JPH06102806B2 - Smelting reduction furnace - Google Patents

Description

TECHNICAL FIELD The present invention relates to a smelting reduction furnace for smelting and reducing iron ore or the like to obtain pig iron.

(Prior art) In recent years, instead of the method of producing pig iron using blast furnace method such as coke and sinter, smelting reduction to obtain molten iron by pre-reducing raw ore or powdered ore and then smelting and reducing with coal powder etc. A method has been developed (JP-A-60-145307, etc.). In such a smelting reduction method, in addition to reduced iron in the smelting reduction furnace, carbon materials such as coal powder, slag-forming agents such as limestone, and oxygen for coal combustion, hydrocarbons for cooling nozzles, inert gas, etc. It is necessary to inject or input raw fuel of.

For this reason, it is necessary to install lances, tuyere, nozzles, etc. suitable for each purpose at appropriate positions. The smelting reduction method has been developed in recent years, and there are few technical examples of blowing reducing ore into an iron bath.

(Problems to be Solved by the Invention) As described in the section of the prior art, in the smelting reduction method, it is necessary to blow or add various kinds of raw materials to an iron bath or a slag bath. However, since the raw fuel to be blown has different purposes and properties, it is necessary to blow it in accordance with the purpose.

That is, it is necessary to blow the reducing ore into the iron bath or the slag bath while paying attention to the reoxidation, oxygen is blown so as to effectively burn the carbonaceous material, and the carbonaceous material is as much as possible to the iron bath. It is necessary to blow it so that it makes contact. It is also necessary to blow limestone or quicklime powder as a slag forming agent, and in some cases, in order to improve the reactivity by stirring the iron bath, an inert gas such as argon or carbon dioxide gas may be blown into the iron bath. Will be needed. As described above, in the smelting reduction method through the iron bath, it is required to blow various raw materials, combustion and the like into the furnace according to their respective purposes.

(Means for Solving Problems) In the smelting reduction furnace 1 for melting and reducing iron ore or the like according to the present invention, the reducing ore as the main raw material is directly supplied to the iron bath 8 as the main reaction zone. The side portion of the smelting reduction furnace 1 is selected as the best position, and the tuyere 4 is provided at this position. Next, oxygen, fuel, and coal as a reducing agent are sprayed onto the slag bath 7 or the iron bath 8 from the upper part of the furnace using a lance. Nozzle 5 for injecting stirring gas and coal powder or slag forming agent into the bottom of the furnace
Is provided.

(Operation) In the present invention, reoxidation of the reduced ore can be prevented by blowing the reduced ore into the iron bath 8 from the tuyere 4 provided on the side of the furnace body.

The top-blown oxygen jet by the oxygen blowing lance 2 is blown into the slag so as to effectively burn the carbonaceous material. That is, if the blown in of reduced iron is blown into the slag in a trapped state, there is still a possibility of being reoxidized by the oxygen jet. In this respect, in the case of direct blowing into the iron bath, since the oxygen jet is blocked by the slag, there is almost no opportunity for reoxidation and the blowing can be performed. Since the lance 3 for blowing oxygen, coal, etc. is provided so as to blow onto the slag bath 7 or the iron bath 8, oxygen effectively burns the carbonaceous material, while the carbonaceous material contacts the iron bath 8 as much as possible. It can be blown in as if to make it. In addition, since the nozzle 5 for blowing the stirring gas and the coal powder or the slag forming agent is provided at the bottom of the furnace, it is possible to effectively blow limestone or quick lime powder as the slag forming agent. An inert gas such as argon or a carbon dioxide gas, which is a working gas, can be blown into the iron bath 8, so that the stirring of the iron bath 8 is performed more completely and the improvement of the smelting reduction reaction of the smelting reduction furnace 1 is promoted. In some cases, the nozzle at the bottom of the furnace may be made into a multiple pipe and the reduction ore may be blown from a part thereof.

Embodiment An embodiment of the present invention will be described below with reference to the drawings.

Smelting reduction furnace 1 for melting and reducing iron ore etc. Oxygen blowing lance 2 and coal blowing lance 3 in the upper part of the main body
A tuyere 4 for blowing a main material such as reduced iron, preferably into an iron bath or into a slag bath, is provided on the side of the furnace body. The bottom of the furnace is provided with a nozzle 5 for blowing a stirring gas, coal powder, a slag forming agent and the like. A part of the oxygen lance blown from the upper part of the furnace serves as a porous lance 6 to burn the gas generated in the smelting reduction furnace and give the combustion heat to the iron bath.

In the figure, 9 is the tap hole of the smelting reduction furnace, and 10 is the tap hole.

(Effect of the Invention) According to the present invention, smelting reduction can be effectively performed.
That is, since the reduction ore is blown into a place where the reaction is easily performed without being reoxidized, the productivity is increased, and the coal is blown into a place where it is most likely to contribute to the reaction, so that the combustion efficiency is efficiently performed. It has excellent effects such as low heat loss, high productivity of the iron bath smelting reduction furnace, and high fuel efficiency and energy efficiency.

[Brief description of drawings]

The drawings are explanatory views showing an embodiment of the present invention. 1 is a smelting reduction furnace, 2 is an oxygen blowing lance, 3 is a coal blowing lance, 4 is a tuyere, 5 is a nozzle, 6 is a porous lance, 7 is a slag bath, 8 is an iron bath, 9 is a tap hole, and 10 is Debris mouth.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Shinichi Matsunaga 2-6-3 Otemachi, Chiyoda-ku, Tokyo Inside Nippon Steel Corp. (56) Reference JP-A-62-228413 (JP, A)

Claims (1)

[Claims] 1. A smelting reduction furnace for reducing iron ore or the like while melting it, and a lance for blowing oxygen, coal or the like on the upper part of the furnace, and a wing for blowing a raw material such as reduced iron into an iron bath on the side of the furnace body. A smelting reduction furnace having a mouth and a nozzle for blowing a stirring gas and coal powder or a slag forming agent at the bottom of the furnace.