CN105755195B - A method of molten steel is directly prepared from high-silicon iron ore - Google Patents
A method of molten steel is directly prepared from high-silicon iron ore Download PDFInfo
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- CN105755195B CN105755195B CN201610225839.4A CN201610225839A CN105755195B CN 105755195 B CN105755195 B CN 105755195B CN 201610225839 A CN201610225839 A CN 201610225839A CN 105755195 B CN105755195 B CN 105755195B
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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
- C21B13/10—Making spongy iron or liquid steel, by direct processes in hearth-type furnaces
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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
- C21B13/0006—Making spongy iron or liquid steel, by direct processes obtaining iron or steel in a molten state
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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
- C21B13/12—Making spongy iron or liquid steel, by direct processes in electric 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
- C21B13/14—Multi-stage processes processes carried out in different vessels or furnaces
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- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22B—PRODUCTION AND REFINING OF METALS; PRETREATMENT OF RAW MATERIALS
- C22B1/00—Preliminary treatment of ores or scrap
- C22B1/14—Agglomerating; Briquetting; Binding; Granulating
- C22B1/24—Binding; Briquetting ; Granulating
- C22B1/242—Binding; Briquetting ; Granulating with binders
- C22B1/244—Binding; Briquetting ; Granulating with binders organic
Abstract
The invention discloses a kind of method for directly preparing molten steel from high-silicon iron ore, method includes: biomass carbon preparation and crushes；High-silicon iron ore is crushed and ball milling；Carbonaceous pelletizing preparation；Direct-reduction；High temperature slag iron separation.Compared with the method for existing processing high-silicon iron ore, the present invention prepares biomass carbon using the extensive agricultural biomass waste in source and prepares carbonaceous pelletizing as reducing agent, and carries out direct-reduction and molten point of electric furnace high-temperature using commercialized FASTMELT technique.By controlling reducing condition, extremely low carbon residue high metal pellet is obtained in the direct-reduction stage.High temperature melting directly obtain molten steel stage by stage and steel quality directly reach or more than converter tapping standard.The present invention has many advantages, such as that iron recovery height and gained liquid low carbon low silicon steel quality are good.The invention avoids conventional sintering-blast furnace-converter iron-making and steel-making processes, to greatly simplifie the process of processing high-silicon iron ore.
Description
Technical field
The invention belongs to belong to Ferrous Metallurgy-non-blast furnace ironmaking field, it is related to difficulty and selects high-silicon iron ore (high siliceous hematite)
Using technique, especially a kind of method that molten steel is directly prepared from high-silicon iron ore.
Background technique
With in worldwide abundant ore source it is increasingly poor, previous some unvalued iron ore deposits started to be opened
It adopts and utilizes.Since the gangue content of these iron ores is high, and it is difficult to improve Iron grade or reduction by conventional technique of preparing
Gangue content, therefore, the utilization of these Complex Iron Ores are just very restricted.Wherein high-silicon iron ore (also known as high siliceous red iron
Mine) it is a kind of common difficult iron ore inferior, in southern some provinces (such as Hainan Province) of China, such high-silicon iron ore ratio
Relatively universal (Hainan mining and metallurgy, 1 (1997): 1-3).Simultaneously as import price is extremely low, China is also from overseas (such as African country's hair
Li Taniya) some such high-silicon iron ores of import.The mineral phase structure of the mineral is mainly bloodstone, quartz and pole
A small amount of calcium oxide, magnesia and alumina impurities, quartz are mutually embedded in bloodstone phase with small particulate form；Remaining is harmful
Element such as sulphur, phosphorus content are extremely low or even micro.After conventional ore dressing, the Iron grade of the mine has a more substantial increase, Ke Yida
To 55wt% or more, but the content of silica is between 9-14wt%.
Current blast furnace generally carries out the system of low silicon smelting.The low silicon smelting of blast furnace is that blast furnace itself ironmaking is energy-efficient first
It is required that.If SiO in blast furnace burden2Content it is high, will lead to blast furnace ironmaking cost and be substantially increased.It is mainly shown as: blast furnace refining
The iron coke per ton ratio of iron rises；Sintering feed alkalinity CaO flux additive amount will increase；The ton scum amount of blast furnace ironmaking rises；In molten iron
Silicone content rises.Requirement of the followed by subsequent pneumatic steelmaking to molten iron silicon content.Converter current steel-making does not allow into furnace iron generally
Water silicon content is more than 0.3wt%.And more stringent requirements are proposed for less-slag operation and the silicone content without slag steel-making to molten iron.With this
Dioxide-containing silica is no more than 5wt% in the Steel Production Flow Chart requirement sinter of blast furnace-converter.Therefore, for SiO2Contain
Amount is greater than the high-silicon iron ore of 10wt%, and the viewpoint of most domestic iron and steel enterprise is " the type high-silicon iron ore give for free all should not ".
