In carbon steelmaking it is important to ensure foaming slag conditions, which increases energy efficiency of the eaf. Such a slag acquires liquid mobility and trickles down the furnace away from the site where it starts distorting plastically, as soon as possible. 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. 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. Viscosity decreases with basicity for high alumina blast furnace slags with increase in basicity and caf 2. Blastfurnace slag article about blastfurnace slag by. Mechanochemical modification of cement with high volumes of. Use of aircooled blast furnace slag as coarse aggregate. Grain size effect in elution test of electric arc furnace slag mdpi. Development of engineered cementitious composites with. Blast furnace slag concrete can be reliably pumped when the slag is supplied to the readymix production in a saturated condition. The results of chemical analysis determined according to astm standard c311 12 are shown in table 1. The primary components of iron and steel slag are limestone cao and silica sio 2. In the case of steelmaking slag, the slag contains metal elements such as iron in oxide form.
The ground granulated blast furnace slag is a byproduct of iron manufacturing industry. The slag composition that has the minimum corrosion ability is obtained. Effect of blast furnace slag powder on compressive strength. Blast furnace slag material description user guidelines. 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. Portland blastfurnace slag cement is a mixture of ordinary portland cement and not more than 65 wt. 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. A portland cement mixed with a designated amount of ground granulated blast furnace slag. Jan 10, 2014 ld slag has a series of advantages over natural rock in the field of road construction.
Effect of ground granulated blast furnace slag as partial. These slags are combined with any carryover of furnace slag and assist in absorbing. Blast furnace slag is a coproduct of the iron making process. 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. The mineralogical phase composition of the pozzo lan was determined by the use of powder xray. A portland cement mixed with a designated amount of ground granulated blastfurnace slag. Influence of curing time on the drying shrinkage of. They showed that slag of the following composition 35% al 2 o 343. Appendix a contains a list of tag members and appendix b gives its terms of reference. Significant influence for steel desulphurization has content of. It is a nonmetallic product, consisting of silicates and aluminosilicates of. 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. 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.
In the case of steelmaking slag, the slag contains metal elements such as iron in oxide form, however because the refining time is short and the amount of limestone contained is large, a portion. Analysis of slag flow in blast furnace during the extraction. Yet from the available heat in the hearth point of view,1 the blast furnace slag should be neither very. Recommended citation oberlink, anne elizabeth, nonportland cement activation of blast furnace slag 2010. 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. Cdic can now conduct more than 100 mechanical tests, out of which, 55 tests come under the nabl accreditation. The chemical composition of a slag varies considerably depending on the composition of the raw materials in the iron production process. Properties significant chemoresistance, and suppression of alkaliaggregate reaction type b and c. Early stage dissolution characteristics of aluminosilicate glasses.
Blast furnace slag as a concrete aggregate mf 1638 a. This can perhaps be explained by the vast amount of blast furnace slag available 6. It is then processed and used for various iron and steel slag converter applications. Iron is extracted from iron ore in a blast furnace by a process known as reduction. 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. The composition of slag varies upon the type of furnace and charge, the desired grade of steel purity and the furnace operation conditions. Blastfurnace slag cement article about blastfurnace slag.
A study on selected hotmetal and slag components for. This group of materials is characterized by high ductility in the range of 37%, tight crack width of around 60. The rapid cooling of molten slag by large quantities of water produces sandlike granule aggregate. In this study, aluminosilicate glasses as models for blast furnace slag and. Dicalcium silicate ca 2 sio 4 14284232, merwinite ca 3 mgsi 2 o 8 8644, and gehlenite ca 2 al 2 sio 7 2563. 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.
Ggbfs is divided into three classifications based on its activity index. Online slag composition analysis for electric arc furnaces. 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 use of yield factors in the model raised the question if variation in hot metal and slag composition during and between taps exist. 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. Because of the disputes over the composition of the cement, the manufacturers of cements containing blast furnace slag founded the association of german iron. It consists of nonferrous components contained in the iron ore together with limestone as an auxiliary materials and ash from coke. Such fact indicates a possibility to produce portland cement, since decrease the bofs basicity caosio2. 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. Astm c989 c989m 18a standard specification for slag. Use of the cementatious properties of ground granulated blast furnace ggbf slag was reported as early as 1774.
Approximately 290 kg of slag is generated for each ton of pig iron. The slag shall contain no additions and shall conform to the sulfide sulfur and sulfate chemical composition requirement. Ground granulated blast furnace slag is commonly used in combination with portland cement in concrete for many applications10,11 7. 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 composition of the slag glass was determined by electron microprobe analysis of powder, embedded in resin, ground and polished flat. Aluminachrome brick is the suitable refractory to freeze lining in submerged arc furnace. 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. 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. Blast furnace slag an overview sciencedirect topics. Other components of blast furnace slag include alumina alsub2o3 and.
Effects of fineness and chemical composition of blast furnace. The mortar flow diameter decreased with increasing slag content, this means that the workability decreased with increasing slag content. Significant influence for steel desulphurization has content of easily reducible oxides in slag. It is removed from the blast furnace and allowed to cool. The chemical composition of a slag varies considerably depending on the composition of the raw materials in the. Slag cement benefits and use in concrete slag cement news. Ground granulated blast furnace slag ggbfs is designated in astm c 989 and consists mainly of silicates and aluminosilicates of calcium. Effect of blast furnace slag powder on compressive. 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. Slag handling is an important aspect of modern blast furnace operation.
