron blast furnace is rapidly chilled, producing glassy granules that yield. With increase in silica activity in the range of 0.
The influence order to lining corrosion and permeation are kinds of refractories, feo content, sio 2 mgo and basicity. Moreover, deep bluegreen color shown by interior part of slag concrete and can be noticed from slag concrete broken parts, for example, after compressive strength test. The use of yield factors in the model raised the question if variation in hot metal and slag composition during and between taps exist. A study on selected hotmetal and slag components for. Recommended citation oberlink, anne elizabeth, nonportland cement activation of blast furnace slag 2010. Dicalcium silicate ca 2 sio 4 14284232, merwinite ca 3 mgsi 2 o 8 8644, and gehlenite ca 2 al 2 sio 7 2563. In this study, aluminosilicate glasses as models for blast furnace slag and. The samples were collected from seven steelmakers located.
Characterization of basic oxygen furnace slag and granite waste. Effects of blastfurnace slag on natural pozzolanbased geopolymer cement ceramics silikaty 55 1 6878 2011 69 its pozzolanic activity. It consists primarily of silicates, aluminosilicates, and calciumaluminasilicates. Approximately 290 kg of slag is generated for each ton of pig iron. The composition of slag varies upon the type of furnace and charge, the desired grade of steel purity and the furnace operation conditions. Granulated blast furnace slag granulated blast furnace slag is a glassy granular material that varies, depending on the chemical composition and method of production, from a coarse, popcornlike friable structure greater than 4.
Granulated blast furnace slag has a cellular structure resulting from rapid quenching in water, is cementitious in nature, and sets to form a solid concretelike mass. Slag cement benefits and use in concrete slag cement news. Due to light color of blast furnace slag, color of slag concrete is lighter in comparison with conventional concrete. The blast furnace slag should be a freeflowing one at the operating temperatures to ensure efficient slagmetal separation. This action exposes fresh sites for further reaction and is supposedly responsible for enhanced slag metal reaction rates, influencing the blast furnace operations and the quality of the metal. The majority of components in granulated blast furnace slag are various glassy metallic silicates iron, calcium, magnesium, aluminum, and titanium silicates, including. Roads constructed using ld slag demonstrate reduced rutting. The microprobe was a cameca camebax operating voltage of 15 kv and probe current of 3. Ground granulated blastfurnace slag ggbfs, sometimes simply referred to as slag, is a glassy granular material formed when molten blastfurnace slag is rapidly chilled, as by immersion in water. This action exposes fresh sites for further reaction and is supposedly responsible for enhanced slagmetal reaction rates, influencing the blast furnace operations and the quality of the metal. Silicate and aluminate impurities from the ore and coke are combined in the blast furnace with a flux which lowers the viscosity of the slag. Blast furnace slag is formed when iron ore or iron pellets, coke and a flux either limestone or dolomite are melted together in a blast furnace. It must have appreciable affinity for the gangue constituents to facilitate the production of metal of choice.
Slag cement is commonly found in readymixed concrete, precast concrete, masonry, soil cement and high temperature resistant building products. Blast furnace slag consists principally of silicates and aluminosilicates of lime and other bases developed simultaneously with iron in a blast furnace. This can perhaps be explained by the vast amount of blast furnace slag available 6. Use and properties of blast furnace slag as a building. Supersulfated cement usually contains about 80% ground granulated blast furnace slag, 15% gypsum or anhydrite, and a small amount of portland clinker to act as an activator.
Use of blast furnace slag as an alternative of natural. Page 2 blast furnace slag as a concrete aggregate part i properties of blast furnace slag our natural aggregates, such as stone and gravel of suitable quality for concrete making, are rapidly becoming depleted in many localities. Primarily ground into a cement replacement known as ground granulated blast furnace slag ggbs this is used in readymixed and precast concrete and masonry, floor levelling compounds and high temperature resistant building products. Ecc, short for engineered cementitious composites, is a class of ultra ductile fiber reinforced cementitious composites originally invented at the university of michigan in the early 1990s.
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