Análise da injeção simultânea de gás natural e diferentes misturas de carvões pulverizados (PCI) utilizando o modelo total do alto-forno

• Autor(a) principal: Matos, Ulysses Forastieri de
• Data de Publicação: 2006
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da Universidade Federal Fluminense (RIUFF)
• Texto Completo: https://app.uff.br/riuff/handle/1/21020
• topic: Alto-forno; Metalurgia extrativa; Carvão; Gás natural; CNPQ::ENGENHARIAS::ENGENHARIA DE MATERIAIS E METALURGICA

Much effort have been made in order to minimize coke consumption in the blast furnace process. Pulverized coal injection is currently used aiming at achieving coke consumption decrease, high productivity smooth blast furnace operation. Further improvement on the pulverized coal injections technique is the replacement of the pulverized coals used in the actual operation by blending with coals of different chemical composition, expanding the range of raw materials suitable for using in the PCI operation. However, the use of new raw materials for PCI injection requires detailed investigation regarding the performance of the blast furnace. Computer simulation of the blast furnace process has proved highly efficient for predicting the inner condictions of the reactor under severe injection conditions. Aiming at improving the blast furnace modelling, this work purposes the simulation of the combined injection of blended pulverized coal and natural gas. Some mixtures with different composition, sulphur, phosphorus and manganese were analyzed. The model is based on six-phases, where the movement, heat and chemical species are described by transport equations. The set of differential equations are discretized and solved applying the finite volume method in a non-orthogonal coordinate system. The mechanism of phosphorus, sulfur and manganese reactions were considered in the model in order to analyze the effect of the chemical composition of the coal on the quality of the hot metal and inner state of the blast furnace. The model predictions the major operational parameters on a show consistency with the actual blast furnace practice. The chemical reaction rates were adapted from literature and had constants adjusted to represent the industrial process. The manganese, phosphorus and sulfur composition of the hot metal revealed to play important role when new operation techniques based on coal blending is aimed at. Simulation results pointed out that a maximum of 75% of pulverized coal with relatively high sulfur content(0.9% S) combined with 25% of low sulfur coal(0.27% S) and injection rates of 130 kg PCI/thm was possible with smooth operation and hot metal quality suitable to use in integrated steelworks (0.035% S). The productivity of the blast furnace process was also enhanced when the combined injection of blending coals and natural gas of around was used. The natural gas played important role in the inner condictions of the furnace reduction and diluted the deleterious effect of high sulfur pulverized coal