The use of pellets comprising one or more thermoplastic material(s) of more than 40%, based on the total dry weight of the pellets and one or more cellulosic material(s) of more than 20%, based on the total dry weight of the pellets, as a reducing agent in a process for making pig iron in a blast furnace. The pellets can be provided in unground form, as a partial replacement of coke through the top of the blast furnace, or can be provided as reducing agent in the raceway in an amount of higher than 10 kg/ton iron.

A blast furnace operation method comprising a blast furnace to start up smoothly and perform operation after suspending air blowing by removing as much as possible residual coke that remains inside the furnace during suspension of air blowing and becomes an obstacle to discharging solidified matter. In this blast furnace operation method, air blowing is suspended with the height of a surface of a raw material-filled layer immediately above a blast-furnace tuyere reduced below the height of an upper end of a blast-furnace bosh and then air blowing is resumed. After air blowing into the blast furnace is suspended, oxygen or oxygen and a combustible gas are blown in through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce the volume of residues inside the furnace, and after new coke is charged to a region where the volume decreased, air is blown through a tuyere.

A blast furnace operation method comprising a blast furnace to start up smoothly and perform operation after suspending air blowing by removing as much as possible residual coke that remains inside the furnace during suspension of air blowing and becomes an obstacle to discharging solidified matter. In this blast furnace operation method, air blowing is suspended with the height of a surface of a raw material-filled layer immediately above a blast-furnace tuyere reduced below the height of an upper end of a blast-furnace bosh and then air blowing is resumed. After air blowing into the blast furnace is suspended, oxygen or oxygen and a combustible gas are blown in through a burner inserted into a taphole to combust coke remaining inside the furnace and reduce the volume of residues inside the furnace, and after new coke is charged to a region where the volume decreased, air is blown through a tuyere.

A method of operating a shaft furnace includes inserting a mixture including anthracite coal and coke into a cavity defined by the furnace, and disposing a metal feedstock within the cavity. The method includes injecting natural gas at a natural gas flow rate and a first quantity of oxygen gas at a first oxygen gas flow rate into the cavity simultaneously through at least one burner. The method also includes driving a second quantity of oxygen gas at a supersonic oxygen gas flow rate into the cavity through at least one lance, wherein the supersonic oxygen gas flow rate is greater than the first oxygen gas flow rate. The method also includes combusting the mixture within the cavity to produce a stack gas, melting the metal feedstock to produce a melted metal material, and monitoring the stack gas to thereby operate the shaft furnace. A shaft furnace is also disclosed.

A method of operating a shaft furnace includes inserting a mixture including anthracite coal and coke into a cavity defined by the furnace, and disposing a metal feedstock within the cavity. The method includes injecting natural gas at a natural gas flow rate and a first quantity of oxygen gas at a first oxygen gas flow rate into the cavity simultaneously through at least one burner. The method also includes driving a second quantity of oxygen gas at a supersonic oxygen gas flow rate into the cavity through at least one lance, wherein the supersonic oxygen gas flow rate is greater than the first oxygen gas flow rate. The method also includes combusting the mixture within the cavity to produce a stack gas, melting the metal feedstock to produce a melted metal material, and monitoring the stack gas to thereby operate the shaft furnace. A shaft furnace is also disclosed.

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.

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 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 method for a blast furnace includes pulverizing coal to make pulverized coal, and pulverizing iron ore to make pulverized iron ore, and injecting the pulverized coal and the pulverized iron ore from a tuyere. A loss on ignition of the iron ore is greater than or equal to 9% by mass and less than or equal to 12% by mass, an injection rate of the pulverized coal is greater than or equal to 150 kg/tp, and an injection rate of the pulverized iron ore is greater than or equal to 2.5 kg/tp and less than or equal to 50.0 kg/tp.

A method for a blast furnace includes pulverizing coal to make pulverized coal, and pulverizing iron ore to make pulverized iron ore, and injecting the pulverized coal and the pulverized iron ore from a tuyere. A loss on ignition of the iron ore is greater than or equal to 9% by mass and less than or equal to 12% by mass, an injection rate of the pulverized coal is greater than or equal to 150 kg/tp, and an injection rate of the pulverized iron ore is greater than or equal to 2.5 kg/tp and less than or equal to 50.0 kg/tp.