Title

IMPROVING BLAST FURNACE TAPH0LE OPERATIONS BY CO-ORDINATED IMPROVEMENTS IN TAPH0LE CLAY, GUNS AND DRILLS

IMPROVING BLAST FURNACE TAPH0LE OPERATIONS BY CO-ORDINATED IMPROVEMENTS IN TAPH0LE CLAY, GUNS AND DRILLS

Authorship

SMITH, MARTIN; FRANKLIN, SAM; FONSECA, FABIANA

SMITH, MARTIN

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FRANKLIN, SAM

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FONSECA, FABIANA

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DOI

10.5151/2594-357x-35Red - 550-556

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Abstract

Taphole refractory operations are critical to the safe and economic operation of the casthouse. The latest generation of taphole clays are sophisticated materials based on synthetic mineral, with a high price per tonne. Good taphole practice results in improvements in many aspects of furnace operation. Control of taphole length minimises hearth refractory wear and contributes to long campaigns. The clay should be resistant to erosion and abrasion by the iron and slag stream but must be capable of being drilled. A high solids content results in improved abrasion and chemical resistance and reduces curing shrinkage but makes injection more difficult. The clay selected for a particular furnace must consider the ability of the gun to push the clay and the drill to drill it. New taphole equipment allows the selection of the latest taphole clays having greater erosion resistance. Similarly, the choice of clay affects the design of the taphole equipment. A pitch bonded clay softens at moderate temperatures and requires the gun to be held in position for longer times than a resin bonded clay. This may require water cooling of the barrel to prevent curing of the clay in the gun. The condition of the equipment also affects the refractory consumption – wear of the pistons results in oil leaks and leads to clay losses, poor nozzle design leads to dead spots and thus clay wastage. Finally factors such as feed hatch size affect the ease of equipment operation and the opportunity to minimise waste. These considerations have lead to the development of the taphole concept, where a combined package of taphole clay and equipment can be offered to optimise taphole and furnace operation at the same time as minimising expenditure.

Taphole refractory operations are critical to the safe and economic operation of the casthouse. The latest generation of taphole clays are sophisticated materials based on synthetic mineral, with a high price per tonne. Good taphole practice results in improvements in many aspects of furnace operation. Control of taphole length minimises hearth refractory wear and contributes to long campaigns. The clay should be resistant to erosion and abrasion by the iron and slag stream but must be capable of being drilled. A high solids content results in improved abrasion and chemical resistance and reduces curing shrinkage but makes injection more difficult. The clay selected for a particular furnace must consider the ability of the gun to push the clay and the drill to drill it. New taphole equipment allows the selection of the latest taphole clays having greater erosion resistance. Similarly, the choice of clay affects the design of the taphole equipment. A pitch bonded clay softens at moderate temperatures and requires the gun to be held in position for longer times than a resin bonded clay. This may require water cooling of the barrel to prevent curing of the clay in the gun. The condition of the equipment also affects the refractory consumption – wear of the pistons results in oil leaks and leads to clay losses, poor nozzle design leads to dead spots and thus clay wastage. Finally factors such as feed hatch size affect the ease of equipment operation and the opportunity to minimise waste. These considerations have lead to the development of the taphole concept, where a combined package of taphole clay and equipment can be offered to optimise taphole and furnace operation at the same time as minimising expenditure.

Keywords

Blast furnace, Taphole, Operation, Refractory

Blast furnace, Taphole, Operation, Refractory