JPS6015692B2 - Method of charging raw materials into electric furnace for ferroalloy - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses crushed sized minerals such as manganese ore, limestone, and silica stone, which are the main raw materials, and reducing materials when producing ferroalloys such as high carbon ferromanganese and silicomanganese in an electric furnace. Regarding a method of charging coke, which is a coke, and pellets, etc., which are obtained by agglomerating the powder and granules of the magnet using a sintering machine or the like, into a raw material tank attached to an electric furnace, in particular, a method for charging the raw materials together The present invention relates to a raw material burying method that prevents the generation of steam and the generation of dust caused by the steam during and during the transfer of a container containing raw materials to a raw material tank.

Generally, raw materials entering an electric furnace are sized to improve air permeability within the furnace, prevent unevenness of the raw materials, and equalize electrical resistance.

In other words, the ores, limestone, quartz, etc. are crushed into pieces of 10 to 60 pieces, but those smaller than 1 piece are crushed together with auxiliary raw materials such as limestone powder and miscellaneous ores (ores that have fallen from transportation equipment, etc.). It is formed into calcined mackerel or pellets (hereinafter also referred to as agglomeration) that approximately satisfy the above-mentioned size using a sintering machine or an agglomeration device, and then charged. By the way, these agglomeration lines are generally not directly connected to the electric furnace charging line, so the agglomerated ores are usually cooled before being injected.

However, agglomerated ores have a high heat content, and it is uneconomical in terms of energy to cool them down and then put them in bags and reheat them. Therefore, a so-called hot charge method has been proposed in which the material is charged while still at high temperature. With this method, the heat during agglomeration is brought into the electric furnace, which reduces the melting power cost in the electric furnace. The method of charging is being adopted. There are also cases where a method is employed to preheat the lump ore to be charged into the electric furnace to promote reduction, but even in such cases it is considered advantageous to bring this amount of heat into the electric furnace. In addition, when loading raw material ores such as agglomerated synthetic stones and lump ores as described above into the raw material tank attached to the electric furnace, a one-way container system is used to transport these raw materials in a mixed manner. In some cases, the container is configured to automatically receive the respective raw materials at a specific position, automatically reach the upper part of the raw material tank, and charge the stored raw materials into the tank.

These raw materials are stored individually or mixed if necessary at room temperature in a storage hopper, and the heat-retaining raw materials such as the agglomerated ore are stored in an insulated hopper equipped with measures to prevent heat radiation. However, in such a mixed conveyance/charging method, heat exchange takes place within the container, but at this time, the water contained in the coke may vaporize and eject from the gap in the container, or may Dust may be emitted.

These steam and dust blow-outs are particularly noticeable during the bagging stage of raw material tanks, deteriorating the working environment and hindering the maintenance and management of these automatic raw material charging devices. The present invention has been made with attention to these circumstances, and it suppresses heat exchange within the container as much as possible, reduces the ejection of steam and dust, maintains a favorable working environment, and improves the efficiency of the container. And the automatic raw material bagging device can be used stably for a long time.

However, the present invention is such that the water-containing minerals such as coke and the heating minerals such as competitive ore are housed in a layer in a container, reducing the contact surface between them.
This is designed to suppress heat exchange within the tank. The present invention will be explained in detail below based on the drawings, but all the drawings are only schematic representations, and the electric furnace and container are only schematic representations of appropriate ones. However, the present invention is not limited to this, and may be changed to a suitable device and container in accordance with the spirit of the above and later descriptions.

Furthermore, the embodiments described in the claims do not limit the present invention. Fig. 1 is an explanatory side view schematically showing the outline of an electric furnace to which the present invention is applied, Figs. 2 and 3 are vague diagrams for explaining the introduction of raw materials, and Figs. 4 and 5 are containers and their equipment. 6 to 11 are explanatory diagrams showing embodiments of the present invention.

