On Properties and Wear Mechanism of Carbon Bricks for Blast Furnace

Abstract

Application of carbon blocks to blast furnace bottom initiated in 1951 at Yawata. Since then, troubles of bottom linings have decreased prominently and total iron production of a furnace has increased.
At Yawata, six carbon bottom furnaces have been blown out up to today and properties of used carbon blocks have been investigated. As the results, it is found that carbon blocks absorb considerably large amounts of foreign components, especially molten iron before wear proceeds, resulting in disintegration of brick texture, strength lowering, pore enlargement, crack formation and shrinkage. These property changes were considered to accelerate wearing rate of carbon blocks. From the investigation of used carbon blocks, the wear mechanism of carbon blocks is discussed in relation with carburization, oxidization, floatation and so on. To reduce the degree of property alteration, the authors have studied on improvement of carbon block quality and found anthracite superior to metallurgical coke in high temperature stability and alkali attack resistance. At Yawata, anthracite base carbon blocks are adopted and trouble-free operation is established since 1966.