CN106755973B

CN106755973B - A method of reducing Ore Sintering Process NO discharges

Info

Publication number: CN106755973B
Application number: CN201611162793.2A
Authority: CN
Inventors: 王海风; 张春霞; 齐渊洪; 严定鎏; 王�锋; 高建军; 郄俊懋
Original assignee: CISRI SHENGHUA ENGINEERING TECHNOLOGY Co Ltd
Current assignee: Linyi Iron And Steel Industry Collaborative Innovation Center; CISRI Sunward Technology Co Ltd
Priority date: 2016-12-15
Filing date: 2016-12-15
Publication date: 2018-10-09
Anticipated expiration: 2036-12-15
Also published as: CN106755973A

Abstract

The present invention relates to a kind of methods of reduction Ore Sintering Process NO discharges.This approach includes the following steps：In sintering burden process bringing into for N element is reduced from source, including iron ore, fuel, flux, return to material, wherein iron ore bring that N element amount accounts for general input into 30% 40%, fuel brings 40% 50% that N element amount accounts for general input into, while the sintering flue gas of sintering machine is divided into two parts according to discharge characteristics：First part's flue gas corresponds to first part's bellows, this partial fume temperature is low, SO₂Concentration is low, NO_xConcentration is high；Second part flue gas corresponds to second part bellows, this partial fume temperature is high, SO₂Concentration is high, and NOx concentration is low；After first part's flue gas and the vertical heat exchange of sinter, NO is removed using existing SCR methods_x；Second part flue gas is recycled into sintering machine use.NOx emission is reduced, compared with ordinary sinter technique, 25% or more is reduced, reduces investment, can be transformed due to existing sintering process.

Description

A method of reducing Ore Sintering Process NO discharges

Technical field

The present invention relates to Ferrous Metallurgy SINTERING TECHNOLOGY field, more particularly to a kind of reduction Ore Sintering Process NO discharges Method.

Background technology

For steel production in China based on blast furnace-converter " long flow ", sintering is the main production process of blast furnace raw material, sintering Mine accounts for the 70~75% of blast furnace burden, particularly important to the development of China's steel and iron industry.But influence of the sintering production to environment Also very big, not only pollutant kind is more, but also discharge capacity is big, including smoke-dust, SO2, NOx, fluoride, heavy metal, two Evil English etc. is one of main process of Air Pollutant Emission in integrated iron and steel works.According to statistics, China's sintering circuit in 2013 Smoke-dust discharge capacity is 189085.47 tons, and SO2 discharge capacitys are 557962.14 tons, and NOx discharge is 260697.43 tons, respectively Account for about 40.9%, 76.3% and the 47.6% of China's Key Iron And Steel total emission volumn.It can be seen that sintering circuit smoke pollution The comprehensive treatment of object is the key that steel industry emission reduction.

Currently, there are many sintering flue gas pollutant removing sulfuldioxide type, but it is the end treatment for Single Pollution object mostly Technique, such as electrostatic precipitator, sulfur removal technology (including calcium method, magnesium processes, ammonia process), denitrating technique etc., since sintering flue gas amount is non- Chang great, about 3000~4000m3/t, and the pollutant concentrations such as SO2 and NOx are relatively low, lead to the investment running cost of end treatment equipment With very high, and it is less efficient.With China in 2012《Steel sintering, pelletizing industrial air pollution object discharge standard》 (GB28662-2012) publication, it is tighter to sintering flue gas pollutant emission request, reach pollutant only by end treatment Discharge standard, not only technology is difficult, and cost is also very high.In addition, pollutant kind requires more, to increase NOx and two The emission limit of Evil English, for bioxin, there are no ripe industrialized units, and it is effectively treated in China at present.

In conclusion the control method of sintering flue gas pollutant belongs to the end treatment facility having a single function more at present, with Increasing for pollutant kind limitation, end treatment facility is difficult to meet emission request, and its investment operating cost is very high, because This, needs to start with from process control, develops significantly more efficient sintering process energy-saving and emission-reducing technique.

