Flow characteristics of a blast furnace taphole stream and its effects on trough refractory wear

An investigation consisting of plant trials and water modelling studies has been carried out with the aim of gaining a better understanding of flow characteristics of a blast furnace taphole stream and its effect on the trough refractory wear. It has been found that the entrainment of the blast gas into the taphole is the most likely root cause for splashy taphole stream, which is believed to greatly contributes to refractory wear on the trough in the region above the liquid level and on the trough cover. Based on the findings from the present studies, changes were made to furnace operation and casting practices at BHP Steel's Flat Products Division No. 6 Blast Furnace (BF6) to minimise splashy taphole streams. As a result, the refractory wear on the trough and its cover has been significantly reduced. The trough cover life of BF6 has been improved, from 60 000 to 300 000 tonnes of hot metal.