JP2000103656A - Burner for treatment of steel-making waste - Google Patents

Abstract

PROBLEM TO BE SOLVED: To permit the dust that is regarded as a steel-making waste as well as an industrial waste and the reducing slag that is similarly regarded as a steel-making waste as well as an industrial waste to be utilized effectively at the same time. SOLUTION: This burner for treating steel-making waste has the fuel-feeding hole 5a that is opened at the center of the forefront face, the primary oxygen- feeding slit 5b that is annularly opened on the outside of the fuel-feeding hole 5a, the dust and reducing slag feeding holes 5d that is composed of a plurality of elliptically shaped, long hole 5c that are opened in an annular arrangement on the outside of the primary oxygen-feeding slit 5b and the secondary oxygen feeding holes 5f that are composed of a plurality of round holes 5e that are annularly opened on the outside of the dust and reducing slag-feeding holes 5d.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to dusts that are discharged during steel making and have been discarded because they have little use value, and that dusts that have been discharged during steel making and have little use value have been discarded. The present invention relates to a burner for treating steelmaking emissions, which is suitable for effectively utilizing reduced slag.

[0002]

2. Description of the Related Art An electric furnace is often used for melting steelmaking raw materials such as steel scrap, and even in steelmaking work using such an electric furnace, the furnace capacity is increased and the electric power (UHP) is increased. , Water cooling box, degassing method (D
(H method, RH method), ladle refining, DC furnace, etc.

[0003] In steel making operations using such electric furnaces and the like, dust collectors of a direct type or a building type are installed in order to prevent air pollution. Is discharged. Similarly, in a steelmaking operation using such an electric furnace, steel scraps and the like put into the furnace are tapped through a melting phase, an oxidation phase, a slag removal process, and a reduction phase. The oxidized slag and reduced slag, which are emissions, are discharged.

[0004]

Among such steelmaking emissions, dust has a high ZnO content (for example, about 1%).
(0 to 25% by weight), but it is hardly reused. This dust has a high Fe content as an Fe oxide (for example, about 50 to 60% by weight as FeO or Fe ₂ O ₃ ), and the Fe oxide is reduced to be recovered as Fe. It is not economical, though not impossible.

On the other hand, oxidized slag is reused, for example, as a roadbed material for asphalt-paved roads. However, reduced slag has a large CaO content in its components, and this CaO reacts with water to form CaO (quicklime). ) + H ₂ O (water) → Ca
Since the volume expands about twice by changing to (OH) ₂ (slaked lime), when this reduced slag is used as a roadbed material as it is, the reaction with rainwater and the like progresses as the days pass and the volume decreases. It is not preferable because it expands and lifts the asphalt pavement surface.

Therefore, when the reduced slag is used as a roadbed material, the volume is expanded by performing a so-called aging process of exposing it to rainwater for a long period of time, immersing it in a reservoir, or contacting it with steam on a factory site or the like. Although it is necessary to change to Ca (OH) ₂ , such aging work is not very preferable because it requires a long period of time and requires a large site for accumulation.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned conventional problems, and has the following features.
It is an object of the present invention to provide a burner for treating steelmaking waste, which makes it possible to simultaneously reuse reduced slag which is also a steelmaking waste.

[0008]

According to the present invention, a burner for treating a steelmaking effluent according to the present invention supplies reduced slag, which is a steelmaking effluent as well as dust, which is a steelmaking effluent, into a high-temperature frame and melts it into oxidized slag. According to the first aspect of the present invention, there is provided a fuel supply hole opened at the center of the front end face, a ring-shaped primary oxygen supply slit opened outside the fuel supply hole, and a ring outside the primary oxygen supply slit. A dust and reduction slag supply hole composed of a plurality of elliptical elongated holes that are arranged and opened, and a secondary oxygen supply hole composed of a plurality of circular holes that are annularly arranged and opened outside the dust and reduction slag supply hole The fuel supply hole is formed at the center of the front end surface, the ring-shaped primary oxygen supply slit is formed outside the fuel supply hole, and the primary oxygen supply slit is formed. Outside A steelmaking discharge dust supply comprising a secondary oxygen supply hole comprising a plurality of round holes that are arranged and opened in an annular shape, and a plurality of elliptical elongated holes that are annularly arranged and opened outside the secondary oxygen supply hole. A dust and reduced slag supply hole opened at the center of the tip end face, a gas fuel supply hole opened outside the dust and reduced slag supply hole, It has a ring-shaped primary oxygen supply slit opened outside the fuel supply hole, and a secondary oxygen supply hole composed of a plurality of round holes opened annularly outside the primary oxygen supply slit.

