KR950012402B1 - Fe-mn smelting reduction process and equipment - Google Patents

Abstract

The iron melt is manufactured by mixing Mn ore and iron ore, and reducing and smelting the mixture to use carbon containing materials as heat source and reducing agent. The apparatus comprises: a Mn containing iron making furnace(10) with an oxygen lance(12) and a fine ore and coal combustion device(50); an ore supply device(20) for supplying large grain ore, general coal and additional material to the iron making furnace(10); a process gas circulation device(30) for separating iron, fine Mn system ore and coal dust from the process gas generated from the iron making furnace(10), and for discharging the process gas; a fine ore supply device(40) for supplying iron, fine Mn system ore, coal dust, prereduced fine ore and fine coal to the fine ore and coal combustion device(50).

Description

Manganese iron manufacturing method and apparatus therefor

1 is a partial cross-sectional schematic diagram of the apparatus for manufacturing manganese iron in accordance with the present invention.

2 is a cross-sectional view of the spectral coal combustion apparatus used in the present invention.

3 is a bar graph showing the particle size change of particulate ores by the spectroscopic carbon combustion device.

Figure 4 is a graph showing the coal combustion rate according to the oxygen / coal molar ratio in the spectral coal combustion device.

5 is a graph showing the change of oxide concentration in slag according to the content of manganese in molten iron.

* Explanation of symbols for main parts of the drawings

10: iron manganese steel manufacturing furnace 20: ore supply device

21: raw material storage device 22: proper quantity supply device

30: process gas circulation section 32, 34: the first and second high temperature cyclone

40: spectroscopy device 50: spectral coal combustion device (burner)

The present invention relates to a method and apparatus for manufacturing manganese iron for producing a high concentration of manganese iron using high-cost manganese ore and carbonaceous material directly.

Manganese is an essential element of steel and plays an important role in improving mechanical properties.

Currently, manganese is mainly used in an alloy state such as Si-Mn or Fe-Mn, rather than being used alone. The current general manufacturing process is the reduction of manganese ore pretreated to a certain size and composition, mainly in shaft type or electric furnace, to produce high carbon alloy iron of about 70% Mn.

In the case of low carbon and manganese alloy iron, high purity silica is loaded with manganese ore as a raw material to produce high carbon Mn-Si, and then decarburized using manganese ore as an oxidizing agent.

The manufactured manganese alloy iron is mainly used as an additive of manganese in the steel industry and is added to the level of 1% Mn for ordinary steel, but in the future, the demand for manganese alloy will increase for bazaar steel production containing 25% or more of manganese. It is expected. Current manufacturing method of high manganese iron is to prepare a molten iron of the desired composition by mixing separately prepared molten iron and iron at room temperature.

This conventional manufacturing method has a problem in lowering the molten steel temperature and component control due to mixing because the high-manganese alloy and molten steel at room temperature are mixed in a separate process. At present, the manganese alloy manufacturing process is mainly made by the arc electric furnace method, and all of the energy is supplied by expensive electricity. It is known that the electric power required per ton of iron manganese iron is about 3500-4000Kwh, and expensive carbon electrode or coke is used as reducing agent. In addition, since about 60% of the manganese ore is calculated in the form of spectroscopy, the pretreatment called aggregation process is required to manufacture by the electric furnace. Pretreatment processes include briquetting, sintering and calcining pellets, and there are many facilities and costs. Recently, a new manufacturing method for the electric furnace method is presented in Korean Patent Laid-Open Publication No. 89-672, in which molten metal is injected into a coal-filled layer to prepare molten metal using powder ore. It is a method of manufacturing.

However, this method has a problem that it is necessary to secure a coal packed bed having a stable height in the furnace for blowing powdered ores.

The present inventors have conducted research to solve the above-mentioned problems of the conventional methods, and based on the results, the present invention proposes the present invention. An object of the present invention is to provide a manufacturing method and a device for manufacturing manganese iron, which can be efficiently manufactured directly by manufacturing a manganese iron by spraying through a spectral coal combustion apparatus located above the melt reduction furnace.

