CN107532223A - The processing of low calorific value waste gas - Google Patents
The processing of low calorific value waste gas Download PDFInfo
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- CN107532223A CN107532223A CN201680018898.2A CN201680018898A CN107532223A CN 107532223 A CN107532223 A CN 107532223A CN 201680018898 A CN201680018898 A CN 201680018898A CN 107532223 A CN107532223 A CN 107532223A
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/14—Multi-stage processes processes carried out in different vessels or furnaces
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
- C21B13/0013—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state introduction of iron oxide into a bath of molten iron containing a carbon reductant
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B13/00—Making spongy iron or liquid steel, by direct processes
- C21B13/14—Multi-stage processes processes carried out in different vessels or furnaces
- C21B13/143—Injection of partially reduced ore into a molten bath
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/56—Manufacture of steel by other methods
- C21C5/567—Manufacture of steel by other methods operating in a continuous way
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B14/00—Crucible or pot furnaces
- F27B14/08—Details peculiar to crucible or pot furnaces
- F27B14/14—Arrangements of heating devices
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/004—Systems for reclaiming waste heat
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D17/00—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases
- F27D17/008—Arrangements for using waste heat; Arrangements for using, or disposing of, waste gases cleaning gases
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21B—MANUFACTURE OF IRON OR STEEL
- C21B2100/00—Handling of exhaust gases produced during the manufacture of iron or steel
- C21B2100/60—Process control or energy utilisation in the manufacture of iron or steel
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C5/00—Manufacture of carbon-steel, e.g. plain mild steel, medium carbon steel or cast steel or stainless steel
- C21C5/28—Manufacture of steel in the converter
- C21C5/30—Regulating or controlling the blowing
- C21C5/305—Afterburning
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B14/00—Crucible or pot furnaces
- F27B2014/002—Smelting process, e.g. sequences to melt a specific material
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27B—FURNACES, KILNS, OVENS, OR RETORTS IN GENERAL; OPEN SINTERING OR LIKE APPARATUS
- F27B14/00—Crucible or pot furnaces
- F27B2014/002—Smelting process, e.g. sequences to melt a specific material
- F27B2014/004—Process involving a smelting step, e.g. vaporisation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F27—FURNACES; KILNS; OVENS; RETORTS
- F27D—DETAILS OR ACCESSORIES OF FURNACES, KILNS, OVENS, OR RETORTS, IN SO FAR AS THEY ARE OF KINDS OCCURRING IN MORE THAN ONE KIND OF FURNACE
- F27D19/00—Arrangements of controlling devices
- F27D2019/0003—Monitoring the temperature or a characteristic of the charge and using it as a controlling value
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- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Manufacturing & Machinery (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Waste-Gas Treatment And Other Accessory Devices For Furnaces (AREA)
Abstract
Disclose a kind of direct melting method for being used to process low calorific value waste gas.Methods described includes being fed to carbonaceous material in the liquid-bath of the metal in direct smelting container and slag, and, to make the reacting gas after-combustion in the liquid-bath in the headroom, and it will thus produce waste gas in the headroom above the hot gas blast supply from stove to the liquid-bath.Methods described includes fuel gas, waste gas and oxygen-containing burning gases being fed to the stove and makes the fuel gas, waste gas and burning gases burning to heat the stove, and when the calorific value of the waste gas is less than 1.8MJ/Nm3When (being based on HHV), by the way that the waste gas is fed into the stove to control the dome temperature in the stove together with the fuel gas and the burning gases.Further disclose a kind of direct smelting plant for being used to metal-containing material be smelted into molten metal in the liquid-bath of metal and slag.The equipment runs process as described above.
Description
Technical field
The present invention relates to a kind of method for melting metal-containing material.
Term " metal-containing material " is understood herein to include solid feed and also includes part also in the range of it
Former metal-containing material.
The present invention, although more specifically, never exclusively, being related to a kind of be used for by metalliferous feed material production molten metal
Method of smelting based on liquid-bath, the metalliferous feed material is injected into melting container, the melting container has in liquid-bath by gas
Body separate out caused by bath/slag fountain by force, the wherein gas evolution is at least partly to contain carbon materials by being injected into the liquid-bath
Caused by material.
Specifically, although never exclusively, the present invention relates to a kind of iron-bearing materials for melting such as iron ore and life
The method for producing molten iron.
The present invention specifically, although never exclusively, being related to a kind of including the main chamber for melting metal-containing material
Melting container in the method for smelting that carries out.
More particularly it relates to such as in the fusion process starting period during the time that there is low heat value (CV) when waste gas
Between in direct smelting plant process the waste gas from the fusion process.