Based on the above reasons, in some iron and steel enterprises, such high-silicon iron ore only by with after other fine iron breeze rational ore matchings
A small amount of application can be obtained in sintering, the additional amount of current such high-silicon iron ore is about to be sintered 10% left side of miberal powder total amount
It is right.It is more extensive for be sintered-process of blast furnace ironmaking is difficult to realize.Such as want further to remove titanium dioxide in the high-silicon iron ore
To meet the requirement of blast furnace ironmaking, common beneficiation method cannot achieve silicone content, need using complicated technique of preparing.At present
Iron is mentioned except the method for silicon includes: sodium roasting joint magnetic separation (mining metallurgical engineering, 35 (2015): 117-123) to such iron ore, is divided
Grade the combined and staged magnetic separation of fine grinding (mining metallurgical engineering, 31 (2011): 36-39) and multi-stage magnetic separation joint multistage flotation (mining metallurgical engineering, 32
(2012): 62-66) etc..Due to the long flow path and complexity of these methods, so that beneficiation cost is substantially increased；Simultaneously for such
The high-silicon iron ore of type, there is also following disadvantages for above method: since silica gangue mineral is with superfine small granularity disperse
Be embedded in iron mineral phase, it is necessary to mineral be milled to superfine granularity (less than 20 μm) be possible to so that silica gangue with
Iron Ore Powder is separated to obtain preferable desiliconization effect, therefore iron loss is high.The defect of above-mentioned complex ore dressing process makes
It is economically very uneconomical using high-silicon iron ore in blast furnace ironmaking.
Other than the Steel Production Flow Chart of blast furnace-converter, non-blast furnace ironmaking technology has obtained quick development in recent years.Its
Middle rotary hearth furnace direct-reduction joint electric furnace melts division technique (i.e. FASTMELT, by MIDREX company of the U.S. and Japan's KOBE steel public affairs
Department's invention) commercialized running more than 30 years (JOM, 63 (2001): 36-43；JOM, 65 (2003): 30-34).It is burnt with tradition
Knot-blast furnace ironmaking process is compared, and FASTMELT technique is low to ingredient requirement, and various iron-bearing materials and carbon raw material may be used to
The preparation of carbonaceous pelletizing；And rotary hearth furnace direct-reduction working condition is flexible, by adjusting carbonaceous pelletizing ingredient and control reduction
Condition can carry out accurate chemical component to metallized pellet product and degree of metalization controls.
In blast furnace ironmaking, if SiO in sinter2Too high levels, due to SiO in blast furnace2Reaction (reaction between C
1), the silicone content in blast-melted will be made to be unable to control in reduced levels.By the behavior of silicon in blast furnace it is found that if to iron
C content is controlled in water, so that it may inhibit migration of the silicon from clinker to molten iron, so as to efficiently control the silicon in molten iron
Content.
(SiO2)+2C=2 [Si]+2CO (g) (1)
Rotary hearth furnace direct-reduction mainly uses coal base carbonaceous pelletizing in FASMELT at present, and reducing agent is mainly coal dust or coke
Powder.Must excessively match since the gasification performance of coal dust or coke powder is lower, in carbonaceous pelletizing carbon (carbon oxygen molar ratio be greater than 1.0) and
In the available molten degree of metalization (being greater than 80%) required stage by stage of (1200 DEG C or more) ability of higher reduction temperature, therefore
Residual carbon content in metallized pellet product is higher, it is subsequent it is molten stage by stage, (1- is mainly reacted in the reaction for being related to carbon residue
2), therefore, the quality of molten iron obtained by FASMELT technique and blast-melted mass difference are little.It is clear that if directly sharp
With conventional FASTMELT process high-silicon iron ore, migration of the silicon from clinker to molten iron can not be inhibited.
(FeO) (2)+2C=2Fe+2CO (g)
During molten point, the FeO in Si and slag in molten iron can also have following reaction (3) to occur.
2 (FeO)+[Si]=[SiO2]+2Fe (3)
But after slag iron separation, interfacial reaction of the above reaction (3) between slag iron, the interfacial reaction rate is existed by Si
The limitation of iron liquid and the FeO diffusion rate in slag, after especially silicone content is reduced to 0.15wt% in molten iron, molten iron is pretreated
Desiliconization is difficult.It must extend between molten timesharing or using enhancements (as stirred).Secondly the FeO in slag has refractory material
Biggish corrosion function extends between melting timesharing to mean to melt and furnace lining durability is divided greatly to shorten.
In addition, carbon residue more in metallized pellet exists, violent reaction between carbon and oxygen (reaction during molten point can be caused
(2)), simultaneously because ferrous oxide rapidly depletes in slag, the ferrous oxide content in slag is very low, so that slag viscosity liter
It is high, it is easy to form foamed slag.Therefore it melts slag iron during dividing and mixes the quick separating that seriously cannot achieve slag iron.It needs to add
Additional fluxing agent is added to carry out slugging (such as magnesia), these measures increase the quantity of slag of the ton iron of molten point process and technique mistake
Journey complicates.
