JPS62227013A - Device for transferring preliminarily reduced ore in iron making installation by melt reduction - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a prereduced ore transfer device in a smelting reduction ironmaking facility for a smelting reduction method using a fluidized bed prereduction furnace and a smelting reduction furnace.

[Conventional technology]

The conventional hot metal production technology uses a blast furnace.

The mainstream method was to melt iron ore reduced in a shaft furnace in an electric furnace.

However, as an alternative to these various methods, direct iron manufacturing methods using shaft reduction furnaces and arc furnaces have already been realized in commercial plants, and smelting reduction iron manufacturing methods have recently attracted particular attention.

The smelting reduction furnace used in this smelting reduction iron manufacturing method was developed for the purpose of producing molten iron-based alloys using smaller-scale equipment without being restricted by the raw materials used. In addition, since the two steps of sintering and coking in the blast furnace method can be omitted, inexpensive powdered ore can be used as the raw material.

Equipment for such a smelting reduction iron manufacturing method includes a fluidized bed pre-reduction furnace for pre-Di# reduction of powdery raw material ore containing metal oxides, and a smelt-reduction furnace for melting and reducing the pre-reduced ore. It is equipped with a furnace.

A transfer system for transporting the pre-reduced ore in the form of powder and granules from the fluidized bed pre-reduction furnace to the smelting reduction furnace is installed.

An example of a melt reduction equipment equipped with such a transfer system is described in Japanese Patent Application Laid-open No. 171516/1983. This has a furnace body structure in which the preliminary reduction furnace is provided with a plurality of discharge ports for the preliminary reduced ore, and the smelting reduction furnace is similarly provided with a plurality of holes for blowing the preliminary reduced ore into the furnace. These discharge ports and tuyeres are connected to each other by a plurality of transfer pipes, and a carrier gas inlet for pneumatic feeding is provided midway through the transfer pipes.

[Problem that the invention seeks to solve]

By the way, the raw material powder ore that has been fluidized and pre-reduced in the fluidized bed pre-reduction furnace is supplied to the smelting reduction furnace through a transfer pipe by gas transport.

In the fluidized pre-reduction process of fine ore in a fluidized bed pre-reduction furnace, it is difficult to size the pre-reduced ore to a uniform particle size distribution. In addition, in the fluidized reduction process, it is inevitable that large particles of raw material powder ore are mixed in due to sintering and agglomeration.

From the above, when pre-reduced ore is cut out from a transfer pipe directly connected to a pre-reduction furnace, the transfer capacity of the transfer pipe will vary due to the influence of fluctuations in the particle size distribution within the furnace. Therefore, the flow of the pre-reduced ore to the smelting reduction furnace is accompanied by flow rate fluctuations, making it difficult to uniformly supply the ore. In addition, when large particles that have been sintered or agglomerated are present, the particles are too large and heavy to be transported by gas, making it difficult to transport the gas itself, and the power required for transportation. There are also problems such as the need for a large amount of energy.

On the other hand, in order to enhance the reaction within the smelting-reduction furnace, the smelting-reduction furnace is provided with a plurality of tuyeres so that raw materials can be introduced from a plurality of locations. Therefore, a plurality of transfer pipes are required to connect the fluidized bed pre-reduction furnace and the melt reduction furnace, making the piping system considerably complicated.

Furthermore, it is necessary to provide a large number of discharge ports in the fluidized bed pre-reduction furnace, and the lower part of the fluidized bed pre-reduction furnace becomes complicated. Furthermore,
Since the fluidized bed pre-reduction furnace has a large number of discharge ports, it is difficult to control the amount of discharge from each discharge port and maintain uniformity.

Therefore, when designing equipment, the degree of freedom is restricted by this piping system, and equipment costs also increase.

The present invention was created in view of these problems, and is intended to smoothly transport pre-reduced ore from the fluidized bed pre-reduction furnace to the smelter reduction furnace in smelting reduction ironmaking equipment, and to simplify the transfer piping system. The purpose is to

[Means for solving problems]

In order to achieve the above objects, the present invention provides a smelting reduction facility that is equipped with a fluidized bed pre-reduction furnace and a smelting reduction furnace, and a transfer system for pre-reduced ore is arranged between the two furnaces. The present invention is characterized in that a circulation device is provided in which particles of the pre-reduced ore are circulated, and a transfer pipe leading to the smelting reduction furnace is connected to the middle of the circulation flow path of the circulation device.

