Indian ore high-proportion ore blending method based on ore blending of magnetite concentrate and sintered ore

Abstract

The invention relates to the technical field of blast furnace ironmaking, in particular to an Indian ore high-proportion ore blending method based on magnetite concentrate sinter ore blending, which comprises the following steps: S1, inputting chemical components and basic characteristics of sinter raw materials, iron ore, flux and fuel used by sinter, and establishing a database; s2, based on the conditions in S1, on the basis of the iron-containing material ore blending scheme in the reference period, according to the constraint conditions that Indian ore in the iron ore is blended by 10-20%, the water content of a mixture is 7.2-7.5%, secondary mixing granulation is 70% or above, and the temperature of the mixture is 45 DEG C or above, the blending proportion of raw materials of the sintered ore is adjusted, and chemical components of the sintered ore are theoretically calculated; s3, on the basis of the chemical components of the sintered ore obtained through theoretical calculation in the S2, basic conditions of liquid phase generation of the sintered ore are ensured, and an ore blending scheme of the iron-containing material after the Indian ore is blended is obtained; and S4, on the basis of the chemical components of the sintered ore obtained through theoretical calculation in the S2, technological parameter constraint conditions of the sintering procedure are set, and the technological parameter constraint conditions comprise the ignition temperature, the ignition negative pressure, the sintering negative pressure, the sintering time, the mixture temperature and the mixture granularity.

Description

Technical Field

[0001] This invention belongs to the field of blast furnace ironmaking technology, and specifically relates to a high-proportion blending method for Indian ore based on magnetite concentrate sinter blending. Background Technology

[0002] The steel industry is a vital pillar of the national economy, but it is also a major consumer of energy and a significant emitter of carbon. Iron ore is the fundamental mineral resource supporting blast furnace ironmaking. However, in China, especially in the north, the iron ore is mostly low-grade magnetite. The fine particle size of the ore results in a thin sintering bed, which is not conducive to increasing sintering output. Adding some imported ore can solve this problem, but currently, the main sources are Australian and non-African ore, which puts significant cost pressure on the industry. Low-priced Indian ore currently accounts for no more than 8% of the domestic blend. Therefore, increasing the proportion of Indian ore and reducing pig iron costs is in line with the national steel industry development strategy.

[0003] However, adding more than 10% Indian ore will lead to the risk of reduced metallurgical performance of sinter and reduced mineralization rate. How to develop a new method for blending large proportions of Indian ore with finely ground magnetite has become an urgent problem to be solved.

[0004] Existing technologies primarily focus on the production of magnetite concentrate sinter, which involves adding hematite concentrate powder or a multi-variety iron ore blend with hematite concentrate as the main component. However, none of these methods can solve the problem of deteriorated mineralization after adding a high proportion of Indian ore. Currently, the addition ratio does not exceed 10%, and the recommended addition ratio is no more than 8%.

[0005] Therefore, it is necessary to invent a high-proportion blending method for Indian ore based on magnetite concentrate sinter blending, so as to make reasonable use of low-priced Indian ore and provide an idea and method for determining the most reasonable blending. Summary of the Invention

[0006] The technical problem to be solved by this invention is to provide a 20% Indian ore blending method based on magnetite concentrate sintered ore blending. In view of the limitations of foreign ore resources and prices such as Australian and South African ore, this method supplements the insufficient production of magnetite concentrate blending and the limitation of the thickness of the ore layer for large proportion of concentrate powder blending, increases Indian ore to 20%, reduces blending costs and develops new ore sources to achieve breakthroughs in the cost and variety of blending.

[0007] To achieve the above objectives, the present invention employs the following technical solution: A high-proportion blending method for Indian ore based on magnetite concentrate sinter blending includes: S1. Input the chemical composition and basic properties of the sintering raw materials used in sintering, such as iron ore, flux, and fuel, and establish a database; S2. Based on the conditions in S1, and on the basis of the iron-bearing ore blending scheme in the baseline period, with Indian ore added at 10-20%, the moisture content of the mixture at 7.2-7.5%, the secondary granulation at 70% or more, and the temperature of the mixture at 45℃ or more, the proportion of sinter raw materials is adjusted, and the chemical composition of the sinter is theoretically calculated according to the following formula. Sinter content = 100kg × raw material composition % × addition ratio % × (1 - loss on ignition %) × ore yield S3. Based on the chemical composition of the sinter obtained from the theoretical calculation in S2, ensure the basic conditions for the formation of the liquid phase of the sinter. The chemical composition of the sinter requires: MgO≥2.2%, FeO≥9%, and basicity R=1.90±0.05. The iron-containing ore blending scheme after adding Indian ore is obtained. S4. Based on the chemical composition of the sintered ore obtained from the theoretical calculation in S2, set the process parameter constraints for the sintering process, including ignition temperature, ignition negative pressure, sintering negative pressure, sintering time, mixture temperature, and mixture particle size.