According to the burner for treating steelmaking emissions according to the present invention, the dust supplied to the high-temperature frame formed at the tip of the burner and the reduced slag are melt-mixed by the above-mentioned structure, whereby the oxidized slag is formed. In addition, dust is mixed and melted in the molten reduced slag in the container, and oxidized slag is obtained.This oxidized slag is used as a roadbed material of asphalt paved road without aging treatment. Therefore, both dust, which is a steelmaking effluent and was conventionally treated as industrial waste, and reduced slag, which is also a steelmaking effluent and was also treated as industrial waste, are produced. It can be effectively used at the same time.

[0010]

FIG. 2 shows an embodiment in which a steelmaking waste is treated by using the steelmaking waste treatment burner according to the present invention. The treatment vessel 2 is placed on a table 1 and
A slag pan (or water tank) below the gutter 3 of the processing container 2
4 are installed.

A lid 2a is put on the upper part of the processing vessel 2, and an oxygen burner (pure oxygen burner in this embodiment) 5 which is a burner for treating a steelmaking waste is provided through the lid 2a. . The fuel 7 is supplied to the oxygen burner 5 through a pipe 6, and
Through oxygen (primary oxygen 10a, secondary oxygen 10a
b) 10 is delivered and this oxygen 10
The fuel 7 is burned by the oxygen burner 5
The high-temperature frame 11 comes out from the tip of.

The oxygen burner 5 has a pipe 12 (1
2a), powder dust 14 in the dust hopper 13 is supplied. At this time, the supply of the dust 14 is carried by a carrier gas (air in this embodiment) 16 fed from a pipe 15. This is done by the flow of. Similarly, the oxygen burner 5 has a pipe 1
2 (12b), the powdery reduced slag 18 in the slag hopper 17 is supplied.
At this time, the supply of the reduction slag 18 is performed by the flow of the carrier gas (air in this embodiment) 20 sent from the pipe 19. Further, inside the oxygen burner 5, a cooling water 22 is caused to flow through a pipe 21 in order to cool a jacket of the oxygen burner 5.

FIG. 1 is a view showing a front end surface of the oxygen burner 5, and shows a fuel supply hole 5a opened at the center of the front end surface.
A ring-shaped primary oxygen supply slit 5b opened outside the fuel supply hole 5a, and a plurality of oval-shaped long holes 5 arranged annularly outside the primary oxygen supply slit 5b.
c and a secondary oxygen supply hole 5f composed of a plurality of round holes 5e that are arranged annularly and open outside the dust and reduction slag supply hole 5d.

From the central fuel supply hole 5a,
The pressurized fuel 7 in a spray state is supplied, the primary oxygen 10 (10a) is supplied from the primary oxygen supply slit 5b outside the fuel supply hole 5a, and the primary oxygen 10 (10a) is supplied from the outermost secondary oxygen supply hole 5f. Secondary oxygen 10 (10b) is supplied. The dust 14 and the reduced slag 18 are supplied together with the carrier gases 16 and 20 from the dust and reduced slag supply hole 5d. Although not shown in FIG. 1, as described above, the water cooling structure in which the cooling water 22 flows on the outside of the oxygen burner 5 is provided.

In the oxygen burner 5 used here,
The position of the dust and reduced slag supply hole 5d does not need to be a specific position, and a long hole 5c for supplying powder may be formed on the outermost side of the oxygen burner 5, as shown in FIG. When the fuel supplied from the fuel supply hole 5a is a gas, there is no need to spray the gas. Therefore, as shown in FIG. The fuel supply hole 5a, the primary oxygen supply slit 5b, and the secondary oxygen supply hole 5f may be opened in this order.

In FIG. 2, each dust hopper 1
3 and the slag hopper 17 are provided with valves or rotary feeders 13a, 13a capable of adjusting the flow rate.
7a is provided so that the supply amounts of the dust 14 and the reduction slag 18 can be adjusted.