From the point of view of the part of test results of the present inventor, using the FASTMELT technique of coal-based direct reduction+high temperature melting point
Such high-silicon iron ore of route processing, it is molten that degree of metalization is divided to contain for the silicon in resulting metallic iron final after 90% metallized pellet
Measuring is 0.5~1.5wt%, and gained iron sample poor quality, wherein containing more field trash and stomata.That is, using
Coal-based direct reduction, part SiO in metallized pellet gangue2It is reduced during molten point into molten iron.It is unable to get suitable
Hot metal containing low silicon needed for closing pneumatic steelmaking.
In addition to coal dust and coke powder, biomass carbon is also a kind of carbon containing reducing agent abundant, therefore be can also be used as directly also
Former reducing agent.Biomass carbon is also referred to as charcoal, biological coke, is biomass high temperature (< 700 under anaerobic or nearly anaerobic state
DEG C) pyrolysis charring generate first stability carbon rich material matter, be mostly powdered granule.The raw material for preparing biomass carbon is mainly agriculture
The crop generated in industry activity and forest stubble, wood-curing waste etc..Such as straw charcoal, corncob charcoal, rice straw charcoal, bamboo charcoal, wood
Charcoal etc..China is a large agricultural country, and the raw material sources of biomass carbon are very extensive and cheap, in addition its production technology phase
To simple, industrialization production (Scientia Agricultura Sinica, 46 (2013): 3324-3333) easy to accomplish.The present invention also contributes to China
The effective use of huge agriculture waste resource.Carbonaceous pelletizing is prepared in CO using biomass carbon2In/CO mixed atmosphere directly also
It is former.Compared with coal or coke, there are advantages below for part biological matter charcoal: [1] .CO2Under the conditions of gasification reaction (4) gasification
Start temperature is low；[2] is under high temperature (being greater than 800 DEG C), and to reaction (4), biomass carbon has better gasification than coal dust or coke powder
Performance.
C+CO2(g)=2CO (g) (4)
The characteristics of based on biomass carbon described above, the present inventor's proposition make direct-reduction reducing agent using biomass carbon,
Using the process route of FASTMELT process high-silicon iron ore.Specifically: containing using the preparation of suitable biomass carbon first
Carbon pellets；Secondly, obtaining the metallized pellet of extremely low carbon residue by rotary hearth furnace direct-reduction under suitable reducing condition；Most
Afterwards, low carbon residue metallized pellet directly obtains low carbon low silicon molten steel by high temperature slag iron separation.In high temperature slag iron separation process,
Since the residual carbon content of metallized pellet is low, SiO in gangue phase can be inhibited2Reduction, gained is molten to divide product to be low silicon
Low-carbon molten steel.Meanwhile a small amount of remaining FeO can form FeO-SiO molten stage by stage in metallized pellet2The slag system of-CaO,
It is effectively reduced the viscosity of slag, slag iron is promoted quickly to be completely separated and reduces the field trash in gained molten steel.Be conducive to improve steel
The cleanliness of water.
Summary of the invention
The purpose of the present invention is to provide a kind of efficiently using the method for difficult high-silicon iron ore resource i.e. from high-silicon iron ore
The method for directly preparing molten steel.The present invention is greater than 55wt% and SiO primarily directed to Iron grade2Content is greater than the high silicon of 10wt%
Iron ore.The cheap biomass carbon of proposed adoption of the present invention prepares carbonaceous pelletizing+CO2/ CO mixed atmosphere direct-reduction+high temperature slag iron separation
Technology path.In the present invention, the raising of biomass carbon gasification performance is the pelletizing containing biomass carbon using suitable preparation condition
It can get the metallized pellet of low carbon residue after rotary hearth furnace direct-reduction, the metallized pellet of low carbon residue passes through high temperature slag iron point again
Low carbon low silicon molten steel is directly obtained from after.
To achieve the above object, the invention adopts the following technical scheme:
A method of molten steel directly being prepared from high-silicon iron ore, the described method comprises the following steps:
Step 1: abandoned biomass, air thermal dissociation is completely cut off under the conditions of 300-500 DEG C, life is made by the preparation of biomass carbon
Substance charcoal, gained biomass carbon pass through ball milling beading shape charcoal powder；
Step 2: mineral aggregate is broken, high-silicon iron ore is prepared into miberal powder；
Step 3: prepared by pelletizing, by miberal powder, biomass charcoal powder and CaO are sufficiently mixed according to preset ratio, and addition is certain
Pelletizing is made after the organic binder and water of ratio；
Step 4: pelletizing is dry, pelletizing obtained is sufficiently dry；
Step 5: direct-reduction, according to rotary hearth furnace direct-reduction technique, by the pelletizing after drying in CO and CO2Mixing is also
It is restored under Primordial Qi atmosphere；
Step 6: high temperature melting point, high temperature slag iron separation directly obtains molten steel.
Further, in the step 1, the fixation carbon content of prepared biomass charcoal powder is greater than 60wt%, volatile matter
Content is greater than 30wt%, and content of ashes is less than 5wt%, and the granularity of acinous biomass charcoal powder is less than 80 μm, in 1000 DEG C and CO2
Partial pressure is greater than under conditions of 0.5atm, and the powdered carbon of granularity less than 80 μm is gasified totally in 10 minutes.