The electric furnace to which the present invention is applied is applied to electric furnaces that are conventionally known or will be developed in the future, but these electric furnaces are each equipped with a raw material tank, and the charged raw material is transferred to the raw material tank by a container. direction and loaded. Additionally, in general, some of these raw materials are packed in bags in a heated state, and other raw materials contain moisture, and as long as these are transported in containers, the type of raw materials must be determined. The present invention is applicable regardless of the case. The electric furnace is composed of a furnace 1 and one or more electrodes 2 installed in the furnace so as to be able to move up and down (Fig. 1), and melts and smelts minerals packed in bags in the furnace using resistance heat. .

3 indicates the mantle of the electrode 2, and 4 indicates an electrode lifting device.

The charged mineral is charged into a raw material tank 5 provided above the furnace 1, and is charged from the tank 5 via a sinking tube 6. As mentioned above, the container 9 is used to bag raw materials into the tank 5, and the container 9 can be moved up and down within the framework 8 attached to the automatic raw material loading crane 7, etc., and can be opened and closed. A bell member 11 is provided at the lower part of the bell member 11 so as to be closed in a suspended state.
A bell rod 10 is attached to the bell member 11 and the rod 10 is passed through the upper part of the container 9. That is, the container 19 containing the raw material and reaching the top of the raw material tank 5 is lowered into the loading port 20 (FIG. 5) of the raw material tank 5, and the bell rod 10 is lowered to lower the bell member 11 and open the opening. The raw material is charged into the raw material tank 5 from the beginning. As for the raw minerals stored in the container 9, the room temperature lump ore 12 and coke 13, which have been sized as described above, are stored in the hopper.

(FIG. 2) The bran ore is sintered and sized in a Z sintering machine 15, and stored as a heated mineral 14 in an insulated hopper. In addition, these heated minerals 14 may be heat-treated briquettes (including pellets) or preheated minerals, but in the following, these will be referred to as Z.
It will be explained as a representative sintered ore. When these raw materials are stored in the container 9, conventionally, predetermined amounts of each material weighed by a weighing device 16 installed in each hopper or a weighing device installed in these conveyors are simultaneously weighed. The mixture is delivered to a rotating container 9 and mixed. Alternatively, as shown in FIG. 3, a mixture of lump ore 12 and coke 13 is stored in the storage hopper 17, and when the mixture is stored in the rotating container 9, these mixed ores are mixed with the above-mentioned Akio ore 14. may be stored and mixed in a rotating container 9 while being simultaneously weighed by two weighing devices 16, 16, respectively. Therefore, in the container-9, as described above, the heated dawn concretion 14 and the coke 13 containing moisture exchange heat and generate steam, and the bell rod 10 of the container-9 as shown in FIG. Steam 19 is ejected from the through-end cover portion, and dust is blown out along with the ejection of steam. Also, when charging the raw material tank 5,
As shown in Figure 5, from the opening □ gap and the container-9.
Dust 2 along with steam 3 is emitted from the penetrating end of the bell rod 10.
1 was gushing out and worsening the work environment. The present inventors investigated the causes of these problems and found that these raw materials were
They focused on the fact that if they are stored in a layered manner, the number of heat exchange surfaces will be reduced, resulting in less steam generation and less dust blowing out.

Although this reduces the mixing effect when the container is stored in one container, long-term tests have shown that the purpose of these mixtures is mostly fulfilled when the raw materials are packed into tank bags, and even if they are stored in layers within the container, the electricity It was confirmed that this had no effect on furnace operation at all. That is, in the present invention, as illustrated in FIGS. 6 to 11, the raw materials contained in a container 9 are stored and transported individually or in groups layered. When storing the container 9, the entire amount of phosphorite 14 is stored, and then the lump ore 12 and coke 1 are stored.
The mixed ore 14 may be accommodated (FIG. 6), or the mixed ore 14 may be accommodated after the mixed ore is accommodated (FIG. 7).
Further, if necessary, the lump ore 12 and the coke 13 can be stored separately. In such a case, the lump ore 12 with less moisture is stored after the entire amount of the sintered ore 14 is stored.
It is recommended to contain coke 13 last (8th
figure). Further, if necessary, the coke 13 may be accommodated first and then the sintered ore 14 and lump ore 12 layers may be formed (FIG. 9). In the illustrated example, predetermined amounts of individual or mixed minerals are accommodated at the same time, but it is also possible to accommodate one or both of these minerals separately. That is, FIG. 10 shows an example in which the competitive ore 14 is accommodated in two parts. First, half of the predetermined capacity is accommodated, then the entire amount of mixed minerals is accommodated, and finally the remaining amount of competitive ore 14' is stored.
to accommodate. In addition, as illustrated in FIG.
and mixed minerals may be alternately housed in half amounts, and the order of housing may be changed as appropriate. However, when storing each container separately in this way, as each of these layers becomes thinner, heat exchange occurs due to the dawn feed, so although these divisions may be influenced by the capacity of the container, it is not necessary to divide them into two. It is preferable not to exceed. In the present invention, the heated minerals to be charged into the electric furnace are housed in a container in a layered manner as described above, so the contact surface with the hydrated minerals is reduced, heat exchange within the container is suppressed, and steam generation is reduced. In addition to preventing dust from blowing out, it is now possible to maintain the temperature of the heated mineral at a high temperature while injecting.