[0008] S2 base period iron ore blending scheme: 45% magnetite concentrate, 35% Australian ore 1, 10% Australian ore 2, 4% sludge, and 3% steel slag by mass percentage.

[0009] The process parameters for the sintering process in S3 must meet the following constraints: ignition temperature 1030-1070℃, ignition negative pressure 5-9kPa, sintering negative pressure 12-16kPa, sintering time 30-40min, mixture temperature 40-60℃, and the mass percentage of particles larger than 3mm in the mixture ≥70%.

[0010] Compared with existing technologies, the beneficial effects of this invention are: 1. The proportion of Indian ore has been increased to 10-20%, thus broadening the scope of iron ore resource utilization; 2. The sintered ore has a stable composition, meeting the requirements for blast furnace smelting; 3. The liquid phase formation conditions are favorable, and the metallurgical properties of the sinter are acceptable; 4. The process parameters are controllable and suitable for industrial production. Detailed Implementation

[0011] It should be noted that, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art; the terminology used herein in the specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. The reference to "embodiment" herein means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of this invention without inventive effort are within the scope of protection of this invention.

[0012] A high-proportion blending method for Indian ore based on magnetite concentrate sinter blending includes: S1. Input the chemical composition and basic properties of the sintering raw materials used in sintering, such as iron ore, flux, and fuel, and establish a database; S2. Based on the conditions in S1, and on the basis of the iron-bearing ore blending scheme in the baseline period, with Indian ore added at 10-20%, the moisture content of the mixture at 7.2-7.5%, the secondary granulation at 70% or more, and the temperature of the mixture at 45℃ or more, the proportion of sinter raw materials is adjusted, and the chemical composition of the sinter is theoretically calculated according to the following formula. Sinter content = 100kg × raw material composition % × addition ratio % × (1 - loss on ignition %) × ore yield S3. Based on the chemical composition of the sinter calculated theoretically in S2, ensure the basic conditions for the formation of the liquid phase of the sinter. The chemical composition of the sinter requires: MgO ≥ 2.2%, FeO ≥ 9%, and basicity R of 1.90 ± 0.05. It is necessary to ensure the range of MgO, FeO and basicity, otherwise the low-temperature pulverization index will drop significantly. The FeO requirement cannot be achieved by increasing the fuel alone. It is also necessary to ensure that the moisture content of the mixture is greater than 7.2%. If it is possible to adjust the temperature of the mixture to 50-60℃, the moisture content can be increased to 7.5%, thus obtaining the iron-containing ore blending scheme after adding Indian ore. S4. Based on the chemical composition of the sintered ore obtained from the theoretical calculation in S2, set the process parameter constraints for the sintering process, including ignition temperature, ignition negative pressure, sintering negative pressure, sintering time, mixture temperature, and mixture particle size.

[0013] S2 base period iron ore blending scheme: 45% magnetite concentrate, 35% Australian ore 1, 10% Australian ore 2, 4% sludge, and 3% steel slag by mass percentage.

[0014] The process parameters for the sintering process in S3 must meet the following constraints: ignition temperature 1030-1070℃, ignition negative pressure 5-9kPa, sintering negative pressure 12-16kPa, sintering time 30-40min, mixture temperature 40-60℃, and the mass percentage of particles larger than 3mm in the mixture ≥70%.

