A method for preparing coal which is to be injected into a blast furnace includes: a step (S1) for analyzing the ash of coal in a raw-coal stage and determining the contents (wt %) of At Si, Ca and Mg in the ash; a step (S2) for deriving the ash melting point of the coal on the basis of the obtained data: a step (S3) for selecting a metal species to be supported on the coal and deriving the amount thereof to be supported on the basis of the obtained data so as to adjust the melting point of the ash of the coal to 1200 to 1400 C.; a step (S4) for making the metal supported on the coal in the derived amount by an ion-exchange method; and a step (S5) for carbonizing the coal obtained in the step (4).

A method for preparing coal which is to be injected into a blast furnace includes: a step (S1) for analyzing the ash of coal in a raw-coal stage and determining the contents (wt %) of At Si, Ca and Mg in the ash; a step (S2) for deriving the ash melting point of the coal on the basis of the obtained data: a step (S3) for selecting a metal species to be supported on the coal and deriving the amount thereof to be supported on the basis of the obtained data so as to adjust the melting point of the ash of the coal to 1200 to 1400 C.; a step (S4) for making the metal supported on the coal in the derived amount by an ion-exchange method; and a step (S5) for carbonizing the coal obtained in the step (4).

The present disclosure discloses a system and a method for controlling gas injection in blast furnace. The system for controlling gas injection in blast furnace includes a coke oven gas pipeline, a decarbonized gas pipeline, a protection nitrogen pipeline, and a main gas pipeline. The coke oven gas pipeline and the decarbonized gas pipeline are connected with the main gas pipeline, and distributing branch pipelines of main gas pipeline are located at nozzles of tuyeres of blast furnace. The protection nitrogen pipeline is connected to the main gas pipeline. A group of measuring components are used for each of the pipelines to detect operation status thereof. The system controls operation status of the pipelines by controlling pipelines with valves. The system and method may ensure that the system for injecting coke oven gas through tuyeres can stop running safely in abnormal situations.

The present disclosure discloses a system and a method for controlling gas injection in blast furnace. The system for controlling gas injection in blast furnace includes a coke oven gas pipeline, a decarbonized gas pipeline, a protection nitrogen pipeline, and a main gas pipeline. The coke oven gas pipeline and the decarbonized gas pipeline are connected with the main gas pipeline, and distributing branch pipelines of main gas pipeline are located at nozzles of tuyeres of blast furnace. The protection nitrogen pipeline is connected to the main gas pipeline. A group of measuring components are used for each of the pipelines to detect operation status thereof. The system controls operation status of the pipelines by controlling pipelines with valves. The system and method may ensure that the system for injecting coke oven gas through tuyeres can stop running safely in abnormal situations.

A blast furnace blower device includes a body, a flow guidance structure and a cooling module. The body is hollow inside. The body includes an inlet area, an outlet nozzle area, and a fuel nozzle area. The fuel nozzle area is located between the outlet nozzle area and the inlet area, and a channel is formed from the inlet area to the outlet nozzle area. The flow guidance structure is deployed continuously or discontinuously along an inner wall of the body. The flow guidance structure is located between the fuel nozzle area and the outlet nozzle area. The flow guidance structure has a nozzle distance range along an axial direction of the body to the outlet nozzle area. The cooling module is located outside the body.

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 blast furnace includes: a blast furnace body; raw material charging means for charging raw material into the blast furnace body; hot air blowing means for blowing hot air into the blast furnace body; a drying apparatus etc. for evaporating moisture in low-grade coal; a dry distillation apparatus etc. for carbonizing dried coal; a cooling apparatus etc. for cooling carbonized coal; a pulverization apparatus etc. for pulverizing the carbonized coal cooled by the cooling apparatus; a storage tank for storing powdered coal; a nitrogen gas supply source, a conveyor line and a cyclone separator etc. for conveying the powdered coal pulverized by the pulverization apparatus to the inside of the storage tank by generating a gas flow with the nitrogen gas; and an injection lance etc. for feeding the powdered coal inside the storage tank to hot air that is blown into the blast furnace body.

A blast furnace includes: a blast furnace body; raw material charging means for charging raw material into the blast furnace body; hot air blowing means for blowing hot air into the blast furnace body; a drying apparatus etc. for evaporating moisture in low-grade coal; a dry distillation apparatus etc. for carbonizing dried coal; a cooling apparatus etc. for cooling carbonized coal; a pulverization apparatus etc. for pulverizing the carbonized coal cooled by the cooling apparatus; a storage tank for storing powdered coal; a nitrogen gas supply source, a conveyor line and a cyclone separator etc. for conveying the powdered coal pulverized by the pulverization apparatus to the inside of the storage tank by generating a gas flow with the nitrogen gas; and an injection lance etc. for feeding the powdered coal inside the storage tank to hot air that is blown into the blast furnace body.

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.

When CO.sub.2 is removed from a blast furnace gas containing unused CO gas and CO gas after removing CO.sub.2 is again injected into a blast furnace, nitrogen accumulates in the blast furnace. O.sub.2 is thus injected instead of blast. This causes the absence of nitrogen in front of a tuyere, so that a volume of gas generated in front of the tuyere is insufficient and a temperature in front of the tuyere rises, resulting in a difficulty in the blast furnace operation. N.sub.2 gas or CO.sub.2 gas is thus injected together with the CO gas injected through the tuyere, and circulated.