• Title/Summary/Keyword: EAF reduction slag

Search Result 13, Processing Time 0.022 seconds

Experimental Study on the Application of Concrete Admixture using the EAF Reduction Slag (전기로 환원 슬래그 미분말의 콘크리트용 혼화재 적용성에 관한 실험적 연구)

  • Choi, Jae-Seok;Jang, Pil-Sung;Jo, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.15 no.11
    • /
    • pp.6890-6897
    • /
    • 2014
  • EAF reduction slag has unstable properties of expansion and destruction. Therefore, it cannot be used as a construction material. The purpose of this study was to use EAF reduction slag as a concrete admixture. EAF reduction slag contains $11CaO{\cdot}7Al_2O_3{\cdot}CaF_2$ and ${\beta}-C_2S$ (calcium aluminate compounds). To confirm the properties of EAF reduction slag as a concrete admixture, the condensation, compressive strength and activity factor due to substitution rate of EAF reduction slag were measured. Originally, EAF reduction slag was cured rapidly because of its chemical composition ($11CaO{\cdot}7Al_2O_3{\cdot}CaF_2$). On the other hand, when 8% gypsum was added, its properties of condensation and compressive strength were similar to the plain specimen. When 6% gypsum was added, the quality of the KS F 2536 standards (quality standard number 3) were met in terms of activity factor. Overall, 8% gypsum addition is the most appropriate by considering the activity factor in the long-term compressive strength.

An Experimental Study on the Development of Soft Ground Firming Agent Using EAF Reduction Slag (전기로 환원 슬래그를 이용한 연약지반 고화재 개발에 관한 실험적 연구)

  • Lee, Kang-Seok;Lee, Yoon-Kyu;Choi, Jae-Seok;Han, Man-Hae
    • Proceedings of the Korean Geotechical Society Conference
    • /
    • 2010.09a
    • /
    • pp.998-1001
    • /
    • 2010
  • Most firming agent used in Korea is cement-firming agent. Cement-firming agent absorb water for combination, and then it makes ettringite. Through this chemical process, soft ground is firmed by cement-firming agent. Although most cement-firming agent used in Korea made from CSA, it relies on imports. Therefore, the development of soft ground firming agent using new materials is required. In this study, we suggested that EAF reduction slag not used for anything in the steel industry is available for material of soft ground firming agent. If EAF reduction slag is used in soft ground firming agent, it will be possible to solve the problem with treatment of slag and improvement of soft ground.

  • PDF

A Study on the Reduction of Iron Oxide from Slag in the EAF Process (전기로 공정에서 슬래그 중 산화철의 환원 회수에 관한 연구)

  • Kim, Young-Hwan;Yoo, Jung-Min
    • Resources Recycling
    • /
    • v.25 no.4
    • /
    • pp.54-59
    • /
    • 2016
  • EAF processed slag which contains about 20 ~ 35 weight percent FetO is poured to slag pot and cooled. If we recover Fe from molten slag by the reduction, we will improve steel yield rate and reduce slag quantity poured from the furnace. Usually, carbon is used as a reductant and slag foaming agent in the EAF process. In this experiment, after melt the metal in induction furnace and then add slag with carbon and Al dross powder as a reductant, we investigated the reduction of FetO from slag and change of Phophorus content. As the result, when we use Al dross as a reductant, recovery rate is two times more than carbon. Phosphorus pick up is less than 50ppm with reduction of EAF slag.

Effect of Carbon Materials on the Slag Foaming in EAF Process (전기로 슬래그 포밍에 미치는 가탄재 종류의 영향)

  • Kim, Young-Hwan;Yoo, Jung-Min;Um, Hyung-Sic
    • Resources Recycling
    • /
    • v.28 no.2
    • /
    • pp.40-45
    • /
    • 2019
  • During steelmaking in EAF, recycled scraps is used as a main material, melted by arc, and electricity use as a main energy. Slag foaming is an important technology for reducing electrical energy. CO gas generated by the reaction between injection carbon and (FeO), [C] and injection {$O_2$}. CO gas generated by this reaction is collected in slag, resulted in slag foaming. In general, the carbon materials used in the EAF process is anthracite and coke. This study investigated the effects of the carbon materials used on slag foaming in the steelmaking process. As a result of this study, the slag foaming height is increased by cokes rather than anthracite, and with an increase in the amount of particles samller than $500{\mu}m$. Based on these results, the application to the operation resulted in increase of slag forming height, reduction of injection carbon, and reduction of electrical energy.

Study on the Reduction of Molten EAF Slag (용융 전기로 슬래그의 환원반응에 관한 연구)

  • Joo, Seong-Woong;Shin, Jong-Dae;Shin, Dong-Kyung;Hong, Seong-Hun;Ki, Jun-Sung;Hwang, Jin-Il;You, Byung-Don
    • Korean Journal of Metals and Materials
    • /
    • v.50 no.10
    • /
    • pp.753-761
    • /
    • 2012
  • The reduction behavior of low level oxides such as (T.Fe), (MnO) and ($P_2O_5$) in molten EAF slag was investigated using commercial reductants. In an air atmosphere, the slag volume increased and the reduction rate of the slag was very low due to the oxidation loss of reductants by oxygen in the air. The reduction rate of the slag was also low when a commercial reductant was used alone in an Ar gas atmosphere. The reason is probably because the material transfer through the interface between the slag and reductant is difficult due to the formation of high melting point oxide. When reductants were mixed with burnt lime in order to form low melting point reaction products, the reduction rate of the slag increased up to the range of 45-70%. By using the mixtures of reductants and burnt lime so as to form a low melting point slag at the reaction end, the reduction rate of the slag was improved up to 60-85%.