Further, in the step 2, all iron content of the high-silicon iron ore is greater than 55wt%, and dioxide-containing silica is big
In 10wt%；The powder particle size is less than 80 μm.
Further, in the step 3, when miberal powder and biomass charcoal powder are mixed, fixed carbon in biomass charcoal powder
With the molar ratio (m of the oxygen in miberal powder in ferriferous oxideC/mO) range be 0.70-0.80.
Further, CaO weight percent and SiO in the step 3, after addition CaO in the pelletizing2Weight
The ratio between percentage (CaO wt%/SiO2It wt%) is 1.0-2.0.
Further, in the step 3, the organic adhesive dosage used in the process of ball processed is no more than 2%, and water used contains
Amount is no more than 10%.
Further, in the step 4, drying temperature is 200-300 DEG C, drying time 2-3h.
Further, in the step 5, reduction temperature is 1100-1200 DEG C, recovery time 15-20min；Also Primordial Qi
CO and CO in atmosphere2Intrinsic standoff ratio PCO2/PCOIt is 1.0.After carrying out reduction in metal pelletizing obtained, degree of metalization is 80% or more,
Residual carbon content is lower than 1.0wt%.
Further, in the step 6, the molten of high temperature melting point divides 1550-1600 DEG C of temperature, melts 5-10min between timesharing,
Atmosphere is N2Or inert gas.Gained steel quality meets or exceeds pneumatic steelmaking tapping standard.
The beneficial effects of the present invention are:
[1] biomass charcoal source is agricultural biomass waste from a wealth of sources, and pyrolytical condition is easy to control.Have
Biomass is easy the biomass carbon of the high gasification property of preparation.
[2] due to the content of ashes of biomass carbon it is low, high temperature melting divides process ton scum amount few.Ash content is brought into simultaneously
Harmful element (sulphur and phosphorus) content is few.
[3] direct reduction equipment is rotary hearth furnace, and melting subset is electric arc furnaces, and production equipment needed for the present invention is steel
Mature enlarged production equipment, with short production cycle in industry, high-efficient.
[4] carbonaceous pelletizing of biomass carbon preparation there is a problem of in reduction process there are easy dusting and intensity are low, at this
In invention, due to use owe with carbon technique (C/O molar ratio is 0.7-0.8 and the suitable CaO of addition, in reduction process with
After reduction, the dusting of carbonaceous pelletizing is inhibited, and enough intensity can be kept in pelletizing reduction process.
[5] during molten point of, the viscous of melting slag is can be effectively reduced in remaining appropriate ferrous oxide in metallized pellet
Degree, it is no longer necessary to which additional slagging agent can realize the ideal separating effect of slag iron.Gained molten iron inclusion content is few.
[6] the molten point resulting high quality molten steel of is conducive to the step of subsequent refining is greatly reduced and reduces energy consumption.Gained
Molten steel is also conducive to manufacture high added value steel products.
[7] the present invention is also applied for the direct steelmaking of general iron ore simultaneously, has quickly and efficiently handled iron mineral.It keeps away
Conventional sintering-blast furnace-converter iron-making and steel-making process is exempted from.
Detailed description of the invention
Fig. 1 is the process flow chart that the present invention realizes high-silicon iron ore direct steelmaking using biomass carbon；
Fig. 2 is biomass charcoal powder gasification performance (gasification condition: biomass charcoal powder maximum particle size prepared in embodiment one
Less than 80 μm, abundant devolatilization and moisture at 1000 DEG C, gasification atmosphere are PCO/PCO2=1.0)；
In Fig. 3: (a) in sample microsctructural photograph metallized pellet obtained by direct-reduction in embodiment one in the present invention
The microscopic appearance of the miberal powder of miberal powder；It (b) is the microstructure of region A in (a)；It (c) is the EDS power spectrum at midpoint (b) 1；(d) it is
(b) the EDS power spectrum at midpoint 2；
In Fig. 4: gained typical metal sample is microcosmic after (a) dividing for metallized pellet high temperature melting in embodiment one in the present invention
Microscopic appearance；It (b) is the microstructure of region B in (a)；It (c) is the EDS power spectrum at midpoint (b) 1；
Fig. 5 is that (gasification condition: coal dust maximum particle size is less than 80 μm, at 1000 DEG C for coal dust gasification performance used in embodiment five
Abundant devolatilization and moisture down, gasification atmosphere are PCO/PCO2=1.0).
Specific embodiment
In order to make the objectives, technical solutions, and advantages of the present invention clearer, below in conjunction with attached drawing 1-5 and implementation
Example, is explained in further detail the present invention.It should be appreciated that specific embodiment described herein is used only for explaining this hair
It is bright, it is not intended to limit the present invention.On the contrary, the present invention cover it is any be defined by the claims in spirit and scope of the invention
On substitution, modification, equivalent method and the scheme made.Further, in order to make the public have a better understanding the present invention, below
It is detailed to describe some specific detail sections in datail description of the invention.For a person skilled in the art without this
The present invention can also be understood completely in the description of a little detail sections.