Further, a dust collection duct 27 for collecting exhaust gas 26 discharged together with the molten slag 25 from the gutter 3 is installed above the slag pan (or water tank) 4. High Zn in secondary dust
O dust is collected.

In the steelmaking waste treatment facility shown in FIG. 2, the fuel 7 is burned by oxygen 10 and
High temperature frame 1 from the tip of oxygen burner 5 having the configuration shown in FIG.
1 was generated.

The fuel 7 used here is kerosene, and the supplied primary oxygen 10 (10a) and secondary oxygen 10 (10b)
Is the theoretical amount of oxygen required for complete burning of kerosene (ie, an oxygen ratio of 1.0). The amount of air as the carrier gas 16, 20 was an air amount containing 5% of the theoretical oxygen amount required for complete combustion of kerosene. Therefore, the oxygen ratio with respect to kerosene in the high-temperature frame 11 at this time is 1.05, which is a slight oxygen excess state.

In such a state, the steelmaking discharge, Table 1
Of the main component shown in Table 1 and the reduced slag 18 of the main component also shown in Table 1, which is the steelmaking discharge, in three ratios of 1: 0 (melting only dust) and 1: 1, 1: 3. The opening or the rotation speed of the valves or the rotary feeders 13a and 17a and the flow rates of the carrier gases 16 and 20 are adjusted and supplied into the high-temperature frame 11 so that the dust 14 and the reduction slag 1
8 was melt-mixed and passed through a slag pan 4 through the bottom of the vessel 2 and the gutter 3, and was recovered as oxidized slag 29 of the main component shown in Table 2. When a water tank was used instead of the slag pan 4, it was possible to obtain granular oxide slag by the surface tension of the glassy fluid. Further, the ZnO concentration in the secondary dust collected through the dust collection duct 27 at this time was also as shown in Table 2.

[0021]

[Table 1]

[0022]

[Table 2]

The oxidized slag thus obtained can be used as it is or by a lighter aging treatment than conventional reduced slag as a roadbed material for asphalt-paved roads. As was reusable.

As another embodiment, an embodiment different from the above embodiment only in the following points will be described. In this embodiment, primary oxygen 10 (10a) and secondary oxygen 10 (10a) are supplied.
The total amount of (10b) is supplied to the fuel 7 while being suppressed to 95% or less of the theoretical oxygen amount required for complete combustion.

In this case, the oxygen ratio in the high temperature flame 11 becomes 1.0 or less, and CO gas is generated due to lack of oxygen. This CO gas reacts with ZnO in the high-temperature frame 11 as described below to generate Zn gas.

ZnO + CO → Zn (gas) + CO ₂

Therefore, a large amount of Zn gas is present in the exhaust gas, and the Zn gas is reoxidized in the dust collecting duct 27, so that the ZnO concentration in the secondary dust tends to increase. This tendency is advantageous for recovery of ZnO.

As an example, the primary oxygen 10 (10
When the total amount of a) and secondary oxygen 10 (10b) was 85% of the theoretical oxygen amount, the ZnO concentration in the secondary dust increased by 7 to 2% from the value shown in Table 2. However, in this case, since the combustion is not complete, the temperature of the high-temperature frame 11 and the calorific value in the high-temperature frame 11 decrease, resulting in the use of a large amount of fuel, which is economically disadvantageous as a method for obtaining oxidized slag. Was.

FIG. 3 shows still another embodiment of the treatment of the steelmaking effluent using the steelmaking effluent treatment burner having the structure shown in FIG. A lid 32a is placed on the ladle 32, and an oxygen burner 35 is installed through the lid 32a. This oxygen burner 35 has a pipe 36
Fuel 37 is supplied through the pipes 38, 3
Through 9 (primary oxygen 40a, secondary oxygen 4a
0b) 40 is supplied, and when the fuel 37 is burned by the oxygen 40, the high-temperature flame 41 comes out from the tip of the oxygen burner 35.

The oxygen burner 35 passes through a pipe 42 through a powder dust 4 in a dust hopper 43.
4 is supplied. At this time, dust 44 is supplied.
Is supplied by the flow of the carrier gas 46 sent from the pipe 45. Further, inside the oxygen burner 35, a cooling water 52 is caused to flow through a pipe 51 in order to cool a jacket of the oxygen burner 35.

