scholarly journals Investigation on the Chemical and Thermal Behavior of Recycling Agglomerates from EAF by-Products

2020 ◽  
Vol 10 (22) ◽  
pp. 8309
Author(s):  
Thomas Willms ◽  
Thomas Echterhof ◽  
Stefan Steinlechner ◽  
Matti Aula ◽  
Ahmed Abdelrahim ◽  
...  

In addition to the blast furnace converter route, electric steel production in the electric arc furnace (EAF) is one of the two main production routes for crude steel. In 2019, the global share of crude steel produced via the electric steel route was 28%, which in numbers is 517 million metric tons of crude steel. The production and processing of steel leads to the output of a variety of by-products, such as dusts, fines, sludges and scales. At the moment, 10–67% of these by-products are landfilled and not recycled. These by-products contain metal oxides and minerals including iron oxide, zinc oxide, magnesia or alumina. Apart from the wasted valuable materials, the restriction of landfill space and stricter environmental laws are additional motivations to avoid landfill. The aim of the Fines2EAF project, funded by the European Research Fund for Coal and Steel, is to develop a low-cost and flexible solution for the recycling of fines, dusts, slags and scales from electric steel production. During this project, an easy, on-site solution for the agglomeration of fine by-products from steel production has to be developed from lab scale to pilot production for industrial tests in steel plants. The solution is based on the stamp press as the central element of the agglomeration process. The stamp press provides the benefit of being easily adapted to different raw materials and different pressing parameters, such as pressing-force and -speed, or mold geometry. Further benefits are that the stamp press process requires less binding material than the pelletizing process, and that no drying process is required as is the case with the pelletizing process. Before advancing the agglomeration of by-products via stamp press to an industrial scale, different material recipes are produced in lab-scale experiments and the finished agglomerates are tested for their use as secondary raw materials in the EAF. Therefore, the tests focus on the chemical and thermal behavior of the agglomerates. Chemical behavior, volatilization and reduction behavior of the agglomerates were investigated by differential thermogravimetric analysis combined with mass spectroscopy (TGA-MS). In addition, two melts with different agglomerates are carried out in a technical-scale electric arc furnace to increase the sample size.

2014 ◽  
Vol 46 (1) ◽  
pp. 83-93 ◽  
Author(s):  
M. Ranitovic ◽  
Z. Kamberovic ◽  
M. Korac ◽  
M. Gavrilovski ◽  
H. Issa ◽  
...  

This paper presents investigation of possibility for electric arc furnace dust (EAFD) and electronic waste (e-waste) valorization trough stabilization process, in order to achieve concurrent management of these two serious ecological problems. EAFD is an ineviTab. waste material coming from the electric arc furnace steel production process, classified as a hazardous waste. Furthermore, it is well known that residual materials generated in the ewaste recycling process, like LCD (Liquid crystal displays) waste glass, are not suiTab. for landfill or incineration. In this study, these two materials were used for investigation of possibility for their valorization in ceramic industry. Thus, an innovative synergy of waste streams from metallurgical and e-waste recycling industry is presented. Investigation included a complex characterization of raw materials and their mixtures, using chemical methods, optical microscopy, scanning electron microscopy, as well as methods for determining the physical and mechanical properties. Based on these results, it was found that material suiTab. for use in ceramics industry as a partial substituent of quartzite and fluxing components can be produced. Besides solving the environmental problem related to EAFD and LCD disposal, by replacement of raw materials certain economic effects can be achieved.


2018 ◽  
Vol 178 ◽  
pp. 08008
Author(s):  
Mihnea Costoiu ◽  
Adrian Ioana ◽  
Augustin Semenescu ◽  
Dragos Marcu ◽  
Massimo Polifroni

The article presents the technological advances and modernizations carried out at national and / or world level in the field of increasing the electric steel quality. In this context, conventional complex steel processing methods are analyzed outside the electric arc furnace, in order to increase the electric steel quality. Special non-conventional procedures for the production of quality steels are also presented. The progress achieved in the field of steel production, mainly aimed at increasing productivity and quality, had as a basic premise the "secondary metallurgy" or the treatment of the metal outside the primary production aggregate (furnace or converter). This concept involves transforming the furnace or the converter into a specialized fast-melting aggregate, the rest of the processes specific to advanced steel refining being carried out in pots (which is why the "pot metallurgy" denomination is also used). We will also present in the article a revolutionary concept for the steel production in the electric arc furnace, a procedure which is the subject of a patent application belonging to the authors of this article, applying the pyramid effect for the steel production in the electric arc furnace.


2015 ◽  
Vol 22 (S1) ◽  
pp. 10-16 ◽  
Author(s):  
Qi-xing Yang ◽  
An-jun Xu ◽  
Peng Xue ◽  
Dong-feng He ◽  
Jian-li Li ◽  
...  

Author(s):  
Ebrahim Hajidavalloo ◽  
Hamzeh Dashti

In this paper, energy and exergy analysis of an existing steel electric arc furnace (EAF) was performed to estimate the furnace potential for increasing the efficiency and decreasing the electrical energy consumption. The results of analysis show that the energy and exergy efficiencies of the furnace are 56.9% and 40.5%, respectively. Field data show that mass flow rate of hot flue gas is around 10.4 kg/s in average which contains 18.3% and 12.2% of total input energy and exergy, respectively. By using energy of flue gas for preheating the sponge iron, electrical energy consumption of the furnace could be reduced up to 88 GJ which means 21.2% reduction in electrical energy consumption and 13.6% increase in steel production. Also, exergy efficiency improves about 10.8% by using preheating scheme.


