A method for reducing the feo content of sinter and improving the metallurgical properties of sinter

Abstract

The application discloses a method for reducing FeO content of sinter and improving metallurgical properties of sinter, and belongs to the technical field of steel metallurgy. The method is characterized by: fuel is divided into fuel I and fuel II, fuel I is mixed with sinter raw materials to form granules, the obtained sintering materials are distributed on a sintering machine, and fuel II is distributed on the surface of the sintering materials; after the distribution is completed, ignition (using a twice ignition mode), heat preservation, sintering and cooling are sequentially performed to obtain sinter; the method adopts the technical means of "fuel addition" combined with "twice ignition", can supply more heat to the upper layer of the sintering materials, increase the high-temperature holding time of the upper layer of the sintering materials, reduce the cooling speed of the upper layer of the sintering materials, simultaneously solve the problem of excessive heat in the lower layer, make the heat distribution in the height direction of the sintering material layer more uniform, and can not only reduce the solid fuel consumption of sintering, but also reduce the FeO content of sinter and obtain sinter with excellent metallurgical properties.

Description

TECHNICAL FIELD

[0001] The application relates to a sinter production method, in particular to a method for reducing the FeO content of sinter and improving the metallurgical properties of sinter, and belongs to the technical field of iron and steel metallurgy. BACKGROUND

[0002] As the core raw material of blast furnace ironmaking, sinter accounts for as high as 70% in the blast furnace burden, and its chemical composition and metallurgical properties directly affect the stability, energy efficiency and carbon emission intensity of the blast furnace. The FeO content is one of the key indicators for evaluating the quality of sinter. At present, in order to improve the low-temperature reduction and pulverization index of sinter, many steel plants use high fuel ratio operation in sintering, increase FeO to reduce the hematite content in sinter and reduce the probability of hematite reduction expansion. However, the increase of FeO content in sinter will lead to poor reducibility, which will increase the fuel ratio of the blast furnace, resulting in high fuel ratio and carbon emission in the total ironmaking process. Research shows that for every 1% reduction in FeO content of sinter, the fuel ratio of the blast furnace can be reduced by 1.5% to 2%, and the output can be increased by 1.5% to 2%. If the low-temperature reduction and pulverization index of sinter can be maintained while reducing the FeO content of sinter, the reducibility can be further improved, which will greatly reduce the fuel ratio and carbon emission of sintering and blast furnace.

[0003] Chinese patent (CN119120892B) discloses a production method of ultra-low FeO sinter. The method is to divide the fuel into two parts, fuel I and fuel II. Fuel I is mixed with sintering raw materials to obtain sintering material. The sintering material is distributed on the sintering machine, and fuel II is distributed on the sintering material layer. Ignition, insulation, sintering and cooling are carried out. During the sintering process, oxygen-rich gas medium is sprayed on the sintering material layer. During the cooling process, the sintering material is first cooled on the sintering machine, and then unloaded to the circular cooler for cooling. This method can produce sinter with ultra-low FeO content (<6.5%) by reducing the sintering fuel ratio to improve the oxygen potential of the sintering material layer and improve the FeO oxidation efficiency of the sinter. This method can greatly reduce the solid fuel consumption of sintering and the FeO content of sinter, but the low-temperature reduction and pulverization index RDI of sinter will be reduced. +3.15

[0004] In the prior art, there are reports of using secondary ignition in the sintering process, the main purpose of which is to increase the sintering layer combustion zone width to improve the upper layer yield. For example, Japanese patent (JP7464844B2) discloses that in the flame heating method, two times of ignition can increase the sintering layer combustion zone width, thereby improving the upper layer yield. However, there is no report on the coupling of “fuel addition” and “two times of ignition” to reduce the FeO of the upper layer sinter and promote the generation and crystallization of calcium ferrite. SUMMARY

