Summary of the invention
It is raw material with the distinctive high-Ti type V-Ti magnetite concentrate of Flos Bombacis Malabarici that technical problem to be solved by this invention provides a kind of, the preparation method of preparation high titan type high alkalinity sinter.This method is finished by following steps:
Agglomerate is the preparation method may further comprise the steps: A, batching, B, mixing, C, cloth, D, igniting, sintering, E, heat fragmentation, F, heat screening, G, cooling, H, screening is characterized in that: raw materials for sintering is a high-Ti type V-Ti magnetite concentrate, and its component content contains by weight: TFe 52-55%, FeO 29-32%, SiO
23-4%, CaO 1.5-2.0%, MgO2.0-2.5%, Al
213-15%, S 0.4-0.6%; Wherein, sintering temperature is 1300-1400 ℃ among the step D.
Because Flos Bombacis Malabarici v-ti magnetite concentrate w (TiO
2) reach more than 13% w (Al
3) more than 4.5%, its fusing point is up to more than 1350 ℃, the amount of liquid phase of generation is few, lacks 10-20% than common ore deposit sintering amount of liquid phase; And this kind granularity of concentrate is thick, and＜200 purpose grain size contents have only 40-50%, and balling property is poor, causes mixture ventilation poor, and vertical sintering speed is slow, and the agglomerate yield and quality is low.Under reducing atmosphere, (, adding coke powder or hard coal in sintering improve sintering temperature because of acting as a fuel, when improving sintering temperature, supervene reducing atmosphere) when sintering temperature is lower than 1300 ℃, can produce the sintered material infusibility, amount of liquid phase is few, the serious consequence that descends of sinter strength and yield rate.And when being higher than 1400 ℃, will produce uhligite in sintering process (is CaOTiO
2These mineral are that v-ti magnetite concentrate is too high owing to joining charcoal in sintering process, under pyritous reducing atmosphere condition more than 1350 ℃, form, its poor toughness, hardness are big and crisp, fusing point causes the sintering fusing point further to raise up to 1970 ℃, and amount of liquid phase reduces), uhligite plays destruction to sinter strength, shortens equipment life but also can aggravate equipment attrition.
Wherein, steps A batching: by weight percentage: v-ti magnetite concentrate 50-80%, common fine ore 0-30%, Wingdale 1-20%, unslaked lime 0-7.5%, coke powder 1-5%, hard coal 1-7%, 30-50% returns mine.
Wherein, step C cloth: bed thickness is 500-680mm.Can bring into play the function of deep-bed sintering, improve sinter strength, remedy the defective of high-Ti type V-Ti sinter strength difference.
Wherein, step D igniting, sintering: ignition temperature 980-1100 ℃, are responsible for 100-115 ℃ of spent air temperture, 250-300 ℃ of sintering end point temperature, sintering negative pressure 12000-14500Pa by sintering temperature 1300-1400 ℃.
Use prepared agglomerate of the present invention, need not equipment is improved, easy and simple to handle, sintering and high basicity sinter smelt, the capacity factor of a blast furnace, coke ratio, coal technico-economical comparison such as compare and all are improved.By improving vanadium titanium sinter basicity to 2.0-3.2, the mixed carbon comtent that control is suitable increases amount of liquid phase, fundamentally improves the mineral composition of vanadium titanium agglomerate, improves sinter strength, improves metallurgical performance.
Agglomerate preparation method of the present invention may further comprise the steps: A, batching, B, mixing, C, cloth, D, igniting, sintering, E, heat fragmentation, F, heat screening, G, cooling, H, screening.Screening back blast furnace can be smelted.Particularly, step B mixing can be carried out twice mixing; The screening of step H can be carried out sintering screening and ditch screening down.
Raw materials for sintering is based on v-ti magnetite concentrate that Flos Bombacis Malabarici is produced, and proportioning can cooperate a small amount of common rich ore powder, flux, fuel again up to 50%-80%, and joining outward returns mine etc. carries out sintering, and independent concentrate also can carry out sintering.The component content of this v-ti magnetite concentrate (by weight) contains: TFe 52-55%, FeO 29-32%, SiO
23-4%, CaO 1.5-2.0%, MgO2.0-2.5%, Al
213-15%, S 0.4-0.6%; And coarse size is 40-50% only less than 200 order grain size contents, causes balling property poor, influences the sintered material ventilation property.This concentrate has the characteristics of the high impurity of low-grade high titanium, belongs to the difficult ore that burns.
Return mine and be that the screen underflow of each time of agglomerate screening, major ingredient are agglomerate and the unsintered compounds of granularity＜5mm; And the finished product screen underflow that produces down with the blast furnace ditch in the sintering process, granularity＜5mm, major ingredient are little agglomerate.
Steps A batching is preferred: by weight percentage: v-ti magnetite concentrate 50-80%, common fine ore 0-30%, Wingdale 1-20%, unslaked lime 0-7.5%, coke powder 1-5%, hard coal 1-7%, 30-50% returns mine.
