JPH0285311A - Smelting reduction method of iron ore and scrap - Google Patents

Abstract

PURPOSE:To continuously smelt iron ore, etc., with small scale equipment at good efficiency and to obtain a large quantity of molten iron by blowing finely powdered iron ore, iron-containing dust, etc., into a circular flow type reaction furnace, in which blows fine coal powder and air and is partially burnt at high load. CONSTITUTION:The air or O2 sent under pressurizing through feeding hole 3, is blown into the circular flow type reaction furnace 1 from a tangent line direction together with the fine coal powder and the finely powdered iron ore and iron-containing dust or mill scale conveyed through conveying hole 2. Then, the fine coal powder is partially burnt at high load while circularly moving and also the iron ore and the above dust, etc., are reduced with high temp. partial combustion gas and melted together with ash content in the fine coal powder, and the molten iron 4 and the molten ash are stored in the furnace 1 bottom. By this method, smelting reduction can be continuously executed to the iron ore, etc., with the small scale equipment, such as the above furnace 1, at good efficiency. Further, the above molten iron 4 and the melting ash are introduced into a refining furnace 5 connected with the furnace 1 and refined, and the molten steel 7 can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for melting and reducing iron ore and scrap.

[Prior art and its section B] There have been various methods for melting and reducing iron ore, but all of them required large-scale equipment. For this reason, a method of melting and reducing iron ore using small-scale equipment has recently been desired. In addition, conventionally, scrap has been melted using recycling means such as electric furnaces and converters in order to be recycled as an iron source, but since the energy cost is high and it is difficult to process in large quantities, melting, which can be processed in large quantities at low cost, has been used. A reduction method is desired.

Incidentally, a method is conventionally known in which pulverized coal and air are injected together into a swirling flow reactor, and most of the ash is melted and removed by high-load partial combustion.

[Object of the Invention] The present invention was made in view of the above circumstances, and involves melting and reducing iron ore using a swirling flow reactor, and melting scrap in a melting furnace provided following the swirling flow reactor. The purpose is to provide a method.

[Means for Solving the Problems] One of the present inventions for solving the above problems is to provide pulverized coal and dust or mill scale containing pulverized iron ore and iron in a swirling flow reactor, This is an iron ore melting and reducing method characterized by melting and reducing iron ore to obtain molten iron by partially burning pulverized coal in a reducing atmosphere by blowing air or oxygen together in a tangential direction.

Another aspect of the present invention is that pulverized coal is contained in a swirling flow reactor,
Pulverized iron ore and dust or mill scale containing iron are tangentially blown in with air or oxygen, and the pulverized coal is partially combusted in a reducing atmosphere to melt and reduce the iron ore to obtain molten iron. Thereafter, the molten iron and molten ash are introduced into a melting furnace following the swirling flow reactor, and the molten iron is refined using oxygen, a reducing agent such as pulverized coal or char, and a fluxing agent. It's a method.

Yet another aspect of the present invention is to tangentially inject pulverized coal, dust or mill scale containing pulverized iron ore and iron, and air or oxygen into a swirling flow reactor to reduce the Iron ore is melted and reduced by partially burning pulverized coal in an atmosphere to obtain molten iron, molten iron and molten ash are introduced into a melting furnace following the swirling flow reactor, and scrap is introduced into the melting furnace, and oxygen and This is a method for melting and reducing iron ore and scrap, which is characterized by melting scrap by injecting a reducing agent such as pulverized coal or char and a fluxing agent.

[Function] As described above, the method for melting and reducing iron ore, which is one of the aspects of the present invention, includes pulverized coal, pulverized iron ore, dust or mill scale containing iron, and air or oxygen in a swirling flow reactor. is injected from the tangential direction, pulverized coal is partially combusted under high load, and iron ore is reduced by high-temperature partially combusted gas.
In addition, since the iron ore is melted together with the ash in the pulverized coal to obtain molten iron, iron ore can be continuously and efficiently melted using small-scale equipment to obtain a large amount of molten iron. Furthermore, since iron ore and the like are melted using high-temperature partially combusted gas from combustion of pulverized coal, energy costs can be reduced.