[0005] ​To solve the technical problems in the prior art, the purpose of the present application is to provide a method for reducing the FeO content of sinter and improving the metallurgical properties of sinter, which is characterized in that the new technical means of "fuel addition" combined with "two-stage ignition" is adopted, which can increase the high-temperature holding time of the sintering combustion zone of the sintering material, facilitate the generation and crystallization of calcium ferrite, and at the same time, the secondary ignition has a heat preservation effect on the upper layer of sinter, reduces the cooling rate of the upper layer of sinter, reduces the FeO content in the upper layer of sinter, and at the same time, can reduce the fuel ratio of the overall sintering mixture to a certain extent, thereby further reducing the FeO content of the overall sinter, under this method, the maximum temperature of the sintering material layer is reduced, the high-temperature holding time is prolonged, the generation of skeletal hematite is reduced and the generation of composite calcium ferrite is promoted, not only the solid fuel consumption of sintering is reduced, the FeO of sinter is reduced, but also the low-temperature reduction pulverization index, reducibility of sinter is improved, and high drum strength and yield are maintained, further reducing the coke ratio of blast furnace, providing a new method for carbon reduction and emission reduction in the ironmaking and sintering process of the steel industry, which can produce great economic and environmental benefits.

[0006] In order to achieve the above technical purpose, the present application provides a method for reducing the FeO content of sinter and improving the metallurgical properties of sinter, which comprises the following steps:

[0007] 1) The fuel is divided into two parts, fuel I and fuel II, the fuel I is mixed with the sintering raw material to form granules, and the sintering material is obtained; the fuel The mass percentage composition of the fuel II is 94%~97% : 3%~6%;

[0008] 2) The sintering material is distributed on the sintering machine, and the fuel II is distributed on the surface of the sintering material;

[0009] 3) After the distribution is completed, ignition, heat preservation, sintering and cooling are carried out in sequence to obtain sinter;

[0010] Wherein, the ignition adopts two-stage ignition mode, the temperature of the first ignition is 1000±50℃, the time is 50~70s, the second ignition is carried out after 30~60s, the temperature of the second ignition is 800±50℃, the time is 50~70s.

[0011] After a large number of experimental researches, it is found that the distribution rule of FeO content in sinter along the height direction of sintering material layer is as follows Figure 1The FeO content in the uppermost layer of sinter is the highest, which can reach 10.74%, the FeO content in the middle layer (2-5 layers) of sinter is the lowest, and the FeO content in the lower layer (7-8 layers) of sinter has an upward trend. In view of the phenomenon of the sinter, the technical scheme of the present application mainly adopts the new technical means of "fuel adding" combined with "twice ignition", which can not only reduce the FeO content in the sinter, but also improve the metallurgical properties of the sinter.

[0012] On the one hand, based on the thick material layer sintering, the heat accumulation principle can be well utilized, thereby reducing the sinter solid fuel consumption, but the uneven degree of heat distribution in the material layer increases, the heat of the upper material layer is seriously insufficient, and the heat of the lower material layer is excessive, and by adopting the "fuel adding" technology, part of the fuel can be distributed to the sintering material surface, so that the heat distribution in the material layer is more uniform, the fuel proportion of the middle and lower layers of sinter is reduced, the reducing atmosphere in the sintering process is weakened, and the overall FeO content of the sinter will be reduced, but the surface layer of the sintering material layer will lead to further increase of the FeO content due to the increase of the fuel proportion, and in order to overcome the technical problem, the twice ignition technology is adopted, the second ignition can increase the high temperature maintaining time of the combustion zone in the sintering process, which is beneficial to the generation and crystallization of calcium ferrite, and the second ignition also has the effect of heat preservation on the upper layer of sinter, which reduces the cooling rate of the upper layer of sinter, thereby reducing the FeO of the upper layer of sinter. It should be noted that the time interval between the two ignitions is 30-60s, which can effectively prevent the overburning phenomenon caused by long-time ignition, which deteriorates the permeability of the sintering material layer and the sintering index. The temperature of the first ignition is about 1000 DEG C, after the first ignition, the sintering combustion zone has been formed, and there is only a small amount of unburned residual carbon on the surface of the sintering material layer, and the temperature of the second ignition needs to be controlled at about 800 DEG C, which can prolong the high temperature maintaining time of the upper material layer, and if the temperature of the second ignition is too high, it will lead to excessive heat on the surface, which will cause the surface sinter to be over-melted.