In order to improve basicity: can increase flux such as Wingdale (CaO 52.5%) with addition of amount,, can make sinter basicity (CaO/SiO to improve the CaO of agglomerate
2) bring up to 2.0-3.2 from 1.70.The flux proportioning is brought up to 17.5-28% to amount to the Wingdale proportioning from 15%.Flux also uses 7% unslaked lime (CaO 86.5%), alternative 10.5% Wingdale.Using unslaked lime to strengthen granulates and sintering.
Wherein, step C cloth:
Bed thickness is 500-680mm, and this thickness can be brought into play the function of deep-bed sintering, promptly prolongs the high temperature hold-time, makes the agglomerate crystallization more abundant, thereby improves sinter strength, remedies the defective of high-Ti type V-Ti sinter strength difference.
Wherein, step D igniting, sintering:
980-1100 ℃ of control ignition temperature belongs to the low temperature igniting, and purpose is to need to reduce ignition temperature under thick bed of material condition, prevents top layer agglomerate superfusion and the deterioration ventilation property.
1300-1400 ℃ of control sintering temperature guarantees that the v-ti magnetite concentrate sintering can produce enough high temperature and amount of liquid phase, can prevent to generate the uhligite (CaOTiO of intensity difference again under high-temperature reductibility atmosphere
2), sinter strength is played destruction.
100-115 ℃ of spent air temperture is responsible in control, can guarantee that the bed of material grills thoroughly, and spent air temperture can not cause damage to main exhauster again, reduces calorific loss simultaneously.
250-300 ℃ of control sintering end point temperature belongs to optimum controling range, is responsible for spent air temperture and can guarantees to grill thoroughly and can burning in this scope, improves the agglomerate yield and quality.
Control sintering negative pressure 12000-14500Pa belongs to typical high negative pressure sintering, increases draft and air quantity, and it is poor to overcome the v-ti magnetite concentrate bed permeability, the defective that the sintering resistance is big.
Control machine speed 1.5-1.80m/min belongs to slow machine speed operation, and purpose is to descend in thick bed of material condition to hanging down vertical sintering velocity, prolongs the high temperature hold-time, improves sinter strength.
Control mixture moisture 6.8-7.4% belongs to low moisture control, because the hydrophobicity of Flos Bombacis Malabarici v-ti magnetite concentrate is relatively poor to the avidity of moisture, can not control excessive moisture, otherwise produce excessive moistening layer in sintering process, influences yield and quality.
Control fixed carbon 2.8-3.0% belongs to low charcoal sintering, and the Flos Bombacis Malabarici v-ti magnetite concentrate contains the FeO more than 30%, and oxidation heat liberation in sintering process can be saved fixed carbon; If it is too high to join simultaneously charcoal, will produce high temperature and reducing atmosphere, generate fusing point height, hardness greatly, poor toughness, property is crisp, intensity is low minerals calcium titanium ore (CaOTiO
2), sinter strength is played destruction.
The sintering of common ore deposit or low Ti type V-Ti magnetite concentrate can not be controlled at this scope still can ordinary production, and Flos Bombacis Malabarici high-Ti type V-Ti magnetite concentrate sintering control can ordinary production like this, otherwise can't reach the required quality requirements of blast-furnace smelting.
The contriver is in the technical study process, and employed sinter machine condition is 3 * 130m
2: long 52m * wide 2.5m; 2 * 145m
2: long 52m * wide 2.79m; 1 * 173.6m
2: long 62.2m * wide 2.79m, but the sinter machine of other specification also can be implemented setting and improvement by above-mentioned processing condition, makes the sinter basicity for preparing and get to 2.0-3.2, fundamentally improves the mineral composition of vanadium titanium agglomerate, improve sinter strength, improve metallurgical performance.
For the further improvement of aforementioned techniques scheme, can also select one or mix to adopt following method, improve the high-titanium type sinter yield and quality.
1, implement hyperoxia position sintering, agglomerate w (FeO) is controlled at 7-8%.
2, use the 20-30% rich ore powder to improve sintered material size composition.
3, prolong 0.5-1.0min ignition time.
4, use low TiO
2The common rich ore powder of concentrate and some amount reduces agglomerate TiO
5, improve agglomerate w (MgO) 0.2-0.3%.
The main iron ore composition that following examples prepare the agglomerate use sees Table 1, the following A of preparation method, batching, B, mixing, C, cloth, D, igniting, sintering, E, heat fragmentation, F, heat screening, G, cooling, H, screening.Can carry out blast-furnace smelting after the screening.
The iron ore composition (%) that table 1 sintering uses
|V-ti magnetite concentrate
|Australia's fine ore
|Domestic higher-grade fine ore
|Grade fine ore in domestic
Annotate: TFe is an iron level.Wherein, V in the v-ti magnetite concentrate
5Content be 0.556%, TiO
2Content be 12-77%, granularity＜200 purposes account for 50%.