[Effect]

In order to enhance the pre-reduction reaction, the in-furnace superficial velocity of the reducing gas blown into the fluidized bed pre-reduction furnace is increased to the extent that raw material particles such as fine ore are scattered and fluidized within the furnace. A cyclone installed at the outlet of the fluidized bed pre-reduction furnace collects particles such as fine ore that have been scattered in the exhaust gas and are returned to the fluidized bed pre-reduction furnace using an external circulation device. These circulating particles are suspended and scattered by the reducing gas in the fluidized bed pre-reduction furnace, and are sized into particles suitable for gas transport by a kind of wind sieve effect. Therefore, by discharging the pre-reduced ore from the middle of this external circulation system, gas transport to the smelting reduction furnace is stabilized, and the pre-reduced ore in a high temperature state is transferred to the smelting reduction furnace.

Furthermore, in order to enhance the reaction within the smelting reduction furnace, a pneumatic distributor is connected to the smelting reduction furnace through a plurality of channels, and pre-reduced ore is blown into the smelting reduction furnace from a plurality of positions.

〔Example〕

Hereinafter, the present invention will be specifically described based on embodiments shown in the drawings.

FIG. 1 shows a system of a preliminary reduced ore transfer device according to the present invention.

In the figure, a fine ore raw material A is pre-reduced in the fluidized bed pre-reduction furnace 1 in a system equipped with a fluidized bed pre-reduction furnace 1 and a melt reduction furnace 2. Further, the preliminary reduced ore is supplied to the smelting reduction furnace 2 by a transfer system provided between the two furnaces 1 and 2.

Reducing gas B discharged from the smelting reduction furnace 2 is supplied to the fluidized bed pre-reduction furnace 1, and the fine ore raw material A is pre-reduced in the fluidized bed pre-reduction furnace 1 by this reducing gas B. In addition,
In the reduction operation within the fluidized bed pre-reduction furnace 1, the superficial velocity of the supplied reducing gas B is increased to such an extent that the fine ore raw material A is scattered within the fluidized bed pre-reduction furnace 1.

Particles of fine ore scattered by the reducing gas B blown into the fluidized bed pre-reduction furnace 1 are discharged from the outlet of the fluidized bed pre-reduction furnace 1 together with the exhaust gas. The discharged fine ore particles are collected in a circulation device 3 attached to the outside of the fluidized bed pre-reduction furnace 1.
is returned to the fluidized bed pre-reduction furnace 1 again. That is, the discharged fine ore particles are collected by a cyclone 5 provided at the outlet of the fluidized bed pre-reduction furnace 1, and temporarily stored in a hopper 6 located below the cyclone 5. Next, the fine ore particles are sent from the hopper 6 to a pneumatic ivy feeder 7, and returned to the fluidized bed pre-reduction furnace 1 by the pneumatic ivy feeder 7.

In this way, the fine ore is pre-reduced while being circulated between the fluidized bed pre-reduction furnace 6 and the external circulation device 3. In addition, the particles circulating in the external circulation device 3 are subjected to wind sieving action in the fluidized bed reduction furnace 1, and are classified and sized to have the optimum particle size distribution for gas transfer to the melting reduction furnace 2. .

A transfer pipe 10 is connected to the V8 ring pipe 4 of the circulation device 3 as a transfer system for supplying pre-reduced ore to connect the fluidized bed pre-reduction furnace 1 and the smelting reduction furnace 2. The connection point of this transfer pipe 10 is located between the hopper 6 and the pneumatic feeder 7.

By the way, the discharge partial pressure of the fluidized bed pre-reduction furnace 1 and the blowing pressure of the smelting reduction furnace 2 are generally different.

Therefore, in order to prevent mutual gas intrusion or outflow between the two furnaces 1.2 caused by this pressure difference, a gas seal is required in the transfer system. Further, in order to increase the reactivity within the smelting reduction furnace 2, it is preferable that the preliminary reduced ore be injected into the smelting reduction furnace 2 in a distributed manner.

From the above, a plurality of blowing nozzles 11 are arranged in the melting reduction furnace 2, and a pneumatic distributor 12 is installed to branch the flow paths to these blowing nozzles 11 and seal the gas.
is connected to the transfer pipe 10.