As shown in Figure 1, a kind of method for directly preparing molten steel from high-silicon iron ore, the method is using biomass carbon as containing
Carbon pellets reducing agent, specifically includes the following steps:
Step 1: the preparation of biomass carbon: abandoned biomass completely cuts off air thermal dissociation under the conditions of 300-500 DEG C and biology is made
Matter charcoal, gained biomass carbon pass through ball milling beading shape charcoal powder.
Carbon content is fixed in biomass charcoal obtained in this step greater than 60wt%, volatile matter content is greater than 30wt%,
Ash content is less than 5wt%；After broken and ball milling, the granularity of acinous biomass charcoal powder is less than 80 μm.In 1000 DEG C and CO2Point
Pressure is greater than 0.5atm, which can be gasified totally in 10min.
Step 2: mineral aggregate is broken: taking high-silicon iron ore is raw material, and all iron content of the high-silicon iron ore is greater than 55wt%, two
Silica content is greater than 10wt%, is broken into acinous miberal powder with crusher and ball mill, powder particle size is less than 80 μm.
Step 3: prepared by pelletizing: miberal powder and biomass charcoal powder being mixed according to a certain percentage, then added a certain proportion of
CaO, the material after mixing adds a certain proportion of organic binder and the pelletizing that diameter is 10mm is made in water, wherein ball processed is viscous
It ties agent and uses organic binder, the organic adhesive dosage used in the process of ball processed is no more than 2%, and water content used is no more than
10%.
In this step, when miberal powder and powdered carbon are mixed, ferriferous oxide is (predominantly in fixed carbon and miberal powder in powdered carbon
Fe2O3) in oxygen molar ratio (mC/mO) it is approximately equal to 0.70, belong to and owe with carbon range, for example, the range of the molar ratio is limited
Between 0.70-0.80.The additive amount of CaO meets the following conditions: in the pelletizing of preparation in the weight percent and miberal powder of CaO
SiO2The ratio between weight percent (CaOwt%/SiO2It wt%) is 1.0-2.0.
Step 4: pelletizing is dry: the degree of drying in order to guarantee pelletizing, can by pelletizing after spontaneously drying 24 hours,
It is further 2-3 hours dry under the conditions of 200-300 DEG C, reach abundant drying.
Step 5: direct-reduction: the carbonaceous pelletizing prepared restores under certain reducing condition.
In this step, reduction temperature is 1100-1200 DEG C in signified reducing condition, and recovery time 15-20min is passed through
CO and CO2Gaseous mixture, reducing atmosphere keep PCO2/PCOEqual or approximately equal to 1.0.In Direct Reduction, biomass carbon is same
When participate in previous reaction (4) and following reaction (5).
3C+Fe2O3=2Fe+3CO (g) (5)
Wherein, in direct-reduction early period, biomass charcoal powder is mainly used for the direct-reduction of ferriferous oxide in miberal powder and continuous
Reduce (reaction (5))；In the reduction later period, as the degree of metalization of iron in pelletizing improves, consumption of the ferriferous oxide to biomass carbon
Seldom, powdered carbon is mainly by the CO in surrounding atmosphere2It further consumes and reduces (reaction (4)).Restore later period biomass carbon
Gasification constantly consumption while also prevent reoxidizing for metallic iron in pelletizing, such as react shown in (6).In the direct-reduction later period
Miberal powder degree of metalization meeting fraction reduces but also further decreases the carbon residue in pelletizing.In reduction latter stage, in metallized pellet
The consumption of powdered carbon almost all.
Fe+CO2(g)=FeO+CO (g) (6)
Step 6: high temperature melting point: by the good pelletizing of above-mentioned reduction, a point realization slag iron separation is melted in high temperature furnace.
In this step, the molten slitting part of high temperature melting point is to melt to divide 1550-1600 DEG C of temperature, melts 5-10min between timesharing, atmosphere
For N2Or inert gas, to realize slag iron quick separating.High temperature melting point directly obtains hot molten steel, wherein the silicon of hot molten steel
Content is less than 0.05wt%, and carbon content is less than 0.05wt%, and metal iron recovery is greater than 80%.The quality of hot molten steel has reached
Quality to molten steel when pneumatic steelmaking tapping can be directly entered refining steel making working procedure after deoxidation.
Method of the invention is described in detail below in conjunction with specific embodiment, high-silicon iron ore used in the embodiment of the present invention
The chemical component of powder is as shown in table 1.
1 high-silicon iron ore chemical component (wt%) of table
Embodiment one
[1] prepared by biomass carbon: discarded jujube timber is carbonized in 400 DEG C of pyrolysis, is prepared into biomass carbon.Gained biology
The results are shown in Table 2 for the Industrial Analysis of matter charcoal.The gasification performance of gained biomass carbon is as shown in Figure 2.Prepared biomass carbon
By ball milling, granularity is less than 80 μm.