[0015] To make the objectives, technical solutions, and technical effects of this invention clearer, the technical solutions in the embodiments of this invention are now described clearly and completely. However, the embodiments described below are only some embodiments of this invention, not all embodiments. All other embodiments obtained by those skilled in the art in conjunction with the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0016] Example High-proportion blending methods for Indian ore based on magnetite concentrate sinter blending include: Enter the chemical composition and basic characteristic indicators of the iron ore, flux, and fuel used in sintering, and establish a ore blending calculation model. Relevant data are shown in Tables 1 and 2: Table 1. Composition and basic properties of iron ore and flux, % Table 2. Fuel composition and basic characteristic indicators, % Based on the iron ore blending scheme of the baseline period, Indian ore is added to the iron ore at 20%, the moisture content of the mixture is 7.2-7.5%, the secondary granulation is above 70%, and the temperature of the mixture is above 45℃. Under the constraints of adjusting the proportion of raw materials added to the sinter, the chemical composition of the sinter is theoretically calculated and shown in Table 3. The relative error of the theoretical calculation is controlled within 0.05%. Table 3. Theoretical calculation of sinter composition, % Based on the preset chemical composition of the sinter, the basic conditions for the formation of the liquid phase of the sinter are ensured. The chemical composition of the sinter is: MgO≥2.2%, FeO≥9%, and basicity2.0±0.05. The iron-bearing ore blending scheme with 20% Indian ore is shown in Table 4.

[0017] Table 4 Iron-bearing ore blending scheme Table 5 compares the sintering blending scheme of the baseline period with that of adding 20% ​​Indian ore. Indian ore has high burn-off and coarse particle size, requiring additional fuel to maintain the sintering temperature.

[0018] Table 5 Sintering Ore Blending Scheme The process parameters for the sintering process must meet the following constraints: ignition temperature 1030-1070℃, ignition negative pressure 5-9kPa, sintering negative pressure 12-16kPa, sintering time 30-40min, mixture temperature 40-60℃, and the mass percentage of particles larger than 3mm in the mixture ≥70%. The process parameters for the sintering process with 20% Indian ore added are shown in Table 6.

[0019] Table 6 Sintering Cup Parameters The results of the analysis of the composition of the sinter with 20% Indian ore are shown in Table 7.

[0020] Table 7. Composition of sinter with 20% Indian ore added, % Table 8 shows the comparison of the metallurgical properties of sintered ore with 20% Indian ore added during the baseline period.

[0021] Table 8 Comparison of metallurgical properties of sintered ores with 20% Indian ore Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method of high proportion of blending of Indian ore based on magnetite concentrate sinter blend base, characterized by, Comprise: S1. The chemical composition and basic properties of sinter raw materials, iron ore, flux, and fuel used in sintering are recorded to establish a database; S2. Based on the conditions in S1, under the constraint conditions of adding 10-20% of Indian ore in the iron ore, the moisture content of the mixed material being 7.2-7.5%, the particle content of the second mixed material being more than 70%, and the temperature of the mixed material being more than 45℃, the sinter raw material addition ratio is adjusted based on the iron-bearing material blending scheme in the reference period, and the chemical composition of the sinter is theoretically calculated according to the following formula: Sinter content = 100 kg × raw material component % × addition ratio % × (1- burn loss %) × ore yield S3. Based on the sinter chemical composition obtained by theoretical calculation in S2, the basic conditions for liquid phase generation of sinter are ensured, and the requirements for sinter chemical composition are: MgO≥2.2%, FeO≥9%, and basicity R is 1.90±0.05, to obtain the iron-bearing material blending scheme after adding Indian ore; S4. Based on the sinter chemical composition obtained by theoretical calculation in S2, the process parameter constraint conditions of the sintering process are set, including ignition temperature, ignition negative pressure, sintering negative pressure, sintering time, mixed material temperature, and mixed material particle size.

2. The method of high proportion of ore blending based on magnetite concentrate sinter ore blending base as claimed in claim 1, wherein, The iron-bearing material blending scheme in the reference period in S2 is: 45% magnetite concentrate, 35% Australian ore 1, 10% Australian ore 2, 4% sediment, and 3% steel slag.

3. The method of high proportion of ore blending based on magnetite concentrate sinter ore blending base as claimed in claim 1, wherein, The process parameter constraint conditions of the sintering process in S3 need to meet: ignition temperature 1030-1070℃, ignition negative pressure 5-9kPa, sintering negative pressure 12-16kPa, sintering time 30-40min, mixed material temperature 40-60℃, and the mass percentage of particles greater than 3mm in mixed material particle size≥70%.

Images