[0013] On the other hand, the low-temperature reduction disintegration index of sinter is closely related to the mineral phase structure of sinter, such as the hematite form and quantity that causes reduction expansion. According to the existing reports, the low-temperature reduction disintegration of sinter is mainly caused by the reduction expansion of sintered hematite, which is generated near the surface of the sinter layer in a sintered state and has the characteristics of an inclusion from the structure. The difference in reduction speed between hematite and its internal crystalline inclusions is the main cause of expansion. The sintered hematite is generated by oxidation when the liquid-phase magnetite is cooled to the hematite crystallization temperature range, so reducing the generation of liquid-phase magnetite can reduce the generation of sintered hematite. After the adoption of the "fuel addition" combined with the "two-stage ignition" technology, the maximum temperature of the sintering layer can be reduced and the reducing atmosphere can be weakened, thereby reducing the generation of sintered hematite precursors, and thus reducing the sintered hematite. Although the remaining hematite content in the sinter will increase slightly, its impact on the low-temperature reduction disintegration of sinter is weak. In addition, the low-temperature reduction disintegration of sinter is closely related to the content and form of the binding phase that resists expansion stress and crack propagation. The binding phase in the sinter is mainly composite calcium ferrite and silicate, and the strength of the composite calcium ferrite is the highest, and the strength of the silicate is lower, so increasing the content of the composite calcium ferrite can improve the resistance of the sinter to the reduction expansion stress of hematite and inhibit the propagation of cracks. Common calcium ferrite structures include acicular calcium ferrite, columnar calcium ferrite and dissolved calcium ferrite, and the acicular calcium ferrite has the strongest ability to resist reduction expansion stress and crack propagation, and its generation temperature is about 1275℃. The adoption of the "fuel addition" combined with the "two-stage ignition" technology can increase the high-temperature retention time of the combustion zone and promote the generation of acicular calcium ferrite. It should be noted that hematite and calcium ferrite are more easily reduced than magnetite and fayalite, and the reduction of the sinter is improved by reducing the FeO content in the sinter, increasing the liquid phase of calcium ferrite and increasing the acicular calcium ferrite.

[0014] Fuel in the fuel of the present application The mass ratio of fuel is 3%~6%. After adopting the "two-stage ignition" technology, the fuel added to the surface of the sintering layer should not be too high, otherwise it will cause excessive heat in the upper part, and if the proportion is too low, it will not have the effect of uniformizing the heat distribution, so it is best to control the fuel distribution ratio to 3~6%.

[0015] The "two-stage ignition" technology adopted in the present application sets a time interval between the two ignitions mainly to avoid the surface sinter from being overheated and melted excessively due to long-time ignition, forming a brittle glass structure and reducing the strength of the finished product. Similarly, if the ignition time is too short, the ignition cannot be completed, and if the ignition time is too long, it may cause uneven temperature distribution in the sintering layer, affecting the uniformity and metallurgical properties (such as reducibility and cold strength) of the sinter.

[0016] As a preferred scheme, the particle size distribution of the fuel is as follows: the mass ratio of particle size <3 mm is greater than 85%, and the mass ratio of particle size <1 mm is less than 20%. If the fuel particle size is too large, coarse particles are prone to significant segregation during the distribution process, resulting in enrichment in the lower part of the layer. This uneven distribution causes the upper part of the sintering layer to be relatively insufficient in fuel ratio, making it difficult to form sufficient and uniform liquid phase, thereby weakening the drum strength of the sinter and degrading its particle size composition. At the same time, the lower layer of the material is excessive due to the enrichment of fuel, and the local temperature is too high. This high-temperature environment inhibits the formation of composite calcium ferrite (SFCA) and may promote the decomposition of existing calcium ferrite into hematite or magnetite; in addition, hematite itself is not stable at high temperatures and will further decompose to form magnetite, ultimately leading to an increase in the FeO content in the sinter. Conversely, too fine fuel particles will accelerate the combustion rate, shorten the duration of the high-temperature zone of the material layer, and make the sintering liquid phase insufficient, which also damages the overall quality of the sinter, resulting in a simultaneous decrease in drum strength and yield. Moreover, fine fuel particles are easily entrained by the gas flow, significantly deteriorating the permeability of the sintering layer.