Another aspect of the present invention, a method for melting and reducing iron ore, is as follows:
After obtaining molten iron by the above-mentioned melting method, the molten iron and molten ash are introduced into a melting furnace following the swirling flow reactor, and refined using oxygen, a reducing agent such as pulverized coal or char, and a fluxing agent. Molten steel can be obtained efficiently with small-scale equipment. Moreover, since the molten iron process and the molten steel process are directly connected, there is no transportation of molten iron, and the productivity of molten steel is good.

Furthermore, another method of melting and reducing iron ore and scrap according to the present invention includes obtaining molten iron by the above-mentioned smelting-reduction method, and then leading the molten iron and molten ash to a melting furnace following the swirling flow reactor. Scrap melting is carried out by charging scrap, a reducing agent such as pulverized coal or char, and a fluxing agent into the melting furnace, so the temperature of the molten iron is determined by the amount of pulverized coal input into the swirling flow reactor and the amount of oxygen into the melting furnace. By controlling by adjusting the amount of injected reducing agent such as pulverized coal or char, the amount of melted scrap can be easily adjusted and molten iron with a high scrap rate can be obtained.

[Example] An example of a method for melting and reducing iron ore, which is one aspect of the present invention, will be described with reference to FIG. Pulverized coal, pulverized iron ore, and dust or mill scale containing iron are tangentially fed into the swirling flow reactor 1 through the transfer port 2, and air or mill scale is fed under pressure through the feed port 3. When oxygen is also blown in from the tangential direction, the pulverized coal undergoes high-load partial combustion while rotating, and the dust or mill scale containing iron ore and iron is reduced by the high-temperature partial combustion gas, and the pulverized coal is The molten iron 4 and molten ash are melted together with the ash, and the molten iron 4 and molten ash accumulate at the bottom of the swirling flow reactor 1.

The combustion reaction at this time is as follows.

2G+ 0□-e-2GO+ 58400KcafFe
203+3[:→2Fe +3GO-147 caR In this way, iron ore and the like are continuously and efficiently melted and reduced in a small-scale facility called the swirling flow reactor 1, and a large amount of molten iron 4 is obtained. Furthermore, since iron ore and the like are melted using high-temperature partial combustion gas produced by partial combustion of pulverized coal, energy costs are low.

Next, an embodiment of a method for dissolving and reducing iron ore, which is another aspect of the present invention, will be described with reference to FIG. This example is molten iron 4
Since the process is exactly the same as the previous embodiment until obtaining , the explanation thereof will be omitted. The molten iron 4 and molten ash accumulated at the bottom of the swirling flow reactor 1 are led to the melting furnace 5 connected to the swirling flow reactor 1, and are fed with oxygen, a reducing agent such as pulverized coal or char, and flux through an oxygen injection lance 6. The molten steel 7 is obtained by injecting a refining agent and refining.

The reaction at this time is as follows.

Fe2O3+ 5G+ 02 2Fe + 500
+ 58253 CaZ Thus molten steel 7 with small-scale equipment
can be obtained efficiently. Moreover, since the process of obtaining the molten iron 4 and the process of obtaining the molten steel 7 are directly connected, there is no need to transport the molten iron 4, and the productivity of the molten w47 is good.

The molten steel 7 is taken out from an outlet 8 provided at the bottom of the melting furnace 5, placed in a pot 9, and transported, and the molten ash 7a floating on the molten steel 7 is discharged as slag from an outlet 10 provided at the side wall of the melting furnace 5. The slag is placed in a slag pot 11 and transported.

In the case of the previous embodiment in which oxygen blowing is not performed, the molten iron 4 is taken out from the outlet 8 at the bottom of the melting furnace 5, placed in a ladle 9, and transported.

The high-temperature combustion gas is sucked in by the operation of the suction blower 13 in the middle of the duct 12 installed at the top of the melting furnace 5, cooled by the cooling device 14, collected by the dust collector 15, and passed through the suction blower 13. After entering the desulfurization device 16 and being desulfurized, it passes through a gas dissipation tube (not shown) and is burned at the top and dissipated into the atmosphere.