Metals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1069
Author(s):  
Marcus Sommerfeld ◽  
Claudia Vonderstein ◽  
Christian Dertmann ◽  
Jakub Klimko ◽  
Dušan Oráč ◽  
...  

Due to the increasing demand for battery raw materials such as cobalt, nickel, manganese, and lithium, the extraction of these metals not only from primary, but also from secondary sources like spent lithium-ion batteries (LIBs) is becoming increasingly important. One possible approach for an optimized recovery of valuable metals from spent LIBs is a combined pyro- and hydrometallurgical process. According to the pyrometallurgical process route, in this paper, a suitable slag design for the generation of slag enriched by lithium and mixed cobalt, nickel, and copper alloy as intermediate products in a laboratory electric arc furnace was investigated. Smelting experiments were carried out using pyrolyzed pelletized black mass, copper(II) oxide, and different quartz additions as a flux to investigate the influence on lithium-slagging. With the proposed smelting operation, lithium could be enriched with a maximum yield of 82.4% in the slag, whereas the yield for cobalt, nickel, and copper in the metal alloy was 81.6%, 93.3%, and 90.7% respectively. The slag obtained from the melting process is investigated by chemical and mineralogical characterization techniques. Hydrometallurgical treatment to recover lithium is carried out with the slag and presented in part 2.


Metals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 826 ◽  
Author(s):  
Marcus Kirschen ◽  
In-Ho Jung ◽  
Gernot Hackl

The electric arc furnace (EAF) process for steelmaking of Cr and Ni high alloyed stainless steel grades differs significantly from the steelmaking process of carbon steel due to the special raw materials and generally lower oxygen consumption. The special slag chemistry in the EAF process affects slag foaming and refractory wear characteristics due to an increased content of CrOx. A special slag diagram is presented in order to improve monitoring and control of slag compositions for Cr alloyed heats, with special focus on saturation to MgO periclase and dicalcium silicate C2S in order to minimize MgO losses from the refractory lining and to improve slag refining capability by avoidance of stable C2S. With the same diagram different EAF process strategies can be efficiently monitored, either at elevated CaO and basicity with lower spinel concentration and more liquid process slags near C2S saturation or at lower CaO content and basicity with increased spinel concentration and stiffer slags at MgO saturation but certainly no C2S stability. Examples for three industrial EAFs are given.


2015 ◽  
Vol 36 (2) ◽  
pp. 263-271 ◽  
Author(s):  
Aneta Magdziarz ◽  
Monika Kuźnia ◽  
Michał Bembenek ◽  
Paweł Gara ◽  
Marek Hryniewicz

Abstract Dust generated at an electric arc furnace during steel production industry is still not a solved problem. Electric arc furnace dust (EAF) is a hazardous solid waste. Sintering of well-prepared briquetted mixtures in a shaft furnace is one of possible methods of EAFD utilisation. Simultaneously some metal oxides from exhaust gases can be separated. In this way, various metals are obtained, particularly zinc is recovered. As a result, zinc-free briquettes are received with high iron content which can be used in the steelmaking process. The purpose of the research was selecting the appropriate chemical composition of briquettes of the required strength and coke content necessary for the reduction of zinc oxide in a shaft furnace. Based on the results of the research the composition of the briquettes was selected. The best binder hydrated lime and sugar molasses and the range of proper moisture of mixture to receive briquettes of high mechanical strength were also chosen and tested. Additionally, in order to determine the thermal stability for the selected mixtures for briquetting thermal analysis was performed. A technological line of briquetting was developed to apply in a steelworks.


2011 ◽  
Vol 378-379 ◽  
pp. 719-722 ◽  
Author(s):  
Zorica Bacinschi ◽  
Cristiana Zizi Rizescu ◽  
Elena Valentina Stoian ◽  
Dan Nicolae Ungureanu ◽  
Aurora Anca Poinescu ◽  
...  

The processing and recycling experiments of dust from Electric Arc Furnace (EAF) in industrial conditions aimed at highlighting the minimizing possibility of this waste by transforming it into a by-product that can represent either a secondary raw material for steel making in EAF or to recover iron, zinc and lead (the Waltz process). Electric-arc furnace dust (EAFD) is a by-product of steel production and recycling. This fine-grained material contains high amounts of zinc and iron as well as significant amounts of potentially toxic elements such as lead, cadmium and chromium. Therefore, the treatment and stabilization of this industrial residue is necessary. Leaching test is a method of evaluating the impact of waste that is stored (soil, water table).


2014 ◽  
Vol 1024 ◽  
pp. 235-238 ◽  
Author(s):  
Mohamad Hasmaliza ◽  
Anasyida Abu Seman ◽  
Wei Long Gan

Electric arc furnace slag (EAFS) is a solid waste from steel making industrial. Previously, EAFS was deposited, recycled or used as fertilizer. In present study, EAFS is used as one of the raw materials in ceramic tile production. EAFS added tiles samples have been prepared by mixing of EAFS with ball clay, quartz and feldspar. The feldspar content was varied at various weight percentages (0, 10 and 20 %) to observe their effect on the produced samples. The raw materials mixture was pressed and then sintered at temperature range 1100°C-1175°C for 1 hour. In general, results shows that, sample with higher content of feldspar require shorter vitrification range and having relatively higher density and good strength properties. In addition, MOR value was increasing as the sintering temperature was increasing. However when the temperature reached 1175°C, the MOR was dropped which may be due to the early vitrification of the compositions, resulting in over firing, grain growth and recrystallization. Whereas the density values are relatively higher than the conventional vitreous ceramic tiles due to the presence of high amount of iron oxide from the EAFS.


Sign in / Sign up

Export Citation Format

Share Document