Invention content

In order to achieve the above object, this approach includes the following steps：

A method of Ore Sintering Process NO discharges are reduced, reduce the band of N element from source in sintering burden process Enter, including iron ore, fuel, flux, return material, return mine, wherein iron ore brings the 30%- that N element amount accounts for general input into 40%, fuel brings the 40%-50% that N element amount accounts for general input into, while by the sintering flue gas of sintering machine according to discharge characteristics It is divided into two parts：First part's flue gas corresponds to first part's bellows, this partial fume temperature is low, and SO2 concentration is low, NOx concentration It is high；Second part flue gas corresponds to second part bellows, this partial fume temperature is high, and SO2 concentration is high, and NOx concentration is low；By first Divide flue gas with after the vertical heat exchange of sinter, NOx is removed using existing SCR methods；Second part flue gas, which is recycled into sintering machine, to be made With.

Further, 27 bellows are disposed with from sintering machine entrance to outlet, entrance starts the 1-16 bellows and is First part's bellows, share the first flue, behind 17-27 bellows be second part bellows, share the second flue；First flue It is connect with the vertical device of sinter, makes first part's flue gas with after the vertical heat exchange of sinter, NOx is removed using existing SCR methods, the Second part flue gas is returned to sintering machine petticoat pipe by two flues.

Further, about 80 DEG C of first part's flue-gas temperature, about 250 DEG C of the temperature of second part flue gas.

Further, iron ore leaded wastewater is controlled 0.2% hereinafter, the control of fuel leaded wastewater is below 0.8%.

Further, iron ore leaded wastewater is controlled 0.15% hereinafter, the control of fuel leaded wastewater is below 0.4%.

Further, the fuel is coke powder and/or coal dust.

Further, it is sintering electro-precipitating dust, blast furnace gravitational dust, blast furnace cloth bag ash, slag and/or steel rolling oxidation to return to material Iron sheet.

Further, by after first part's flue gas and the vertical heat exchange of sinter, NOx therein is removed with existing activated coke method It substitutes and removes NO using existing SCR methods_x。

Compared with the conventional method, the beneficial effects of the present invention are：1, reduction NOx is brought by reducing N element from source It generates.2, it using sintering process feature, takes flue gas segmentation from heat exchange mode, reduces exhaust gas volumn, improve flue-gas temperature, using now There are SCR techniques, reduce NOx emission, compared with ordinary sinter technique, reduces 25% or more, reduce investment, it can be due to existing sintering Technological transformation.

Description of the drawings

Fig. 1 erects the air layer pressure loss of pot type cooling.

Fig. 2 erects the Temperature Distribution of the cooling mine of pot type cooling.

Fig. 3 erects the air themperature distribution of pot type cooling.

Specific implementation mode

Certain factory is sintered specific implementation mode

Raw material iron ore, fuel, flux, return to material, the index returned mine see the table below 1-3

1 iron ore of table, fuel, solvent main component (mass percent, %)

Table 2 is returned mine main component (mass percent, %)

Ingredient	TFe	SiO₂	CaO	Al₂O₃	MgO	S
							Content	56.03	5.00	9.75	2.57	1.30	0.023

Table 3 returns to material main component (mass percent, %)

Above-mentioned raw materials progress dispensing is obtained into sinter mixture, is shown in Table 4.

4 sinter mixture main component of table (mass percent, %)

N element is reduced from source bringing into, including iron ore, fuel, flux, return to material, return in sintering burden process Mine, wherein iron ore bring the 30%-40% that N element amount accounts for general input into, and fuel brings N element amount into and accounts for general input 40%-50%, while the sintering flue gas of sintering machine is divided into two parts according to discharge characteristics：First part's flue gas corresponds to first Part bellows, this partial fume temperature is low, and SO2 concentration is low, and NOx concentration is high；Second part flue gas corresponds to second part bellows, this Partial fume temperature is high, and SO2 concentration is high, and NOx concentration is low；After first part's flue gas and the vertical heat exchange of sinter, using existing There are SCR methods to remove NOx；Second part flue gas is recycled into sintering machine use.It is sintered each bellows smoke discharge amount and temperature is shown in Table 5。

Table 5 is sintered each bellows smoke discharge amount and temperature

1-16# bellows mix, and the mixing of 17-27# bellows, Gas Parameters are shown in Table 6-1 and table 6-2 after mixing.