Next, an embodiment of a method for melting and reducing iron ore and scrap, which is still another aspect of the present invention, will be described with reference to FIG. This example is also exactly the same as the previous example until the molten iron 4 is obtained, so the explanation thereof will be omitted. The molten iron 4 and molten ash accumulated at the bottom of the swirling flow reactor 1 are led to the melting furnace 5, and a certain amount of scrap 19 is collected from the scrap storage tank 18 at the upper end of the scrap input tube 17, which is installed at the top of the melting furnace 5 and also serves as a duct. The scrap metal is cut out and fed into the melting furnace 5 through the scrap input tube 17, where it is mixed into the molten iron 4 and melted. In melting this scrap 19, the temperature of the molten iron 4 is determined by the amount of pulverized coal immersed into the swirling flow reactor 1 and the oxygen injection lance 6 into the melting furnace.
By controlling by adjusting the amount of oxygen blown from
The amount of melted scrap 19 can be easily adjusted, and molten iron 4 with a high scrap rate can be obtained.

The molten iron 4 is taken out from the outlet 8 at the bottom of the melting furnace 5, placed in a pot 9, and transported, and the molten ash 8 floating on the molten iron 4 is transferred as slag to the outlet i at the side wall of the melting furnace 5.

The slag is then discharged, placed in a slag pot 11, and transported.

The high-temperature combustion gas is sucked in by the operation of the suction blower 13 in the middle of the duct 17' branched at the upper part of the scrap input tube 17, cooled by the cooling device 14, and then passed through the dust collector 15.
After passing through the suction blower 13 and entering the desulfurization device 16 to be desulfurized, it passes through a gas dissipation cylinder (not shown) and is burned at the top and dissipated into the atmosphere.

[Effects of the Invention] As can be seen from the above explanation, according to the method for melting and reducing iron ore of the present invention, iron ore can be continuously and efficiently melted in a small-scale facility called a swirling flow reactor, and molten iron can be produced. It can be obtained in large quantities, and energy costs can be reduced because iron ore and the like are melted using high-temperature combustion gas through combustion of pulverized coal.

In addition, in another iron ore smelting reduction method of the present invention, molten iron obtained in a swirling flow reactor is led to a melting furnace following the swirling flow reactor and refining with oxygen, so it requires small-scale equipment. Molten steel can be obtained efficiently, and since the process of obtaining molten iron and the process of obtaining molten steel are directly connected, there is no need to transport the molten steel, and the greenness of the molten steel is reduced by transferring the molten iron obtained in the swirling flow reactor to the melting furnace. Therefore, by controlling the temperature of the molten iron, the amount of molten scrap can be easily adjusted and molten iron with a high scrap rate can be obtained. be.

1... Swirling flow reactor, 2... Transfer port, 3... Inlet port, 4... Molten iron, 5... Melting furnace,
6... Oxygen injection lance, 7... Molten steel,
7a...Melted ash, 8...Outlet, 9.
... pot, 10 ... discharge port, 11 ... slag pot, 12 ... duct, 13 ... suction blower, 14 ... cooling device, 15 ... slag collecting device, 1
6...Desulfurization equipment, 17...Duct also doubles as scrap input, 17'...
・Duct, 18... Scrap storage tank, 19...
·scrap.

Claims (1)

[Claims] 1) Pulverized coal, dust or mill scale containing pulverized iron ore and iron, and air or oxygen are tangentially blown into a swirling flow reactor to create a reducing atmosphere. A method for melting and reducing iron ore, which comprises partially burning pulverized coal to obtain molten iron. 2) Pulverized coal, pulverized iron ore and iron-containing dust or mill scale, and air or oxygen are tangentially blown into a swirling flow reactor, and the pulverized coal is partially combusted in a reducing atmosphere. The iron ore is melted and reduced to obtain molten iron, and then the molten iron and molten ash are introduced into the melting furnace following the swirling flow reactor, and the molten iron is melted with oxygen, a reducing agent such as pulverized coal or char, and a fluxing agent. A method for melting and reducing iron ore, which comprises refining iron ore. 3) Pulverized coal, pulverized iron ore and iron-containing dust or mill scale, and air or oxygen are tangentially blown into a swirling flow reactor, and the pulverized coal is partially combusted in a reducing atmosphere. The iron ore is smelted and reduced to obtain molten iron, the molten iron and molten ash are introduced into a melting furnace following the swirling flow reactor, and scrap is introduced into the melting furnace, and oxygen and a reducing agent such as pulverized coal or char are added to the melting furnace. A method for melting and reducing iron ore and scrap, which comprises blowing in a fluxing agent and melting the scrap.