Background technology
The known smelting technology based on liquid-bath is commonly known as HIsmelt techniques, and a considerable amount of patent with
And to be described in the nominal patent application of the applicant.
HIsmelt techniques are especially relevant with producing molten iron by iron ore or another iron-bearing materials.
In the case where producing molten iron, HIsmelt techniques comprise the following steps：
(a) bath of molten iron and slag is formed in the main chamber of melting container；
(b) following item is injected in the bath：(i) generally in the iron ore of fine powder form；(ii) solid carbonaceous material, allusion quotation
It is coal, it serves as the reducing agent and energy source of iron ore material type；And
(c) by molten iron ore Cheng Tie in the bath.
Term " melting " should be understood to mean hot-working herein, wherein the chemical reaction of reducing metal oxide occurs with life
Produce molten metal.
In HIsmelt techniques, form is led to for the solid feed of metal-containing material and solid carbonaceous material together with carrier gas
Cross in multiple spray gun injection liquid-baths, these spray guns are tilted with vertical direction to extend downwardly and inwardly the master by melting container
The side wall of chamber and the lower area for extending into the container, so as to which at least part of solid feed is delivered into the main chamber bottom
In the metal level in portion.These solid feeds and the carrier gas penetrate into the liquid-bath and cause molten metal and/or slag to be ejected into the bath
The space of surface simultaneously forms transition region.By the spray gun that extends downwardly by one oxygen-containing gas (typically oxygen-enriched air
Or pure oxygen) be injected into the container main chamber upper area so that the reacting gas discharged in the liquid-bath is in the container
After-combustion is carried out in upper area.Molten metal and/or slag that the rising favorably measured then declines in the transition region be present
Drop or splashings or stream, these provide Effective medium with will above the bath by reacting gas after-combustion and caused
Heat energy passes to the bath.
Typically, in the case where producing molten iron, when using oxygen-enriched air, it is produced and big in hot blast stove
In the upper area for the main chamber for being fed to container at a temperature of about 1200 DEG C.
Discharged by exhaust piping from the upper area of melting container by the reacting gas after-combustion institute in the melting container
Caused waste gas.
The melting container includes the side wall of the refractory-lined part in lower furnace and the main chamber of the container
With the cooled plate in top plate, and these cooled plates are continuously circulated through in successive loops reclaimed water.
HIsmelt techniques make it possible to produce substantial amounts of molten iron by carrying out melting in single compact container, typical case
Ground is at least 500,000 tons/year.
HIsmelt techniques include solid is injected into the liquid-bath in melting container by water-cooled solid injectable spray gun.
In addition, a key feature of the technique can work in it in following melting container, these melting containers
The forehearth of the main chamber is connected to including the main chamber for melting metal-containing material and via forehearth connector, the forehearth connects
Fitting causes metallic product continuously to be flowed out from these containers.Forehearth is used as the siphon seal of molten metal filling, natural
Ground by produce when melting container in superfluous molten metal " spilling ".This just can understand the melting in the main chamber of melting container
Metal liquid level and controlled in less deviation-this is vital for the security of factory.Molten metal bath
Position must be maintained at the safe distance less than water cooling element (such as extending to the solid injectable spray gun in main chamber) (all the time), no
Then, it may occur that vapour explosion.Exactly because this reason, this forehearth is just considered as the melting of HIsmelt techniques
The intrinsic part of container.
Term " forehearth " is interpreted as referring to herein the chamber of melting container, and the chamber is to atmosphere opening and via passage
(referred to here as " forehearth connector ") the main molten refining chamber of melting container is connected to, and under reference operating condition, includes chamber
Indoor molten metal, wherein the forehearth connector is completely filled with molten metal.
In the normal operation period, cleaning typically containing about 20%-22%CO and has through wet-SRV waste gas for washing
In 3-3.5MJ/Nm3Calorific value in the range of (being based on HHV).Such gas can be in appropriately designed buner system
Burnt with the flame temperature of about 1000 DEG C -1100 DEG C of stabilization, and without using any significant auxiliary fuel.
However, in start-up course, there is be poor (typically in 0.5-2MJ/Nm when SRV waste gas3In the range of) when
Notable period.This waste gas, once it is washed and cleaned, unusual difficult to burn.Co contents (6-12%v/v) and H2S
Content (300ppm or higher) is typically too high without allowing safety discharge.Flaring is generally unattractive, because will need
The auxiliary fuel (such as natural gas) of amount is with the stable flame of realization.In trial (demonstration) plant, solution is to be sent to this waste gas
The burner tube (to reclaim remaining chemical energy in waste gas as much as possible) of main boiler, and increase if necessary to the natural of boiler
Gas is supplied to realize at least 900 DEG C -1000 DEG C of flame temperature.This consumes extra natural gas, but due to lacking any reality
The alternative solution on border and be tolerated.
