SELECTING AND TESTING LINING MATERIALS TO ACHIEVE LONG AND PRODUCTIVE BLAST FURNACE HEARTH CAMPAIGNS
When designing,engineering and constructing the hearth wall of a blast furnace,traditional thinking predicts that the hearth wall will erode to the locations of the 1150?C isotherm.This philosophy is based on the fact that at elevated carbon content (>2%),iron solidifies at 1150?C.In strict thermo-chemical theory,it is impossible for a carbon hearth wall refractory to wear beyond that point.Operators even use this theory in their online thermal models to estimate current wear by extrapolating the location of the 1150?C isotherm from actual temperature measurements.As we will show examples of in this paper,the theory fails to explain why in reality,most large-block hearth walls experience much more severe wear over their lifetimes.It is often reported that block hearth walls have minimal refractory remaining,the carbon blocks are cracked and brittle,and that the wear dictated the end of the furnace campaign,or at least a major repair.Such results are inconsistent with the theory,yet its use continues without regard for its shortcomings.It is also well known that oxidation,thermal stress and chemical attack occur at such elevated temperatures in the blast furnace hearth wall.This paper discusses these root causes of hearth failure in more detail and suggests how these should be taken into consideration when selecting refractory materials and designing hearth walls for best performance in modern high productivity blast furnaces,in line with steel companies’ continuous drive for better results.The paper will also discuss possible refractory improvements developed to extend campaign length expectations,especially well-suited for unstable and less monitored furnace operations,as well as new and improved oxidation test methods that will better simulate actual blast furnace conditions,compared to the very basic and not overly accurate ones utilized by refractory suppliers and laboratories today.These are technologies that support the drive for continuous improvement and ultimately higher profitability for ironmakers worldwide.
Peter Sylvén Peter L Duncanson Henry Yu
国际会议
Asia Steel International conference 2012(第五届亚洲钢铁大会)
北京
英文
1-14
2012-09-23（万方平台首次上网日期，不代表论文的发表时间）