Elaboration and realization of new approaches to diagnostic and control of blast furnace heat

Abstract

Under conditions of unstable supply of quality charge materials and technological fuel, the elaboration of new effective means of blast furnace heat control becomes actual for reaching acceptable technical and economic indices of its operation. Results of the studies carried out at the BF No. 3 of Enakievo steel-works (EMZ, Ukraine) during the period from October 2011 until December 2016 presented. During the period, various fuel additives to the blast were used within a wide range of their variation, and composition of charge materials was characterized by numerous components and variable quality. In the charge content, various additives were used: iron ore, limestone, BOF slag, briquettes of pellets siftings, manganese-containing additives. The new approach to the selection of rational charging programs was justified, providing stable economic BF running under variation of heat technological conditions. For the first time the temperature indices of estimation of gas stream distribution along the furnace radius were elaborated, the rational ranges of their variation at the operation under various gas-dynamic and fuel conditions determined, requirements to the gas stream temperature distribution along the furnace radius formulated. Based on analysis of information about lining temperature along the furnace height over the five year of EMZ BF No. 3 running, its values were ascertained, showing the partial or complete lining wear in the middle and upper part of the shaft. For the lining of the furnace bottom and other parts the temperature was ascertained, showing the formation in the lower zone unstable protective scull, as well the temperature characterizing its complete absence. The influence of blast mode during addition into it an increased volume of steam, natural gas and pulverized coal on variation of distribution of peripheral gas stream temperature along the furnace height from the tuyere zone to the top studied. It became a reason for an elaboration a method of the identification of the viscous-plastic state zone border in the peripheral zone of the furnace. Regulations of the blowing-in of blast furnaces after a long time stoppage without tapping the emergency hot metal elaborated. The technology of usage manganese-containing materials in the BF charge adjusted, which demonstrated the most effective washing out of the hearth under conditions of low and unstable charge materials quality and pulverized coal injection.