The present invention is partly to obtain the achievement of experience in a trial (demonstration) plant of operation HIsmelt techniques.This factory exists
2002-2003 is built in the Perth of Western Australia, and natural gas price is less than $ A3/GJ at that time.It is similar at this after several years
When first factory runs completely in not, natural gas has been increased to higher than $ A8/GJ.As a result, configuration " should be built " as former state
(high consumption natural gas is designed to due to initial low cost) faces serious commercial pressure.
It is described above to be not intended as accreditation above is Australia and common knowledge elsewhere.
The content of the invention
The present invention based on the recognition that：Low CV gases produce (such as direct fusion process startup or restart)
During such period, hot blast stove provides the auxiliary fuel consumption for absorbing the substantial portion of chance of the gas without correlation
Increase.
Air or oxygen-enriched air are generally heated to about 1200 DEG C by hot blast stove from environmental condition.They pass through with (logical
Often) two or three stoves for including a large amount of gas-permeable refractory elements specially designed realize this point, described resistance to
Fiery material elements were alternately heated and cooled down with the work period of about 30-60 minutes.Pass through burn gas fuel (such as day first
Right gas, the SRV waste gas of normal intensity or the air blast furnace gas in the case of blast furnace) heat the refractory material.Once the fire resisting
Material is warm enough, and stove is just pressurized, and cold air (or oxygen-enriched air) is admitted into.Then by with hot refractory material
The cold flow is heated to about 1200 DEG C -1250 DEG C and (generally bypassed with cold with hybrid system to keep outlet temperature by direct contact
It is constant).This " thermal storage device " exhausts within about 30-60 minutes, and at the end of this period, one of other stoves are ready to connect
Replace, it is allowed to rekindle the stove exhausted and be used for its next cycle.
Important consideration to such stove is vault (or flame) temperature.Typically, stove is with higher than hot drum air temperature
About 100 DEG C -250 DEG C of highest dome temperature operation.If producing hot blast at 1200 DEG C, flame or dome temperature typical case
Ground is needed in the range of 1300 DEG C -1450 DEG C.Especially since engineering/thermal capacity limitation, is operated with higher dome temperature
It is worthless.The stove adjusted typically is operated with 10%-15% excess air, causes the about 0.8%- in flue gas
1.3% oxygen (v/v).
During startup, these stoves are lighted by the auxiliary fuel 100% of usually natural gas.In this combustion
It will cause too high dome temperature or close to burning under stoichiometric condition under material type.In order to avoid such case, lead to
Often it is necessary that and adds extra cold air in combustion chamber so that the dome temperature of gained is (or only appropriate in normal range (NR)
Rise).Under these conditions, excess air is typically 50%-60%, and wherein flue oxygen is about 6-9%v/v.
When by this way operate stove when, burning needed for air capacity on air capacity (i.e. " excess air " part,
The about 30%-40% of typically total air mass flow) exist basically as cooling medium to dilute flame and reduce vault temperature
Degree.The core of the present invention is following understanding：Poor SRV waste gas can replace this most of " excess " combustion air, without triggering
Any fuel gas loses (not needing extra auxiliary fuel).In fact, it is present in the combustible material in poor SRV waste gas
(CO gases) still can burn and can make contributions in a positive manner, cause fuel gas use to proportionally reduce.
Related (actual) requirement of crucial security is that stove does not allow drift to enter the combustion air with deficiency
Oxygen deprivation pattern.The possible suddenly change of SRV waste gas composition, and system is required to respond accordingly to.This was substantially program control
Problem processed, the problem can solve in the following manner：
1. dome temperature and flue oxygen content can be monitored in real time.If for example, oxygen drops below given set
Pinpoint (such as 1.0%v/v), then can increase air mass flow automatically, while the SRV exhaust gas flows for entering stove reduce automatically.
2. in operating process in this section, stove can be operated so that industrial grade oxygen is injected in combustion air flow.
Now, breathing equipment will typically have spare capacity because SRV to the demand of oxygen well below the need associated with normal operating
Ask.By adjusting the amount of the oxygen injected in stove combustion air flow, even if likely ensure that SRV waste gas calorific values increase suddenly, in stove
By there are still enough oxygen to ensure safety operation.
