ORAL

SESSION: IronTueAM-R10	5th Intl. Symp. on Advanced Sustainable Iron and Steel Making
Tue Oct, 24 2017	Room: Maria Mercedes & Maria Beatriz
Session Chairs: Jose Carlos D Abreu; Paulo Von Kruger; Session Monitor: TBA

12:00: [IronTueAM03]
Cleaning Process of the Coarse Steel Maker Sludge with Recovery of the Metallic Content and Consequent Carbon Sequestration
Erivelto Souza¹ ; Fernando Gabriel Silva Araujo² ; Cristovam Paes Oliveira³ ; Jose Emanuel Lopes Gomes³ ; ¹Universidade Federal de Sao Joao Del-Rei, Ouro Branco, Brazil; ²UNIVERSIDADE FEDERAL DE OURO PRETO, Ouro Preto, Brazil; ³Fundacao Gorceix, Ouro Preto, Brazil;
Paper Id: 200 [Abstract]

This work describes a process of steel waste treatment— primarily steelmaking— of thick sludge, through a technique of ultrasonic bombing aiming to recover the metal content of this waste. During the manufacturing process of steel in LD converters, the liquid iron designed in oxidizing atmosphere converter, solidifies in the form of small spheres with a wide range of sizes. However, not all the spheres are perfect, because some will ultimately not be able to complete spheres formation due to variations in size, cooling speed, and surface tensions. The smaller the size of the spherical particles, the greater the degree of oxidation, which forms a dust that generates a "cement" ligand upon contact with water, and aggregates the other spheres with non-metallic particles involved in the production of steel (slag; Coke; Cao; etc.). This "dust" fills even some of the cavities’ hollow spheres. After washing of gases, the "sludge" formed will contain steel bead, which will then be bonded with each other and with impurities through the aggregate action of fine particles, here called "dust". The technique in question consists of the application of ultrasonic waves on a pulp, formed by the addition of water to the thick sludge. This ultrasonic bombing promotes dispersion of micro-particles of sludge binders and, consequently, of larger particles, causing individualization and cleaning of the interior of the hollow particles. After the break, the particles that make up the pulp will be completely released. The pulp is then forwarded to a gravity concentration step for recovery of spherical particles of high metal content (90 to 96% Fe). Each ton of recovered metallic material is used as scrap in steel fabrication while avoiding the consumption of 1.4 t of ore, 1.5 t of CO2 generated, and 440 kg of Coke consumption, to the same productivity of steel.

SESSION: AdvancedMaterialsTueAM-R6	Marquis International Symposium on New and Advanced Materials and Technologies for Energy, Environment and Sustainable Development(3rd Intl Symp. on New and Advanced Materials and Technologies for Energy, Environment and Sustainable Development)
Tue Oct, 24 2017	Room: Condesa IA
Session Chairs: Yail Jimmy Kim; Sandra E. Rodil; Session Monitor: TBA

16:00: [AdvancedMaterialsTueAM08]
Process of Chemical Stabilization and Mechanical Improvement of Slag through CO2 Capture
Erivelto Souza¹ ; Orimar Reis² ; Higor Coelho¹ ; Leandro Duarte¹ ; Tales Oliveira¹ ; Denise Pereira³ ; Walinton Sousa¹ ; Reimar Lourenco¹ ; ¹Universidade Federal de Sao Joao Del-Rei, Ouro Branco, Brazil; ²Instituto Federal de Minas Gerais, Ouro Preto, Brazil; ³UNIPAC - Conselheiro Lafaiete, Conselheiro Lafaiete, Brazil;
Paper Id: 115 [Abstract]

Metallurgy is one of the most important sciences developed by mankind, the steel industry is, in turn, the most important technique practiced within metallurgy. In order to produce the steel, for a long time, the objective products were generated, but also the process residues, which were discarded succinctly. With the evolution of the recycling processes, several of these residual materials became commercial use, as is the case of blast furnace slag. However, slags from steel mill processes, because of their high free CaO content, still had direct use restrictions. What is proposed here is a process that treats steel slag through a recomposition of this free CaO, leading it to become a calcium carbonate. Blast furnace slag is used for various processes where its chemical stability and mechanical strength is critical. The steel slag presents chemical instability, because, due to its high degree of hydration, this slag undergoes expansion and becomes mechanically weak, by the transformation of free CaO into Ca(OH)2. By means of this change the slag happens to present a better mechanical property, and no longer becomes susceptible to expansion by hydration. Associated with this advantage is the fact that each ton of processed slag allows to recover, on average, 136 kg of CO2 of the gases generated by the company itself. Thus, in addition to improving the properties of this specific steel residue, the process also allows a carbon capture of the generated gases.