[0017] As a preferred scheme, the mass of the fuel is less than 3.5% of the mass of the sintering material. Under thick-layer sintering conditions, the proportion of sintering fuel should not be too high to prevent the increase in FeO content and improve the reducibility of the sinter. The mass of the fuel is further preferably 3.2-3.5% of the mass of the sintering material. By using the "fuel addition" combined with the "two-stage ignition" technology, the present application can reduce the required fuel proportion in the sintering mixture by 5-10% compared to conventional sintering. However, if the fuel reduction proportion is too high, the sintering heat is excessive, and the maximum temperature is still high, making it difficult to reduce the overall FeO content of the sinter. If the fuel reduction proportion is too low, the sintering heat supply will be insufficient, which cannot guarantee the yield and liquid phase amount.

[0018] As a preferred scheme, the distribution thickness of the sintering material on the sintering machine is 900-1000 mm. Thick-layer sintering can effectively utilize the sintering heat accumulation principle and significantly reduce the sintering fuel ratio. Under thick-layer conditions, the potential for reducing the fuel ratio is greater.

[0019] As a preferred scheme, the iron grade in the sintering material is not less than 57%, the mass content of MgO is <1.8%, the mass content of SiO2 is 5.0-5.5%, the mass content of Al2O3 is 1.5-2.0%, and the binary basicity is 1.8-2.2. The optimization design of the chemical composition of the sintering material in the present application is based on the following mechanism: the addition amount of MgO needs to be controlled within 1.8% because excessive MgO 2+ will replace Fe in the magnetite lattice 2+, which occupies the octahedral interstitial position, thereby reducing the lattice defects, enhancing the magnetite stability and leading to the increase of FeO content; meanwhile, too low SiO2 content is not conducive to the generation of composite calcium ferrite, and SiO2 is easy to react with Fe3O4 to generate fayalite phase under low temperature conditions, and too high SiO2 content will also promote the increase of FeO; the introduction of appropriate Al2O3 is helpful to the generation of calcium ferrite and the development of composite calcium ferrite, and can improve the sintering liquid phase fluidity and promote the oxygen ion migration to optimize the oxidation process, but excessive Al2O3 will aggravate the low-temperature reduction pulverization tendency of sinter; in addition, maintaining the basicity above 1.8 can ensure that the proportion of calcium ferrite phase reaches 30% to 40%, thereby ensuring the sinter strength, but too high basicity will reduce the iron grade and increase the blast furnace slag amount, affecting the blast furnace smelting efficiency.

[0020] Compared with the prior art, the technical scheme of the present application has the beneficial technical effects:

[0021] The present application adopts the new technical means of "fuel split" combined with "two-time ignition" in the sinter preparation process, not only realizes the reduction of sinter solid fuel consumption and the reduction of sinter FeO, but also improves the low-temperature reduction pulverization index, reducibility, high drum strength and yield of sinter, further reduces the coke ratio of blast furnace, provides a new method for carbon reduction and emission reduction in the ironmaking and sintering process of the steel industry, and can produce huge economic and environmental benefits; more specifically:

[0022] (1) It can make the heat distribution of the sintering material layer more uniform, reduce the total fuel ratio of sinter, reduce the FeO content of the lower layer of sinter, and at the same time reduce the cooling rate of the upper layer of sinter, promote the oxidation of FeO in the upper layer of sinter, thereby reducing the FeO content of sinter as a whole.

[0023] (2) On the basis of reducing the total fuel ratio, the sintering maximum temperature is reduced and the reducing atmosphere of the material layer is weakened, the skeletal hematite generated by the oxidation of magnetite under high temperature is reduced, and the high-temperature holding time of the sintering material is increased, which is helpful to the generation of sintering liquid phase calcium ferrite and enhances the resistance of sinter to low-temperature reduction pulverization.

[0024] (3) It can increase the generation amount of hematite and calcium ferrite with good reducibility, which is conducive to the improvement of reducibility and realizes the reduction of fuel ratio and energy saving and emission reduction of blast furnace.

[0025] (4) Through the control of the temperature and time interval of twice ignition and other conditions, the metallurgical properties of the sintered ore can be effectively improved. On the one hand, the time interval set between the two ignitions is 30-60s, which can effectively prevent the overburning phenomenon caused by the excessive concentration of heat on the upper layer due to continuous long-time ignition, and deteriorate the permeability of the sintering material layer and the sintering index, on the other hand, the temperature of the first ignition is about 1000℃, after the first ignition, the sintering combustion zone has been formed, and there is only a small amount of unburned residual carbon on the surface of the sintering material layer, and the temperature of the second ignition needs to be controlled at about 800℃, which can prolong the high-temperature holding time of the upper layer, and if the temperature of the second ignition is too high, it will cause excessive heat on the surface and lead to over-melting of the surface sintered ore.