The notable benefit associated with this operator scheme is related to the amount in the available auxiliary fuel in given position.If
The total amount of auxiliary fuel is restricted, then the ability of " incineration " a certain amount of waste gas (does not trigger any related fuel in stove
Gas consumption is lost) mean elsewhere to need the balance of waste gas incinerated (typically in the burner tube of main boiler)
By with to the bigger close to so that it is easier to burn of surplus auxiliary fuel.By this way, it is directly molten
Refining equipment can operate more easily and in smaller total supply maximum of auxiliary fuel.
Under the raw material background containing metal in iron ore form, the invention provides one kind to utilize melting container and one group
Hot blast stove starts the method for (including restarting) smelting technology.
More specifically, the present invention based on the recognition that：Such as under the conditions of starting or restarting, when SRV fuel gas product
Matter is less than 1.8MJ/Nm3When (be too low to allow in hot blast stove normal SRV gas-operateds (not a large amount of
Auxiliary fuel under)), waste gas is still admitted into stove.In other words, when the calorific value of waste gas is 0 to less than 1.8MJ/Nm3When,
This includes allowance waste gas and enters stove.The amount for the waste gas being admitted under these conditions can be the 5%- of main burning air mass flow
30%.
One aspect of the present invention provides a kind of direct melting method, and this method includes carbonaceous material being fed to direct
Metal in melting container and in the liquid-bath of slag, and by the headroom above the hot gas blast supply to liquid-bath from stove
In to make the reacting gas after-combustion from liquid-bath in headroom, and thus produce waste gas, this method includes：
(a) by fuel gas, waste gas and oxygen-containing burning gases be fed to the stove and the fuel gas that burns, waste gas and
The burning gases are to heat the stove；And
(b) when the calorific value of the waste gas is less than 1.8MJ/Nm3When (being based on HHV), by by the waste gas and the fuel
Gas and the burning gases are fed to the stove to control the dome temperature in the stove together.
When container waste gas has low heat value, i.e., less than 1.8MJ/Nm3(being based on HHV)) and sometimes zero calorific value when, this method is special
Do not start to a technique having no progeny or restarting is related.However, this method is applied to produce other techniques of low calorific value waste gas
State, such as " holding " and " free time " state." holding " state is characterised by that carbonaceous material and hot blast are supplied to container
It is hot to keep liquid-bath." free time " state is characterised by supplying hot blast without coal is injected in the bath.From the free time
The calorific value of the waste gas of state is relatively low, and the calorific value of the waste gas from hold mode is variable.When waste gas has low heat value
When, a large amount of fuel gas are fed to stove to heat them.This, which is provided, makes the chance of waste gas completely burned (i.e. combustion residue exists
Any CO or C in waste gas are to produce CO2), while control dome temperature.Returned in addition, less waste gas is sent into used heat
Receiving unit means to use less fuel gas in waste heat recovery unit.Therefore, direct melting method generally use compared with
Few fuel gas.
This method can include controlling in response to leaving the dome temperature in oxygen content and/or stove in the flue gas of stove
System is fed to the volume of the waste gas of these stoves.
This method can include continuous monitoring dome temperature and oxygen content in flue gas and in response to leaving stove
The dome temperature in oxygen content and/or stove in flue gas controls the volume for the waste gas for being fed to these stoves.
The volume that control is fed to the waste gas of stove can be included to control dome temperature higher than 100 DEG C of hot drum air temperature extremely
Speed supply waste gas in the range of 250 DEG C.
The volume that control is fed to the waste gas of stove can be included so that the oxygen content in flue gas is maintained above into 0.5%
V/v speed supply waste gas.
This method can also include in response to the oxygen content in flue gas will to the burning gases of stove supply regulation to
Lower speed, is combined with the supply of waste gas, and the oxygen content in flue gas is maintained above 1.0%v/v by the speed.
This method can include shunting waste gas, and a stream is supplied into stove, and another stream is supplied into used heat
Recovery unit and with fuel gas burning waste gas to produce heat.
The waste gas stream for being fed to stove can be the burning gases for being fed to stove 5 to 30%v/v, and can be by surplus
Waste gas is fed to waste heat recovery unit.
The waste gas for being fed to stove can be the burning gases for being fed to stove 15 to 30%v/v, and can be by surplus
Waste gas is fed to waste heat recovery unit.
This method can also include injecting metal-containing material in liquid-bath and the metal-containing material is smelted into metal and produced
Raw other reacting gas is to causing the elevated degree of liquid-bath buoyancy so that melted material is ejected into headroom and is exposed to
Pass through heat caused by the after-combustion of reacting gas.
The metal-containing material and carbonaceous material can be in the form of fine powder of the key dimension less than 6mm.
This method can include pre-processing the metal-containing material by heating and the prereduction metal-containing material.