Hereinafter, the present invention will be described in detail by the drawings.

As shown in Figure 1, the manganese iron manufacturing apparatus 100 of the present invention is a manganese iron manufacturing furnace 10, ore supply device 20, the process gas circulation unit 30, the spectroscopic supply device 40 ), And a spectroscopic and coal dust burner (hereinafter, referred to as a "burner").

The iron-manganese iron manufacturing furnace 10 is a furnace for manufacturing iron-manganese iron by dissolving iron ore and manganese ore supplied from the ore supply device 20, the lower odor gas supply pipe for supplying a low odor gas (11) is provided, and the upper part is provided with the oxygen injection lance 12 for blowing in oxygen.

The ore supply device 20 is a raw material storage device 21 for storing allel ore, ordinary coal and secondary material limestone, and a suitable amount supply device for quantitatively discharging raw materials and auxiliary materials stored in the raw material storage device 21 ( 22) and a raw material supply pipe 23 for gravitationally dropping the raw materials and sub-materials quantitatively discharged by the proper quantity supply device 22 to the iron-manganese steel manufacturing furnace 10.

The process gas circulation part 30 is a process gas first induction pipe 31 for inducing process gas (exhaust gas) generated in the manganese-manganese iron manufacturing furnace 10, and the high temperature induced through the induction pipe 31. A first high temperature cyclone 32 and a second high temperature cyclone 34 for separating iron and manganese spectroscopy and coal dust in the process gas, and the first high temperature cyclone 32 and the second high temperature cyclone The clone 34 is connected to the process gas by the process gas second induction pipe 33.

As described above, the process gas separated by iron, manganese spectroscopy and coal dust separated by the first and second high temperature cyclones 32 and 34 is discharged through the hot gas transport pipe 36.

The spectroscopic supply device 40 is a spectroscopic storage device for storing the iron, manganese spectroscopy and coal dust and the like and the pre-reduced spectroscopy and powdered coal from the spectroscopic or preliminary reduction reactor (35). 41), the spectroscopic amount extraction device 41 for extracting the spectroscopy, powdered coal, etc. stored in the spectroscopic storage device 41 by a predetermined amount, and the spectroscopy, powdered coal, etc. extracted by the spectroscopic amount extraction device 42, burner 50 It is configured to include a spectroscopic transport pipe 30 for transporting).

As shown in FIG. 2, the burner 50 is supported by the first support 51 and the second support 52 on the furnace wall of the iron-manganese steelmaking furnace 10, and transports the coal dust in the interior thereof. A pipe 53 is formed, and the powdered coal transport pipe 53 is connected to the spectroscopic transport pipe 43 of the spectroscopic feeder 40 to transport the powdered coal inlet 54 and the powder transported spectroscopic coal for introducing the powdered coal. It is connected to a gas source and connected to a transport gas inlet 55 for introducing a transport gas for transporting spectral coal.

An oxygen transport pipe 56 for supplying oxygen to the iron manganese iron manufacturing furnace 10 is formed outside the coal dust spectroscopy transport pipe 53, and the oxygen transport pipe 56 is connected to an oxygen supply source. It is connected to the oxygen inlet portion 57 through which oxygen is introduced.

The front end of the oxygen transport pipe 56 is connected to the injection nozzle 58, the powdered coal, the spectral transport pipe 53 is located by a predetermined length inside the injection nozzle 58, this injection nozzle 58 ) Is positioned inside the manganese-manganese iron manufacturing furnace (10), and the powdered coal, spectroscopic, and oxygen transported by the coal-spray transport pipe (53) and the oxygen transport pipe (56), respectively. Sprayed on.

Hereinafter, a method for manufacturing manganese iron using the manganese iron manufacturing apparatus of the present invention configured as described above will be described.