Gas Parameters I after table 6-1 mixing

Gas Parameters II after table 6-2 mixing

Flue gas is shown in Fig. 1-3 with the parameter for erecting tank after the vertical heat exchange of sinter.

27 bellows are disposed with from sintering machine entrance to outlet, it is first part's wind that entrance, which starts the 1-16 bellows, Case, share the first flue, behind 17-27 bellows be second part bellows, share the second flue；First flue is perpendicular with sinter Formula device connects, and after making first part's flue gas and the vertical heat exchange of sinter, NOx is removed using existing SCR methods, and the second flue is by the Two partial fumes return to sintering machine petticoat pipe.About 80 DEG C of first part's flue-gas temperature, the temperature about 250 of second part flue gas ℃。

Using above-mentioned sintering process, NOx emission reduces 30% compared with ordinary sinter.

The foregoing is only a preferred embodiment of the present invention, but scope of protection of the present invention is not limited thereto, Any one skilled in the art in the technical scope disclosed by the present invention, the change or replacement that can be readily occurred in, It should be covered by the protection scope of the present invention.

Claims

1. a kind of method reducing Ore Sintering Process NO discharges, it is characterised in that：In sintering burden process N is reduced from source Element is brought into, including iron ore, fuel, flux, return material, return mine, wherein iron ore brings N element amount into and accounts for general input 30%-40%, fuel bring the 40%-50% that N element amount accounts for general input into, while by the sintering flue gas of sintering machine according to discharge Feature is divided into two parts：First part's flue gas corresponds to first part's bellows, this partial fume temperature is low, SO₂Concentration is low, NO_xIt is dense Degree is high；Second part flue gas corresponds to second part bellows, this partial fume temperature is high, SO₂Concentration is high, and NOx concentration is low；By first Partial fume removes NO with after the vertical heat exchange of sinter using existing SCR methods_x；Second part flue gas is recycled into sintering machine It uses.

2. the method for reducing Ore Sintering Process NO discharges as described in claim 1, it is characterised in that：From sintering machine entrance to Outlet is disposed with 27 bellows, and it is first part's bellows that entrance, which starts the 1-16 bellows, shared first flue, behind the 17-27 bellows are second part bellows, share the second flue；First flue is connect with the vertical device of sinter, makes first part Flue gas removes NOx, second part flue gas is returned to sintering machine by the second flue with after the vertical heat exchange of sinter using existing SCR methods Petticoat pipe.

3. a kind of method reducing Ore Sintering Process NO discharges according to claim 1 or 2, it is characterised in that：It is described 80 DEG C of first part's flue-gas temperature, 250 DEG C of the temperature of second part flue gas.

4. a kind of method reducing Ore Sintering Process NO discharges according to claim 1 or 2, it is characterised in that：Iron ore The control of stone leaded wastewater is 0.2% hereinafter, the control of fuel leaded wastewater is below 0.8%.

5. a kind of method reducing Ore Sintering Process NO discharges according to claim 4, it is characterised in that：Iron ore contains The control of N amounts is 0.15% hereinafter, the control of fuel leaded wastewater is below 0.4%.

6. a kind of method reducing Ore Sintering Process NO discharges according to claim 5, it is characterised in that：The fuel For coke powder and/or coal dust.

7. a kind of method reducing Ore Sintering Process NO discharges according to claim 5, it is characterised in that：Returning to material is Sintering electro-precipitating dust, blast furnace gravitational dust, blast furnace cloth bag ash, slag and/or steel rolling iron scale.

8. a kind of method of reduction Ore Sintering Process NO discharges described in claim 5, it is characterised in that：By first part's cigarette Gas removes NOx replacements therein with existing activated coke method and removes NO using existing SCR methods with after the vertical heat exchange of sinter_x。