The metal-containing material can be preheated so that the metal-containing material is injected at the feed points of spray gun in entrance solid is
300 DEG C or hotter, the metal-containing material is transported in the liquid-bath by the solid injectable spray gun.
This method can include prereduction metal-containing material.
Direct smelting container can include refractory-lined main chamber and be connected to main molten refining by forehearth connector
The refractory-lined forehearth of chamber, and wherein methods described includes metal-containing material being smelted into molten metal and half
Continuously or remove the molten metal continually by forehearth and periodically remove slag.
The metal-containing material can be iron ore.
The carbonaceous material can be coal.
Control be fed to stove waste gas volume can include with by the oxygen content in flue gas maintain 0.5 to
Speed supply waste gas in the range of 5.0%v/v.
This method, which can include having, is less than 1.8MJ/Nm3The waste gas of (being based on HHV) calorific value is fed to stove without volume
Outer fuel gas.
It is used to be smelted into metal-containing material in the liquid-bath of metal and slag another aspect provides a kind of
The direct smelting plant of molten metal, the equipment include：
(a) direct smelting container, the top that the container is included above slag and the liquid-bath of metal and the liquid-bath are empty
Between, the container includes the gas injection spray gun and two or more injection carbonaceous materials of one or more injection oxygen-containing gas
Solid injectable spray gun, and make the reacting gas after-combustion from the liquid-bath, be less than 1.8MJ/Nm so as to produce to have3
The waste gas of (being based on HHV) calorific value；
(b) exhaust hood and washer connected with the headroom, it receives the waste gas from the container and cooling
With the cleaning waste gas；
(c) waste heat recovery unit, it is received and a part of waste gas from the direct smelting container of burning is with from described
Waste gas recovery heat；And
(d) stove, it receives a part of cold of fuel gas, oxygen-containing burning gases and the dome temperature that is enough to control the stove
But with the mixture of waste gas that cleaned, and the admixture of gas that burns is to heat the stove.
One or more of described solid injectable spray gun can inject metal-containing material.
Brief description
Direct melting method according to embodiments of the present invention is further described with reference to the accompanying drawings, wherein：
Fig. 1 is to show showing for the one embodiment of HIsmelt direct melting methods for being configured to operate according to the present invention
Meaning property flow chart.
Embodiment
Fig. 1 shows HIsmelt direct melting method flow charts.The following explanation of embodiments of the invention is in basis
The flow chart melting iron ore fines shown in HIsmelt techniques and Fig. 1 are to produce under the background of molten iron.
However, it will be appreciated that present invention can apply to any by any suitable method of smelting melting based on liquid-bath
Metal-containing material (including ore, partial reduction ore and waste stream containing metal) and it is not restricted to HIsmelt techniques.
In normal operating (that is, producing molten iron) in the equipment of the flowchart operation in Fig. 1, this method includes
Following steps：
(i) particle that 6mm fine powder forms are typically less than in key dimension is injected into liquid-bath by injection lance 104
The iron ore of coal, cosolvent and preheating, wherein preheating iron ore typical case at the feed points for entering injection lance 104 is located in
In 300 DEG C or higher of temperature；
(ii) Gas top injected the hot rich oxygen containing air from stove in the melting container above the liquid-bath is empty
Between, with by producing heat in the headroom burning combustible gas to maintain melting reaction in the bath；
(iii) liquid-bath/slag fountain is produced by the drop and splashings that then decline from liquid-bath rising so that heat
Amount is transferred to the liquid-bath so as to maintain melting reaction from the headroom；
(iv) molten iron semi-continuously or is continuously removed by the forehearth and passes through the water cooling installed in the container side wall
Slag discharger periodically removes slag；
(v) waste gas from smelting furnace discharged from the melting container is cooled to less than about 300 DEG C and removes grit and produce tool
Have in 2.5-4MJ/Nm3Calorific value, cold, purification fuel gas in the range of (being based on HHV)；
(vi) at least a portion, the clean fuel gas feed typically between 15% and 35% to hot blast stove are made
For the fuel gas for the refractory material in heating furnace.
Charging (will optionally be blended) with some flux materials such as dolomite in the metalliferous feed material 101 of iron ore form
Into ore pretreatment unit 102, the unit can be any suitable device, such as CFB preheaters, rotary kiln or ore are done
Dry machine.Pretreated iron ore 103 (temperature and prereduction degree with the property depending on ore pre-treatment step) is existed
At 300 DEG C or hotter of temperature (melting is arranged on using suitable conveying gas such as nitrogen feed to solid injectable spray gun 104
In container 105) arrival end.
