JPS5930774B2 - How to form reduced iron - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method for carburizing reduced iron.

Conventionally, when adding a heat-generating material such as carbon to a sponge-like reduced iron, the CO in the reducing gas is decomposed and reacted in a reduction furnace and attached to the surface of the reduced iron. It could not be freely adjusted or kept constant.

Furthermore, since an expensive reducing gas is used, there is a drawback that the product cost increases.

The present invention addresses the above-mentioned problems, and when feeding sponge-like reduced iron discharged from a reduction furnace to a feeder of a compression molding device, a heat generating material such as fine carbon is simultaneously fed into the feeder of a compression molding device. A method for carburizing reduced iron, which is characterized by supplying the reduced iron to a feeder and adding it to the reduced iron, and then forming the reduced iron using forming rolls of a compression molding device, the purpose of which is to form a heat-generating material. The blending ratio of iron to reduced iron can be freely adjusted or kept constant.

Product costs can be reduced. Another object of the present invention is to provide an improved method for forming reduced iron in which a heat-generating material can be mixed into the reduced iron in a uniformly distributed state.

In the method for carburizing reduced iron of the present invention, when the sponge-like reduced iron discharged from the reduction furnace is fed to the feeder of the compression molding device, a heating material such as fine carbon is fed into the heating material supplying device. Since the heat-generating material is supplied to the same feeder and added to the reduced iron, the amount of heat-generating material supplied to the feeder can be controlled by the heat-generating material supply device, and the mixing ratio of the heat-generating material to the reduced iron can be freely adjusted. can also be kept constant.

In the latter case, the exothermic material supply device may be operated in synchronization with the production speed of the compression molding device.

Further, in the method for carburizing reduced iron of the present invention, when feeding the sponge-like reduced iron to the feeder of the compression molding device as described above, a heat generating material such as fine carbon is supplied to the feeder by the heat generating material supply device. After adding the reduced iron to the above-mentioned reduced iron, the reduced iron is molded using a forming roll of a compression molding device. Therefore, not only carbon but also inexpensive carbonaceous material that acts as a heat generating material such as SiC, FeSi, etc. can be used. can be used to reduce product costs.

In addition, as mentioned above, since the exothermic material is supplied to the feeder of the compression molding machine and added to the sponge-like reduced iron, it has the effect of mixing the exothermic material into the reduced iron in a uniform distribution state, which can be obtained by the reduction method. It is very useful as a hot or cold compression molding method for reduced iron, or a hot or cold compression molding method for fine scrap.

Next, to specifically explain the method for carburizing reduced iron of the present invention, 1 in FIG. 1 is a reducing furnace.

Although a shaft furnace, a fluidized bed furnace, a fixed bed furnace, etc. can be used as the reduction furnace 1, a type that hotly discharges sponge-like reduced iron is preferable.

The spongy reduced iron discharged from the reduction furnace 1 is once
It is charged into a container 2 and sent to a compression molding device 3.

Note that this container 2 is of a closed type, making it possible to keep the sponge-like reduced iron warm and prevent it from re-oxidizing.

The container 2 is directly connected to a silo 4 provided above the compression molding apparatus 3, and the sponge-like reduced iron is charged into the silo 4 without being exposed to the atmosphere.

Between the silo 4 and the forming roll 6, there is a forced feed type feeder 5, for example, a set of screws, and the feeder 5 forcibly feeds the sponge-like reduced iron to the forming roll 6.

On the other hand, the feeder 5 is supplied with spongy reduced iron and at the same time a heat generating material such as fine carbon, for example, a fine powder of coke, silicon carbide, etc. via a hopper 70, a tariff feeder 8, and a screw conveyor 9.

Note that the supply amount of the heat generating material can be controlled by employing a control system, such as a rotation speed control system, that is linked to the operation of the forming roll 6 portion.

Further, in order to mix the heat generating material into the reduced iron in a uniform distribution state, the forced pressure feeding type feeder 5 is effective.

In addition, the surroundings of the silo 4, feeder 5, and forming roll 60 are preferably kept in an inert atmosphere (parallel shaded areas) to prevent re-oxidation.

If the capacity of the container 2 is increased, the silo 4 can be omitted and the container 2 and the feeder 5 can be directly connected.

The temperature of the product hot compression molded by passing through the forming roll 6 section is as high as 600° C. or higher, and the product is enclosed in a product container 10 in order to prevent this sensible heat from escaping.

Note that this container 10 is unnecessary in the case of cold compression molding.

FIG. 2 shows an example of a cross section of a product obtained by this method.

Numeral 11 is the heat generating material, and 12 is the grain boundary of the reduced iron.The heat generating material 11 is uniformly distributed throughout the product, resulting in a strong shaped reduced iron.

In addition, in order to provide the product with physical properties similar to those of molded pig iron, the carbon content is adjusted to 3 to 5% and the apparent specific gravity is 6 To
n/m'' or more.

The present invention has been described above with reference to embodiments, but of course the present invention is not limited to such embodiments, and modifications of God's design may be made without departing from the spirit of the present invention. .

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an embodiment of the method for carburizing reduced iron according to the present invention, and FIG. 2 is a sectional view of the obtained product. 3... Compression molding device, 5... Feeder, 6... Forming roll, 7, 8, 9...
Heat generating material supply device.

Claims (1)

[Claims] 1 When feeding the sponge-like reduced iron discharged from the reduction furnace to the feeder of the compression molding device, a heat generating material such as fine carbon is fed to the feeder by the heat generating material supply device and added to the reduced iron. , a method for carburizing reduced iron characterized by forming the same reduced iron using forming rolls of a compression molding device.