August 20, 2009

Blast Furnace Taphole Clay Materials (Refractories)

With the prevailing trend of increasing capacities of Blast Furnaces the conditions for applications of Taphole Clay (refractory materials) have become more stringent as there has been a significant increase both in the pig iron temperatures and taping durations. These requirements are met by increasing Al2O percent and adding some SiC (around 15 to 20 percent) along with metals and nitrides as special additives in blast furnace taphole materials (refractories). Hence, depending on the capacity of the Blast Furnace the specifications of Taphole Clay to be used would vary. The binders used vary from purely coal tar based mixes to resin bonded ones or a dual bond.

The function of the taphole clay (taphole material) in a blast furnace is to enable smooth operation of the taphole, maintain constant taphole length and ensure separation of hot metal and slag. The following table depicts the various functions and property matrix for taphole clay.

Table: Function vs. Property Matrix of Blast Furnace Taphole Clay

Closing Hole

Easy plugging and drilling.

=> Plasticity of fireclay.

=> Good gas permeability.

=> Proper sintering.

Hearth Protection

Constant length.

=> Resistance to hot metal and slag.

=> High stickiness to the furnace wall.

Constant Delivery

Erosion resistance.

=> Expansive nature.

=> Resistance to hot metal and slag.


Related Posts

Blast Furnace - Refractory Lining Pattern

Blast Furnace (BF) - Design and Ironmaking

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