Coal 106 is fed in coal drying/grinder 107, then mixes and goes forward side by side with fluxing agent 108 (typically burnt lime)
Expect in injection lance 104.According to standard HIsmelt techniques as described earlier, solid injectable spray gun 104 consolidates all
Body injects in bath and carries out melting.Discharged by metal caused by melting reaction 110 via forehearth 20, and slag 111 via
The dirt-excluding groove 22 formed in the side wall of container 105 is discharged, the metal that the dirt-excluding groove is in liquid-bath 28 under static state
At level above interface between layer 24 and molten slag layer 26.
Fig. 1 shows that container 105 includes two solid injectable spray guns 104.It will be appreciated, however, that container 105 can include
More than two solid injectable spray gun 104.
The oxygen 112B of air 112A and technical grade (the latter comes from low temp air fractionation system 28) is mixed and in hot drum
It is heated in wind furnace 121 1200 DEG C of (typically).The mixture contains the oxygen of 35%-40% by volume, and this is mixed
Thing is flowed through from pipeline 112 and hot blast spray gun 30 as hot blast and supplied from stove 121 to container 105.Spray gun 30 is from container 105
Upper area is extended downwardly so that (headroom of hot blast feeding melting container 105 and burning process gas, are passed through into melting
React and by reacting gas caused by the devolatilization of the coal in liquid-bath 28), to produce the heat for fusion process.
Although Fig. 1 shows the container 105 with a gas injection spray gun 30, the container can include being more than one
Individual gas injection spray gun 30, the spray gun are supplied with the hot gas air blast from stove 121.
Waste gas (as indicated by arrows 113) flows out from container 105, and is cooled down in exhaust hood 114, and is washed afterwards in wet type
Wash and washed in device 115.There to be 3-3.5MJ/Nm with (in normal operating) at a temperature of about 45 DEG C3The cleaning gas of calorific value
Body 116 is divided into two parts, and a portion 117 (typically overall 25%-35%) is used as the fuel in hot blast stove 121,
And surplus 118 is burnt in boiler 34 with air feed 36 to reclaim chemical energy from waste gas 118.
Optionally, the waste gas stream from washer 115 is divided into three parts, wherein two parts are guided to as described above
In hot blast stove 121 and boiler 34, and Part III is fed to other units in direct smelting plant, such as ore is pre-
Hot device 102.For example, the waste gas of Part III can be supplied to ore preheater to preheat ore.Although it is fed to ore
The main function of the waste gas stream of preheater 102 will be preheating ore, but there may be some prereduction.
In normal operating, the auxiliary fuel 120 of waste exhaust gases 117 and stove combustion air 119A and very low amount (or zero)
Burnt together in stove 121, to realize the dome temperature in the range of 1300 DEG C -1450 DEG C.Now, oxygen stream 119B is zero.Can
Roughly the same temperature is transported to stove 121 during with by waste gas 117 to leave washer 115 with it.Alternately, can be handed in heat
Waste gas 117 is pre-heated to the temperature in the range of 100 DEG C to 300 DEG C in parallel operation 32, the heat exchanger is supplied with from stove 121
Hot flue gases (i.e. combustion product).Although respectively by heat exchanger 32, they are mixed by waste gas 117 and combustion air 119A
Together, and stove 121 is then fed to for burning.
During starting or restarting from production disruption, when waste exhaust gases calorific value is below about 2MJ/Nm3When, open oxygen
Flow 119B so that the oxygen concentration of mixed flow 119 is in the range of 21%-28%.Waste gas stream 117 is maintained at from container 105
Total waste gas stream about 15%-30%, wherein surplus 118 combines the combust of auxiliary fuel (not shown) one in boiler 34.
The volume of waste gas stream 117 from 15% to 30% change of total waste gas is needed the oxygen content of flue gas 122
0.5%v/v is kept above to ensure the result of the completely burned of waste gas 117 and fuel gas 120 in stove.Especially, in cigarette
In the case that oxygen content in road gas 122 approaches or descends below 0.5%v/v, the waste gas 117 supplied to stove is reduced.However,
The lower limit for the oxygen content being preferably based in flue gas 122 is that 1.0%v/v is operated, so as to from container 105
Bigger safe clearance is provided in the case of the composition suddenly change of waste gas 117.
Oxygen content in waste gas 122 also by " excess air " that stove 121 is fed in combustion air 119 amount shadow
Ring.Therefore, the control of the oxygen content in flue gas 122 includes controlling combustion air 119 to flow to stove 121 and controls burning empty
The oxygen content of gas 119.The flow of combustion air 119 is adjusted simultaneously with the change of the flow of waste gas 117, to ensure in cigarette
Exist in road gas 122 and be more than minimum oxygen content.It is oxygen-enriched to provide extra oxygen 119B can be supplied to combustion air 119A
Combustion air 119.