The Industrial Analysis result (wt%) of biomass carbon used in 2. embodiment one of table
[2] mineral aggregate is broken: taking above-mentioned high-silicon iron ore 500g, preliminary broken and after abundant ball milling, granularity is less than
80μm。
[3] prepared by pelletizing: above-mentioned Iron Ore Powder and powdered carbon and a certain amount of CaO are mixed.Wherein biomass carbon dosage is
The molar ratio that 122g, i.e. its amount meet C/O in carbonaceous pelletizing is 0.8.Wherein CaO additional amount meets CaOwt%/SiO2Wt%=
2.0.The pelletizing that diameter is 10.0mm is made in material after mixing.Ball binder processed uses 2.0% secondary stock.
[4] pelletizing is dry: after pelletizing spontaneously dries for 24 hours, further in 300 DEG C of dry 2h.
[5] is reduced directly: being restored in the following conditions: being used tube furnace, reduction temperature is 1200 DEG C, and the recovery time is
15min is passed through CO/CO2P in gaseous mixture 1L/min and gaseous mixtureCO2/PCO=1.0.To simulate furnace atmosphere as PCO2/PCO=
1.0.The degree of metalization of metal pelletizing obtained is 88% after carrying out reduction, and metallized pellet residual carbon content is 0.90wt%.Institute
Shown in the microscopic appearance such as Fig. 3 (a) for obtaining metallized pellet, after reduction shown in the microstructure of miberal powder such as Fig. 3 (b).By Fig. 3 (b)
Middle EDS energy spectrum analysis (Fig. 3 (c-d)) is as can be seen that short grained quartz is still embedded in metallic iron.
[6] slag iron separation: the pelletizing that will have been restored melts in Si-Mo rod high temperature box furnace and divides.It is molten that temperature is divided to be 1550
DEG C, respectively 5min and 10min between timesharing is melted, realizes slag iron separation.
Gained metal-like impurity content is [%C]: 0.02wt% when be 5min between molten timesharing, [%Si]:
0.02wt%, [%Mn]: < 0.01wt%, [%S]: 0.02wt%, [%P]: < 0.01wt%, [%O]: 0.178wt%, [%
N]: 0.045wt%；Metal recovery rate 90%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content have reached
The standard of converter tapping.Shown in the microscopic appearance of gained metal-like such as Fig. 4 (a), the microstructure of field trash such as Fig. 4 in metal-like
(b) shown in.Field trash is less in gained metal-like it can be seen from the EDS energy spectrum analysis (Fig. 4 (c)) of Fig. 4 (b) and granularity very
It is small.This indicates that gained metal-like has good cleanliness.
Gained metal-like impurity content is [%C]: 0.036wt% when be 10min between molten timesharing, [%Si]:
0.03wt%, [Mn]: < 0.01wt%, [%S]: 0.02wt%, [%P]: < 0.01wt%, [%O]: 0.168wt%, [%N]:
0.049wt%；Metal recovery rate 89%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content had reached converter
The standard of tapping.
Embodiment two
[1] prepared by biomass carbon: with embodiment one.
[2] mineral aggregate is broken: taking above-mentioned high-silicon iron ore 500g, preliminary broken and after abundant ball milling, granularity is less than
80μm。
[3] prepared by pelletizing: above-mentioned Iron Ore Powder and powdered carbon and a certain amount of CaO are mixed.Wherein biomass carbon dosage is
The molar ratio that 122g, i.e. its amount meet C/O in carbonaceous pelletizing is 0.8.Wherein CaO additional amount meets CaOwt%/SiO2Wt%=
1.0.The pelletizing that diameter is 10.0mm is made in material after mixing.Ball binder processed uses 2.0% secondary stock.
[4] pelletizing is dry: after pelletizing spontaneously dries for 24 hours, further in 300 DEG C of dry 2h.
[5] is reduced directly: being restored in the following conditions: being used tube furnace, reduction temperature is 1100 DEG C, and the recovery time is
20min is passed through CO/CO2P in gaseous mixture 1L/min and gaseous mixtureCO2/PCO=1.0.To simulate furnace atmosphere as PCO2/PCO=
1.0.The degree of metalization of metal pelletizing obtained is 84% after carrying out reduction, and metallized pellet residual carbon content is 0.33wt%.
[6] slag iron separation: the pelletizing that will have been restored melts in Si-Mo rod high temperature box furnace and divides.It is molten that temperature is divided to be 1550
DEG C, respectively 5min and 10min between timesharing is melted, realizes slag iron separation.
Gained metal-like each element content is [%C]: 0.046wt% when be 5min between molten timesharing, [%Si]:
0.02wt%, [%Mn]: < 0.01wt%, [%S]: 0.03wt%, [%P]: < 0.01wt%, [%O]: 0.252wt%, [%
N]: 0.039wt%；Metal recovery rate 84%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content have reached
The standard of converter tapping.