[0026] (5) Based on the "fuel split", the surface layer of the sintering material layer will increase the FeO content in the sintered ore due to the increase of the fuel ratio, and at the same time, the carbon residual amount of the upper layer of the sintering material layer will also increase, and the "twice ignition" technical means adopted by the present application can well solve the technical problems brought by "fuel split", and the "twice ignition" process can compensate for the uneven heat distribution of the upper layer, so that the heat distribution of the material layer is more uniform, and at the same time, the high-temperature holding time is widened, so that the calcium ferrite content of the upper layer of the material layer is increased, the crystallization is more sufficient, and the strength is higher; the "twice ignition" process can greatly slow down the cooling rate, ensure the oxidation of FeO in the sintered ore, reduce the FeO content of the surface layer and the upper layer of the sintered ore, and the second ignition can ignite the residual carbon in the upper layer of the material layer, and provide more heat, reducing the loss of heat. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 The distribution of the FeO content in the sintered ore in Example 1 along the height direction of the sintering material layer. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of the content of the present application, the following will combine the preferred embodiments to describe the present application more fully and in detail, but the protection scope of the claims of the present application is not limited to the following specific embodiments.

[0029] Unless otherwise defined, all the professional terms used in the following are the same as the meanings commonly understood by those skilled in the art. The professional terms used in this paper are only for the purpose of describing the specific embodiments, and are not intended to limit the protection scope of the claims of the present application.

[0030] Example 1

[0031] According to the sintering mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, the coke powder ratio is 3.42%, wherein the coke powder particle size <3mm accounts for 87%, <1mm accounts for 15%, and 94% of the total amount of coke powder is mixed with the sintering mixture to form a particle, the mixture is laid on the sintering machine, the laying height is 950mm, then the remaining (total amount 6%) coke powder is laid on the surface of the sintering mixture. Ignition at 1000±50℃ for 1min, then interval 40s, secondary ignition at 800±50℃ for 1min, then sintering under negative pressure 12kPa, when the sintering flue gas temperature reaches the highest point, it is the sintering endpoint, after using the method described in this embodiment, the sinter FeO distribution is as shown in Figure 1 Table 1, the influence of sintering index, FeO content, and metallurgical properties is shown in Table 2.

[0032] Example 2

[0033] According to the sintering mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, the coke powder ratio is 3.42%, wherein the coke powder particle size <3mm accounts for 87%, <1mm accounts for 15%, and 94% of the total amount of coke powder is mixed with the sintering mixture to form a particle, the mixture is laid on the sintering machine, the laying height is 950mm, then the remaining (total amount 6%) coke powder is laid on the surface of the sintering mixture. Ignition at 1000±50℃ for 1min, then interval 40s, secondary ignition at 800±50℃ for 1min, then sintering under negative pressure 12kPa, when the sintering flue gas temperature reaches the highest point, it is the sintering endpoint, after using the method described in this embodiment, the sinter FeO distribution is as shown in

[0034] Example 3

[0035] According to the sintering mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, the ratio of coke powder is 3.32%, wherein the particle size of coke powder <3mm accounts for 87%, <1mm accounts for 15%, take 97% of the total amount of coke powder and mix the sintering mixture, the mixture is laid on the sintering machine, the laying height is 1000mm, then the remaining (3% of the total amount) coke powder is laid on the surface of the sintering mixture. Ignite for 1min under the condition of 1000±50℃, then interval 50s, ignite for 1min under the condition of 800±50℃, then sinter under the condition of negative pressure 12kPa, when the sintering flue gas temperature reaches the highest point, it is the sintering endpoint, after using the method described in this embodiment, the influence on sintering index, FeO content, metallurgical properties is shown in Table 1, Table 2.

