Distribution of Zn, Pb, K, and Cl in Blast Furnace Lining

Abstract

The furnace campaign of a blast furnace represents an important factor for the iron-making industry due to the fact that maintenance such as relining is not only costly but also time consuming. The furnace campaign is largely determined by the functionality of the lining, which is influenced by wear mechanisms and the damaging behavior of certain elements.To these unwanted elements that may attack the lining belong, for example, Zinc (Zn), Lead (Pb), Potassium (K), and Chlorine (Cl). In this paper, the distribution of Zn, Pb, K, and Cl within the lining of a blast furnace at the end of its furnace campaign is investigated and discussed. The results demonstrate that the content of some elements (Zn, Cl, Pb) in the lining and also their penetration depth significantly varies over the blast furnace height. For Zn and Pb, the highest contents (43 g Zn kg À1 and 0.14 g Pb kg À1 ) are observed in the inner lining stones (adjacent to the hot metal), whereas for Cl, a contrary distribution pattern is observed. The highest contents are detected in the outer stones of the lining at the top of the blast furnace.

Effect of Lead and Zinc Impurities in Ironmaking and the Corresponding Removal Methods: A Review

“…The allowable amount of Pb and Zn in the raw materials should be less than 0.15 kg/t. The effect of these impurities on the furnace is evident, especially in refractory areas [18]. Traditional refractory materials for BF hearth lining comprise carbon bricks and ceramic cup.…”

“…Further research should focus on the relevance of the process conditions (e.g., different counter pressure at the blast furnace top) and input composition with respect to the damage mechanism of the elements present in the BF lining. Such information can lead to the generation of the limits for these elements in the BF, as well as to the development of an improved internal recycling strategy (e.g., additional knowledge about the maximum chargeable Zn content, which can improve the amount of top gas dust internally recycled at the sinter plant) [18].…”

Occurrence State and Behavior of Carbon Brick Brittle in a Large Dissected Blast Furnace Hearth

“…Fan et al [ 14 ] proved that the local expansion of volume caused by the introduction of harmful elements leads to the erosion of the refractory, whereas the enhanced erosion from the throat to the bottom of the furnace can be explained by the increasing temperature. Trinkel et al [ 15 ] investigated the distribution of Zn, Pb, K, and Cl within the lining of the blast furnace and proved that these unwanted elements may attack the lining. Jiao et al [ 16 ] investigated that the maximum concentration of zinc near the tuyere is about 80 times that in the charge, whereas potassium and sodium in the belly can be enriched by about 50 times.…”

Thermodynamic Simulation and Transformation Behaviours of Lead during Iron Ore Sintering

“…3) During the iron-making process, lead compounds are reduced easily into metallic Pb. 4,5) On the one hand, Pb penetrates into gaps and fine pores of the refractory lining in the bottom part of the blast furnace, which leads to internal stress and cracks of the lining. 6) On the other hand, Pb vapor condenses on the upper area of the blast furnace, leading to accretions formation.…”