Iron ore and manganese ore, together with ordinary coal and secondary raw material lime, so that the concentration of manganese in the molten iron is the desired concentration, through the raw material storage device (21), fixed-quantity supply device (22) and raw material supply pipe (23) Gravity falls to the molten iron manufacturing furnace (10).

Iron, manganese ore and coal dust collected in the first high temperature cyclone 32 and the second high temperature cyclone 34 are collected in the spectroscopic storage device 41 together with the reduced spectroscopy and coal dust pre-reduced in the spectroscopic or prereduction furnace. After storage, the sample is extracted by a predetermined amount by the spectroscopic amount extraction device 42 and supplied to the burner 50 through the spectroscopic transport tube 43.

The burner 50 is located in the upper part of the chromium iron making furnace 10 to inject and dissolve the spectroscopy. The burner 50 uses a transport gas for the purpose of smoothly supplying spectral coal. At least one gas selected from the group consisting of some process gas, argon gas, carbon monoxide gas, carbon dioxide gas, hydrogen gas, and nitrogen gas separated from the hot cyclone is used.

Hereinafter, the burner (spectral coal combustion apparatus) 50 and the spectroscopy, the injection and combustion processes of the coal dust will be described in more detail.

The burners 50 are positioned above the manganese iron manufacturing furnace 10 to spray and dissolve the spectroscopy, and two or more burners 50 are preferably installed symmetrically. The front end of the burner 50 (that is, the front end of the injection nozzle 58) is introduced through the transport gas inlet 55 by oxygen introduced through the oxygen inlet 57 and the oxygen transport pipe 56. Combustion of the pulverized coal separated from the transport gas, that is, CO, H ₂ , or first and second high temperature cyclones 32 and 34 in the process flue gas occurs, and a high temperature zone (outside the flame) is generated by the combustion. Will be.

Therefore, at the same time, the spectral ore injected at the same time dissolves the fine powder (fine ore) in the whole process and the ore (neutral ore) having a relatively large particle size dissolves only the surface and merges ores into a semi-molten state. It falls to the slag layer (S) of the manganese iron manufacturing furnace (10).

As shown in FIG. 3 showing the particle size change after the fine ore of 0.71 mm or less is injected by the spectral jet burner, the grain size increases greatly as the fine ore passes through the combustion zone of the spectral jet burner. It can be seen that, accordingly, the redusting of the blown spectral is greatly suppressed.

Burner 50 used in the present invention for this purpose has a double tube structure, the spectral powder supplied from the spectral transport pipe 43 and the inlet through the coal dust inlet 54 is transported through the inlet port 55 The transport gas is transported to the injection nozzle 58 through the pulverized spectroscopic transport pipe 53, and is injected hydrodynamically continuously from the injection nozzle 58, whereby an oxygen inlet is formed between the outer tube and the inner tube. Oxygen necessary for combustion of the powdered coal is supplied through the 57 and the oxygen transport pipe 56.

The burner 50 is provided with water cooling means (not shown) to cool the outside and the inside to protect against thermal damage due to combustion and abrasion due to the supply of spectral coal, and facilitates high temperature combustion. In order to appropriately control the flame shape at the tip of the jet nozzle 58, that is, the jet nozzle 58, the tip of the powdered spectroscopy transport pipe 53, which is an inner tube, is arranged to be located further inward than the jet nozzle 58. .

Further, in order to concentrate the high temperature combustion heat by concentrating the oxygen supply, it is preferable to design the tip portion of the injection nozzle 58 to be narrowed toward the center. In addition, in order to facilitate dissolution coagulation of the spectral in the burner 50, it is preferable to maintain the amount of spectral powder to be injected and the amount of the transport gas at an appropriate level. In order to completely burn and dissolve the spectral coal in the high temperature combustion zone, it is necessary to control the reaction time passing through the high temperature combustion zone at the tip of the burner 50 by the amount of transport gas used.