In addition, even if the blending ratio of these heated minerals is increased, no dust is generated.
Hot charging of Akatsuki Mine becomes possible. Not only that, but the melting power in the electric furnace could be reduced. An example of these actual results is shown below, and it has been confirmed that the present invention can reduce the electric power consumption rate and eliminate dust generation even when the sintered ore is heated to a high temperature.

As explained above, according to the present invention, it is possible to operate an electric furnace at a low cost, and it also improves the working environment and facilitates maintenance management of the automatic material charging device, thereby streamlining the operation of the electric furnace.

[Brief explanation of the drawing]

Figure 1 is an explanatory side view showing the electric furnace and raw material bags, Figure 2
Figures 3 and 3 are schematic diagrams for explaining the storage of raw materials in container 1, Figure 4 is a sectional view for explaining the structure and operation of container 1, Figure 5 is a sectional view for explaining bagging raw materials from the container into the raw material tank, and Figure 6 is a sectional view for explaining the storage of raw materials from the container. Figures 11 through 11 are schematic diagrams showing examples of raw materials stored in a container. 1...furnace, 2...electrode, 3...mantle, 4...
・Electrode lifting/lowering direct, 5... Raw material tank, 6... Submerged source pipe, 7... Automatic raw material loading crane, 8... Frame, 9
... Container 1, 10... Bell rod, 11... Bell member, 12... Lump ore, 13... Coke, 14...
... Sintered ore, 15 ... Evening machine, 16 ... Weighing device,
17...Mixing hopper, 18...Bell hopper, 1
9... Steam ejected, 20... Charging section, 21... Dust ejected.纂 1 廂 哂 2 婂厂 3 婂 图 图 5 卫 6 fig.

Claims (1)

[Scope of Claims] 1. Mineral raw materials in a heated state and other steelmaking raw materials containing moisture at room temperature are weighed and discharged into a container, and the container is transported onto a raw material tank of an electric furnace. When charging these raw materials into the electric furnace, the heated ore raw material and the water-containing raw material stored in the container are sequentially discharged and stored in layers, and when charged into the raw material tank, they are mixed. A method for charging raw materials into an electric furnace for ferroalloy, characterized by: 2. In claim 1, the heated ore raw material and the water-containing raw material stored in the container are a raw material charging method in which the water-containing raw material is stored in the upper layer. 3. In claim 1, the heated ore raw material and the water-containing raw material stored in the container are a raw material charging method in which the heated ore raw material is stored in the upper layer. 4. The raw material charging method according to claim 1, 2, or 3, wherein either or both of the heated ore raw material and the water-containing raw material are housed in a plurality of layers. 5 In claims 1, 2, or 3, the heated ore raw material and the water-containing raw material contained in the container are each 2
A raw material charging method in which raw materials are stored alternately in layers. 6. The raw material charging method according to claims 1 to 4 or 5, wherein the water-containing raw material is a mixture of lump ore and coke. 7. The raw material charging method according to claims 1 to 4 or 5, wherein the heated ore raw material is sintered ore. 8. The raw material charging method according to claims 1 to 4 or 5, wherein the heated ore raw material is pellets. 9. A raw material charging method according to claims 1 to 4 or 5, wherein the heated ore raw material is preheated lump ore.