JPH01215919A - Method for starting melting in reactor ironmaking - Google Patents

Abstract

PURPOSE:To produce molten seed metal by itself without charging it from outside by charging scrap and carbonic material on coke bed in a furnace and blowing oxygen from furnace bottom tuyere at the time of producing molten iron melted by charging scrap into the converter, which the molten iron is used as the molten seed metal, and blowing the carbonic material and oxygen. CONSTITUTION:At the time of starting reactor steelmaking for producing the molten iron at low cost by charging the scrap at low cost into the converter, in which the molten iron as the molten seed metal exists, and blowing O2 and fine powdered coal from the bottom part tuyere 12 and the upper part tuyere 13 to melt the scrap, as the molten seed metal is nothing, the granular coke 3 is packed in the reactor 1 to form the bed 7, and on this, the mixing material of the scrap 4A and coke powder 5A is charged. Successively, the mixing material of the O2 and fine powdered coal is blown from the bottom part tuyere 12 and the upper part tuyere 13, and by combustion of the fine powdered coal, the coke bed 7 is burnt and the scrap 4A is melted, to produce the molten seed metal by itself. Further, a preheating chamber 21 is arranged at the upper part of converter 11 and exhaust gas of the converter is secondarily burnt in a combustion tower 22 to make high temp. exhaust gas, and the additional scrap 4B and coke 5B into the converter 1 is preheated, and heat efficiency of the apparatus is improved.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a method for starting melting in reactor steel manufacturing. [Prior Art] The inventors have developed a method called "reactor iron manufacturing" in which iron (including pig iron and steel) is manufactured by melting scrap using carbonaceous materials and oxygen gas without using expensive electricity. Established the technology and announced the basic method
4363, JP-A No. 60-181213),
Japanese Patent Publication No. 58-13330 for Disclosing Reactor Steel Manufacturing Equipment
No. 9, No. 58-199808, No. 59 = 150005
JP-A-60-181213@, JP-A-61-15907-9@, and JP-A-61-201713). The principle of the reactor iron manufacturing method is that C and 02 are blown into molten iron stored in a furnace as seed water, and the C is combusted into CO, and some GO, which is provided in the upper space of the furnace, is combusted into CO2. The heat generated by this melts the charged scrap and increases the amount of molten iron. Until now, the seed metal used in reactor steelmaking has been intended to be molten iron obtained by other melting means, such as molten metal from scrap melted in an arc furnace, hot metal from a blast furnace, or molten steel from a converter. Although such seed water is often readily available, it is not always possible to secure it due to the factory environment or operational circumstances, which limits the implementation of the reactor steelmaking method. There is.

[Problem to be solved by the invention]

The purpose of the present invention is to remove the above-mentioned restrictions on the reactor iron manufacturing method, to prepare a seed water on the spot in the reactor without relying on other melting means, and to perform reactor iron manufacturing anywhere and anytime as desired. An object of the present invention is to provide a method for starting melting in reactor steel manufacturing. [Means for Solving the Problems] The method for starting melting in reactor steelmaking of the present invention involves putting scrap into a furnace containing molten iron serving as a seed water, and blowing carbonaceous material and oxygen gas to burn C. In reactor steelmaking, which uses the heat of combustion to melt scrap and increase the amount of molten iron, at the start of operations, the bottom of the furnace is filled with granular carbonaceous material to form a bed. The furnace is characterized by preparing seed hot water on the spot by charging scrap mixed with carbonaceous material and burning carbon by blowing oxygen gas through the bottom and top tuyeres of the furnace. The carbonaceous material forming the bed is preferably one with high compressive strength, such as coke. What is mixed with the scrap and what is blown through the tuyere can be of low quality. If the carbonaceous material mixed with the scrap is insufficient, it is recommended to provide a supply port in the upper part of the furnace, separate from the scrap input port, and supply the carbonaceous material through the supply port. Lump-like or coarse-grained coal is suitable for this purpose. Alternatively or in addition thereto, it is also advantageous to inject and burn pulverized coal through one or both of the upper tuyere and the bottom tuyere. In particular, blowing pulverized coal through the bottom tuyere is a recommended practice because it reduces the consumption of carbon in the bed and helps the bed function as described below.