The passing time of the inputted coal dust in the combustion zone is shortened by the increase of the transport gas volume, the transport gas components such as nitrogen in the combustion zone increases, and the combustion zone temperature decreases. Will be lowered.

This excessive use of transport gas leads to the generation and redusting of unburned coal and undissolved coalescence spectroscopy. However, if the amount of spectral coal transport gas is too small, the amount of spectral powder that can be injected decreases, and also the spectral powder is stagnant in the burner 50 and the coal powder supply is not smooth, making it difficult to form a stable high temperature combustion zone.

As an example, when using nitrogen gas as a transport gas of 1 kg of spectral coal, at least 0.05 Nm ³ of transport gas was required to form a stable high temperature combustion zone, and when the supply gas supply amount exceeded 0.5 Nm ³ , the high temperature combustion zone was unstable. Due to the high-speed flight of particles and particles, unburned coal and undissolved spectroscopy are dusted more than 8% of the total input amount, so the operation burden and separation efficiency of the first high temperature cyclone 32 are rapidly decreased, and the overall dust generation amount is greatly reduced. Will increase.

Therefore, when using nitrogen gas as the transport gas, it is preferable to set the nitrogen supply amount per 1 kg spectral coal powder in the range of 0.05-0.5 Nm ³ to form a stable high temperature combustion zone to facilitate the combustion and dissolution reaction of the injected feedstock. More preferably, it is 0.05-0.3 Nm <^2> .

The energy required for dissolution coagulation of spectroscopy is separated from the first and second high temperature cyclones 32 and 34, and the pulverized coal supplied to the burner 50 together with the spectroscopy is supplied with oxygen supplied through the oxygen transport pipe 56. It is supplied by burning together.

Therefore, it is necessary to mix and supply the spectral feed amount at an appropriate level of spectroscopy. If the mixing ratio is too low, the energy necessary for dissolving the spectra becomes insufficient and the spectroscopy is re-dusted without dissolving. Therefore, it is easy to cause thermal damage of the burner 50 due to an increase in the operating burden of the burner 50 and excessive temperature rise of the tip.

As an example, when the spectral powders of 0.71 mm or less were blown in, the mixed spectroscopy was less than 0.2 when the mixed weight ratio of spectral / powder was less than 0.2, and the dust was almost re-dusted. When the mixing ratio was 3.0 or more, the front end of the burner 50 was cooled. Excessively elevated temperature causes damage of burner 50, and rapid increase or damage of spectral injection of furnace wall refractory material of iron manganese steelmaking furnace 10 to which burner 50 is attached is relatively decreased, and thus, manganese having a predetermined manganese concentration. It is preferable to adjust the weight mixing ratio of spectroscopy / powder coal to about 0.2-0.3 because it causes a problem in supplying the spectroscopy for producing molten iron.

When the oxygen supply amount of the burner 50 is smaller than the coal dust amount, coal may be redusted or the temperature of the hot burning zone is lowered, so that the melting of manganese ore does not proceed, resulting in redusting of spectroscopy. If too much, the unused oxygen is used for the secondary combustion of the exhaust gas in the manganese-manganese iron making furnace 10, damage the refractory material of the chromium-containing iron making furnace 10, there is a fear to shorten the life.

Therefore, the oxygen supply amount to the burner 50 can maintain the temperature of the combustion zone according to the oxygen supply higher than the melting point of the manganese ore, and at least 50% of the secondary combustion rate should be maintained to supply the amount of heat required for melting. It is necessary to adjust the range not to exceed the secondary combustion rate of 100%.

As an example, as shown in FIG. 4, by supplying 1.0 Nm ³ -O ₂ / kg / Coal (mole ratio of oxygen / pulverized coal of 0.6) of manganese ore coal amount, a secondary combustion rate of about 50% or more was obtained. If less oxygen is supplied, redusting of the spectral coal starts to occur.