The dust hopper 43 is provided with a valve or a rotary feeder 43a capable of adjusting the flow rate, so that the supply amount of the dust 44 can be adjusted. A dust collection duct 57 is connected to the lid 32a.

In the steelmaking waste treatment facility shown in FIG. 3, the fuel 37 is burned with oxygen 40 to generate a high-temperature flame 41 from the tip of the oxygen burner 35, and the steelmaking waste dust is generated. 44 is supplied into the high-temperature frame 41, and the dust in the molten state is mixed and melted in the smelting reduction slag 48 in the ladle 32, and thereafter, the ladle 31 is tilted to be collected as the oxidized slag (59).

At this time, the oxidized slag (59) in the molten state
By dropping into a water tank, granular oxide slag can be obtained due to the surface tension of the glassy substance. Secondary dust having a high ZnO concentration was recovered as a Zn raw material through the dust collection duct 57.

The oxidized slag (59) thus obtained
It could be used as it is or by a lighter aging treatment than conventional reduced slag, as a roadbed material for asphalt-paved roads, and high ZnO secondary dust could be reused as a Zn raw material.

[0035]

The burner for treating steelmaking waste according to the present invention is configured to supply reduced slag, which is the same as steelmaking discharge, as well as dust, which is the steelmaking discharge, into the high-temperature frame formed by the burner. Dust and reduced slag are melted into oxidized slag, or dust is supplied into molten reduced slag in a container and melted into oxidized slag.This oxidized slag is used, for example, as a roadbed material for asphalt-paved roads. It is possible to use it, and there is provided a remarkably excellent effect that dust and reduced slag, which are regarded as industrial waste, can be effectively used at the same time.

[Brief description of the drawings]

FIG. 1 is a view showing a tip surface of an embodiment of a burner for treating a steelmaking waste according to the present invention.

FIG. 2 is an explanatory view showing an example of the treatment of the steelmaking waste by the burner for treating the steelmaking waste according to the embodiment of FIG. 1;

FIG. 3 is an explanatory view showing another example of the treatment of the steelmaking discharge.

FIG. 4 is a view showing a tip surface of another embodiment of the burner for treating steelmaking waste according to the present invention.

FIG. 5 is a view showing a tip end surface of still another embodiment of the burner for treating steelmaking emissions according to the present invention.

[Explanation of symbols]

5, 35: oxygen burner, 5a: fuel supply hole, 5b: primary oxygen supply slit, 5d: plural oval long holes 5c
And secondary oxygen supply holes composed of a plurality of round holes 5e.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F27D 17/00 105 F27D 17/00 105K (72) Inventor Junichi Tsubokura 3-6-Teramotodai, Chita City, Aichi Prefecture 18 (72) Inventor Isaaki Koizumi 18 A-102, Kagiya-cho, Tokai City, Aichi Prefecture

Claims (3)

[Claims] 1. A fuel supply hole opened at the center of a front end face,
A ring-shaped primary oxygen supply slit opened outside the fuel supply hole, a dust and reduction slag supply hole comprising a plurality of elliptical elongated holes that are annularly arranged and opened outside the primary oxygen supply slit, And a secondary oxygen supply hole comprising a plurality of circular holes which are annularly arranged and opened outside the dust and reduced slag supply holes. 2. A fuel supply hole opened at the center of the front end face,
A ring-shaped primary oxygen supply slit opened outside the fuel supply hole, a secondary oxygen supply hole composed of a plurality of circular holes opened annularly outside the primary oxygen supply slit, and the secondary oxygen supply hole. A burner for treating a steelmaking effluent having a steelmaking effluent dust supply hole comprising a plurality of elliptical elongated holes which are annularly arranged and opened outside the supply hole. 3. A dust and reduction slag supply hole opened at the center of the front end surface, a gas fuel supply hole opened outside the dust and reduction slag supply hole, and a ring shape opened outside the gas fuel supply hole. A burner for treating steelmaking emissions, comprising: a primary oxygen supply slit; and a secondary oxygen supply hole composed of a plurality of round holes that are annularly arranged and opened outside the primary oxygen supply slit.