The Direct Recycling of Electric Arc Furnace Stainless Steelmaking Dust

  • Zhang, Chuanfu;Peng, Bing;Peng, Ji;Lobel, Jonathan;Kozinski, Janusz A.
    • Proceedings of the IEEK Conference
    • /
    • 2001.10a
    • /
    • pp.404-408
    • /
    • 2001
  • This paper focuses on the pilot-scale investigation of direct recycling of electric arc furnace (EAF) stainless steelmaking dust. The direct recycling of EAF dust is to make pellets with the mixture of the dust and the reducing agent carbon, then introduce the pellets to the EAF. The valuable metals in the dust are reduced and get into the steel as the alloying elements. Experiments simulating direct recycling in an EAF were performed using an induction furnace. But it seems difficult to reduce all metal oxides in the dust so that some metal reducing agents added in the late stage of reduction process. The valuable metals in the dust were reduced partly by carbon and partly by metal reducing agent for the economical concern. The recovery of iron, chromium and nickel from the flue dust and the amount of metal oxides in the slag were measured. The results showed that the direct recycling of EAF stainless steelmaking dust is practicable. It wes also found that direct recycling of flue EAF stainless steelmaking dusts does not affect the chemistry and quality of stainless steel produced in the EAF. It is benefit not only for the environmental protection but also for the recovery of valuable metal resources in this way.

  • PDF

Status of Pyrometallurgical Treatment Technology of EAF Dust (제강분진의 건식 처리기술 현황)

  • Sohn, Ho-Sang
    • Resources Recycling
    • /
    • v.27 no.2
    • /
    • pp.68-76
    • /
    • 2018
  • EAF (Electric arc furnace) dust is an important secondary resource such as zinc, lead, and iron. Recycling of EAF dust is benefit to solving disposal and environmental problems caused by the heavy metals entrained in the dust. In this study, pyrometallurgical treatment technology of EAF dust reviewed for the improvement of conventional process and development of new process. The existing technologies categorized into four groups: those by rotary kiln process, rotary hearth furnace (RHF) process, shaft type process, and reduction smelting process. The product of these processes are ZnO and Fe or slag as a waste. Their mechanisms for the production of ZnO from EAF dust were carbothermic reduction and oxidation of zinc gas with air.

A Study on the Reduction of Electric Arc Furnace Dust with Carbon (탄소에 의한 전기로 분진의 환원반응에 관한 연구)

  • 진영주;김영진;박병구;이광학;김영홍;이재운
    • Resources Recycling
    • /
    • v.7 no.3
    • /
    • pp.27-35
    • /
    • 1998
  • EAF dust generated from electric arc steelmaking process is classified as "hazardous" materials by tbe environmental regulation because of the existence of water leachable heavy metals such as Fe, Zn, Pb, and Cd. However, Fe and Zn among t the elements in the dust can be recovered to high valuable materials by applying a proper process. Therefore, in order to study t the possibility of recovery of iron from EAF dust, the effect oE carbon content and basicity, of synthesized EAF dust on the reduction rate of iron oxide was studied. Experimental results are as follows: TIle softening and melting temperature of the slag w was illcreased with increasing carbon addition amount [or carbon reduction eqUIvalent. At the carbon addition amount of 100% for carbon reduction equivalent and basicity of 1.7, reduction rate of $Fe_2O$ in the slag was the highest. The reaction order fur reduction of $Fe_2O$ by carbon was nearly first order.

  • PDF

Hydration Property of Electric Arc Furnace Reduction Slag (전기로(電氣爐) 환원(還元) 슬래그의 수화반응(水和反應) 특성(特性) 연구(硏究))

  • An, Yong-Jun;Han, In-Kyu;Choi, Jae-Seok;Bae, Kwang-Hyun;Kim, Hyung-Seok
    • Resources Recycling
    • /
    • v.19 no.6
    • /
    • pp.93-101
    • /
    • 2010
  • In this study, we have studied hydration properties and compressive strength of the electric arc furnace reduction slag as a cement admixture. The reduction slag is mainly consisted of 17.1% of f-CaO and rapid curing clinker minerals, 37.1% of $C_{11}A_7CaF_2$, and 21.0% of $C_3A$. When the substitution rate of the slag on OPC was 30%, the initial setting time and final setting time has been shortened from 305 min. and 425 min. to 10min. and 30min. When the substitution rate of the slag on OPC was 7%, the compressive strength of mixed cement mortars has been increased than that of OPC during all period. When the substitution rate of the slag on OPC was over 20%, the compressive strength of mortars has been reduced than that of OPC at initial and final compressive strength. As a result of hydration properties of reduction slag, $C_{11}A_7CaF_2$ transfer to $C_3AH_6$ but as the substitution rate of slag on OPC increases, increased f-CaO and the metastable hydrates $C_4AH_{13}$ increased. Therefore, we should control the substitution rate of the slag on OPC was under 7% in order to use EAF reduction slag as a cement admixture.

Reduction Rate of Electric Arc Furnace Dust with Solid Carbon (전기로 더스트의 고체탄소에 의한 환원반응속도)

  • 박병구;이광학;김영홍;신형기
    • Resources Recycling
    • /
    • v.7 no.1
    • /
    • pp.34-40
    • /
    • 1998
  • This shdy was invcsligated on reduction rate of EAF dust wth solid carbon cantents. The rate equation for reduction ofEAF dust was obtaincd in the tempcrahlrc range cot 910-108O"C, and the ratio of zinc removal and metallization raho of ironoxides to thc reaction time was also analysed. From the XRD analysis for slag residues '||'&'||'er reaction, the cxistcncc DI themixture of Akemmite[Ca2MgSi2O.] and SiO, was identified.ed.

  • PDF