Hereinafter, the final reduction, melting, and charcoal in the manganese-manganese iron manufacturing furnace 10 will be described in more detail.

As described above, the lump ore and the lumped coal supplied through the spectroscopy and the raw material supply device 20 supplied to the burner 50 are supplied to the iron-manganese steelmaking furnace 10 and mixed in the slag layer S. By burning the carbonaceous material by the oxygen blown by the oxygen lance 12 on the slag layer S, the energy required in the furnace is supplied to finally reduce, dissolve, and burnt.

The generated gas is exhausted through the process gas circulation unit 30. The semi-melt mixed ore dropped in the slag layer (S) is present in an emulsion state under the slag layer (S) by the carbonaceous material suspended in the slag layer (S), dissolved carbon in the molten metal, and the stirring gas below. Final reduction is performed by the metal grains, and the process is as follows.

Natural manganese ore consists of most of the stoichiometric MnO ₂ and Mn ₂ O ₃ and Fe ₂ O ₃ and white ore. The lower slag layer (S) is a strong reducing component crisis, so the unreduced ore proceeds simultaneously with melting and reducing.

According to the basic experiment for the present invention, Fe oxide in the manganese ore is reduced preferentially in a reducing atmosphere, and the manganese ore is dissolved in the form of manganese oxide and finally reduced by carbonaceous material in slag or carbonaceous in molten iron. The gangue component is slagized.

Manganese oxide dissolved in slag is reduced by the following reaction by solid carbon and dissolved carbon in molten iron particles in molten metal and slag.

MnO + C = Mn + CO

MnO ₂ + 2C = Mn + 2CO

FeO + C = Fe + CO

In general, in order to increase the reduction rate of manganese oxide and to suppress the fire damage by manganese oxide, it is preferable to lower the target oxide concentration (manganese oxide concentration in slag + iron oxide concentration in slag) to 6 wt% or less. For this purpose, it is important to promote the reaction with the carbonaceous material in the slag by sufficiently stirring the slag layer.

In the case of manganese alloy iron, the higher the manganese content, the better. However, as can be seen from FIG. 5, which shows the concentration change of manganese and iron oxides in the slag according to the manganese content in molten iron at 1562 ° C., when manufacturing manganese-containing iron having a manganese content of 60 wt% or more, Manganese content is abnormally high.

Therefore, it is desirable to produce manganese-containing iron containing about 60wt% or less of manganese. If the manganese content of the manganese iron increases, the amount of manganese ore is also increased, so the treatment burden of the burner increases, so it is desirable to increase the amount of burner installed. If necessary, it is also possible to further supply coal dust to the spectroscopic dissolving device.

In order to save coal consumption, which is an energy source when manufacturing manganese iron, secondary combustion in the iron manganese iron manufacturing furnace (100 × (% CO ₂ +% H ₂ O) / (% CO +% H ₂ +% CO ₂ +% H ₂ O) needs to be maintained at an appropriate level, but excessive secondary combustion raises the exhaust gas temperature to about 2000 ° C, which significantly shortens the life of the furnace and furnace body by manufacturing manganese iron, but if the secondary combustion rate is too low, As the coal consumption is greatly increased and the amount of gas generated is greatly increased, the redusting rate of raw materials is increased, and the burden of the burner is increased accordingly, and the input amount of manganese ore is reduced. Therefore, the secondary combustion rate is maintained at about 60%. It is preferable.

As described above, the present invention not only eliminates pretreatment of raw materials by directly using spectroscopy using a burner, but also prevents redusting during the input of spectroscopy and recycles coal dust as fuel to reduce dust generation. It is an effect that can provide the manufacturing method and apparatus for iron-manganese iron which can be greatly reduced.

