scholarly journals Characterization of a Chromium-Bearing Carbon Steel Electric Arc Furnace Slag after Magnetic Separation to Determine the Potential for Iron and Chromium Recovery

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 47
Author(s):  
Kathy Bru ◽  
Alain Seron ◽  
Agnieszka Morillon ◽  
David Algermissen ◽  
Catherine Lerouge ◽  
...  
Keyword(s):  
Carbon Steel ◽  
Magnetic Separation ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Small Scale ◽  
Arc Furnace ◽  
X Ray Diffraction ◽  
Eaf Slag ◽  
Pre Treatment ◽  
Electric Arc Furnace Slag

This study investigates the potential to recover iron and chromium from a chromium-bearing carbon steel Electric Arc Furnace (EAF) slag. This slag contains indeed about 30 wt.% Fe and 2.5 wt.% Cr. However, the minerals are intergrown at small scale (<100 µm) and iron and chromium are mostly contained in spinel phases which makes the separation challenging. Several methods including Mössbauer spectroscopy, X-ray Diffraction, Scanning Electron Microscopy (SEM) and electron microprobe analysis were used in order to fully characterize the products obtained after a low-intensity magnetic separation of this carbon steel EAF slag, with the objective to define a pre-treatment process allowing the recovery of iron-rich particles and of a chromium-upgraded fraction. The results show that even if the magnetic separation seems to be not efficient in a first approach for producing an iron-rich/chromium-poor fraction, this fraction can be obtained by adding an attrition step which means that some separation mechanisms still occurred during the magnetic separation. However, it was not possible to produce a chromium-rich fraction. The main bottleneck for reaching a good separation is most probably the very fine liberation size of the iron and chromium bearing minerals.

scholarly journals The Influence of Slag Tapping Method on the Efficiency of Stabilization Treatment of Electric Arc Furnace Carbon Steel Slag (EAF-C)

Minerals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 706 ◽  
Author(s):  
Davide Mombelli ◽  
Andrea Gruttadauria ◽  
Silvia Barella ◽  
Carlo Mapelli
Keyword(s):  
Chemical Composition ◽  
Carbon Steel ◽  
Steel Slag ◽  
Toxic Metal ◽  
Electric Arc Furnace ◽  
Sem Analysis ◽  
Electric Arc ◽  
Arc Furnace ◽  
Stabilization Treatment ◽  
Electric Arc Furnace Slag

Studies conducted over the past 10 years have demonstrated the technical suitability of the electric arc furnace slag as an alternative to natural stone in several applications. Steel slag can be profitably used as a road surface layer, for foundations and embankments, or for concrete aggregates. However, a strong limitation to their use is due to the presence of toxic metals (Ba, Cr, V, Mo, etc.) that can be released into the environment in particular conditions, especially for unbound products in which the slag can come into contact with water. Recent studies have investigated the role of chemical composition and microstructure of slag on toxic metal leaching, allowing for the design of suitable stabilization treatments for hindering such leaching. In this work, four batches of electric arc furnace carbon steel slag underwent a stabilization treatment and the obtained results were compared. In two batches, the stabilizer was added directly in the slag pot and the slag was cooled down in the same pot. The other two batches were stabilized during the downfall from slag door to slag pit. Several slag samples were collected before and after the stabilization treatment and were characterized by means of ED-XRF, XRD, and SEM analysis. Leaching tests were carried out in agreement with EN 12457-2 standard on 4 mm granulated slag, and the leachate concentration was compared with the current Italian limits listed in D.M. 3 August 2005 N. 201 and D.M. 5 April 2006 N. 186. The results clearly indicated that the cooling in the slag pot improved the efficiency of the stabilization treatment, leading to a complete transformation of the microstructure by a full development of homogeneous gehlenite matrix and a coarsening of Cr-spinels, assuring better toxic metal retention behavior. On the contrary, stabilization in the slag-pit was rapid and reduced the interaction between slag and stabilizer, leading only to partial transformation of larnite into gehlenite, and also reducing the coarsening of Cr-spinel. In addition, a layering effect was observed, resulting in an inhomogeneous product from top to bottom in terms of chemical composition, microstructure, and leaching behavior.

scholarly journals Grain Size Effect in Elution Test of Electric Arc Furnace Slag

2020 ◽  
Vol 10 (2) ◽  
pp. 477 ◽  
Author(s):  
Alessandro Riboldi ◽  
Giovanna Cornacchia ◽  
Marcello Gelfi ◽  
Laura Borgese ◽  
Annalisa Zacco ◽  
...  
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Leaching Tests ◽  
Arc Furnace ◽  
X Ray Diffraction ◽  
X Ray ◽  
Lombardy Region ◽  
Electric Arc Furnace Slag ◽  
Test Requirements ◽  
Furnace Slag

In this paper we discuss the effects of deslagging practices and the size of electric arc furnace (EAF) slags on structural, microstructural, composition and leaching tests. The samples were collected from seven steelmakers located in Brescia (Lombardy Region, Italy). Nine granularity fractions of four samples were tested to evaluate the influence of the granularity on the leaching tests. The results showed that, in general, the release of the elements arises when the size of the particle decreases, except in one sample, in which vanadium and zinc displayed the opposite trend. X-ray diffraction results suggest that behavior may be ascribed to the effect of the grinding, which causes a different percentage of the phases in the various fractions. In conclusion, the possible effects of the size should also be carefully considered when defining new leaching test requirements for EAF slags.