Asms then further process the blast furnace slag into useful products for the construction industry such as concrete aggregates and road base products. The molten slag, which absorbs much of the sulfur from the charge, comprises about 20 percent by. It is a recovered industrial byproduct of an iron blast furnace. Nonportland cement activation of blast furnace slag anne elizabeth oberlink university of kentucky, anne. 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 elemental composition of bf slag was investigated by xray fluorescence spectrometry xrf1800, shimadzu, japan, with a rh target used as the target. The latent hydraulic property of the blast furnace slag gives excellent longterm strength. It consists primarily of silicates, aluminosilicates, and calciumaluminasilicates. Properties of hardened concrete with blast furnace slag. Wash with cool water and a ph neutral soap or a mild skin detergent. In the same way as aircooled blast furnace slag, converter slag is cooled slowly by natural cooling and water spray in a cooling yard.
Grade 80 has a low activity index and is used primarily in mass structures because. Microwave roasting of blast furnace slag for carbon dioxide. 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. It must have appreciable affinity for the gangue constituents to facilitate the production of metal of choice. The samples were collected from seven steelmakers located. 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 and properties of blast furnace slag as a building. 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. Pelletized slag, ground granulated blast furnace slag ggbfs, blast furnace slag, steel slag, granulated slag, pelletized slag, metallic slag, air cooled slag, nonmetallic slag, slag cement, hydraulic slag cement, slag manufacturer. The raw materials iron ore, coke and fluxes are fed into the top of the furnace. Blast furnace slag is a nonmetallic coproduct produced in the process. 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. After solidi fication, cooling may be accelerated by applications. Composition and microstructure of 20yearold ordinary. Effects of blastfurnace slag on natural pozzolanbased geopolymer cement ceramics silikaty 55 1 6878 2011 69 its pozzolanic activity. 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. A technical advisory group tag was set up to bring together representatives from the environment agency, wrap and industry. Blast furnace slag is recovered by melting separation from blast furnaces that produce molten pig iron. Blast furnace slag material description user guidelines for.
Slag cement is commonly found in readymixed concrete, precast concrete, masonry, soil cement and high temperature resistant building products. The latent hydraulic property of the blastfurnace slag gives excellent longterm strength. Using slag cement in concrete can greatly decrease the amount of portland cement typically used for a specific mixture of concrete. 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. The studied slag metal distributions were also showing strong, trendlike relationships, which was not affected by the operational status of the blast furnace during the studied sampling period. Blast furnace slag consists principally of silicates and aluminosilicates of lime and other bases developed simultaneously with iron in a blast furnace. Molten slag diverted from the iron blast furnace is rapidly chilled, producing glassy granules that yield. 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. Portland blast furnace slag cement is a mixture of ordinary portland cement and not more than 65 wt. 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. Due to light color of blast furnace slag, color of slag concrete is lighter in comparison with conventional concrete.
Use of blast furnace slag as an alternative of natural. Blastfurnace slag cement article about blastfurnace. Blast furnace slag granulation ironmaking our activities. 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. The blast furnace slag should be a freeflowing one at the operating temperatures to ensure efficient slag metal separation. Grinding reduces the particle size to cement fineness. 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. There are two distinct types of slag produced at the bluescope steel port kembla site. Steel slag material description user guidelines for waste and.
Characteristics of portland blastfurnace slag cement. The influence order to lining corrosion and permeation are kinds of refractories, feo content, sio 2 mgo and basicity. At the present, most industrial slags are being used without taking full advantage of their properties or disposed rather than used. Solution compositions were measured from the very first minutes of. The blast furnace slag should be a freeflowing one at the operating temperatures to ensure efficient slagmetal separation. Blast furnace control using slag viscosities and liquidus. While there are many applications and benefits of slag cement, a few are highlighted below and detailed information sheets are located here. 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. This paper studies the blast furnace slag glass phase structure by a series of analysis methods.
Alkaliactivated slag aas binders are produced by alkaline activation of watercooled ground granulated blast furnace slag ggbfs, which is. 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. Groundgranulated blast furnace slag is highly cementitious and high in csh calcium silicate hydrates which is a strength enhancing. The microprobe was a cameca camebax operating voltage of 15 kv and probe current of 3.
Approximately 110 kg of slag is generated for each ton of converter steel. 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. With increase in silica activity in the range of 0. Ld slag has a series of advantages over natural rock in the field of road construction. 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. 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. The chemical composition of slag is usually expressed in terms of simple. However, this statement can be considered only partially correct. Characterization of basic oxygen furnace slag and granite waste.
Blastfurnace slag is the glassy granular material formed when molten blastfurnace slag is rapidly chilled, as by immersion in water virgalitte et al. Blast furnace slag is nonreactive in a high alkali environment, such as concrete and soils. 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. The heat of hydration is dependent on the portland. Ground granulated blast furnace ggbf slag used in concrete. Nonportland cement activation of blast furnace slag. Rinse eyes thoroughly with water for at least 15 minutes, including under lids, to remove all particles.