Hole-opening bit and tap hole opening method using same

Abstract

A hole-opening bit that can simplify an operation for opening a tap hole for installing a burner lance for raising the temperature of a furnace bottom of a blast furnace, which allows the blast furnace to be started up in a relatively short time after long-time blast stoppage or after a furnace cooling accident, by efficiently heating the furnace bottom, and a tap hole opening method using the hole-opening bit. A hole-opening bit used to open the tap hole in the furnace bottom of the blast furnace including chips on rear surfaces of a furnace drilling surface of the hole-opening bit such that outermost ends of the chips are located inside of an outermost end of the hole-opening bit.

Dependencies are inferred from the claim text.