Claims (5)

An apparatus for producing manganese-containing iron by mixing and reducing and melting manganese or iron ore using a carbon-containing material as a heat source and a reducing agent, wherein an oxygen lance 12 is provided and a spectral coal combustion device 50 is attached. A manganese iron manufacturing furnace 10; An ore supply device 20 configured to supply allelic ore, general coal and secondary raw materials to the manganese iron manufacturing furnace 10; A process gas circulation unit 30 configured to separate iron, manganese-based spectroscopy, and coal dust in the process gas generated in the manganese-manganese iron manufacturing furnace 10 and then exhaust the process gas; And a spectroscopic supply device configured to supply iron, manganese spectroscopy and coal dust collected in the process gas circulation unit 30 and spectroscopy and coal dust preliminarily reduced in the preliminary reduction reactor to the spectroscopic coal combustion apparatus 50. Manganese iron manufacturing apparatus, characterized in that comprises a 40). In the method for producing manganese-containing iron by mixing and reducing and melting manganese or iron ore using a carbon-containing material as a heat source and a reducing agent, the ore supply device for the coal or secondary material in the manganese ore (20) Supply to the manganese iron manufacturing furnace 10 through; Supplying the fine ore and coal dust collected in the heavy and fine ore in the powdered manganese ore and the process gas of iron-manganese iron to the spectral coal combustion apparatus 50; Spectroscopy and powdered coal supplied to the spectral coal combustion apparatus 50 are transported by a transport gas of 0.05 to 0.5 Nm ³ / kg-spectral and powdered coal and sprayed together with oxygen to the iron-manganese steelmaking furnace 10; Alleles, medium and fine ores supplied to the manganese-manganese iron making furnace 10 are mixed under secondary combustion rate conditions of 60% or less, and are finally reduced, melted and charred; And iron, manganese and coal dust in the process gas generated in the manganese-manganese iron manufacturing furnace 10 is collected by the process gas circulation unit 30, and mixed with the fine ore, the spectral coal combustion apparatus The method of manufacturing iron manganese iron, characterized in that configured to be supplied to (50) supplied to the iron manganese iron manufacturing furnace (10). A method of producing manganese-containing iron by mixing and reducing and melting manganese or iron ore using a carbon-containing material as a heat source and a reducing agent, wherein the ore, coal and minor raw materials in the powdered manganese ore are fed ore (2) Supply to the manganese iron manufacturing furnace 10 through; Supplying the fine ore and coal dust collected in the middle, fine ore, and the process gas of iron-manganese iron in the powdered manganese ore to the spectral coal combustion apparatus 5; Spectroscopy and powdered coal supplied to the spectral coal combustion apparatus 50 are transported by a transport gas of 0.05 to 0.5 Nm ³ / kg-spectral and powdered coal and sprayed together with oxygen to the iron-manganese steelmaking furnace 10; Alleles, medium and fine ores supplied to the manganese-manganese iron making furnace 10 are mixed under secondary combustion rate conditions of 60% or less, and are finally reduced, melted and charred; Deodorizing one gas selected from the process gas, the argon gas and the nitrogen gas generated in the iron-manganese iron manufacturing furnace 10 as the agitation gas of the slag and the molten metal in the iron-manganese iron manufacturing furnace 10; Then, iron, manganese and coal dust in the process gas generated in the manganese-manganese iron manufacturing furnace 10 is collected by the process gas circulation unit 30, and mixed with the fine ore, the spectral coal The method for manufacturing iron manganese iron, characterized in that configured to be supplied to the combustion device 50 is supplied to the iron manganese iron manufacturing furnace (10). 3. The method according to claim 2, wherein the gas selected from among the process gas, argon gas and nitrogen gas generated in the iron-manganese steelmaking furnace 10 is used as a transport gas of fine ore in the spectral coal combustion apparatus 10. Method for manufacturing iron manganese iron. The particle size of the carbon-containing dust injected from the spectral coal combustor 50 is 0.71 mm or less, and the mixing ratio of the ore to carbon-containing dust is 0.2 to 3.0 by weight. Method for producing iron manganese iron, characterized in that limited to.