Flux unslaked lime w (CaO) 85-88% that sintering uses; Wingdale w (CaO) 50-53%, granularity＜3.0mm grade 88-92%; Coke powder ash content 12-16%, granularity＜3.0mm grade 82-90%; Hard coal ash content 16-20%, volatile matter 0.5-1%,＜3.0mm grade 75-80%.
Raw material uses the v-ti magnetite concentrate in the table 1, by weight percentage: v-ti magnetite concentrate 54%, common fine ore 26% (grade fine ore 3% during the domestic higher-grade fine ore of Australian fine ore 11%+ 12%+ is domestic), Wingdale 5.5%, unslaked lime 7.0%, coke powder 4.6% (or hard coal 6.0%), return mine 40%.
Bed thickness is 565mm, machine speed 1.55m/min, and 1087 ℃ of ignition temperatures, 1350 ℃ of sintering temperatures are responsible for 113 ℃ of spent air tempertures, 280 ℃ of sintering end point temperature, sintering negative pressure 12900Pa.
Sinter basicity is brought up to 2.16, and the technique effect of generation is that productivity of sintering machine is 1.322t/m
2H, the ISO tumbler index (＞6.3mm%) be 69.95%, solid burnup is 53.40kgce/t.
Raw material uses the v-ti magnetite concentrate in the table 1, by weight percentage: v-ti magnetite concentrate 53%, common fine ore 27% (grade fine ore 3% during the domestic higher-grade fine ore of Australian fine ore 12%+ 12%+ is domestic), Wingdale 7.2%, unslaked lime 7.0%, coke powder 4.5% (or hard coal 6.0%), return mine 35%.
Bed thickness is 567mm, machine speed 1.53m/min, and 1083 ℃ of ignition temperatures, 1350 ℃ of sintering temperatures are responsible for 112 ℃ of spent air tempertures, 285 ℃ of sintering end point temperature, sintering negative pressure 12830Pa.
Sinter basicity is brought up to 2.45, and the technique effect of generation is that productivity of sintering machine is 1.404t/m
2H, the ISO tumbler index (＞6.3mm%) be 71.55%, solid burnup is 48.72kgce/t.
At v-ti magnetite concentrate 55%, common fine ore 25% (grade fine ore 2% during the domestic higher-grade fine ore of Australian fine ore 11%+ 12%+ is domestic), Wingdale 6.8%, unslaked lime 7.0%, under 35% the batching condition of returning mine, sinter basicity is 2.50,1200 ℃ of sintering parameter ignition temperatures, ignition time 3min, bed thickness 550mm, mixture moisture 7.2%, sintering negative pressure 12000Pa, change dosage of coke control sintering temperature, on the sintered cup of laboratory, carry out the sintering temperature test.Temperature checking method is at 4 insertion thermopairs of sintering cup middle part punching uniform distribution, measures sintering temperature, and test-results sees Table 2.
The different sintering temperatures of table 2 are to the test-results of the influence of sintering technology and economic indicator
||Dosage of coke %
||Sintering temperature ℃
||Utilization coefficient t/m
||ISO barrate strength %
||Yield rate %
||Solid burnup kg/t
||Low temperature reduction degradation index RDI
||Reduction degree RI %
By table 2 as seen, the v-ti magnetite concentrate sintering has produced different effects under different sintering temperatures under the condition of high basicity 2.50, sintering temperature be lower than 1300 ℃ be higher than 1400 ℃, sintering utilization coefficient and intensity all descend, and technique effect is best during 1354 ℃ of sintering temperatures.
(delime stone proportioning is respectively 5.5% in this sample proportioning raw materials of three batches to the different alkalinity sintered ore samples of situ production different batches, 6.0%, outside 6.8%, other proportioning and processing parameter and embodiment 1 and 2 substantially with) carry out the detection of the mineral rock identification of phases and metallurgical performance, the results are shown in table 3, table 4, the blast-furnace smelting effect is listed in table 5.
Table 3 different basicity clinker mineral phase composite and volume fraction (%)
The different alkalinity sintered ore metallurgical performance of table 4 detected result
The different alkalinity sintered ore blast-furnace smelting of table 5 effect
||Utilization coefficient t/m
||Comprehensive coke ratio kg/t
||Ratio of putting coke into furnace kg/t
||Coal compares kg/t
By table 3-5 as seen, agglomerate is along with basicity improves, and bonding increases based on wustite and content, and silicate and uhligite reduce, and the titanomagnetite content is little, and haplotypite obviously reduces, and titanomagnetite and haplotypite are still main iron mineral.Along with the raising of basicity, the agglomerate reductibility improves simultaneously, and low temperature reduction degradation index improves.Blast furnace uses sinter basicity high more, and the iron increasing and coke saving effect is obvious more.The high titan type high alkalinity sinter that gets by preparation method of the present invention preparation is applied to blast-furnace smelting and meets quality standard fully.