Gained metal-like each element content is [%C]: 0.016wt% when be 10min between molten timesharing, [%Si]:
0.04wt%, [%Mn]: < 0.01wt%, [%S]: 0.02wt%, [%P]: < 0.01wt%, [%O]: 0.137wt%, [%
N]: 0.055wt%.Metal recovery rate 83%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content have reached
The standard of converter tapping.
Embodiment three
[1] prepared by biomass carbon: with embodiment one.
[2] mineral aggregate is broken: taking above-mentioned high-silicon iron ore 500g, preliminary broken and after abundant ball milling, granularity is less than
80μm。
[3] prepared by pelletizing: above-mentioned Iron Ore Powder and powdered carbon and a certain amount of CaO are mixed.Wherein biomass carbon dosage is
The molar ratio that 107g, i.e. its amount meet C/O in carbonaceous pelletizing is 0.7.Wherein CaO additional amount meets CaOwt%/SiO2Wt%=
2.0.The pelletizing that diameter is 10.0mm is made in material after mixing.Ball binder processed uses 2.0% secondary stock.
[4] after pelletizing spontaneously dries for 24 hours, further in 300 DEG C of dry 2h.
[5] is reduced directly: being restored in the following conditions: being used tube furnace, reduction temperature is 1200 DEG C, and the recovery time is
15min is passed through CO/CO2P in gaseous mixture 1L/min and gaseous mixtureCO2/PCO=1.0.To simulate furnace atmosphere as PCO2/PCO=
1.0.The degree of metalization of metal pelletizing obtained is 84% after carrying out reduction, and metallized pellet residual carbon content is 0.28wt%.
[6] slag iron separation: the pelletizing that will have been restored melts in Si-Mo rod high temperature box furnace and divides.It is molten that temperature is divided to be 1550
DEG C, it is 10min between molten timesharing, realizes slag iron separation.
Gained metal-like each element content be [%C]: 0.026wt%, [%Si]: 0.02wt%, [%Mn]: <
0.01wt%, [%S]: 0.03wt%, [%P]: < 0.01wt%, [%O]: 0.193wt%, [%N]: 0.056wt%；Metal
The rate of recovery 81%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content had reached the standard of converter tapping.
Example IV
[1] prepared by biomass carbon: with embodiment 1.
[2] mineral aggregate is broken: taking above-mentioned high-silicon iron ore 500g, preliminary broken and after abundant ball milling, granularity is less than
80μm。
[3] prepared by pelletizing: above-mentioned Iron Ore Powder and powdered carbon and a certain amount of CaO are mixed.Wherein biomass carbon dosage is
The molar ratio that 107g, i.e. its amount meet C/O in carbonaceous pelletizing is 0.7.Wherein CaO additional amount meets CaOwt%/SiO2Wt%=
1.0.The pelletizing that diameter is 10.0mm is made in material after mixing.Ball binder processed uses 2.0% secondary stock.
[4] after pelletizing spontaneously dries for 24 hours, further in 300 DEG C of dry 2h.
[5] is reduced directly: being restored in the following conditions: being used tube furnace, reduction temperature is 1100 DEG C, and the recovery time is
20min is passed through CO/CO2P in gaseous mixture 1L/min and gaseous mixtureCO2/PCO=1.0.To simulate furnace atmosphere as PCO2/PCO=
1.0.The degree of metalization of metal pelletizing obtained is 82% after carrying out reduction, and metallized pellet residual carbon content is 0.10wt%.
[6] slag iron separation: the pelletizing that will have been restored melts in Si-Mo rod high temperature box furnace and divides.It is molten that temperature is divided to be 1550
DEG C, it is 10min between molten timesharing, realizes slag iron separation.
Gained obtain metal-like each element content be [%C]: 0.018wt%, [%Si]: 0.02wt%, [%Mn]: <
0.01wt%, [%S]: 0.01wt%, [%P]: < 0.01wt%, [%O]: 0.164wt%, [%N]: 0.037wt%；Metal
The rate of recovery 80%.As it can be seen that the carbon of gained iron sample, silicon, manganese, sulphur and phosphorus content had reached the standard of converter tapping.
Comparative example five
[1] reducing agent uses coal dust, ingredient such as following table.Coal dust passes through ball milling, and granularity is less than 80 μm；Its gasification property
It can be as shown in Figure 5.
The ingredient (wt%) of coal dust in 5. embodiment five of table
[2] meet C/O=1.0 in the preparation of carbonaceous pelletizing, that is, take coal dust 120g；Being reduced directly temperature used is 1200 DEG C,
The direct-reduction time is 20min.
[3] remaining step of is the same as embodiment one.The residual carbon content of gained metallized pellet is 2.8wt%, and degree of metalization is
93%.
It is molten to divide gained metal-like each element content for [%C]: 1.05wt%, [%Si]: 0.55wt%, [%S]:
0.11wt%；Metal recovery rate 97%.Metallic iron sample quality is lower than the standard of converter tapping molten steel, and [%Si] is beyond height in molten iron
The standard of furnace molten iron.
Comparative example six
[1] biomass carbon used in is the same as example 1；
[2] meet C/O=0.9 in the preparation of carbonaceous pelletizing, that is, take biomass charcoal powder 137g.
