The use of coated pellets in optimising the blast furnace operation

Abstract

With the aim to improve the blast furnace process, coating of blast furnace pellets was investigated in laboratory scale as well as in the LKAB experimental blast furnace. Olivine, dolomite and quartzite respectively were applied as coating agents onto the regular LKAB olivine pellet MPBO. Testing of the coated pellets revealed the following: i) Dust generation was significantly decreased when using coated pellets in the blast furnace, ii) Sticking was prevented by the coating material. This was verified in different laboratory tests, as well as by studying probe samples from the blast furnace, and iii) Gas utilisation was higher for all coated pellets, with a lower variation, indicating a smoother blast furnace operation. Coating of pellets is considered as a significant improvement in optimising the blast furnace operation.