[For use]

To explain the case of using a reactor 1 equipped with a preheating device 2 shown in the attached drawings, a mixture of scrap 4A and carbonaceous material 5A is charged onto a bed 7 formed by filling coke 3, Oxygen gas is blown into the bottom tuyere 12 and the top tuyere 13. At this time, it is recommended that pulverized coal is also blown in and combusted. In other words, a pulverized coal burner with excess oxygen is operated. Along with the combustion of C, including the injected pulverized coal, coke in the bed, and carbonaceous materials mixed in the scrap, the "e" in the scrap is also oxidized to some extent to become FeO,
A large amount of heat is generated, the temperature of the scrap rises, and melting begins. The above FeO drips down onto the bed coke in a molten state, where it is directly reduced by C and returns to Fe, and together with the unoxidized and dissolved Fe, molten iron 8 fills the voids in the bed coke. By slowing the consumption of bed coke as much as possible and allowing it to exist for a long time, the above-mentioned direct reduction of FeO can proceed advantageously and the dissolution yield can be increased. Regardless of the oxidation of any carbon source, the generated CO gas In the packed scrap bed, unreacted 02 causes secondary combustion to produce CO2, and the heat generated promotes dissolution.The high-temperature exhaust gas leaving the reactor still contains CO, so it is once taken out to the combustion tower 22. , air is added to combust it, raise the temperature further, and guide it to the preheating chamber 21. In the preheating chamber 21, there is a mixture of the combined scrap 4B and the combined carbonaceous material 5B, which are introduced by opening the upper fi 23. The exhaust gas is held by a damper 24 that separates it from the reactor.The exhaust gas that has passed through this chamber from above to below for heat exchange is guided to the dust collector by a duct 25.The preheated mixture is transferred to the reactor by opening the damper 24. The carbonaceous material is supplied through the supply port 14 provided at the top of the furnace as shown in the figure.The significance of the carbonaceous material supplied from the top is that it particularly promotes the melting of scrap. In other words, even if the scrap is preheated and charged, its temperature is at most 700'C, and even if the 02 from the upper tuyere touches it,
The temperature will not reach such a level that it will melt immediately. If supplemented carbon is present, it is easily ignited by the 02, resulting in localized high temperatures and melting of the scrap.
For this reason, it is effective to use a separately supplied carbonaceous material with a relatively large particle size. Once the required amount of seed hot water has been prepared as described above, the amount of molten iron is increased in accordance with the known reactor iron manufacturing method. When a certain amount is reached, the reactor is tilted to discharge hot water from the tap 15, and the next operation cycle begins. [Example] A reactor having the structure shown in the drawings was used, and 150 kg of coke was filled in the bottom, and 5 C) OK g of scrap was charged on top. This scrap was mixed with 50:9 granular coal. Similarly, scrap 5
Granular charcoal 35 to 00Kg! A mixture of J was placed in a preheating chamber. 6Nm3/min from the top tuyere, 2Nm from the bottom tuyere
/min of 02 gas was blown. Approximately 10 minutes later, the first continuous loading was performed, and thereafter, 3000 Ky of scrap was melted by continuous loading 4 times at 8 minute intervals, a total of 5 times. The results are as follows. Required time for melting: 55 minutes Carbon consumption (including additional portion > 95Kg/cht Oxygen consumption Unit: 147Nm3/chtFe yield
96.7% thermal efficiency 53
% [Effects of the Invention] According to the melting start method of the present invention, the seed water necessary for carrying out the reactor iron manufacturing method can be prepared without the aid of other melting means. Therefore, reactor steel production can be carried out whenever desired without any restrictions on personnel or equipment regarding operation.

[Brief explanation of the drawing]

The drawing is a vertical cross-sectional view of the main parts of the apparatus for explaining the melting start method for reactor iron production of the present invention. 1...Reactor 11...Furnace body 12...Bottom tuyere 13... Upper tuyere 14.
... Carbonaceous material supply port 15 ... Tap water outlet 2 ... Preheating device 21 ... Preheating chamber 22 ... Combustion tower 23 ...
・M 24...Damper 25...Duct 3...Coke 4A, 4B...Scrap 5A, 5B...Carbonaceous material

Claims (4)

[Claims] (1) Scrap is charged into a furnace containing molten iron as seed water, carbonaceous material and oxygen gas are blown in to combust the C, and the heat of combustion melts the scrap to increase the amount of molten iron. In reactor steelmaking, which consists of the following steps, at the start of operation, the bottom of the furnace is filled with granular carbonaceous material to form a bed, and scrap mixed with carbonaceous material is charged on top of the bed. A method for starting melting in reactor iron making, characterized in that a seed water is prepared on the spot by blowing oxygen gas through a bottom tuyere and an upper tuyere to burn C. (2) The method for starting melting according to claim 1, wherein the carbonaceous material is supplied from the upper part of the furnace through a supply port different from the scrap input port. (3) The method for starting melting according to claim 1, which is carried out by blowing a finely powdered carbonaceous material through the upper tuyere and/or the bottom tuyere. (4) The method for starting melting according to claim 1, wherein carbon steel or stainless steel scrap is used as the scrap.