The volume of waste gas stream 117 is to need to control in stove 121 as described above from 15% to 30% change of total waste gas
The result of dome temperature, the i.e. substitute as some " excess airs " in combustion air 119.Specifically, waste gas supply 117
Some combustion airs 119 can be substituted and incited somebody to action with controlling dome temperature and the operation stove during startup or restarting can be substituted
It is generally necessary to some fuel gas 120 (result being present in due to some combustible products (such as CO) in waste gas 117).
The continuous monitoring of dome temperature and the oxygen content of flue gas 122 is carried out, and responsively adjusts waste gas 117, combustion
Burn air 119A and additional oxygen 119B so that the oxygen content in dome temperature and flue gas is maintained at their own expectation
In the range of.The oxygen content of gas in the vault (roof structure of upper bend) of each stove 121 can be by being placed on arch
Probe in top monitors.Therefore flue gas composition is equally valid also, in vault and stream 122, the probe in vault
The oxygen content monitoring in stream 122 can be substituted.
Whole structure is to be fed to stove 121 and the fuel gas 120 of boiler 34 is reduced.As described above, this is in startup and again
It is in terms of reducing fuel cost during new startup and in terms of the technological feasibility in the position that available fuel gas is limited
Favourable.
Without departing from the spirit and scope of the present invention, the embodiment of the present invention process described on accompanying drawing can be entered
The many modifications of row.
For example, when illustrating embodiment under the background in HIsmelt direct smelting process, it can be readily appreciated that this
Invention is not limited thereto and extends to any smelting technology based on liquid-bath, and the smelting technology includes the heat from one group of stove
Air blast.
Claims (20)
1. a kind of direct melting method, methods described includes carbonaceous material being fed to the metal in direct smelting container and melted
In the liquid-bath of slag, and by the headroom above the hot gas blast supply from stove to the liquid-bath so as at the top
Make the reacting gas after-combustion in the liquid-bath in space, and thus produce waste gas, methods described includes：
(a) fuel gas, waste gas and oxygen-containing burning gases are fed to the stove and the fuel gas that burns, waste gas and described
Burning gases are to heat the stove；And
(b) when the calorific value of the waste gas is less than 1.8MJ/Nm3When (being based on HHV), by by the waste gas and the fuel gas and
The burning gases are fed to the stove to control the dome temperature in the stove together.
2. the method as described in claim 1, methods described includes the oxygen content in the flue gas in response to leaving the stove
And/or the dome temperature in the stove controls the volume for the waste gas for being fed to the stove.
3. method as claimed in claim 2, methods described is included in dome temperature and the flue gas described in continuous monitoring
Oxygen content in oxygen content and flue gas in response to leaving the stove and/or the dome temperature in the stove control
It is fed to the volume of the waste gas of the stove.
4. method as claimed in claim 3, wherein the volume that control is fed to the waste gas of the stove is included to control the arch
Push up temperature and supply the waste gas higher than the speed in the range of 100 DEG C to 250 DEG C of hot drum air temperature.
5. the method as described in claim 3 or claim 4, wherein control be fed to the waste gas of the stove volume include with
The speed that oxygen content in the flue gas is maintained above to 0.5%v/v supplies the waste gas.
6. the method as described in claim 3 or claim 4, wherein methods described also include in response in the flue gas
Oxygen content, to following speed, will be combined, the speed to the supply regulation of the burning gases of the stove with the supply of the waste gas
Oxygen content in the flue gas is maintained above 1.0%v/v by rate.
7. the method as any one of preceding claims, methods described includes shunting the waste gas, and by one
Stream is fed to the stove, and by another stream be fed to waste heat recovery unit and described in fuel gas waste gas to produce
Heat.
8. the method as any one of preceding claims, wherein the waste gas stream for being fed to the stove is to be fed to the stove
Burning gases 5 be fed to the waste heat recovery unit to 30%v/v, and by the waste gas of surplus.
9. the method as any one of preceding claims, wherein the waste gas supply to the stove is from described directly molten
Refine the waste gas of container 15 are fed to the waste heat recovery unit to 30%v/v, and by the waste gas of surplus.
10. the method as any one of preceding claims, including metal-containing material injected in the liquid-bath and by institute
State metal-containing material to be smelted into metal and produce other reacting gas to causing the elevated degree of liquid-bath buoyancy so that molten
Melt material to be ejected into the headroom and be exposed to heat caused by the after-combustion of the reacting gas.
11. method as claimed in claim 10, wherein the metal-containing material and the carbonaceous material are small in key dimension
In the form of 6mm fine powder.
