Blast furnace plant (1) and shutdown process for such a blast furnace plant (1). The blast furnace plant comprises a blast furnace (2) and a gas cleaning section (6) for cleaning gas from the blast furnace. Clean gas is released via a clean gas vent line (11) downstream of the gas cleaning section.

Provided is a method of operating a blast furnace, having generating a regenerative methane gas from a by-product gas discharged from the blast furnace, and blowing a blast gas and a reducing agent into the blast furnace from a tuyere of the blast furnace in which the blast gas is oxygen gas and the regenerative methane gas is used as at least part of the reducing agent.

The present invention relates to a method for pneumatically blowing a powdery substitute reducing agent in a dense flow process, by means of a transport gas, into a gasification reactor, or via a tuyere into a blast furnace. The substitute reducing agent is gasified in a gasification reaction. The transport gas comprises a fuel gas, the constituents of which or the oxidation constituents of which are at least partly involved in the gasification reaction.

A refractory-lined equipment includes a vessel defining an interior at least partially lined with a refractory material, and a nozzle assembly coupled to the vessel and extending into the interior. The nozzle assembly includes an outer sleeve fixed to the sidewall and extending through an aperture defined in the sidewall, the outer sleeve defining a central passageway, and a nozzle cartridge assembly positionable within the central passageway and including an inner sleeve, a refractory lining disposed about the inner sleeve, and a nozzle positioned within the inner sleeve. The nozzle cartridge assembly is removably coupled to the outer sleeve external to the vessel.

A method of heating up a furnace bottom and a burner lance used in the method are proposed. The method of heating up the furnace bottom includes a step of opening, in the tap hole, a burner lance insertion hole having a diameter larger than a diameter of the burner lance so as to penetrate into the furnace, a step of installing the burner lance in the opened burner lance insertion hole, a step of filling a gap between the installed burner lance and a furnace exterior side of the tap hole with a refractory, and a step of blowing in gas for heating into the furnace from the burner lance to heat up the furnace bottom.

A reducing gas injection system for a blast furnace having a blast furnace wall, the system including a reducing gas distribution pipe, one or more injectors mounted to the blast furnace wall at a shaft level, where the reducing gas distribution pipe is attached to the blast furnace wall or its supporting structure, where the injector(s) have a nozzle body with a peripheral wall extending along a longitudinal axis from a front portion, with at least one injection hole, to an opposite rear portion with an inlet port, where the nozzle body includes an inner gas channel for guiding reducing gas from the inlet port to the injection holes(s); where the nozzle body is mounted trough an aperture in the blast furnace wall in such a way that the front portion with the injection hole(s) is located on an inner side of the blast furnace, whereas the rear portion with the inlet port is outside of the blast furnace wall, where the nozzle body includes a peripheral mounting portion configured for connecting the injector in a gas tight manner to the aperture in the blast furnace wall, where the inlet port is in fluidic connection with the reducing gas distribution pipe by means of an injector stock, the injector stock including a feeding pipe connected to the reducing gas distribution pipe, an elbow connected to the feeding pipe and an injector pipe connected to the elbow, the injector pipe being flange mounted in a gas tight manner to the inlet port of the injector and the injector pipe and/or an outlet of the elbow having at least one cardan compensation joint.

A device to inject a reducing gas into a shaft furnace including an external casing whose front face is provided with an outlet for gas injection into the shaft furnace, an internal casing located inside the external casing and made of a steel able to resist to a temperature up to 1200° C., this internal casing having an opening matching the gas injection outlet of the front face of the external casing and a refractory layer located between the external casing and the internal casing.

An air blast system for melting furnaces includes: a supply unit supplying hot air into a melting furnace; a bustle pipe connected to the supply unit; a tuyere stock connecting the bustle pipe to the melting furnace to supply hot air from the bustle pipe to the melting furnace in a distributed manner; and a temperature management module determining whether the tuyere stock is damaged by comparing a temperature of the tuyere stock with a preset reference temperature.

A fluid assisted particle injector for a metallurgical furnace, comprising: an injector tube having an entrance end, an exit end and a removable tip; a cover tube disposed over the injector tube; a fluid and particle injector port in line with the longitudinal center axis of the injector tube and a secondary fluid port for directing pressurized fluid over the outside of the injector tube and within the cover tube; the injector tube defining a tapered internal bore having a particle entrance end and a particle exit end, wherein the diameter of the particle exit end is smaller than the diameter of the particle entrance end.

A refractory-lined equipment includes a vessel defining an interior at least partially lined with a refractory material, and a nozzle assembly coupled to the vessel and extending into the interior. The nozzle assembly includes an outer sleeve fixed to the sidewall and extending through an aperture defined in the sidewall, the outer sleeve defining a central passageway, and a nozzle cartridge assembly positionable within the central passageway and including an inner sleeve, a refractory lining disposed about the inner sleeve, and a nozzle positioned within the inner sleeve. The nozzle cartridge assembly is removably coupled to the outer sleeve external to the vessel.