[0036] Comparative Example 1 (reference sintering)

[0037] According to the sintering mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, the ratio of coke powder is 3.6%, after mixing and granulating the sintering material, the mixture is laid on the sintering machine, the laying height is 950mm. Ignite for 1min under the condition of 1000±50℃, then sinter under the condition of negative pressure 12kPa, when the sintering flue gas temperature reaches the highest point, it is the sintering endpoint, after using the method described in this embodiment, the influence on sintering index, FeO content, metallurgical properties is shown in Table 1, Table 2. Figure 1

[0038] Comparative Example 2 (without secondary ignition)

[0039] According to the sintering mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, the ratio of coke powder is 3.42%, wherein the particle size of coke powder <3mm accounts for 87%, <1mm accounts for 15%, take 94% of the total amount of coke powder and mix the sintering mixture, the mixture is laid on the sintering machine, the laying height is 950mm, then the remaining (6% of the total amount) coke powder is laid on the surface of the sintering mixture. Ignite for 1min under the condition of 1000±50℃, then sinter under the condition of negative pressure 12kPa, when the sintering flue gas temperature reaches the highest point, it is the sintering endpoint, after using the method described in this embodiment, the influence on sintering index, FeO content, metallurgical properties is shown in Table 1, Table 2. Figure 1

[0040] ​​Comparative Example 3 (no fuel sub-addition)

[0041] According to the sinter mixture composition TFe = 57.6%, MgO = 1.74%, SiO2 = 5.25%, Al2O3 = 1.86%, binary basicity CaO / SiO2 = 2.0, coke powder ratio is 3.5%, wherein the coke powder particle size <3mm accounts for 87%, <1mm accounts for 15%, the coke powder is mixed and granulated with the sinter mixture, the mixture is laid on the sintering machine, the laying height is 950mm. Ignition at 1000±50℃ for 1min, then interval 40s, secondary ignition at 800±50℃ for 1min, then sintering under negative pressure 12kPa, the sintering end point is when the sintering flue gas temperature reaches the highest point, after using the method described in the embodiment, the FeO distribution of the sinter is as shown in Figure 1 Table 1, the effect of sintering index, FeO content, and metallurgical properties is shown in Table 1 and Table 2.

[0042]

[0043] .

[0044] According to Example 1 and Comparative Examples 1-3, it can be seen that the use of "fuel sub-addition" and "two-stage ignition" alone has no obvious effect on the reduction of FeO content in the sinter and the improvement of the metallurgical properties of the sinter. However, the coupling of "fuel sub-addition" and "two-stage ignition" has a significant synergistic effect. Not only does it reduce the FeO content in the sinter, but also improves the low temperature reduction and pulverization index, reducibility, high drum strength and product rate of the sinter.

Claims

1. A method of reducing the FeO content of sinter and improving the metallurgical properties of sinter, characterised by: Comprise the following steps: 1) the fuel is divided into two parts, fuel I and fuel II, the fuel I is mixed with the sintering raw material to granulate to obtain a sintering material; the fuel and the mass percentage composition of the fuel II is 94%-97%:3%-6%. 2) the sintering material is distributed to the sintering machine, and the fuel II is distributed to the sintering material surface; 3) after the distribution is completed, ignition, holding, sintering and cooling are sequentially performed to obtain sinter; Wherein, the ignition adopts twice ignition mode, the temperature of the first ignition is 1000±50℃, the time is 50~70s, the second ignition is performed after 30~60s interval, the temperature of the second ignition is 800±50℃, the time is 50~70s.

2. A method of reducing the FeO content of sinter and improving the metallurgical properties of sinter according to claim 1, characterized in that: The particle size distribution of the fuel is as follows: the mass ratio of particle size <3mm is greater than 85%, and the mass ratio of particle size <1mm is less than 20%.

3. A method of reducing the FeO content of sinter and improving the metallurgical properties of sinter according to claim 1 or 2, characterised in that: The mass of the fuel is less than 3.5% of the mass of the sintering material.

4. The method of reducing FeO content and improving the metallurgical properties of sinter according to claim 1, characterized in that: The distribution thickness of the sintering material on the sintering machine is 900~1000mm.

5. A method of reducing FeO content and improving metallurgical properties of sinter as claimed in claim 1, wherein the said method is characterized by: The iron grade in the sintering material is not less than 57%, the mass content of MgO is <1.8%, the mass content of SiO2 is 5.0~5.5%, the mass content of Al2O3 is 1.5%~2.0%, and the binary basicity is 1.8~2.2.

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