12. the method as described in claim 10 or claim 11, including pass through metal-containing material described in heating and prereduction
To pre-process the metal-containing material.
13. method as claimed in claim 12, wherein the metal-containing material is preheated so that the metal-containing material exists
It it is 300 DEG C at into the feed points of solid injectable spray gun or hotter, the solid injectable spray gun is defeated by the metal-containing material
It is sent in the liquid-bath.
14. the method as described in claim 12 or claim 13, including metal-containing material described in prereduction.
15. the method as any one of claim 10 to 14, wherein the direct smelting container serves as a contrast including refractory material
In main chamber and the refractory-lined forehearth that the main molten refines chamber, and wherein institute are connected to by forehearth connector
Stating method includes the metal-containing material being smelted into molten metal and semicontinuous or remove continually by the forehearth molten
Melt metal and periodically remove slag.
16. the method as any one of claim 10 to 14, wherein the metal-containing material is iron ore.
17. the method as any one of preceding claims, wherein the volume for the waste gas that control is fed to the stove includes
The waste gas is supplied so that the oxygen content in the flue gas to be maintained to the speed in the range of 0.5 to 5.0%v/v.
18. the method as any one of preceding claims, wherein methods described, which include having, is less than 1.8MJ/Nm3(base
In HHV) waste gas of calorific value is fed to the stove without extra fuel gas.
19. a kind of direct smelting plant for being used to metal-containing material be smelted into molten metal in the liquid-bath of metal and slag,
The equipment includes：
(a) direct smelting container, the container include the headroom above slag and the liquid-bath of metal and the liquid-bath, institute
Stating container includes the gas injection spray gun of one or more injection oxygen-containing gas and consolidating for two or more injection carbonaceous materials
Body injection lance, and make the reacting gas after-combustion from the liquid-bath, it is less than 1.8MJ/Nm so as to produce to have3(it is based on
HHV) the waste gas of calorific value；
(b) exhaust hood and washer connected with the headroom, it receives waste gas from the container and cooled down and clear
The clean waste gas；
(c) waste heat recovery unit, it is received and a part of waste gas from the direct smelting container of burning is with from the waste gas
Reclaim heat；And
(d) stove, its receive fuel gas, oxygen-containing burning gases and the dome temperature for being enough to control the stove part cooling and
The mixture of the waste gas cleaned, and the admixture of gas that burns is to heat the stove.
20. direct smelting plant as claimed in claim 19, wherein one or more of described solid injectable spray gun is injected
Metal-containing material.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2015900328A AU2015900328A0 (en) | 2015-02-03 | Processing of low heating value off-gas | |
| AU2015900328 | 2015-02-03 | ||
| PCT/AU2016/050057 WO2016123666A1 (en) | 2015-02-03 | 2016-02-03 | Processing of low heating value off-gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN107532223A true CN107532223A (en) | 2018-01-02 |
Family
ID=56563235
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201680018898.2A Pending CN107532223A (en) | 2015-02-03 | 2016-02-03 | The processing of low calorific value waste gas |
Country Status (2)
| Country | Link |
|---|---|
| CN (1) | CN107532223A (en) |
| WO (1) | WO2016123666A1 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20220412554A1 (en) | 2019-11-27 | 2022-12-29 | Sms Group Gmbh | Combustion of the CO in secondary metallurgical exhaust gas, with calorific value control and volume flow control |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1926248A (en) * | 2004-02-27 | 2007-03-07 | 技术资源有限公司 | Direct smelting plant and process |
| CN101473050A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Pressure control in direct smelting process |
| CN101473048A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Direct smelting plant with waste heat recovery unit |
| CN101473049A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Pressure control in direct smelting process |
| CN102200392A (en) * | 2005-04-26 | 2011-09-28 | 技术资源有限公司 | Forehearth |
-
2016
- 2016-02-03 CN CN201680018898.2A patent/CN107532223A/en active Pending
- 2016-02-03 WO PCT/AU2016/050057 patent/WO2016123666A1/en active Application Filing
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1926248A (en) * | 2004-02-27 | 2007-03-07 | 技术资源有限公司 | Direct smelting plant and process |
| CN102200392A (en) * | 2005-04-26 | 2011-09-28 | 技术资源有限公司 | Forehearth |
| CN101473050A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Pressure control in direct smelting process |
| CN101473048A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Direct smelting plant with waste heat recovery unit |
| CN101473049A (en) * | 2006-04-24 | 2009-07-01 | 技术资源有限公司 | Pressure control in direct smelting process |
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| Publication number | Publication date |
|---|---|
| WO2016123666A1 (en) | 2016-08-11 |
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Application publication date: 20180102 |