scholarly journals Innovative Reuse of Electric Arc Furnace Slag as Filler for Different Polymer Matrixes

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 832
Author(s):  
Anna Gobetti ◽  
Giovanna Cornacchia ◽  
Giorgio Ramorino
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Environmental Benefits ◽  
Butadiene Rubber ◽  
Arc Furnace ◽  
Sem Images ◽  
Neat Polymer ◽  
Hardness Tests ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag

The European steel industry produces about 70 million tons/year of steel by the electric arc furnace (EAF). The slag consists of about 15% by weight of the produced steel, thus from the perspective of the circular economy, it has a high potential as a co-product. This research aims to assess an innovative reuse of EAF slag as filler in different polymer matrixes: thermoplastic (polypropylene), thermosetting (epoxy resin), elastomeric (nitrile butadiene rubber), and recycled end of life rubber tire. A comparison between neat polymer and polymer filled with a certain amount of EAF slag has been carried out by tensile (or flexural), compression, and hardness tests. Experimental results show that slag as a filler increases the composites’ hardness and elastic modulus at the expense of toughness. For a safe reuse of the slag, the leaching of hazardous elements must comply with current legislation. It was found that, although the used EAF slag releases small amounts of Cr, Mo, and V, incorporating it into a polymer matrix reduces the leaching. The EAF slag particles distribution has been observed by scanning electron microscopy (SEM) images. The obtained results show good technical feasibility of this innovative slag application so that it could pave the way to a new industrial symbiosis between dissimilar sectors, bringing economic and environmental benefits.

Use of Electric Arc Furnace Slag for High Strength Concrete Production

2016 ◽  
Vol 847 ◽  
pp. 537-543
Author(s):  
Flora Faleschini ◽  
Mariano Angelo Zanini ◽  
Katya Brunelli ◽  
Carlo Pellegrino
Keyword(s):  
Microstructural Analysis ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Environmental Benefits ◽  
Recycled Aggregates ◽  
Arc Furnace ◽  
Concrete Production ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag ◽  
Furnace Slag

In this paper the use of Electric Arc Furnace slag (EAF slag) for the production of High-Performances Concrete (HPC) is explored, as a fully replacement of the natural gravel. Several mixtures were produced, varying the water/cement ratio, the cement and the admixture content, with the aim of reaching a strength class between C50/60 and C60/75, and an S4 consistency class, as defined in EN 206-1. Mechanical properties of EAF concretes were compared with reference conglomerates; a complementary microstructural analysis was performed, with SEM observation after concrete specimens' failure. Results indicate that the use of EAF slag in concrete allows reaching higher compressive strength than with coarse natural aggregates. Lastly, the environmental benefits obtained through the use of recycled aggregates are shown, by means of the application of a Life Cycle Assessment (LCA) tool properly developed for this scope.

The EAF Slag as Construction Material

2007 ◽  
Vol 537-538 ◽  
pp. 671-678
Author(s):  
Róbert Márkus ◽  
Oszkár Grega
Keyword(s):  
Ground Water ◽  
Building Material ◽  
Construction Material ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Metallurgical Slag ◽  
Arc Furnace ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag ◽  
Furnace Slag

The metallurgical slag is a normal building material in Europe but not in Hungary. I prove by my own researches that the electric arc furnace slag isn’t harmful to the nature especially the ground water and their physical aspects are similar to the natural rocks. It means that we can use slag to replace them to save our environment and to clear away the old slag dumps.

scholarly journals Reduction Of Environmental Pressure By Giving Cementing Material Properties To The Ferrous Slags

2017 ◽  
Vol 2 (2) ◽  
pp. 65
Author(s):  
Mikheenkov M. A. ◽  
Sheshukov O. Yu. ◽  
Lobanov D. A.
Keyword(s):  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Crude Steel ◽  
Furnace Process ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag ◽  
Cementing Material ◽  
Metallurgy Process ◽  
Furnace Slag

There are two main kinds of slag in modern steelmaking industry: the electric arc furnace slag (the EAF slag) which is produced in the manufacture of crude steel by the electric arc furnace process and the ladle furnace basic slag (the LF slag) which is produced at the final stages of steelmaking, when the steel is desulfurized in the transport ladle, during what is generally known as the secondary metallurgy process.

Hydrothermal synthesis of mixtures of NaA zeolite and sodalite from Ti-bearing electric arc furnace slag

RSC Advances ◽  
2016 ◽  
Vol 6 (10) ◽  
pp. 8358-8366 ◽  
Author(s):  
Yang Li ◽  
Tiehong Peng ◽  
Wenkuan Man ◽  
Liangchen Ju ◽  
Feng Zheng ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Electric Arc Furnace ◽  
Electric Arc ◽  
Arc Furnace ◽  
Naa Zeolite ◽  
Removal Capacity ◽  
Eaf Slag ◽  
Electric Arc Furnace Slag ◽  
Furnace Slag

NaA and sodalite zeolites were synthesized from Ti-bearing EAF slag and the removal capacity of prepared zeolite for Cu2+ can reach 1.346 mmol g−1 for 180 min.

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