FIG. 2 schematically shows the pneumatic distributor 12, in which distribution pipes 14 equal in number to the number of blowing nozzles 11 of the melting reduction furnace 2 are branched from the main body 13. A fluidizing gas nozzle I5 for fluidizing the pre-reduced ore is arranged inside the main body 13, and a carrier gas 16 is supplied to the fluidizing gas nozzle 15 from an external air supply source. Further, the distribution flow rate of the preliminary reduced ore flowing from the main body portion 13 to the distribution pipe 14 is controlled by a flow rate regulating valve 17 arranged for each distribution pipe 14. Furthermore, a carrier gas 16 is connected to the connecting pipe 18 between each distribution pipe 14 and each blowing nozzle 11 through the pneumatic delivery nozzle 1.
9, the pre-reduced ore can be transferred into the smelting reduction furnace 2 by supplying a divided flow and pressurizing the flow.

In addition, there is a coarse particle discharge port 3 in the lower part of the fluidized bed preheating (M reduction furnace 1).
0 is provided, and coarse particles, sintered particles, etc. that stay and flow at the bottom of the fluidized bed are discharged from this coarse particle discharge port 30. this is,
This is a processing operation for pre-reduced ore that is not suitable for pneumatic conveying, and is charged into the smelting reduction furnace 2 by a separate means.

In the above configuration, pre-reduced ore that has been subjected to a uniform particle size distribution and granulation process by the circulation device 3 attached to the fluidized bed pre-reduction furnace 1 flows into the transfer pipe 10.

The inflowing pre-reduced ore is then supplied to the pneumatic distributor 12 by gas transfer in a classification and particle size distribution state that is optimal for gas transfer. Therefore, the pre-reduced ore in the fluidized bed pre-reduction furnace 1 can be transferred in a more stable flow than when the pre-reduced ore is directly discharged. Because of this stable transfer, the pre-reduced ore from the fluidized bed pre-reduction furnace 1 can be quickly supplied to the smelting reduction furnace 2.

Furthermore, in the pneumatic distributor 12, the carrier gas 1
By supplying air 6, the pre-reduced ore is fluidized and cut out in a plurality of flow path directions. Therefore, blowing nozzle 1
The flow in the connecting tubes 18 up to 1 can be similarly stabilized. Then, if the carrier gas 16 is supplied,
Since the flow can also be pressurized by the pneumatic distributor 12 itself, the pre-reduced ore can be charged into the smelting reduction furnace 2 together with the pneumatic nozzle 19 without disturbing the stable transfer.

As described above, since the pneumatic distributor 12 is arranged to branch into a plurality of flow paths toward the melting reduction furnace 2,
The transfer pipe lO from the circulation device 3 can be a single pipe. Therefore, it is sufficient to simply connect a plurality of connecting pipes 18 from the pneumatic distributor 12 to the melting reduction furnace 2, and the piping equipment can be simplified.

The gas seal against the pressure difference between the discharge part of the fluidized bed pre-reduction furnace 1 and the injection part of the smelting reduction furnace 2 is provided by the transfer pipe 10.
The powder sealing effect of the pre-reduced ore filled inside provides an excellent sealing effect.

〔Effect of the invention〕

As explained above, in the pre-reduced ore transfer device of the present invention, an outlet for the pre-reduced ore is provided in the middle of the W1 ring device of the fluidized bed pre-reduction furnace, and the pre-reduced ore is transferred from there to the smelting reduction furnace by gas transport. There is. Therefore, unlike the gas transport of the particle size distribution of the pre-reduced ore in the fluidized bed pre-Dik reduction furnace,
The flow within the transfer pipe can be stabilized. the result,
Preliminary reduced ore in a high temperature state can be quickly supplied to the smelting reduction furnace. In this way, since the pre-reduced ore in a high temperature state is supplied to the smelting reduction furnace, it is effective for the smelting reduction reaction. Furthermore, multiple lines of piping are provided only between the pneumatic distributor and the smelting-reduction furnace, and a single transfer pipe is sufficient, making it possible to simplify the piping system, improve design freedom, and reduce equipment costs. It is possible.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of a preliminary reduced ore transfer device of the present invention, and FIG. 2 is a schematic diagram of a pneumatic distributor.

Claims (1)

[Scope of Claims] 1. In a smelting reduction facility comprising a fluidized bed pre-reduction furnace and a smelting reduction furnace, and a transfer system for pre-reduced ore arranged between the two furnaces, the pre-reduced ore is placed in the fluidized bed pre-reduction furnace. 1. A preliminary reduced ore transfer device in a smelting reduction ironmaking facility, characterized in that a circulation device for circulating particles is provided, and a transfer pipe headed for a smelting reduction furnace is connected to the middle of a circulation path of the circulation device. 2. A preliminary reduced ore transfer device in a smelting reduction ironmaking facility, characterized in that a pneumatic distributor that branches a plurality of flow paths toward a smelting reduction furnace is connected to the transfer pipe according to claim 1. .