[3] remaining step of is the same as embodiment one.The degree of metalization of reduction gained metallized pellet is 91%, and wherein carbon residue contains
Amount is 1.17wt%.
It is molten to divide gained metal-like each element content for [%C]: 0.13wt%, [%Si]: 0.17wt%, [%S]:
0.02wt%；Metal recovery rate 94%.Metallic iron sample quality is lower than the standard of converter tapping molten steel, higher than blast-melted mark
It is quasi-.
It although an embodiment of the present invention has been shown and described, for the ordinary skill in the art, can be with
A variety of variations, modification, replacement can be carried out to these embodiments without departing from the principles and spirit of the present invention by understanding
And modification, the scope of the present invention is by appended claims and its equivalent limits.
Claims (6)
1. a kind of method for directly preparing molten steel from high-silicon iron ore, which is characterized in that the described method comprises the following steps:
Step 1: abandoned biomass, air thermal dissociation is completely cut off under the conditions of 300-500 DEG C, biomass is made by the preparation of biomass carbon
Charcoal, gained biomass carbon pass through ball milling beading shape powdered carbon；
Step 2: mineral aggregate is broken, high-silicon iron ore is prepared into miberal powder；
Step 3: prepared by pelletizing, by miberal powder, biomass charcoal powder and CaO are sufficiently mixed according to preset ratio, add certain proportion
Organic binder and water after pelletizing is made；
Step 4: pelletizing is dry, pelletizing obtained is sufficiently dry；
Step 5: direct-reduction, according to rotary hearth furnace direct-reduction technique, by the pelletizing after drying in CO and CO2Mix reducing atmosphere
Under restored；
Step 6: high temperature melting point, high temperature slag iron separation directly obtains molten steel
Wherein, in the step 1, the fixation carbon content of prepared biomass charcoal powder is greater than 60wt%, and volatile matter content is greater than
30wt%, content of ashes are less than 5wt%；The granularity of acinous biomass charcoal powder is less than 80 μm；In 1000 DEG C and CO2Partial pressure is greater than
Under conditions of 0.5atm, the powdered carbon of granularity less than 80 μm is gasified totally in 10 minutes；
Wherein, in the step 2, all iron content of the high-silicon iron ore is greater than 55wt%, and silica is greater than 10wt%；Institute
Powder particle size is stated less than 80 μm2；
In the step 5, reduction temperature is 1100-1200 DEG C, recovery time 15-20min, CO and CO in atmosphere2Partial pressure
Compare PCO2/PCOIt is 1.0, the degree of metalization of gained metallized pellet is 82-88%, and residual carbon content is less than 1.0wt%.
2. the method that high-silicon iron ore directly prepares molten steel according to claim 1, it is characterised in that: in the step 3, mine
When powder and biomass charcoal powder are mixed, the molar ratio (m of fixed carbon and the oxygen in ferriferous oxide in miberal powder in biomass charcoal powderC/
mO) range be 0.70-0.80.
3. the method that high-silicon iron ore directly prepares molten steel according to claim 1, it is characterised in that: in the step 3, add
Add the CaO weight percent and SiO after CaO in the pelletizing2The ratio between weight percent (CaOwt%/SiO2It wt%) is 1.0-
2.0。
4. the method that high-silicon iron ore directly prepares molten steel according to claim 1, it is characterised in that: in the step 3, system
Organic adhesive dosage used in the process of ball is no more than 2%, and water content used is no more than 10%.
5. the method that high-silicon iron ore directly prepares molten steel according to claim 1, it is characterised in that: in the step 4, institute
The drying temperature for preparing pelletizing is 200-300 DEG C, drying time 2-3h.
6. the method that high-silicon iron ore directly prepares molten steel according to claim 1, it is characterised in that: high in the step 6
Molten point of temperature molten divides temperature to be 1550-1600 DEG C, and melting between timesharing is 5-10min, and atmosphere used is N2Or inert gas, gained steel
Water quality meets or exceeds pneumatic steelmaking tapping standard.
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| CN102586529A (en) * | 2012-03-23 | 2012-07-18 | 北京科技大学 | Rotary hearth furnace iron-making method utilizing biomass carbon-containing pellet to serve as raw material |
| CN103025900A (en) * | 2010-06-30 | 2013-04-03 | K·H·伽达 | Process for extracting metals from aluminoferrous titanoferrous ores and residues |
| CN103290158A (en) * | 2013-05-29 | 2013-09-11 | 北京科技大学 | Method for realizing dephosphorization of olitic high-phosphorus iron ore by use of biomass charcoal |
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| CN102586529A (en) * | 2012-03-23 | 2012-07-18 | 北京科技大学 | Rotary hearth furnace iron-making method utilizing biomass carbon-containing pellet to serve as raw material |
| CN103290158A (en) * | 2013-05-29 | 2013-09-11 | 北京科技大学 | Method for realizing dephosphorization of olitic high-phosphorus iron ore by use of biomass charcoal |
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