Avaliação da utilização de agentes dessulfurantes a base de carbureto de cálcio contendo sodalita em substituição à fluorita em carro torpedo

• Ano de defesa: 2012
• Autor(a) principal: Marcos Antonio da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Engenharia Metalúrgica e de Minas; Engenharia metalúrgica
• Link de acesso: http://hdl.handle.net/1843/BUBD-962LUF

The sulfur is considered an undesirable element in steel. Its presence can reduce the ductility, toughness, formability, weldability and cause the corrosion resistance. Its presence is beneficial only to machinability. Many materials have been used in the process of desulfurization of pig iron in the pretreatment, especially lime (calcium oxide) and calcium carbide. One of the components used in desulfurizing agents is calcium fluoride (fluorite) which function is fluidizing the slag formed in the desulfurization. The fluorite is still used with some restrictions considering that its use may cause the refractory lining wear, furthermore the available fluorine at the slag can be an environmental problem. An alternative to the use of fluorite, in some cases it is the sodalite nepheline, alkali silicate that has aluminium oxide in its constitution. This paper focused on contribute to process information concerning the use of sodalite in desulfurizing agents based calcium carbide in torpedo car using fluorite as an option. The works of monitoring of these experiments were conducted from May to September 2011 in integrated steel mill. During this period, treatments were performed using a desulphurization plant that allows the injection control agent desulfurizing in liquid pig iron and survey of various parameters for comparison, including the K-factor, an indicator that relates the specific consumption of desulfurizing agent with amount of sulfur removal of the metal during the desulfurization.The results showed no difference in efficiency between the desulfurizing agent with fluorite and desulfurizing agent with sodalite. This means that, for agents based desulfurizing agents of calcium carbide for the treatment of pig iron in torpedo cars can be replaced by fluorite sodalite in the same proportion, with a small economic advantage (the sodalite costs an average of 60% less than the fluorite), greater the availability of fluorite over than sodalite and desulfurization slag generated is fluorine-free.